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Sample records for leuconostoc mesenteroides electronic

  1. Degradation of Dextran Produced by Leuconostoc mesenteroides ATCC 13146 using Electron Beam Radiation

    International Nuclear Information System (INIS)

    Hong, Jun Tack; Yoo, Sun Kyun; Kang, Hyun Suk; Lee, Byung Cheol

    2010-01-01

    Dextrans make up a family of glucans that have contiguous alpha-1.6 glucose linkages. Differences in the different dextrans in volve the types, amount, length, and arrangements of the arrangements of the branch chains. The principle type of branch linkages found are alpha-1.3, but alpha-1.2 and-1.4 branch linkages have been also observed. In recent days. dextrans have been investigated as potential macromolecular carriers for delivery of drugs and proteins, primarily to increase the longeveity of therapeutic agents in the circulation. In most previous researches, linear type of dextrans with molecular weigh of Μ w 10,000 to 100,000 have been applied for development of new type of drug delivery agent. Such a size of dextrans have been manufactured by acid hydrolysis, of which processes are multi-steps and time-consumed. Therefore, this objective of this research is to evaluate the characterization of branched degraded by a electron beam radiation. L. mesenteroides ATCC 13146 was cultured on te agar slant medium with the composition of 3.0 g K 2 HPO 4 , 0.01 g FeSO 4 . H 2 O, 0.01 g MnSO 4 . 7H 2 O, 0.01 g NaCl, 0.05 g CaCl 2 , 0.5g yeast extract, 15 g agar and 30 g sucrose per liter deionized water. Medium pH was adjusted to 6.0 prior to sterilization. Dextran production was conducted in a fermentor a working volume of 5 1 by using 18% sucrose under optimum pH condition. The inoculum was 2% of the working volume. Fermentation conditions are 28 C, 100 rpm agitation, and 1 vvm of aeration. The fermentation process continued until sucrose was consumed completely. The branch degree of dextran was evaluated using dextranase and analyzed by TLC. The air-dry dextran and solution dextran was irradiated at room temperature using a electrostatic accelerator. The irradiation doses ranged between 30 kGy to 80 kGy. After irradiation, processed dextran showed still a large of branched form. The degradation degree was increased as radiation intensity. The average molecular weight

  2. Characteristics of the Leuconostoc mesenteroides subsp. mesenteroides strains from fresh vegetables

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    Dimić Gordana R.

    2006-01-01

    Full Text Available Strains synthesizing extracellular polysaccharide dextran on a medium with 10% sucrose were isolated from different kind of vegetables (cabbage, cucumber, cauliflower, kohlrabi, carrot, green beans, red beet, pepper, eggplant, radish. Carbohydrate fermentation was examined using a bioMerieux API 50 CHL test system. Among micropopulations with characteristic spherical cell morphology, 94.9% belonged to Leuconostoc mesenteroides subsp. mesenteroides and 5.1% were identified as Leuconostoc mesenteroides subsp. dextranicum. According to fermentation of pentoses L. mesenteroides strains were divided into three groups with a certain number of biotypes; 10 strains were tested on acid production. .

  3. Production of Dextran from Sugar Cane Molasses by Leuconostoc mesenteroides

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    M Faramarzi

    2013-07-01

    Full Text Available Abstract Background & aim: Dextran is a polysaccharide consisting of glucose monomers that are widely used in medicine as a blood volume extender. The aim of this study was to produce dextran from cane molasses using Leuconostoc mesenteroides bacteria. Methods: In this experimental study, for bacterial growth and dextran production, sugarcane molasses was added to the culture medium at different concentrations. Dextran sedimentation was obtained by shaking and centrifugation by adding ethanol after 48 hours. Response surface design was used for qualitative identification of the polarization of dextran and statistical analysis methods. Results: After assessing the separation and interactive effects of the parameters on the optimum amount of dextran produced from sugarcane molasses as 50 g, 35 º C and 5/8 = pH , the Dextran produced was more than 82 g/l. The correlation of the computational model for the dextran produced was 99.5%, which indicated excellent agreement with the experimental and computational models of high accuracy. Conclusion: Dextran produced by Leuconostoc mesenteroides bacteria and sugarcane molasses as substrate, is a cheap and affordable compared to current methods of dextran production. In addition to producing a clinical product, the molasses pollution could be dramatically decreased. Key words: Dextran, Molasses, Leuconostoc Mesenteroides

  4. Production of Viscous Dextran-Containing Whey-Sucrose Broths by Leuconostoc mesenteroides ATCC 14935

    OpenAIRE

    Schwartz, Robert D.; Bodie, Elizabeth A.

    1984-01-01

    Viscous broths were produced by growing Leuconostoc mesenteroides on a medium containing whey supplemented with sucrose. When combined with similarly produced xanthan-containing broths, a synergistic increase in viscosity was observed.

  5. Genome Sequence of Leuconostoc mesenteroides subsp. cremoris Strain T26, Isolated from Mesophilic Undefined Cheese Starter.

    Science.gov (United States)

    Pedersen, T B; Kot, W P; Hansen, L H; Sørensen, S J; Broadbent, J R; Vogensen, F K; Ardö, Y

    2014-06-05

    Leuconostoc is the main group of heterofermentative bacteria found in mesophilic dairy starters. They grow in close symbiosis with the Lactococcus population and are able to degrade citrate. Here we present a draft genome sequence of Leuconostoc mesenteroides subsp. cremoris strain T26. Copyright © 2014 Pedersen et al.

  6. Regulation of dextransucrase secretion by proton motive force in Leuconostoc mesenteroides

    International Nuclear Information System (INIS)

    Otts, D.R.

    1987-01-01

    The relationship between proton motive force and the secretion of the enzyme dextransucrase in Leuconostoc mesenteroides was investigated. The transmembrane pH gradient was determined by measurement of the uptake of radiolabeled benzoate or methylamine while the membrane potential was determined by measurement of the uptake of radiolabeled tetraphenylphosphonium bromide. Leuconostoc mesenteroides was able to maintain a constant proton motive force of -130 mV when grown in fermenters at constant pH while a value of -140 mV was determined from concentrated cell suspensions. The contribution of the membrane potential and transmembrane pH gradient to the proton motive force varied depending on the cation concentration and pH of the medium. The results of this study strongly indicate that dextransucrase secretion Leuconostoc mesenteroides is dependent on the presence of a proton gradient across the cytoplasmic membrane. The results further suggest that dextransucrase secretion is coupled to proton influx into the cell

  7. Elongated cells of Listeria monocytogenes in biofilms in the presence of sucrose and bacteriocin-producing Leuconostoc mesenteroides A11

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    Regiane Priscilla Ratti

    2010-12-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen which may survive in biofilms and persist in food processing plants. In this study, the ability of Leuconostoc mesenteroides (bac+ and bac- to inhibit biofilm formation by L. monocytogenes ATCC 19115 was studied with stainless steel coupons immersed in BHI broth and BHI broth plus sucrose in combination with the Lactic Acid Bacteria (LAB. Adhered cells were collected with swabs and enumerated on selective agars (Oxford for listeria and MRS for leuconostoc. Leuconostoc mesenteroides bac+ in co-culture with L. monocytogenes was effective to inhibit biofilm formation by listeria for up to 3 hours of incubation, but at 24 hours, biofilm was present in all conditions tested, as confirmed by observations of stainless steel coupons under Scanning Electron Microscopy (SEM. It was also observed that in the presence of L. mesenteroides bac+ in BHI plus sucrose, a high number of elongated cells of L. monocytogenes was present, which may indicate an adaptation response of the pathogen to stress conditions with important implications for food safety.

  8. Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans

    Science.gov (United States)

    We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose in Lactococcus lactis using a nisin-controlled gene expression system. Production of DsrI was optimized using several different background vectors, signal peptides, str...

  9. Draft Genome Sequence of Leuconostoc mesenteroides 406 Isolated from the Traditional Fermented Mare Milk Airag in Tuv Aimag, Mongolia

    OpenAIRE

    Morita, Hidetoshi; Toh, Hidehiro; Oshima, Kenshiro; Nakano, Akiyo; Hano, Chihiro; Yoshida, Saki; Nguyen, Tien Thi Thuy; Wulijideligen,; Tashiro, Kosuke; Arakawa, Kensuke; Miyamoto, Taku

    2016-01-01

    Leuconostoc mesenteroides 406 was isolated from the traditional fermented mare milk airag in Tuv Aimag, Mongolia. This strain produces an antilisterial bacteriocin. Here, we report the draft genome sequence of this organism.

  10. Draft Genome Sequence of Leuconostoc mesenteroides 406 Isolated from the Traditional Fermented Mare Milk Airag in Tuv Aimag, Mongolia.

    Science.gov (United States)

    Morita, Hidetoshi; Toh, Hidehiro; Oshima, Kenshiro; Nakano, Akiyo; Hano, Chihiro; Yoshida, Saki; Nguyen, Tien Thi Thuy; Wulijideligen; Tashiro, Kosuke; Arakawa, Kensuke; Miyamoto, Taku

    2016-03-24

    Leuconostoc mesenteroides406 was isolated from the traditional fermented mare milk airag in Tuv Aimag, Mongolia. This strain produces an antilisterial bacteriocin. Here, we report the draft genome sequence of this organism. Copyright © 2016 Morita et al.

  11. Draft Genome Sequence of Leuconostoc mesenteroides 213M0, Isolated from Traditional Fermented Mare Milk Airag in Bulgan Aimag, Mongolia

    OpenAIRE

    Morita, Hidetoshi; Toh, Hidehiro; Oshima, Kenshiro; Nakano, Akiyo; Hano, Chihiro; Yoshida, Saki; Bolormaa, Tsognemekh; Burenjargal, Sedkhuu; Nguyen, Co Thi Kim; Tashiro, Kosuke; Arakawa, Kensuke; Miyamoto, Taku

    2016-01-01

    Leuconostoc mesenteroides 213M0 was isolated from traditional fermented mare milk airag in Bulgan Aimag, Mongolia. This strain produces a listericidal bacteriocin-like inhibitory substance. Here, we report the draft genome sequence of this organism.

  12. Technological Aptitude and Applications of Leuconostoc mesenteroides Bioactive Strains Isolated from Algerian Raw Camel Milk

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    Zineb Benmechernene

    2013-01-01

    Full Text Available Two strains (B7 and Z8 of the Leuconostoc mesenteroides subspecies mesenteroides that were isolated from Algerian camel milk from an initial pool of 13 strains and demonstrated a high ability to inhibit the growth of Listeria spp. were selected and characterised at the phenotypic and genotypic levels. Probiotic profiling and inhibition spectra against food borne pathogens in mixed cultures were also investigated. The bacteriocin produced by L. mesenteroides strain B7 was identified as leucocin B by specific PCR. In vitro studies demonstrated that both Leuconostoc mesenteroides strains exhibited a marked probiotic profile, showing high survival at low pH (2-3 and 4 in the presence of 0.5%, 1%, and 2% of bile salts and at pH 3 in the presence of 3 mg/mL pepsin. Susceptibility testing against antimicrobial agents was also performed for both strains. When tested in a mixed culture with Listeria innocua, Listeria ivanovii, or Staphylococcus aureus, strain B7 reduced the numbers of these species by 1.87, 1.78, and 1.38 log units, respectively. Consequently, these two strains were found to possess good probiotic properties in vitro and a high capacity for Listeria spp. inhibition in mixed cultures. Therefore, these strains have a favourable technological aptitude and a potential application as novel probiotic starters.

  13. Production of bacteriocin by Leuconostoc mesenteroides 406 isolated from Mongolian fermented mare's milk, airag.

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    Wulijideligen; Asahina, Takayuki; Hara, Kazushi; Arakawa, Kensuke; Nakano, Hiroyuki; Miyamoto, Taku

    2012-10-01

    The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral-pH cell-free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat-stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α-chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24-36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut-off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin-producing Leuconostoc strain from airag. An application to fermented milks would be desired. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  14. Kualitas Nutrisi Silase Berbahan Baku Singkong yang Diberi Enzim Cairan Rumen Sapi dan Leuconostoc mesenteroides

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    S. Sandi

    2010-04-01

    Full Text Available The aim of this experiment was to evaluate the nutrient quality of cassava-based materials silage with cattle rumen liquor enzymes and Leuconostoc mesenteroides as poultry feed. The cassava material was hydrolyzed with cattle rumen liquor enzyme and incubated for 24 hours. The hydrolyzed product was added L. mesenteroides and ensiled in mini silo for 30 days. The experiment was designed in completely randomized design with 15 treatments and 3 replications. The result showed that temperature of cassava-based silage ranged from 26 to 30 oC. The flavor was sour and fresh fragrant and changed in color. Addition of cattle rumen liquor enzyme and L. mesenteroides bacteria significantly affected (P<0.05 pH (3.73-4.86, dry matter(30.14%-43.28%, cyanide (86.71%-96.50% and crude fiber content (0.78%-5.05%, but gave a fluctuate effect on protein content (-1.92%-2.39%. However, the treatment didnot affect dry matter losses (1.20%-2.66%. It is concluded that nutrient quality of cassava-based silage improved when it was added with cattle rumen liquor enzymes and L. mesenteroides by decreasing crude fiber and cyanide content. The best silage quality was obtained on tuber substrate and it increased protein KDUO (peel+leaves+tuber+tapioca waste silage.

  15. Optimization of Alternan production by newly isolated leuconostoc mesenteroides

    International Nuclear Information System (INIS)

    Raafat, E.I.; Bashandy, A.S.; Gamal, R.F; Abdelhady, H.M.; Nasr, S.A

    2010-01-01

    Seven isolates out out of 75 Alternan producing bacterial isolates were selected for their highly efficacy, they identified as leuconostoc mesenteriodes. Two local strains in addition to L. mesenteriodes NRRL B-1355 were tested for Alternan production using shake flasks and bioreactor as batch cultures, they gave the high Alternan production on modified Raemackers and Vandamme medium containing 120 gL -1 sucrose incubated at 30 degree C for for 22 hrs in shake flasks at 200 rpm . Whereas the highest yield of dextran was attained in static cultures. L. mesenteriodes M m6 and L. mesenteriodes C m6 were obtained after exposing the parent strains to gamma radiation dose of 3.0 KGy, which led to increase the Alternan and dextran productivity about 1.93 and 1.82 fold. The agitation rate at 300 rpm using batch bioreactor technique was the best treatment for Alternan production by L. mesenteriodes M m6 , the Alternan yield and productivity was increased by about 11.21 % and 204 %, respectively as compared with that produced in batch shake flasks at 200 rpm.

  16. Characterization of dextransucrase from Leuconostoc mesenteroides T3, water kefir grains isolate

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    Miljković Miona G.

    2017-01-01

    Full Text Available The production of dextransucrase (DS by Leuconostoc mesenteroides T3, novel isolate from water kefir grain, was studied and optimized. Bacterial supernatant reached activity of 3.1 U/ml when the culture was grown at 23 C and under static culture condition using classical Tsuchiya medium for DS production. The increase of sucrose concentration to 7% led to an increase of DS activity by 52% compared to the control. Medium with 2% beef extract and 1% yeast extract resulted in 4.52 U/ml, which was 47% higher than in the control (with 2% yeast extract. Finally, the increase of K2HPO4 concentration from 2 to 3% resulted in the increased enzyme activity by 28%. Enzyme purified by polyethylene glycol 400 fractionation displayed maximum activity at 30°C and pH 5.4. Zymogram analysis confirmed the presence of DS of approximately 180 kDa. The addition of divalent cations Ca2+, Mg2+, Fe2+ and Co2+ led to a minor increase of DS activity, while the addition of Mn2+ was the most prominent with 73% increase. These findings classify dextransucrase from Leuconostoc mesenteroides T3 as promising candidate for production of dextran, which has numerous applications in various industries. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31035

  17. Kocuria rosea, kocuria kristinae, leuconostoc mesenteroides as caries-causing representatives of oral microflora.

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    Ananieva, Maiia M; Faustova, Mariia O; Basarab, Iaroslav O; Loban', Galina A

    2017-01-01

    Recently, opportunistic microflora are increasingly known to be involved in the development of pathological processes in various systems and organs. This situation promotes interest in their detailed study as causative agents of bacterial infections. To study the microbial species residing in carious cavities in acute profound caries. The study involved 14 people with a diagnosis of acute profound caries. Microbiological methods included determining species of microorganisms' cultures from carious cavities in acute profound caries. Final identification was carried out by automatic bacteriological analyzer Vitec-2compact bioMérieux. Among the bacteria isolated, Kocuria rosae, Kocuria kristinae, and Leuconostoc mesenteroides are the focus of the authors' attention due to their identification rate in the patients. These microbial species are little studied due to the lack of data on their cariogenic associations.The meticulous study of the microorganisms, isolated from carious cavities in patients with acute profound caries by automatic bacteriological analyzer Vitec-2 Systems bioMérieux, and findings on their biochemical properties allow us to conclude that Kocuria rosae, Kocuria kristinae, and Leuconostoc mesenteroides are among the microorganisms making up the microflora of carious cavities under acute profound caries and are involved in the development of the caries process.

  18. Dextran synthesized by Leuconostoc mesenteroides BD1710 in tomato juice supplemented with sucrose.

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    Han, Jin; Hang, Feng; Guo, Benheng; Liu, Zhenmin; You, Chunpin; Wu, Zhengjun

    2014-11-04

    The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Draft Genome Sequence of Leuconostoc mesenteroides 213M0, Isolated from Traditional Fermented Mare Milk Airag in Bulgan Aimag, Mongolia.

    Science.gov (United States)

    Morita, Hidetoshi; Toh, Hidehiro; Oshima, Kenshiro; Nakano, Akiyo; Hano, Chihiro; Yoshida, Saki; Bolormaa, Tsognemekh; Burenjargal, Sedkhuu; Nguyen, Co Thi Kim; Tashiro, Kosuke; Arakawa, Kensuke; Miyamoto, Taku

    2016-03-31

    Leuconostoc mesenteroides213M0 was isolated from traditional fermented mare milk airag in Bulgan Aimag, Mongolia. This strain produces a listericidal bacteriocin-like inhibitory substance. Here, we report the draft genome sequence of this organism. Copyright © 2016 Morita et al.

  20. Genetic diversity analysis of Leuconostoc mesenteroides from Korean vegetables and food products by multilocus sequence typing.

    Science.gov (United States)

    Sharma, Anshul; Kaur, Jasmine; Lee, Sulhee; Park, Young-Seo

    2018-06-01

    In the present study, 35 Leuconostoc mesenteroides strains isolated from vegetables and food products from South Korea were studied by multilocus sequence typing (MLST) of seven housekeeping genes (atpA, groEL, gyrB, pheS, pyrG, rpoA, and uvrC). The fragment sizes of the seven amplified housekeeping genes ranged in length from 366 to 1414 bp. Sequence analysis indicated 27 different sequence types (STs) with 25 of them being represented by a single strain indicating high genetic diversity, whereas the remaining 2 were characterized by five strains each. In total, 220 polymorphic nucleotide sites were detected among seven housekeeping genes. The phylogenetic analysis based on the STs of the seven loci indicated that the 35 strains belonged to two major groups, A (28 strains) and B (7 strains). Split decomposition analysis showed that intraspecies recombination played a role in generating diversity among strains. The minimum spanning tree showed that the evolution of the STs was not correlated with food source. This study signifies that the multilocus sequence typing is a valuable tool to access the genetic diversity among L. mesenteroides strains from South Korea and can be used further to monitor the evolutionary changes.

  1. Structural analysis and characterization of dextran produced by wild and mutant strains of Leuconostoc mesenteroides.

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    Siddiqui, Nadir Naveed; Aman, Afsheen; Silipo, Alba; Qader, Shah Ali Ul; Molinaro, Antonio

    2014-01-01

    An exopolysaccharide known as dextran was produced by Leuconostoc mesenteroides KIBGE-IB22 (wild) and L. mesenteroides KIBGE-IB22M20 (mutant). The structure was characterized using FTIR, (1)H NMR, (13)C NMR and 2D NMR spectroscopic techniques, whereas surface morphology was analyzed using SEM. A clear difference in the spectral chemical shift patterns was observed in both samples. All the spectral data indicated that the exopolysaccharide produced by KIBGE-IB22 is a mixture of two biopolymers. One was dextran in α-(1 → 6) configuration with a small proportion of α-(1 → 3) branching and the other was levan containing β-(2 → 6) fructan fructofuranosyl linkages. However, remarkably the mutant only produced dextran without any concomitant production of levan. Study suggested that the property of KIBGE-IB22M20, regarding improved production of high molecular weight dextran in a shorter period of fermentation time without any contamination of other exopolysaccharide, could be employed to make the downstream process more feasible and cost effective on large scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Pharmaceutical significance of Leuconostoc mesenteroides KS-TN11 isolated from Nile Tilapia, Oreochromis niloticus

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    Bilal Ahmad Paray

    2018-05-01

    Full Text Available Aquatic animals are known for their myriad of beneficial bacteria with diverse biologically active compounds. The current study was aimed to isolate and characterize potentially beneficial lactic acid bacteria from Nile Tilapia and evaluate their pharmaceutical applications. The fish samples were dissected and stomach, intestine, and gills were collected and serially diluted for the isolation of lactic acid bacteria (LAB on BCP agar media. Identification of isolate was carried by biochemical and molecular characterization using API kit and 16S rRNA gene sequencing analysis, respectively. Further, KS-TN11 was assessed for α-glucosidase inhibitory potential using the chromogenic method. A lactic acid bacterium KS-TN11 was isolated from the stomach of Nile Tilapia and identified as Leuconostoc mesenteroides. Effect of KS-TN11 on lipid accumulation in adipocytes was done by using Oil Red O staining. The isolate showed strong antibacterial activity against a number of pathogenic bacteria in vitro. In addition, L. mesenteroides KS-TN11 KS-TN11 (50 mg/ml and 100 mg/ml tends to inhibit adipogenesis in 3T3-L1 adipocytes and thus may have possible anti-obesity effects. Moreover, L. mesenteroides KS-TN11 exhibited substantial α–glucosidase inhibitory activities by 41.33% at 50 mg/ml and 64% at 100 mg/ml, respectively. The bacterium showed potent antibacterial activity against a number of pathogenic bacteria; in addition to alpha-glucosidase activity, and inhibition of lipid accumulation in 3T3-L1 cell line. These results reinforce KS-TN11 as a novel bacterium with an impending pharmaceutical application. Keywords: Lactic acid bacteria, Antimicrobial, Fish microflora, Anti-diabetic

  3. Molecular diversity of leuconostoc mesenteroides and leuconostoc citreum isolated from traditional french cheeses as revealed by RAPD fingerprinting, 16S rDNA sequencing and 16S rDNA fragment amplification.

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    Cibik, R; Lepage, E; Talliez, P

    2000-06-01

    For a long time, the identification of the Leuconostoc species has been limited by a lack of accurate biochemical and physiological tests. Here, we use a combination of RAPD, 16S rDNA sequencing, and 16S rDNA fragment amplification with specific primers to classify different leuconostocs at the species and strain level. We analysed the molecular diversity of a collection of 221 strains mainly isolated from traditional French cheeses. The majority of the strains were classified as Leuconostoc mesenteroides (83.7%) or Leuconostoc citreum (14%) using molecular techniques. Despite their presence in French cheeses, the role of L. citreum in traditional technologies has not been determined, probably because of the lack of strain identification criteria. Only one strain of Leuconostoc lactis and Leuconostoc fallax were identified in this collection, and no Weissella paramesenteroides strain was found. However, dextran negative variants of L. mesenteroides, phenotypically misclassified as W. paramesenteroides, were present. The molecular techniques used did not allow us to separate strains of the three L. mesenteroides subspecies (mesenteroides, dextranicum and cremoris). In accordance with previously published results, our findings suggest that these subspecies may be classified as biovars. Correlation found between phenotypes dextranicum and mesenteroides of L. mesenteroides and cheese technology characteristics suggests that certain strains may be better adapted to particular technological environments.

  4. Draft Genome Sequence of Leuconostoc mesenteroides P45 Isolated from Pulque, a Traditional Mexican Alcoholic Fermented Beverage.

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    Riveros-Mckay, Fernando; Campos, Itzia; Giles-Gómez, Martha; Bolívar, Francisco; Escalante, Adelfo

    2014-11-06

    Leuconostoc mesenteroides P45 was isolated from the traditional Mexican pulque beverage. We report its draft genome sequence, assembled in 6 contigs consisting of 1,874,188 bp and no plasmids. Genome annotation predicted a total of 1,800 genes, 1,687 coding sequences, 52 pseudogenes, 9 rRNAs, 51 tRNAs, 1 noncoding RNA, and 44 frameshifted genes. Copyright © 2014 Riveros-Mckay et al.

  5. Production and application of a rare disaccharide using sucrose phosphorylase from Leuconostoc mesenteroides.

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    Morimoto, Kenji; Yoshihara, Akihide; Furumoto, Toshio; Takata, Goro

    2015-06-01

    Sucrose phosphorylase (SPase) from Leuconostoc mesenteroides exhibited activity towards eight ketohexoses, which behaved as D-glucosyl acceptors, and α-D-glucose-1-phosphate (G1P), which behaved as a donor. All eight of these ketohexoses were subsequently transformed into the corresponding d-glucosyl-ketohexoses. Of the eight ketohexoses evaluated in the current study, d-allulose behaved as the best substrate for SPase, and the resulting d-glucosyl-d-alluloside product was found to be a non-reducing sugar with a specific optical rotation of [α]D(20) + 74.36°. D-Glucosyl-D-alluloside was identified as α-D-glucopyranosyl-(1→2)-β-D-allulofuranoside by NMR analysis. D-Glucosyl-D-alluloside exhibited an inhibitory activity towards an invertase from yeast with a Km value of 50 mM, where it behaved as a competitive inhibitor with a Ki value of 9.2 mM. D-Glucosyl-D-alluloside was also successfully produced from sucrose using SPase and D-tagatose 3-epimerase. This process also allowed for the production of G1P from sucrose and d-allulose from D-fructose, which suggested that this method could be used to prepare d-glucosyl-d-alluloside without the need for expensive reagents such as G1P and d-allulose. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. Purification and characterization of a bacteriocin from an oenological strain of Leuconostoc mesenteroides subsp. cremoris.

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    Dündar, Halil; Salih, Bekir; Bozoğlu, Faruk

    2016-05-18

    Malolactic fermentation (MLF), which improves organoleptic properties and biologic stability of some wines, may cause wine spoilage if uncontrolled. Bacteriocins were reported as efficient preservatives to control MLF through their bactericidal effect on malolactic bacteria. Leuconostoc mesenteroides subsp. cremoris W3 isolated from wine produces an inhibitory substance that is bactericidal against malolactic bacteria in model wine medium. Treatment of the culture supernatant of strain W3 with proteases eliminated the inhibitory activity, which proved that it is a true bacteriocin and we tentatively termed it mesentericin W3. The bacteriocin inhibited the growth of food-borne pathogenic bacteria such as Enterococcus faecalis, Listeria monocytogenes, and malolactic bacteria. It was active over a wide pH range and stable to organic solvents and heat. Mesentericin W3 was purified to homogeneity by a pH-mediated cell adsorption-desorption method, cation exchange, hydrophobic interaction, and reverse-phase chromatography. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectroscopy (MS) and partial amino acid sequence analysis revealed that mesentericin W3 was identical to mesentericin Y105.

  7. AISLAMIENTO Y CONTROL MICROBIOLÓGICO DE Leuconostoc mesenteroides, EN UN INGENIO PARA OPTIMIZAR EL RENDIMIENTO DE AZÚCAR Y ETANOL ISOLAMENTO E Leuconostoc Mesenteroides CONTROLE MICROBIOLÓGICO EM UM TALENTO PARA OTIMIZAR O DESEMPENHO DE AÇÚCAR E ETANOL ISOLATION AND MICROBIOLOGICAL CONTROL OF Leuconostoc mesenteroides, IN TO SUGAR REFINERY TO OPTIMIZE THE PERFORMANCE OF SUGAR AND ETHANOL

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    RAÚL A CUERVO MULET

    2010-12-01

    Full Text Available La caña de azúcar (Saccharum officinarum L es exprimida para obtener su jugo que después de ser purificado y neutralizado, deja cristalizar el azúcar. Considerando la importancia que representa la caña de azúcar para la industria azucarera, se hace necesario incrementar el contenido de sacarosa libre de dextrana (destrucción de sacarosa causada por la acción de microorganismos acompañantes de la caña, siendo uno de los más importantes Leuconostoc mesenteroides. En este trabajo de investigación se determinó la inhibición de la bacteria ácido-láctica L mesenteroides aislada en un ingenio azucarero del Valle del Cauca mediante la utilización de microorganismos antagonistas. Para esto, se realizaron aislamientos y cultivos de L. mesenteroides provenientes del jugo de la caña y se realizaron las diferentes pruebas bioquímicas y microbiológicas en el laboratorio para el aislamiento y la identificación de las cepas tanto de Leuconostoc mesenteroides, como las cepas bacterianas antagonistas a ella. Se comprobó que las cepas de los hongos Metharhizium anisopliae y Trichoderma sp, fueron las más eficientes en el control de crecimiento de L mesenteroides, mostrando significativamente un mayor porcentaje de inhibición en comparación de los hongos filamentosos Colletotrichum sp, Thichoderma viridae, Rhizoctonia sp y las bacterias Bacillus subtilis y Serratia marcenses y las levaduras Rhodothorula Rubra y Kloeckera japónica, no presentaron inhibición del crecimiento de Lmesenteroides. Además, se identificó a los hongos Aspergillus sp, Botrytis sp y Streptomyces sp como antagonistas naturales y habituales presentes en el jugo de caña de los Ingenios.Cana (Saccharum officinarum L é comprimida para que seu suco depois de ser purificada e neutralizado, permitiu a cristalizar o açúcar. Considerando a importancia de representar a cana para a indústria de açúcar é necessária para melhorar o conteúdo de sacarose, dextrana livre

  8. EFEITO DE ONDAS ULTRA-SÔNICAS SOBRE A POPULAÇÃO DE Leuconostoc mesenteroides EM CALDO DE CANA-DE-AÇÚCAR THE EFFECT OF ULTRASOUND WAVES ON THE Leuconostoc mesenteroides POPULATION IN SUGARCANE JUICE

    Directory of Open Access Journals (Sweden)

    Manoel Soares Soares Júnior

    2007-09-01

    Full Text Available

    No presente trabalho, irradiou-se caldo de cana-de-açúcar de primeira extração, com ondas ultra-sônicas, com o objetivo de controlar a bactéria Leuconostoc mesenteroides. Foi aplicada a metodologia de superfície de resposta (modelo central composto, para avaliar o efeito dos tratamentos. A variável resposta avaliada foi taxa de mortalidade (TM% da população de L. mesenteroides. Os resultados mostraram que a maior taxa de mortalidade, 10,55%, foi obtida com a potência de 50 W, por 225 segundos, em caldo de cana com 18° Brix, pH 4,5 e 45°C.

    PALAVRAS-CHAVE: Indústria açucareira; cana-de-açúcar; ultra-som.

    In the present work, first extraction sugarcane juice was irradiated with ultrasound waves to control Leuconostoc mesenteroides. Surface response methodology (central composite model was used to evaluate the treatment effects. The response variable was the death rate (DR% of the L. mesenteroides population. The results showed that the highest rate of mortality, 10.55%, was obtained with a power of 50 W for 225 seconds, in sugarcane juice with 18° Brix, pH 4.5 and 45°C.

    KEY-WORDS: Sugar industry; sugarcane; ultrasound.

  9. Leuconostoc mesenteroides growth in food products: prediction and sensitivity analysis by adaptive-network-based fuzzy inference systems.

    Directory of Open Access Journals (Sweden)

    Hue-Yu Wang

    Full Text Available BACKGROUND: An adaptive-network-based fuzzy inference system (ANFIS was compared with an artificial neural network (ANN in terms of accuracy in predicting the combined effects of temperature (10.5 to 24.5°C, pH level (5.5 to 7.5, sodium chloride level (0.25% to 6.25% and sodium nitrite level (0 to 200 ppm on the growth rate of Leuconostoc mesenteroides under aerobic and anaerobic conditions. METHODS: THE ANFIS AND ANN MODELS WERE COMPARED IN TERMS OF SIX STATISTICAL INDICES CALCULATED BY COMPARING THEIR PREDICTION RESULTS WITH ACTUAL DATA: mean absolute percentage error (MAPE, root mean square error (RMSE, standard error of prediction percentage (SEP, bias factor (Bf, accuracy factor (Af, and absolute fraction of variance (R (2. Graphical plots were also used for model comparison. CONCLUSIONS: The learning-based systems obtained encouraging prediction results. Sensitivity analyses of the four environmental factors showed that temperature and, to a lesser extent, NaCl had the most influence on accuracy in predicting the growth rate of Leuconostoc mesenteroides under aerobic and anaerobic conditions. The observed effectiveness of ANFIS for modeling microbial kinetic parameters confirms its potential use as a supplemental tool in predictive mycology. Comparisons between growth rates predicted by ANFIS and actual experimental data also confirmed the high accuracy of the Gaussian membership function in ANFIS. Comparisons of the six statistical indices under both aerobic and anaerobic conditions also showed that the ANFIS model was better than all ANN models in predicting the four kinetic parameters. Therefore, the ANFIS model is a valuable tool for quickly predicting the growth rate of Leuconostoc mesenteroides under aerobic and anaerobic conditions.

  10. Pre-treatment step with Leuconostoc mesenteroides or L. pseudomesenteroides strains removes furfural from Zymomonas mobilis ethanolic fermentation broth.

    Science.gov (United States)

    Hunter, William J; Manter, Daniel K

    2014-10-01

    Furfural is an inhibitor of growth and ethanol production by Zymomonas mobilis. This study used a naturally occurring (not GMO) biological pre-treatment to reduce that amount of furfural in a model fermentation broth. Pre-treatment involved inoculating and incubating the fermentation broth with strains of Leuconostoc mesenteroides or Leuconostoc pseudomesenteroides. The Leuconostoc strains converted furfural to furfuryl alcohol without consuming large amounts of dextrose in the process. Coupling this pre-treatment to ethanolic fermentation reduced furfural in the broth and improved growth, dextrose uptake and ethanol formation. Pre-treatment permitted ethanol formation in the presence of 5.2 g L(-1) furfural, which was otherwise inhibitive. The pre-treatment and presence of the Leuconostoc strains in the fermentation broth did not interfere with Z. mobilis ethanolic fermentation or the amounts of ethanol produced. The method suggests a possible technique for reducing the effect that furfural has on the production of ethanol for use as a biofuel. Published by Elsevier Ltd.

  11. AISLAMIENTO Y CONTROL MICROBIOLÓGICO DE Leuconostoc mesenteroides, EN UN INGENIO PARA OPTIMIZAR EL RENDIMIENTO DE AZÚCAR Y ETANOL ISOLAMENTO E Leuconostoc Mesenteroides CONTROLE MICROBIOLÓGICO EM UM TALENTO PARA OTIMIZAR O DESEMPENHO DE AÇÚCAR E ETANOL ISOLATION AND MICROBIOLOGICAL CONTROL OF Leuconostoc mesenteroides, IN TO SUGAR REFINERY TO OPTIMIZE THE PERFORMANCE OF SUGAR AND ETHANOL

    OpenAIRE

    RAÚL A CUERVO MULET; JOHANNY ÁNGEL LEDESMA; JORGE ANTONIO DURÁN VANEGAS; FRANCISCO E ARGOTE VEGA

    2010-01-01

    La caña de azúcar (Saccharum officinarum L) es exprimida para obtener su jugo que después de ser purificado y neutralizado, deja cristalizar el azúcar. Considerando la importancia que representa la caña de azúcar para la industria azucarera, se hace necesario incrementar el contenido de sacarosa libre de dextrana (destrucción de sacarosa causada por la acción de microorganismos acompañantes de la caña, siendo uno de los más importantes Leuconostoc mesenteroides). En este trabajo de investigac...

  12. Antilisterial Activity of Bacteriocin Isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in the Production of Sremska Sausages: Lactic Acid Bacteria Isolation, Bacteriocin Identification and Meat Application Experiments

    Directory of Open Access Journals (Sweden)

    Marija Škrinjar

    2013-01-01

    Full Text Available Lactic acid bacteria (LAB have an essential role in the production of fermented meat products. The metabolic activity of LAB affects the ripening process, leading to the formation of the desired sensory characteristics of the products, while inhibiting the growth of undesirable microorganisms. Bacteriocins are extracellular peptides or protein molecules, produced by some LAB, which possess bactericidal properties against specific species or genera of microorganisms, usually related bacteria. Bacteriocin production by LAB can act in a selective and competitive way against the surrounding microbiota, which may contain spoilage bacteria or pathogenic microorganisms including Listeria monocytogenes. This pathogen is widely distributed in raw products, it survives in different production areas, and human infections have a high mortality rate, all of which makes the control of this microorganism important in food production. The aim of this work is to determine the possibilities of utilizing a novel bacteriocin isolated from Leuconostoc mesenteroides ssp. mesenteroides IMAU:10231 in order to prevent the survival of Listeria monocytogenes in the production of traditional Serbian Sremska sausages. The bacteriocin-producing strain of Leuconostoc originated from the same sausage, which had been produced in the traditional manner. Bacteriocin was isolated using precipitation procedures with ammonium sulphate, and then its properties (strength and range of activities, relationship to high temperatures and proteolytic enzymes were determined under laboratory conditions. Also, based on the obtained laboratory results, the antilisterial effect of bacteriocin, included as an additive, was examined in the production of traditional Sremska sausages. Expressed antilisterial activity of bacteriocin has an interesting food safety potential which can be used in the meat industry in the production of fermented sausages. Further research will contribute to a better

  13. In vitro and in vivo probiotic assessment of Leuconostoc mesenteroides P45 isolated from pulque, a Mexican traditional alcoholic beverage.

    Science.gov (United States)

    Giles-Gómez, Martha; Sandoval García, Jorge Giovanni; Matus, Violeta; Campos Quintana, Itzia; Bolívar, Francisco; Escalante, Adelfo

    2016-01-01

    Pulque is a Mexican traditional alcoholic, non-distilled, fermented beverage produced by the fermentation of the sap, known as aguamiel, extracted from several maguey (Agave) species. Pulque has traditionally been considered a healthy beverage due to its nutrient content and also a traditional medicine for the treatment of gastrointestinal disorders and intestinal infections. During pulque fermentation, the development of acidity, alcohol and viscosity define its final sensorial properties, developing an enriched environment where dominant lactic acid bacteria (LAB), including diverse Leuconostoc species, are present. Because traditional pulque is consumed directly from the fermentation vessel, the naturally associated LAB are ingested and reach the human small intestine alive. Here, we report the in vitro and in vivo probiotic assessment of Leuconostoc mesenteroides strain P45 isolated from pulque. This isolated LAB species exhibited lysozyme, acid (pH 3.5) and bile salts (0.1 and 0.3 % oxgall) resistance. Antibacterial activity against the pathogens Listeria monocytogenes, enteropathogenic Escherichia coli, Salmonella enterica serovar Typhi and S. enterica serovar Typhimurium were observed in assays involving cell-to-cell contact, cell-free 2× concentrated supernatants and cell-to-cell contact under exopolysaccharide-producing conditions. The in vivo probiotic assessment showed an anti-infective activity of L. mesenteroides P45 against S. enterica serovar Typhimurium in challenged male and female BALB/c mice. Analysis of the available genome sequence of strain P45 allowed identified a pre-bacteriocin coding gene and six peptidoglycan hydrolase enzymes, probably involved in the antimicrobial activity of this strain. The results presented in this study support some potential microbial mechanisms associated with the beneficial effects on human health of this LAB involved in the fermentation of pulque.

  14. Controlling Listeria monocytogenes and Leuconostoc mesenteroides in Uncured Deli-style Turkey Breast Using a Clean Label Antimicrobial.

    Science.gov (United States)

    Weyker, Robert E; Glass, Kathleen A; Milkowski, Andrew L; Seman, Dennis L; Sindelar, Jeffrey J

    2016-03-01

    Interest in natural/organic meat products has resulted in the need to validate the effectiveness of clean label antimicrobials to increase safety and shelf life of these products. A Response Surface Methodology (RSM) was used to investigate the effects of varying levels of moisture, pH, and a commercial "clean-label" antimicrobial (cultured sugar-vinegar blend; CSVB) on the growth rate of Listeria monocytogenes and Leuconostoc mesenteroides in uncured turkey stored at 4 °C for 16 wk. Twenty treatment combinations of moisture (60% to 80%), pH (5.8 to 6.4), and CSVB (2.5% to 5.0%) were evaluated during phase I to develop growth curves for both microbe types, whereas the interactive effects of pH (5.8 to 6.4) and CSVB (0.0 to 4.75) were tested in 16 treatment combinations during Phase II at a single moisture level using L. monocytogenes only. CSVB inhibited L. monocytogenes growth in 14 of the 20 treatments tested in Phase I and in 12 of the 16 treatments in Phase II through 16 and 8 wk, respectively. In contrast, CSVB had little effect on L. mesenteroides, with growth inhibited in only 4 of 20 treatments in Phase I and was therefore not tested further in Phase II. Significant interactions of the RSM design coefficients yielded a predictive model for L. mesenteroides growth rate, but due to lack of growth, no growth rate model was developed for L. monocytogenes. CSVB was found to be an effective antilisteral antimicrobial, while having little effect on a spoilage microorganism. © 2016 Institute of Food Technologists®

  15. Genomic and proteomic characterization of bacteriocin-producing Leuconostoc mesenteroides strains isolated from raw camel milk in two southwest Algerian arid zones.

    Science.gov (United States)

    Benmechernene, Zineb; Fernández-No, Inmaculada; Quintela-Baluja, Marcos; Böhme, Karola; Kihal, Mebrouk; Calo-Mata, Pilar; Barros-Velázquez, Jorge

    2014-01-01

    Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS) which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk.

  16. Genomic and Proteomic Characterization of Bacteriocin-Producing Leuconostoc mesenteroides Strains Isolated from Raw Camel Milk in Two Southwest Algerian Arid Zones

    Directory of Open Access Journals (Sweden)

    Zineb Benmechernene

    2014-01-01

    Full Text Available Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk.

  17. Lime application for the efficient production of nutraceutical glucooligosaccharides from Leuconostoc mesenteroides NRRL B-742 (ATCC13146).

    Science.gov (United States)

    Moon, Young Hwan; Madsen, Lee; Chung, Chang-Ho; Kim, Doman; Day, Donal F

    2015-02-01

    We have previously demonstrated the production of glucooligosaccharides via a fermentation of sucrose with Leuconostoc mesenteroides NRRL B-742 using sodium hydroxide (NaOH) to control the pH. Because NaOH is expensive, we sought to minimize the cost of our process by substituting hydrated lime and saccharate of lime (lime sucrate) in its place. The yield of glucooligosaccharides using either 5 % lime (41.4 ± 0.5 g/100 g) or 5 % lime sucrate (40.0 ± 1.4 g/100 g) were both similar to the NaOH control (42.4 ± 1.5 g/100 g). Based on this, it appears that the cost associated with pH control in our process can be reduced by a factor of approximately 2.4 using lime instead of NaOH. Because our chromatographic stage is based on a Ca(2+)-form resin to separate glucooligosaccharides, the use of lime not only negates the need for costly de-salting via ion-exchange (elimination of two ion-exchange sections) prior to separation, but also greatly reduces the resin regeneration cost.

  18. AISLAMIENTO Y CONTROL MICROBIOLÓGICO DE Leuconostoc mesenteroides, EN UN INGENIO PARA OPTIMIZAR EL RENDIMIENTO DE AZÚCAR Y ETANOL

    OpenAIRE

    CUERVO MULET, RAÚL A; ÁNGEL LEDESMA, JOHANNY; DURÁN VANEGAS, JORGE ANTONIO; ARGOTE VEGA, FRANCISCO E

    2010-01-01

    La caña de azúcar (Saccharum officinarum L) es exprimida para obtener su jugo que después de ser purificado y neutralizado, deja cristalizar el azúcar. Considerando la importancia que representa la caña de azúcar para la industria azucarera, se hace necesario incrementar el contenido de sacarosa libre de dextrana (destrucción de sacarosa causada por la acción de microorganismos acompañantes de la caña, siendo uno de los más importantes Leuconostoc mesenteroides). En este trabajo de investigac...

  19. Proline-Based Cyclic Dipeptides from Korean Fermented Vegetable Kimchi and from Leuconostoc mesenteroides LBP-K06 Have Activities against Multidrug-Resistant Bacteria.

    Science.gov (United States)

    Liu, Rui; Kim, Andrew H; Kwak, Min-Kyu; Kang, Sa-Ouk

    2017-01-01

    Lactobacillus plantarum and Leuconostoc mesenteroides play a prominent role as functional starters and predominant isolates in the production of various types of antimicrobial compound-containing fermented foods, especially including kimchi. In the case of the bioactive cyclic dipeptides, their racemic diastereomers inhibitory to bacteria and fungi have been suggested to come solely from Lactobacillus spp. of these strains. We previously demonstrated the antifungal and antiviral activities of proline-based cyclic dipeptides, which were fractionated from culture filtrates of Lb. plantarum LBP-K10 originated from kimchi. However, cyclic dipeptides have not been identified in the filtrates, either from cultures or fermented subject matter, driven by Ln. mesenteroides , which have been widely used as starter cultures for kimchi fermentation. Most importantly, the experimental verification of cyclic dipeptide-content changes during kimchi fermentation have also not been elucidated. Herein, the antibacterial fractions, including cyclo(Leu-Pro) and cyclo(Phe-Pro), from Ln. mesenteroides LBP-K06 culture filtrates, which exhibited a typical chromatographic retention behavior (t R ), were identified by using semi-preparative high-performance liquid chromatography and gas chromatography-mass spectrometry. Based on this finding, the proline-based cyclic dipeptides, including cyclo(Ser-Pro), cyclo(Tyr-Pro), and cyclo(Leu-Pro), were additionally identified in the filtrates only when fermenting Chinese cabbage produced with Ln. mesenteroides LBP-K06 starter cultures. The detection and isolation of cyclic dipeptides solely in controlled fermented cabbage were conducted under the control of fermentation-process parameters concomitantly with strong CDP selectivity by using a two-consecutive-purification strategy. Interestingly, cyclic dipeptides in the filtrates, when using this strain as a starter, increased with fermentation time. However, no cyclic dipeptides were observed in the

  20. Exploitation of Leuconostoc mesenteroides strains to improve shelf life, rheological, sensory and functional features of prickly pear (Opuntia ficus-indica L.) fruit puree.

    Science.gov (United States)

    Di Cagno, Raffaella; Filannino, Pasquale; Vincentini, Olimpia; Lanera, Alessia; Cavoski, Ivana; Gobbetti, Marco

    2016-10-01

    Strains of Leuconostoc mesenteroides were identified from raw prickly pear (Opuntia ficus-indica L.). Five autochthonous strains were selected based on the kinetics of growth and acidification on prickly pear fruit juice, and the capacity to synthesize exo-polysaccharides. All selected Leuc. mesenteroides strains showed an in vitro mucilage-degrading capability. A protocol for processing and storage of fermented prickly pear fruit puree (FP) was set up. Unstarted FP and chemically acidified FP were used as the controls. Starters grew and remained viable at elevated cell numbers during 21 days of storage at 4 °C. Contaminating Enterobacteriaceae and yeasts were found only in the controls. Viscosity and serum separation distinguished started FP compared to the controls. Colour parameters, browning index, sensory attributes, antimicrobial activity, vitamin C and betalains levels were positively affected by lactic acid fermentation. Increase of free radical scavenging activity in ethyl acetate soluble extract suggested an effect of selected strains on phenolic profiles. Started FP markedly inhibited the inflammatory status of Caco-2/TC7 cells, and also contributed to maintaining the integrity of tight junctions. Started FP scavenged the reactive oxygen species generated by H2O2 on Caco-2 cells. All selected strain variously affected the immunomodulatory activity towards anti- and pro-inflammatory cytokines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Biosíntesis de dextranos de alto peso molecular mediante la inoculación con Leuconostoc Mesenteroides, var. Mesenteroides (atcc 10830 de jugos residuales de la agroindustria de la piña: síntesis y caracterización de hierro-dextranos

    Directory of Open Access Journals (Sweden)

    José Roberto Vega Baudrit

    2013-01-01

    Full Text Available En este trabajo se muestran los estudios realizados para obtener dextranos a partir de desechos de la agroindustria de piña. La fermentación se llevó a cabo en un biorreactor (10 L, se inoculó con un cultivo de Leuconostoc mesenteroides, var. mesenteroides (ATCC 10830. Se centrifugó y se precipitó y purificó con etanol. Fue caracterizado por medio de viscosidad, peso molecular y grupos funcionales por espectroscopía infrarroja. Este dextrano fue tratado con el fin de obtener hierro-dextranos.

  2. Bacteriophages of Leuconostoc, Oenococcus and Weissella

    Directory of Open Access Journals (Sweden)

    Witold P. Kot

    2014-04-01

    Full Text Available Leuconostoc (Ln., Weissella and Oenococcus form a group of related genera of lactic acid bacteria, which once all shared the name Leuconostoc. They are associated with plants, fermented vegetable products, raw milk, dairy products, meat and fish. Most of industrially relevant Leuconostoc strains can be classified as either Ln. mesenteroides or Ln. pseudomesenteroides. They are important flavor producers in dairy fermentations and they initiate nearly all vegetable fermentations. Therefore bacteriophages attacking Leuconostoc strains may negatively influence the production process. Bacteriophages attacking Leuconostoc strains were first reported in 1946. Since then, the majority of described Leuconostoc phages was isolated from either dairy products or fermented vegetable products. Both lytic and temperate phages of Leuconostoc were reported. Most of Leuconostoc phages examined using electron microscopy belong to the Siphoviridae family and differ in morphological details. Hybridization and comparative genomic studies of Leuconostoc phages suggest that they can be divided into several groups, however overall diversity of Leuconostoc phages is much lower as compared to e.g. lactococcal phages. Several fully sequenced genomes of Leuconostoc phages have been deposited in public databases. Lytic phages of Leuconostoc can be divided into two host species-specific groups with similarly organized genomes that shared very low nucleotide similarity. Phages of dairy Leuconostoc have rather limited host-ranges. The receptor binding proteins of two lytic Ln. pseudomesenteroides phages have been identified. Molecular tools for detection of dairy Leuconostoc phages have been developed. The rather limited data on phages of Oenococcus and Weissella show that i lysogeny seems to be abundant in Oenococcus strains, and ii several phages infecting Weissella cibaria are also able to productively infect strains of other Weissella species and even strains of the genus

  3. Production of a bacteriocin-like inhibitory substance by Leuconostoc mesenteroides subsp. dextranicum 213M0 isolated from Mongolian fermented mare milk, airag.

    Science.gov (United States)

    Arakawa, Kensuke; Yoshida, Saki; Aikawa, Hiroki; Hano, Chihiro; Bolormaa, Tsognemekh; Burenjargal, Sedkhuu; Miyamoto, Taku

    2016-03-01

    Strain 213M0 was selected with productivity of a bacteriocin-like inhibitory substance (BLIS) among 235 strains of lactic acid bacteria (LAB) isolated from Mongolian fermented milk 'airag'. Strain 213M0 was species-identified as Leuconostoc mesenteroides subsp. dextranicum by morphological observation, carbohydrate fermentation profiling and sequencing the 16S rRNA gene. Incubation temperature proper to produce the BLIS was 25°C rather than 30 and 37°C, and the production actively proceeded during the exponential growth phase of the producer cells. Antibacterial effect of BLIS 213M0 was limited to all nine strains of Listeria sp. bacteria and seven strains of LAB cocci among 53 tested strains, which corresponds to a typical feature of the class IIa pediocin-like bacteriocins. BLIS 213M0 was not inactivated in every broad pH range solution (pH 2.0-11.0), and was stable against storage at 25°C for 1 week and heating at 121°C for 15 min under pH 4.5. Peptide frame of BLIS 213M0 was confirmed by inactivation with some peptidases, and then its molecular weight was estimated to be 2.6-3.0 kDa using an in situ activity assay following sodium dodecyl sulfate polyacrylamide gel electrophoresis. The estimated size was different from the other Leuconostoc bacteriocins already reported. These results suggest that BLIS 213M0 would be a novel listericidal bacteriocin. © 2015 Japanese Society of Animal Science.

  4. Continuous Production of Dextran from Immobilized Cells of Leuconostoc mesenteroides KIBGE HA1 Using Acrylamide as a Support

    OpenAIRE

    Qader, Shah Ali Ul; Aman, Afsheen; Azhar, Abid

    2011-01-01

    The cells of L. mesenteroides KIBGE HA1 were immobilized for the production of dextran on acrylamide gel and gel concentration was optimized for maximum entrapment. Sucrose at substrate concentration of 10% produced high yield of dextran at 25°C with a percent conversion of 5.82 while at 35°C it was 3.5. However, increasing levels of sucrose diminished dextran yields. The free cells stopped producing dextran after 144 h, while immobilized cells continued to produce dextran even after 480 h. M...

  5. Phytate degradation by Leuconostoc mesenteroides KC51 ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... The mixture was stirred on a vortex mixer and then filtered with 0.45. µm syringe filter; the absorbance of the filtrate was read at 500 nm. Concentration of phytate was shown mean values and standard deviation (n=3). RESULTS AND DISCUSSION. To evaluate the phytate breakdown activity of lactic acid.

  6. Autolysis of dairy leuconostocs and detection of peptidoglycan hydrolases by renaturing SDS-PAGE.

    Science.gov (United States)

    Cibik, R; Chapot-Chartier, M P

    2000-11-01

    The autolysis of lactic acid bacteria plays a major role during cheese ripening. The aim of this study was to evaluate the autolytic properties and peptidoglycan hydrolase content of dairy leuconostocs. Autolysis of 59 strains of dairy Leuconostoc was examined under starvation conditions in potassium phosphate buffer. The ability of dairy leuconostocs to lyse is strain dependant and not related to the species. The peptidoglycan hydrolase profile of Leuc. mesenteroides subsp. mesenteroides 10L was analysed by renaturing gel electrophoresis. Two major activity bands migrating at 41 and 52 kDa were observed. According to the specificity analysis, strain 10L seems to contain a glycosidase and an N-acetyl-muramyl-L-alanine amidase, or an endopeptidase. The peptidoglycan hydrolase profiles of various Leuconostoc species were also compared. Several peptidoglycan hydrolase activities could be detected in the different Leuconostoc species. Further characterization of the peptidoglycan hydrolases will help to control autolysis of leuconostocs in cheese.

  7. Bacteriophages of Leuconostoc, Oenococcus, and Weissella

    DEFF Research Database (Denmark)

    Kot, Witold; Neve, Horst; Heller, Knut J

    2014-01-01

    Leuconostoc (Ln.), Weissella, and Oenococcus form a group of related genera of lactic acid bacteria, which once all shared the name Leuconostoc. They are associated with plants, fermented vegetable products, raw milk, dairy products, meat, and fish. Most of industrially relevant Leuconostoc strains...... can be classified as either Ln. mesenteroides or Ln. pseudomesenteroides. They are important flavor producers in dairy fermentations and they initiate nearly all vegetable fermentations. Therefore, bacteriophages attacking Leuconostoc strains may negatively influence the production process....... Bacteriophages attacking Leuconostoc strains were first reported in 1946. Since then, the majority of described Leuconostoc phages was isolated from either dairy products or fermented vegetable products. Both lytic and temperate phages of Leuconostoc were reported. Most of Leuconostoc phages examined using...

  8. Genomic Characterization of Dairy Associated Leuconostoc Species and Diversity of Leuconostocs in Undefined Mixed Mesophilic Starter Cultures.

    Science.gov (United States)

    Frantzen, Cyril A; Kot, Witold; Pedersen, Thomas B; Ardö, Ylva M; Broadbent, Jeff R; Neve, Horst; Hansen, Lars H; Dal Bello, Fabio; Østlie, Hilde M; Kleppen, Hans P; Vogensen, Finn K; Holo, Helge

    2017-01-01

    Undefined mesophilic mixed (DL-type) starter cultures are composed of predominantly Lactococcus lactis subspecies and 1-10% Leuconostoc spp. The composition of the Leuconostoc population in the starter culture ultimately affects the characteristics and the quality of the final product. The scientific basis for the taxonomy of dairy relevant leuconostocs can be traced back 50 years, and no documentation on the genomic diversity of leuconostocs in starter cultures exists. We present data on the Leuconostoc population in five DL-type starter cultures commonly used by the dairy industry. The analyses were performed using traditional cultivation methods, and further augmented by next-generation DNA sequencing methods. Bacterial counts for starter cultures cultivated on two different media, MRS and MPCA, revealed large differences in the relative abundance of leuconostocs. Most of the leuconostocs in two of the starter cultures were unable to grow on MRS, emphasizing the limitations of culture-based methods and the importance of careful media selection or use of culture independent methods. Pan-genomic analysis of 59 Leuconostoc genomes enabled differentiation into twelve robust lineages. The genomic analyses show that the dairy-associated leuconostocs are highly adapted to their environment, characterized by the acquisition of genotype traits, such as the ability to metabolize citrate. In particular, Leuconostoc mesenteroides subsp. cremoris display telltale signs of a degenerative evolution, likely resulting from a long period of growth in milk in association with lactococci. Great differences in the metabolic potential between Leuconostoc species and subspecies were revealed. Using targeted amplicon sequencing, the composition of the Leuconostoc population in the five commercial starter cultures was shown to be significantly different. Three of the cultures were dominated by Ln. mesenteroides subspecies cremoris. Leuconostoc pseudomesenteroides dominated in two of the

  9. Leuconostoc strains isolated from dairy products: Response against food stress conditions.

    Science.gov (United States)

    D'Angelo, Luisa; Cicotello, Joaquín; Zago, Miriam; Guglielmotti, Daniela; Quiberoni, Andrea; Suárez, Viviana

    2017-09-01

    A systematic study about the intrinsic resistance of 29 strains (26 autochthonous and 3 commercial ones), belonging to Leuconostoc genus, against diverse stress factors (thermal, acidic, alkaline, osmotic and oxidative) commonly present at industrial or conservation processes were evaluated. Exhaustive result processing was made by applying one-way ANOVA, Student's test (t), multivariate analysis by Principal Component Analysis (PCA) and Matrix Hierarchical Cluster Analysis. In addition, heat adaptation on 4 strains carefully selected based on previous data analysis was assayed. The strains revealed wide diversity of resistance to stress factors and, in general, a clear relationship between resistance and Leuconostoc species was established. In this sense, the highest resistance was shown by Leuconostoc lactis followed by Leuconostoc mesenteroides strains, while Leuconostoc pseudomesenteroides and Leuconostoc citreum strains revealed the lowest resistance to the stress factors applied. Heat adaptation improved thermal cell survival and resulted in a cross-resistance against the acidic factor. However, all adapted cells showed diminished their oxidative resistance. According to our knowledge, this is the first study regarding response of Leuconostoc strains against technological stress factors and could establish the basis for the selection of "more robust" strains and propose the possibility of improving their performance during industrial processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Selection of Leuconostoc strains isolated from artisanal Serrano Catarinense cheese for use as adjuncts in cheese manufacture.

    Science.gov (United States)

    Seixas, Felipe Nael; Rios, Edson Antônio; Martinez de Oliveira, André Luiz; Beloti, Vanerli; Poveda, Justa Maria

    2018-08-01

    Serrano Catarinense cheese is a raw bovine milk cheese produced in the region of Santa Catarina, Brazil. Twelve representative strains of Leuconostoc isolated from 20 samples of this artisanal cheese were selected and submitted for evaluation of the acidifying, proteolytic, autolytic, aminopeptidase and lipolytic activities, NaCl and acid resistance, production of dextran and biogenic amines and antimicrobial activity. The aim was to genetically and technologically characterize the Leuconostoc strains in order to use them in mixed starter cultures for cheese manufacture. Leuconostoc mesenteroides subsp. mesenteroides was the species that accounted for the largest proportion of isolates of Leuconostoc genus. Two leuconostoc isolates stood out in the acidifying activity, with reduction in pH of 1.12 and 1.04 units. The isolates showed low proteolytic and autolytic activity. Most of the isolates were dextran producers, presented good resistance to the salt and pH conditions of the cheese and showed antimicrobial activity against cheese pathogen bacteria, and none of them produced biogenic amines. These results allowed the selection of five strains (UEL 04, UEL 12, UEL 18, UEL 21 and UEL 28) as good candidates for use as adjunct cultures for cheese manufacture. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  11. Antibiotic Susceptibility Profiles of Dairy Leuconostoc, Analysis of the Genetic Basis of Atypical Resistances and Transfer of Genes In Vitro and in a Food Matrix.

    Directory of Open Access Journals (Sweden)

    Ana Belén Flórez

    Full Text Available In spite of a global concern on the transfer of antibiotic resistances (AR via the food chain, limited information exists on this issue in species of Leuconostoc and Weissella, adjunct cultures used as aroma producers in fermented foods. In this work, the minimum inhibitory concentration was determined for 16 antibiotics in 34 strains of dairy origin, belonging to Leuconostoc mesenteroides (18, Leuconostoc citreum (11, Leuconostoc lactis (2, Weissella hellenica (2, and Leuconostoc carnosum (1. Atypical resistances were found for kanamycin (17 strains, tetracycline and chloramphenicol (two strains each, and erythromycin, clindamycin, virginiamycin, ciprofloxacin, and rifampicin (one strain each. Surprisingly, L. mesenteroides subsp. mesenteroides LbE16, showed resistance to four antibiotics, kanamycin, streptomycin, tetracycline and virginiamycin. PCR analysis identified tet(S as responsible for tetracycline resistance in LbE16, but no gene was detected in a second tetracycline-resistant strain, L. mesenteroides subsp. cremoris LbT16. In Leuconostoc mesenteroides subsp. dextranicum LbE15, erythromycin and clindamycin resistant, an erm(B gene was amplified. Hybridization experiments proved erm(B and tet(S to be associated to a plasmid of ≈35 kbp and to the chromosome of LbE15 and LbE16, respectively. The complete genome sequence of LbE15 and LbE16 was used to get further insights on the makeup and genetic organization of AR genes. Genome analysis confirmed the presence and location of erm(B and tet(S, but genes providing tetracycline resistance in LbT16 were again not identified. In the genome of the multi-resistant strain LbE16, genes that might be involved in aminoglycoside (aadE, aphA-3, sat4 and virginiamycin [vat(E] resistance were further found. The erm(B gene but not tet(S was transferred from Leuconostoc to Enterococcus faecalis both under laboratory conditions and in cheese. This study contributes to the characterization of AR in the

  12. Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides

    Science.gov (United States)

    Corrosion is one of the most serious and challenging problems faced worldwide by industry. This research investigates the inhibition of corrosive behavior of SAE1010 steel by bacterial exopolysaccharides. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion inhibition of diffe...

  13. Species attribution and strain typing of Oenococcus oeni (formerly Leuconostoc oenos) with restriction endonuclease fingerprints.

    Science.gov (United States)

    Viti, C; Giovannetti, L; Granchi, L; Ventura, S

    1996-10-01

    In several wines, malolactic fermentation is required to improve the organoleptic characters and to stabilize the final product. In order to establish a controlled malolactic fermentation in wine, easy identification and sensitive typing of strains of Oenococcus oeni (new name of the malolactic bacterium Leuconostoc oenos) used as starter cultures are necessary. To accomplish these tasks, several strains of Oenococcus oeni isolated from wines of the Chianti region (Italy), along with reference strains and strains of L. mesenteroides subsp. mesenteroides, L. carnosum, L. fallax, L. pseudomesenteroides, L. lactis and Weisella paramesenteroides, were studied with RFLP of ribosomal genes and ultrasensitive total DNA restriction pattern analysis performed on polyacrylamide gel. With each of four restriction endonucleases used, identical restriction profiles of ribosomal genes were obtained for all strains of O. oeni. These ribopatterns, being strongly dissimilar to profiles of the other lactic acid bacteria tested, appear to be well suited for the attribution of wine lactic acid bacteria to the species O. oeni. Cluster analysis performed on two total DNA restriction profile data sets showed that the species O. oeni possesses a good degree of genomic homogeneity. Very sensitive typing of strains of O. oeni was obtained with total DNA restriction profiles. The potential of an integrated approach using restriction profiles for species assignment and typing of selected malolactic bacteria is demonstrated.

  14. Sequence and comparative analysis of Leuconostoc dairy bacteriophages

    DEFF Research Database (Denmark)

    Kot, Witold; Hansen, Lars Henrik; Neve, Horst

    2014-01-01

    Bacteriophages attacking Leuconostoc species may significantly influence the quality of the final product. There is however limited knowledge of this group of phages in the literature. We have determined the complete genome sequences of nine Leuconostoc bacteriophages virulent to either Leuconostoc...

  15. OBTENCIÓN DE DEXTRANO Y FRUCTOSA, UTILIZANDO RESIDUOS AGROINDUSTRIALES CON LA CEPA Leuconostoc mesenteroides NRRL B512-F

    Directory of Open Access Journals (Sweden)

    Olga Viviana Rodríguez

    2007-06-01

    Full Text Available Debido al gran potencial biotecnológico que presentan los residuos agroindustriales, se desarrolló el presente trabajo para la obtención de oligosacáridos, utilizando como materia prima residuos de cascaras de naranja, piña y cachaza de caña panelera, a escala de laboratorio. Por medio de un diseño experimental se evaluó la concentración y tipo de sustrato y la temperatura del proceso con tres niveles, para lograr la mayor producción. El desarrollo experimental se llevó a cabo con un volumen de 100 mL y 250 mL. En la etapa final se obtuvo como resultado una producción de 3,4 g/L de dextrano y 5,04 g/L de fructosa, utilizando como sustrato cascaras de naranja con estas condiciones: temperatura de 30 °C y concentración de sustrato de 20 g/L; durante el proceso se midieron el consumo de sustrato y la concentración de biomasa y productos. Se observó el desarrollo del microorganismo con los sustratos empleados en la experimentación, sin adición de nutrientes, con una adaptación favorable a éstos. Finalmente, se realizó una caracterización preliminar del polímero obtenido, con lo que se concluyó que puede obtenerse dextrano de grado técnico para su uso como espesante en la industria de alimentos y en el área de tratamiento de aguas residuales como floculante.Due to biotechnological potential that presents the agro-industrial remainders, the present work was developed about obtaining oligosaccharides using like raw material remainders of orange peels, pineapple peels, and panelera cane slowness, at level laboratory. An experimental design was used to evaluate type and concentration of substrate and process temperature at three levels, accordingly the greatest amount of dextran and fructose produced. All volumes worked were 100 mL and 250 mL. In the final phase, the result was a production of dextran 3.4 g/L and fructose 5.04 g/L, using orange peels as substrate, temperature at 30 °C and concentration of substrate of 20 g/L, determining for each sample: consumption of substrate, biomass, and amount of products. The growth of the microorganism was observed; correspondingly to a substrate without addition of nutrients with a favorable adaptation at medium supplied. Finally, an experimental characterization was developed, and it was concluded that technical grade dextran can be obtained used in food like thicker and waste water treatment.

  16. Pre-treatment step with Leuconostoc mesenteroides or L. pseudomesenteroides strains removes furfural from Zymomonas mobilis ethanolic fermentation broth

    Science.gov (United States)

    Furfural (furan-2-carboxaldehyde), formed during dilute acid hydrolysis of biomass, is an inhibitor of growth and ethanol production by Zymomonas mobilis. The present study used a biological pre-treatment to reduce that amount of furfural in a model biofuel fermentation broth. The pre-treatment in...

  17. TEROIDES THE STUDY OF THE EFFECT OF HIGH AND LOW STARTING TITRE IN THE MODEL ENVIRONMENTS TO CHANGES IN ACTIVE AND TITRATABLE ACIDITY DURING THE CULTIVATION OF WHITE CABBAGE VARIETIES PARUS LACTIC ACID BACTERIA L. LACTIS AND L. MESENTEROIDES

    Directory of Open Access Journals (Sweden)

    V. V. Kondratenko

    2017-01-01

    Full Text Available The aim of the research was to study the dynamics of active and titratable acidity with a low and high initial titer, while cultivating white head cabbage of the variety ‘Parus’ with lactic acid bacteria Leuconostoc lactis VKPM V-12150 and Leuconostoc mesenteroides subsp. mesenteroides VKPM V-8818 in the basic model medium (BMS and the modified model medium (MMC during fermentation . In this experiment, two important questions were considered: the creation of favorable conditions for the growth of lactic acid microorganisms and the suppression of undesirable pathogenic microflora, which can eventually lead to product spoilage. One of the key questions is to scale the results of studies related to the fermentation of plant objects by microorganisms on initially non-sterile raw materials that is the requirement to create as possible fast the conditions that restrain the reproduction of Cl. botulinum, preventing toxin accumulation in the product. Therefore, an important factor is the observance for the necessary boundary condition where for international standards, it reaches pH ≤ 4.6, and for Russian standards it reaches pH ≤ 4.2. Hence, an analysis of the experimental data showed that these boundary conditions were reached after the expiration of essentially different time intervals during the cultivation of microorganisms with different starting titers. As a result, it was shown with which lactic acid microorganisms the optimal parameters for the dynamics of active and titratable acidity were obtained, when the boundary condition reached pH 4.2. Since this value determines more "stringent" requirements for product safety. As a result of studies it was found that optimal parameters for the dynamics of active and titratable acidity when a limit pH value of 4.2 is obtained in the cultivation of lactic acid bacteria L. mesenteroides in the MMC, revealing that the value of the starting titer ranging from 3*103 to 3*105 CFU/g.

  18. Plasmid-encoded diacetyl (acetoin) reductase in Leuconostoc pseudomesenteroides

    DEFF Research Database (Denmark)

    Rattray, Fergal P; Myling-Petersen, Dorte; Larsen, Dianna

    2003-01-01

    A plasmid-borne diacetyl (acetoin) reductase (butA) from Leuconostoc pseudomesenteroides CHCC2114 was sequenced and cloned. Nucleotide sequence analysis revealed an open reading frame encoding a protein of 257 amino acids which had high identity at the amino acid level to diacetyl (acetoin...

  19. Leuconostoc Spp. Bacteremia in a Patient with Sigmoid Colon Cancer

    Directory of Open Access Journals (Sweden)

    Havva Avcikucuk

    2013-10-01

    Full Text Available Leuconostoc species are opportunistic pathogens that rarely encountered as an infection agent. It has been reported that, this pathogen could cause infections especially in immunsupressive patients, after invasive procedures and antibiotic treatment. In this report, we aim to present a case with intrinsically vancomycin resistant Leuconostoc spp. that was isolated in blood culture. Fifty six years old male patient with type II diabetes mellitus and chronic obstructive pulmonary disease had been operated for sigmoid colon cancer one a half years ago. He was taken radiotherapy and chemotherapy right after the operation. The patient was admitted to our hospital with a complaint of stenosis in colostomy opening. Empiricial treatment was started for high fever. Gram positive coccus was reported in the blood culture(Bactec 9050, Becton-Dickinson, USA. The isolate was identified as Leuconostoc spp. with API 20 Strep (BioMerieux, French kit. Antibiotic susceptibility test was performed by the disk diffusion method according to CLSI (Clinical and Laboratory Standards Institute recommendations. The isolate was found susceptible to linezolid and quinupristin-dalfopristine, while it was resistant to penicilin, ampicillin, erythromycin, tetracycline, vancomycin and teicoplanin by the disk diffusion method. Vancomycin resistance was confirmed by E-test (AB Biodisk, Solna, Sweden.

  20. Leuconostoc garlicum: an unusual pathogen in the era of vancomycin therapy.

    Science.gov (United States)

    Kumar, Anil; Augustine, Deepthi; Mehta, Asmita; Dinesh, Kavitha R; Viswam, Darsana; Philip, Rosamma

    2012-01-01

    Leuconostoc garlicum, belonging to the family of Leuconostocaceae, is a catalase-negative, Gram-positive ovoid cocci, intrinsically resistant to vancomycin. Clinical infection by Leuconostoc garlicum is rare. We report a case of respiratory tract infection subsequent to vancomycin therapy.

  1. Leuconostoc rapi sp. nov., isolated from sous-vide cooked rutabaga

    DEFF Research Database (Denmark)

    Lyhs, Ulrike; Snauwaert, I.; Pihlajaviita, S.

    2015-01-01

    A Gram-positive, ovoid lactic acid bacterium, strain LMG 27676T, was isolated from a spoiled sous-vide cooked rutabaga. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc kimchi and Leuconostoc miyukkimchii as nearest neighbours (99.......1 and 98.8% 16S rRNA gene sequence similarity towards the type strain, respectively). Phylogenetic analysis of the 16S rRNA gene, multilocus sequence analysis of the pheS, rpoA and atpA genes, and biochemical and genotypic characteristics allowed to differentiate strain LMG 27676T from all established...

  2. Leuconostoc sp. Meningitis in a Patient Treated with Rituximab for Mantle Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Hrvoje Holik

    2015-09-01

    Full Text Available We present a 64-year-old man who was treated with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy for mantle cell lymphoma and developed purulent meningitis, probably caused by Leuconostoc sp. The patient had severe hypogammaglobulinemia, which is a possible complication of rituximab therapy. To our knowledge and after reviewing the available medical literature, this is the first described case of purulent meningitis caused by Leuconostoc sp. in a patient with mantle cell lymphoma that appeared after treatment with the R-CHOP protocol. The diagnosis of purulent meningitis was based on clinical, laboratory and cytological cerebrospinal fluid findings, in addition to blood culture results in which we isolated Leuconostoc sp. The patient was treated with meropenem with full recovery.

  3. Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria.

    Science.gov (United States)

    Filannino, Pasquale; Gobbetti, Marco; De Angelis, Maria; Di Cagno, Raffaella

    2014-12-01

    The metabolism of hydroxycinnamic acids by strictly heterofermentative lactic acid bacteria (19 strains) was investigated as a potential alternative energy route. Lactobacillus curvatus PE5 was the most tolerant to hydroxycinnamic acids, followed by strains of Weissella spp., Lactobacillus brevis, Lactobacillus fermentum, and Leuconostoc mesenteroides, for which the MIC values were the same. The highest sensitivity was found for Lactobacillus rossiae strains. During growth in MRS broth, lactic acid bacteria reduced caffeic, p-coumaric, and ferulic acids into dihydrocaffeic, phloretic, and dihydroferulic acids, respectively, or decarboxylated hydroxycinnamic acids into the corresponding vinyl derivatives and then reduced the latter compounds to ethyl compounds. Reductase activities mainly emerged, and the activities of selected strains were further investigated in chemically defined basal medium (CDM) under anaerobic conditions. The end products of carbon metabolism were quantified, as were the levels of intracellular ATP and the NAD(+)/NADH ratio. Electron and carbon balances and theoretical ATP/glucose yields were also estimated. When CDM was supplemented with hydroxycinnamic acids, the synthesis of ethanol decreased and the concentration of acetic acid increased. The levels of these metabolites reflected on the alcohol dehydrogenase and acetate kinase activities. Overall, some biochemical traits distinguished the common metabolism of strictly heterofermentative strains: main reductase activity toward hydroxycinnamic acids, a shift from alcohol dehydrogenase to acetate kinase activities, an increase in the NAD(+)/NADH ratio, and the accumulation of supplementary intracellular ATP. Taken together, the above-described metabolic responses suggest that strictly heterofermentative lactic acid bacteria mainly use hydroxycinnamic acids as external acceptors of electrons. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  4. Screening and characterization of extracellular polysaccharides produced by Leuconostoc kimchii isolated from traditional fermented pulque beverage.

    Science.gov (United States)

    Torres-Rodríguez, Ingrid; Rodríguez-Alegría, María Elena; Miranda-Molina, Alfonso; Giles-Gómez, Martha; Conca Morales, Rodrigo; López-Munguía, Agustín; Bolívar, Francisco; Escalante, Adelfo

    2014-01-01

    We report the screening and characterization of EPS produced by LAB identified as Leuconostoc kimchii isolated from pulque, a traditional Mexican fermented, non-distilled alcoholic beverage produced by the fermentation of the sap extracted from several (Agave) maguey species. EPS-producing LAB constitutes an abundant bacterial group relative to total LAB present in sap and during fermentation, however, only two EPS-producing colony phenotypes (EPSA and EPSB, respectively) were detected and isolated concluding that despite the high number of polymer-producing LAB their phenotypic diversity is low. Scanning electron microcopy analysis during EPS-producing conditions revealed that both types of EPS form a uniform porous structure surrounding the bacterial cells. The structural characterization of the soluble and cell-associated EPS fractions of each polymer by enzymatic and acid hydrolysis, as by 1D- and 2D-NMR, showed that polymers produced by the soluble and cell-associated fractions of EPSA strain are dextrans consisting of a linear backbone of linked α-(1→6) Glcp in the main chain with α-(1→2) and α-(1→3)-linked branches. The polymer produced by the soluble fraction of EPSB strain was identified as a class 1 dextran with a linear backbone containing consecutive α-(1→6)-linked D-glucopyranosyl units with few α-(1→3)-linked branches, whereas the cell-associated EPS is a polymer mixture consisting of a levan composed of linear chains of (2→6)-linked β-D-fructofuranosyl residues with β-(2→6) connections, and a class 1 dextran. According to our knowledge this is the first report of dextrans and a levan including their structural characterization produced by L. kimchii isolated from a traditional fermented source.

  5. The proton motive force generated in Leuconostoc oenos by L-malate fermentation

    NARCIS (Netherlands)

    Salema, Madalena; Lolkema, Juke S.; San Romão, M.V.; Loureiro Dias, Maria C.

    In cells of Leuconostoc oenos, the fermentation of L-malic acid generates both a transmembrane pH gradient, inside alkaline, and an electrical potential gradient, inside negative. In resting cells, the proton motive force ranged from -170 mV to -88 mV between pH 3.1 and 5.6 in the presence of

  6. Transformation of Leuconostoc carnosum 4010 and evidence for natural competence of the organism

    DEFF Research Database (Denmark)

    Helmark, Søren; Hansen, Michael Edberg; Jelle, B.

    2004-01-01

    Plasmid transformation in Leuconostoc carnosum 4010 was analyzed. A successful transformation protocol for L. carnosum was established by modifying an existing protocol for Lactococcus lactis. Several parameters, including the number of generations that the cells had grown at the time of harvest...

  7. Genome sequences of two Leuconostoc pseudomesenteroides strains isolated from Danish dairy starter cultures

    DEFF Research Database (Denmark)

    Pedersen, Thomas Bæk; Kot, Witold Piotr; Hansen, L.H.

    2014-01-01

    The lactic acid bacterium Leuconostoc pseudomesenteroides can be found in mesophilic cheese starters, where it produces aromatic compounds from, e.g., citrate. Here, we present the draft genome sequences of two L. pseudomesenteroides strains isolated from traditional Danish cheese starters....

  8. Identification of the Receptor-Binding Protein in Lytic Leuconostoc pseudomesenteroides Bacteriophages

    DEFF Research Database (Denmark)

    Kot, Witold Piotr; Hammer, Karin; Neve, Horst

    2013-01-01

    Two phages, P793 and ΦLN04, sharing 80.1% nucleotide sequence identity but having different strains of Leuconostoc pseudomesenteroides as hosts, were selected for identification of the host determinant gene. Construction of chimeric phages leading to the expected switch in host range identified t...

  9. Estudo e otimização da produção da dextranasacarase e caracterização da dextrana produzida por Leuconostoc mesenteroides FT045B

    OpenAIRE

    Vettori, Mary Helen Palmuti Braga [UNESP

    2011-01-01

    Um estudo comparativo de onze métodos para determinação da atividade da dextranasacarase e de enzimas relacionadas foi realizado. Atualmente existem dois métodos usualmente empregados na determinação da atividade da dextranasacarase. Um método relativamente difundido para a reação da enzima com a sacarose consiste na medição dos valores redutores da D-frutose pelo reagente 3,5-dinitrosalicilato (DNS). Outro método é a reação da enzima com 14Csacarose, pela adição de uma alíquota da reação em ...

  10. Identification and characterization of novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15.

    Science.gov (United States)

    Sawa, N; Okamura, K; Zendo, T; Himeno, K; Nakayama, J; Sonomoto, K

    2010-07-01

    To characterize novel multiple bacteriocins produced by Leuconostoc pseudomesenteroides QU 15. Leuconostoc pseudomesenteroides QU 15 isolated from Nukadoko (rice bran bed) produced novel bacteriocins. By using three purification steps, four antimicrobial peptides termed leucocin A (ΔC7), leucocin A-QU 15, leucocin Q and leucocin N were purified from the culture supernatant. The amino acid sequences of leucocin A (ΔC7) and leucocin A-QU 15 were identical to that of leucocin A-UAL 187 belonging to class IIa bacteriocins, but leucocin A (ΔC7) was deficient in seven C-terminal residues. Leucocin Q and leucocin N are novel class IId bacteriocins. Moreover, the DNA sequences encoding three bacteriocins, leucocin A-QU 15, leucocin Q and leucocin N were obtained. These bacteriocins including two novel bacteriocins were identified from Leuc. pseudomesenteroides QU 15. They showed similar antimicrobial spectra, but their intensities differed. The C-terminal region of leucocin A-QU 15 was important for its antimicrobial activity. Leucocins Q and N were encoded by adjacent open reading frames (ORFs) in the same operon, but leucocin A-QU 15 was not. These leucocins were produced concomitantly by the same strain. Although the two novel bacteriocins were encoded by adjacent ORFs, a characteristic of class IIb bacteriocins, they did not show synergistic activity. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  11. Production of freeze-dried lactic acid bacteria starter culture for cassava fermentation into gari

    CSIR Research Space (South Africa)

    Yao, AA

    2009-10-01

    Full Text Available Sixteen lactic acid bacteria, eight Lactobacillus plantarum, three L. pentosus, two Weissella paramesenteroides, two L. fermemtum and one Leuconostoc mesenteroides ssp. mesenteroides were previously isolated from cassava fermentation and selected...

  12. Leuconostoc Strains Unable to Split a Lactose Analogue Revealed by Characterisation of Mesophilic Dairy Starters

    Directory of Open Access Journals (Sweden)

    Maarit Mäki

    2005-01-01

    Full Text Available Mesophilic starter cultures used in dairy industry have been traditionally characterised by metabolic and biochemical methods. As closely related species of lactic acid bacteria have often only minor differences in phenotypic traits, which may also be variable within certain species, clear identification is often complicated. Therefore, techniques of molecular biology have been applied for rapid detection and differentiation of lactic acid bacteria. In this work, some bacterial clones isolated from mesophilic starters, which were preliminary identified as lactococci by phenotypic methods, were found to be Leuconostoc strains by both PCR and PFGE. According to the results, genotypic differentiation methods used in combination with phenotypic tests provide a fast and convenient way to reliably identify lactic acid bacteria displaying atypical metabolic characteristics.

  13. Continuous cider fermentation with co-immobilized yeast and Leuconostoc oenos cells.

    Science.gov (United States)

    Nedovic; Durieuxb; Van Nedervelde L; Rosseels; Vandegans; Plaisant; Simon

    2000-06-01

    Ca-alginate matrix was used to co-immobilize Saccharomyces bayanus and Leuconostoc oenos in one integrated biocatalytic system in order to perform simultaneously alcoholic and malo-lactic fermentation of apple juice to produce cider, in a continuous packed bed bioreactor. The continuous process permitted much faster fermentation compared with the traditional batch process. The flavor formation was also better controlled. By adjusting the flow rate of feeding substrate through the bioreactor, i.e. its residence time, it was possible to obtain either "soft" or "dry" cider. However, the profile of volatile compounds in the final product was modified comparatively to the batch process, especially for higher alcohols, isoamylacetate, and diacetyl. This modification is due to different physiology states of yeast in two processes. Nevertheless, the taste of cider was quite acceptable.

  14. Antifungal activity of Leuconostoc citreum and Weissella confusa in rice cakes.

    Science.gov (United States)

    Baek, Eunjong; Kim, Hyojin; Choi, Hyejung; Yoon, Sun; Kim, Jeongho

    2012-10-01

    The antifungal activity of organic acids greatly improves the shelf life of bread and bakery products. However, little is known about the effect of lactic acid fermentation on fungal contamination in rice cakes. Here, we show that lactic acid fermentation in rice dough can greatly retard the growth of three fungal species when present in rice cakes, namely Cladosporium sp. YS1, Neurospora sp. YS3, and Penicillium crustosum YS2. The antifungal activity of the lactic acid bacteria against these fungi was much better than that of 0.3% calcium propionate. We found that organic acids including lactic and acetic acid, which are byproducts of lactic fermentation or can be artificially added, were the main antifungal substances. We also found that some Leuconostoc citreum and Weissella confusa strains could be good starter species for rice dough fermentation. These results imply that these lactic acid bacteria can be applicable to improve the preservation of rice cakes.

  15. Production, extraction and characterization of exopolysaccharides produced by the native Leuconostoc pseudomesenteroides R2 strain

    Directory of Open Access Journals (Sweden)

    Elinalva M. Paulo

    2012-06-01

    Full Text Available The genus Leuconostoc belongs to a group of lactic acid bacteria usually isolated from fermented vegetables, which includes species involved in the production of exopolysaccharides (EPS. These biopolymers possess considerable commercial potential. Because of the wide variety of industrial applications of EPS, this study aimed to produce and characterize the native exopolysaccharide strain Leuconostoc pseudomesenteroides R2, which was isolated from cabbage collected in a semi-arid region of Bahia. We employed the following conditions for the production of EPS: 10.7% sucrose, pH 8.2, without agitation and incubation at 28ºC for 30 hours. The fermentation broth was treated with ethanol and generated two types of polysaccharide substances (EPS I and EPS II. The identification of EPS I and EPS II was conducted using FT-IR, ¹H, 13C and DEPT-135 NMR spectra. The two substances were identified as linear dextran α polysaccharides (1 → 6 which indicated different characteristics with respect to thermal analysis and density of free packaging, viscosity and time of solubilization. Both dextrans are of low density, possess high thermal stability and exhibited the behavior characteristic of pseudoplastic polymers.O gênero Leuconostoc pertence a um grupo de bactérias lácticas normalmente isoladas de vegetais fermentados, que inclui espécies envolvidas na produção de exopolissacarídeos (EPS. Esses biopolímeros possuem potencial comercial considerável. Devido à grande variedade de aplicações industriais, de EPS, o presente estudo teve como objetivo produzir e caracterizar o nativo exopolissacarídeo cepa Leuconostoc pseudomesenteroides R2, que foi isolado de repolho coletado em uma região semi-árida da Bahia. Utilizamos as seguintes condições para a produção de EPS: 10,7% de sacarose, pH 8,2, sem agitação e incubação a 28º C por 30 horas. O caldo fermentado foi tratado com etanol, gerando dois tipos de substâncias de polissacar

  16. Biomass production and small-scale testing of freeze-dried lactic acid bacteria starter strains for cassava fermentations

    CSIR Research Space (South Africa)

    Edward, VA

    2011-03-01

    Full Text Available Based on their predominance in Gari fermentations, as well as suitable technological properties, Lactobacillus plantarum, Lactobacillus fermentum, Weissella paramesenteroides and Leuconostoc mesenteroides strains were investigated...

  17. Significance of heme-based respiration in meat spoilage caused by Leuconostoc gasicomitatum.

    Science.gov (United States)

    Jääskeläinen, Elina; Johansson, Per; Kostiainen, Olli; Nieminen, Timo; Schmidt, Georg; Somervuo, Panu; Mohsina, Marzia; Vanninen, Paula; Auvinen, Petri; Björkroth, Johanna

    2013-02-01

    Leuconostoc gasicomitatum is a psychrotrophic lactic acid bacterium (LAB) which causes spoilage in cold-stored modified-atmosphere-packaged (MAP) meat products. In addition to the fermentative metabolism, L. gasicomitatum is able to respire when exogenous heme and oxygen are available. In this study, we investigated the respiration effects on growth rate, biomass, gene expression, and volatile organic compound (VOC) production in laboratory media and pork loin. The meat samples were evaluated by a sensory panel every second or third day for 29 days. We observed that functional respiration increased the growth (rate and yield) of L. gasicomitatum in laboratory media with added heme and in situ meat with endogenous heme. Respiration increased enormously (up to 2,600-fold) the accumulation of acetoin and diacetyl, which are buttery off-odor compounds in meat. Our transcriptome analyses showed that the gene expression patterns were quite similar, irrespective of whether respiration was turned off by excluding heme from the medium or mutating the cydB gene, which is essential in the respiratory chain. The respiration-based growth of L. gasicomitatum in meat was obtained in terms of population development and subsequent development of sensory characteristics. Respiration is thus a key factor explaining why L. gasicomitatum is so well adapted in high-oxygen packed meat.

  18. Identification of Mur, an atypical peptidoglycan hydrolase derived from Leuconostoc citreum.

    Science.gov (United States)

    Cibik, R; Tailliez, P; Langella, P; Chapot-Chartier, M P

    2001-02-01

    A gene encoding a protein homologous to known bacterial N-acetyl-muramidases has been cloned from Leuconostoc citreum by a PCR-based approach. The encoded protein, Mur, consists of 209 amino acid residues with a calculated molecular mass of 23,821 Da including a 31-amino-acid putative signal peptide. In contrast to most of the other known peptidoglycan hydrolases, L. citreum Mur protein does not contain amino acid repeats involved in cell wall binding. The purified L. citreum Mur protein was shown to exhibit peptidoglycan-hydrolyzing activity by renaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An active chimeric protein was constructed by fusion of L. citreum Mur to the C-terminal repeat-containing domain (cA) of AcmA, the major autolysin of Lactococcus lactis. Expression of the Mur-cA fusion protein was able to complement an acmA mutation in L. lactis; normal cell separation after cell division was restored by Mur-cA expression.

  19. [Phylogenetic analysis of closely related Leuconostoc citreum species based on partial housekeeping genes].

    Science.gov (United States)

    Lv, Qiang; Chen, Ming; Xu, Haiyan; Song, Yuqin; Sun, Zhihong; Dan, Tong; Sun, Tiansong

    2013-07-04

    Using the 16S rRNA, dnaA, murC and pyrG gene sequences, we identified the phylogenetic relationship among closely related Leuconostoc citreum species. Seven Leu. citreum strains originally isolated from sourdough were characterized by PCR methods to amplify the dnaA, murC and pyrG gene sequences, which were determined to assess the suitability as phylogenetic markers. Then, we estimated the genetic distance and constructed the phylogenetic trees including 16S rRNA and above mentioned three housekeeping genes combining with published corresponding sequences. By comparing the phylogenetic trees, the topology of three housekeeping genes trees were consistent with that of 16S rRNA gene. The homology of closely related Leu. citreum species among dnaA, murC, pyrG and 16S rRNA gene sequences were different, ranged from75.5% to 97.2%, 50.2% to 99.7%, 65.0% to 99.8% and 98.5% 100%, respectively. The phylogenetic relationship of three housekeeping genes sequences were highly consistent with the results of 16S rRNA gene sequence, while the genetic distance of these housekeeping genes were extremely high than 16S rRNA gene. Consequently, the dnaA, murC and pyrG gene are suitable for classification and identification closely related Leu. citreum species.

  20. A high-throughput qPCR system for simultaneous quantitative detection of dairy Lactococcus lactis and Leuconostoc bacteriophages

    DEFF Research Database (Denmark)

    Muhammed, Musemma Kedir; Krych, Lukasz; Nielsen, Dennis Sandris

    2017-01-01

    simultaneous quantitative detection of Lc. lactis 936 (now SK1virus), P335, c2 (now C2virus) and Leuconostoc phage groups. Component assays are designed to have high efficiencies and nearly the same dynamic detection ranges, i.e., from 1.1 x 105 to 1.1 x 101 phage genomes per reaction, which corresponds to 9 x......Simultaneous quantitative detection of Lactococcus (Lc.) lactis and Leuconostoc species bacteriophages (phages) has not been reported in dairies using undefined mixed-strain DL-starters, probably due to the lack of applicable methods. We optimized a high-throughput qPCR system that allows...... 107 to 9 x 103 phage particles mL-1 without any additional up-concentrating steps. The amplification efficiencies of the corresponding assays were 100.1±2.6, 98.7±2.3, 101.0±2.3 and 96.2±6.2. The qPCR system was tested on samples obtained from a dairy plant that employed traditional mother...

  1. Biological characteristics and probiotic effect of Leuconostoc lactis strain isolated from the intestine of black porgy fish

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2013-09-01

    Full Text Available A strain of lactic acid bacteria, Leuconostoc lactis, was isolated from the intestinal tract of black porgy, Sparus macrocephalus, and identified by conventional biochemical characteristics and 16S rDNA gene sequence analysis. The isolated strain had the ability of bile tolerance and resistance to low pH, and survived well in the trypsinase and pepsin solution. But the highly concentrated dose of trypsinase and pepsin affect the viability of the isolated strain. The isolate was resistant to several antibiotics, including Cephalothin, Ceftriaxone, Imipenem and Tobramycin. The isolate could autoaggregate itself and coaggregate with other bacteria in vitro. The autoaggregation percentage increased to 23.29% after 20 h of incubation. The percentage of coaggregation were respectively 31.21%, 29.44%, 10.74%, 16.49%, 24.36%, 24.41% and 20.99% for Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli O157, Salmonella typhimurium, Shigella, Staphylococcus aureus and Proteusbacillus vulgaris after 20 h incubation of a mixed suspension. The supernatant of the strain inhibited the growth of several pathogens, such as V.parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Staphylococcus aureus, Escherichia coli O157, Salmonella typhimurium, Bacillus subtilis, Proteusbacillus vulgaris and Shigella. These results indicated that the isolate, Leuconostoc lactis, might be an attractive candidate for perspectival strain for probiotics in marine aquaculture.

  2. Leucocins 4010 from Leuconostoc carnosum cause a matrix related decrease in intracellular pH of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Fang, Weihuan; Budde, Birgitte Bjørn; Siegumfeldt, Henrik

    2006-01-01

    A mixed culture of single cells of Listeria monocytogenes and the bacteriocin producing Leuconostoc carnosum 4010 showed growth inhibition of L. monocytogenes, although the intracellular pH (pHi) of L. monocytogenes followed by fluorescence ratio imaging microscopy was not affected. Furthermore, L...

  3. High-yield production of mannitol by Leuconostoc pseudomesenteroides CTCC G123 from chicory-derived inulin hydrolysate.

    Science.gov (United States)

    Zhang, Min; Gu, Lei; Cheng, Chao; Zhu, Junru; Wu, Hao; Ma, Jiangfeng; Dong, Weiliang; Kong, Xiangping; Jiang, Min; Ouyang, Pingkai

    2017-08-01

    Chicory is an agricultural plant with considerable potential as a carbohydrate substrate for low-cost production of biochemicals. In this work, the production of mannitol by Leuconostoc pseudomesenteroides CTCC G123 from chicory-derived inulin hydrolysate was investigated. The bioconversion process initially suffered from the leakage of fructose to the phosphoketolase pathway, resulting in a low mannitol yield. When inulin hydrolysate was supplemented with glucose as a substrate for mannitol production in combination with aeration induction and nicotinic acid induced redox modulation strategies, the mannitol yield greatly improved. Under these conditions, significant improvement in the glucose consumption rate, intracellular NADH levels and mannitol dehydrogenase specific activity were observed, with mannitol production increasing from 64.6 to 88.1 g/L and overall yield increase from 0.69 to 0.94 g/g. This work demonstrated an efficient method for the production of mannitol from inulin hydrolysate with a high overall yield.

  4. Development and Diversity of Lactococcus lactis and Leuconostoc Bacteriophages in Dairies Using Undefined Mesophilic DL-Starter Cultures

    DEFF Research Database (Denmark)

    Muhammed, Musemma Kedir

    complete loss of fermentation. Dairy phages have for long time been studied using traditional culture-dependent methods but not using metagenomic approaches. Part of this project was devoted to develop a method for dairy metavirome extraction and analysis. Several whey mixtures derived by defined......Bacteriophages (phages) attacking strains of Lactococcus (Lc.) lactis and Leuconostoc species, used as starter cultures in mesophilic dairy productions, produce huge problems through waste of ingredients, increased processing time, reduced product quality, consistency and safety, and occasionally...... in dairies using undefined starters and of mostly Lc. lactis c2 phages in dairies using defined cultures. Certain evidence indicating possible co-induction of temperate P335 phages and smaller Lc. lactis satellite phages was obtained. Also addressed was the issue of accurate and simultaneous quantification...

  5. Characterization, production, and purification of leucocin H, a two-peptide bacteriocin from Leuconostoc MF215B.

    Science.gov (United States)

    Blom, H; Katla, T; Holck, A; Sletten, K; Axelsson, L; Holo, H

    1999-07-01

    Leuconostoc MF215B was found to produce a two-peptide bacteriocin referred to as leucocin H. The two peptides were termed leucocin Halpha and leucocin Hbeta. When acting together, they inhibit, among others, Listeria monocytogenes, Bacillus cereus, and Clostridium perfringens. Production of leucocin H in growth medium takes place at temperatures down to 6 degrees C and at pH below 7. The highest activity of leucocin H in growth medium was demonstrated in the late exponential growth phase. The bacteriocin was purified by precipitation with ammonium sulfate, ion-exchange (SP Sepharose) and reverse phase chromatography. Upon purification, specific activity increased 10(5)-fold, and the final specific activity was 2 x 10(7) BU/OD280. Amino acid composition analyses of leucocin Halpha and leucocin Hbeta indicated that both peptides consisted of around 40 amino acid residues. Their N-termini were blocked for Edman degradation, and the methionin residues of leucocin Hbeta did not respond to Cyanogen Bromide (CNBr) cleavage. Absorbance at 280 nm indicated the presence of tryptophan residues and tryptophan-fracturing opened for partial sequencing by Edman degradation. From leucocin Halpha, the sequence of 20 amino acids was obtained; from leucocin Hbeta the sequence of 28 amino acid residues was obtained. No sequence homology to other known bacteriocins could be demonstrated. It also appeared that the two peptides themselves shared little or no sequence homology. The presence of soy oil did not affect the activity of leucocin H in agar.

  6. THE INFLUENCE OF THE COMPOSITION OF THE CULTURE MEDIUM ON THE DEVELOPMENT OF LEUCONOSTOC LACTIS PRE-FERMENTATION

    Directory of Open Access Journals (Sweden)

    V. V. Kondratenko

    2017-01-01

    Full Text Available The regularity of the influence of the culture medium (substrate on the development of microflora at the stage of preliminary fermentation of the model medium on the basis of white cabbage varieties "Parus" was studied. During the research, strains of lactic acid microorganisms Leuconostoc lactis were used. Step-by-step mathematical processing of the experimental data was carried out. Functional dependencies are obtained that most adequately approximate experimental data for modified (MMC and basic (BMS model media. Analysis of the experimental data showed that, depending on the type (composition of the medium, the same species of microorganisms exhibit different dynamics of titer growth. In connection with this, an algorithm was developed to determine the optimal duration of pre-fermentation – «stop points». As a result of the research, it can be seen that the modification of the model medium with the addition of table salt and ascorbic acid to it promotes the formation of positive dynamics of the comparison indicator. This dynamics has three extremes, but only extremes are of practical significance, which were in the interval of the monotonic decrease of the titer. For successful development of the starting culture of the stage of the main fermentation, one of the conditions is a relatively small amount of the titer of the first culture at the end of the preliminary fermentation step to exclude competition. Thus, the position of the «stop-point» position corresponds to the period after the last peak of the comparison indicator. The investigated regularity of the effect of the preliminary cultivation of gram-positive microorganisms on the activity of lactic acid microorganisms in the process of fermentation is topical, since the whole process and the production of high-quality products fully depend on this approach.

  7. Influence of starter culture of lactic acid bacteria on the shelf life of ...

    African Journals Online (AJOL)

    A total of eight lactic acid bacteria were isolated from various fermented cereal gruels (ogi). They were identified as Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus acidophilus and Pediococcus acidilactici.

  8. Effect of dextransucrase cellobiose acceptor products on the growth of human gut bacteria

    Science.gov (United States)

    The selective fermentation by human gut bacteria of gluco-oligosaccharides obtained from the reaction between the glucosyl group of sucrose and cellobiose, catalyzed by dextransucrases from Leuconostoc mesenteroides, has been evaluated. Oligosaccharides were fractionated according to their molecula...

  9. Antibacterial Activity of Lactic Acid Bacteria Isolated from Salad ...

    African Journals Online (AJOL)

    To determine the inhibitory capacity of lactic acid bacteria (LAB) due to the action of antagonistic substances, 8 members of the LAB group namely, Lactobacillus brevis, Lactobacillus casei, Lactobacillus cellebiosuis, Lactobacillus delbruesckii, Lactobacillus fermentum, Lactobacillus plantarum, Leuconostoc mesenteroides ...

  10. A novel multi-locus sequence typing (MLST) protocol for Leuconostoc lactis isolates from traditional dairy products in China and Mongolia.

    Science.gov (United States)

    Dan, Tong; Liu, Wenjun; Sun, Zhihong; Lv, Qiang; Xu, Haiyan; Song, Yuqin; Zhang, Heping

    2014-06-09

    Economically, Leuconostoc lactis is one of the most important species in the genus Leuconostoc. It plays an important role in the food industry including the production of dextrans and bacteriocins. Currently, traditional molecular typing approaches for characterisation of this species at the isolate level are either unavailable or are not sufficiently reliable for practical use. Multilocus sequence typing (MLST) is a robust and reliable method for characterising bacterial and fungal species at the molecular level. In this study, a novel MLST protocol was developed for 50 L. lactis isolates from Mongolia and China. Sequences from eight targeted genes (groEL, carB, recA, pheS, murC, pyrG, rpoB and uvrC) were obtained. Sequence analysis indicated 20 different sequence types (STs), with 13 of them being represented by a single isolate. Phylogenetic analysis based on the sequences of eight MLST loci indicated that the isolates belonged to two major groups, A (34 isolates) and B (16 isolates). Linkage disequilibrium analyses indicated that recombination occurred at a low frequency in L. lactis, indicating a clonal population structure. Split-decomposition analysis indicated that intraspecies recombination played a role in generating genotypic diversity amongst isolates. Our results indicated that MLST is a valuable tool for typing L. lactis isolates that can be used for further monitoring of evolutionary changes and population genetics.

  11. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  12. Leuconostoc carnosum 4010 has the potential for use as a protective culture for vacuum-packed meats: culture isolation, bacteriocin identification, and meat application experiments

    DEFF Research Database (Denmark)

    Budde, B.B.; Hornbæk, T.; Jacobsen, T.

    2003-01-01

    A new culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum......-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial...... activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a vacuum...

  13. Leuconostoc gasicomitatum is the dominating lactic acid bacterium in retail modified-atmosphere-packaged marinated broiler meat strips on sell-by-day.

    Science.gov (United States)

    Susiluoto, Tuija; Korkeala, Hannu; Björkroth, K Johanna

    2003-01-15

    Lactic acid bacteria (LAB) in retail, modified-atmosphere-packaged (MAP), marinated broiler meat strips on sell-by-day were mainly identified as Leuconostoc gasicomitatum. A total of 32 packages, three to five packages of seven differently marinated broiler meat products, were studied at the end of the producer-defined shelf life (at 6 degrees C, 7-9 days depending on the manufacturer). Prior to the microbiological analyses, appearance and smell of the product was checked and pH measured. Bacteria were cultured on MRS and Tomato Juice Agar (TJA), Rogosa SL agar (SLA), Plate Count Agar (PCA) and Streptomycin Thallium Acetate Agar (STAA) for the enumeration of LAB, lactobacilli, total bacterial count and Brochothrix thermosphacta, respectively. The average CFU/g of the 32 packages was 2.3 x 10(8) on PCA. The highest bacterial average, 3.1 x 10(8), was recovered on TJA, the corresponding CFU/g averages on MRS and SLA being 2.3 x 10(8) and 1.3 x 10(8), respectively. Despite the high LAB numbers detected, radical spoilage changes such as unpleasant odor, slime production and formation of gas were not seen. B. thermosphacta did not form a significant part of the bacterial population since none of the levels exceeded the spoilage threshold level of 10(5) CFU/g reported in previous studies for this organism. In order to characterize the dominating LAB population, as many as 85, 85 and 88 colonies from MRS, TJA and SLA, respectively, were randomly picked and cultured pure. LAB were identified to species level using a 16 and 23S rDNA HindIiI RFLP (ribotyping) database. Fifty-six of the 170 isolates picked from the non-selective LAB media (MRS and TJA) were identified as L. gasicomitatum, followed by Carnobacterium divergens (41 isolates), Lactobacillus sakei and Lactobacillus curvatus subsp. melibiosus (31 isolates) and L. curvatus subsp. curvatus (20 isolates) species. SLA proved not to be completely selective for lactobacilli because the growth of Leuconostoc spp. was not

  14. Characterization of starter kimchi fermented with Leuconostoc kimchii GJ2 and its cholesterol-lowering effects in rats fed a high-fat and high-cholesterol diet.

    Science.gov (United States)

    Jo, Se Yeon; Choi, Eun A; Lee, Jae Joon; Chang, Hae Choon

    2015-10-01

    The hypocholesterolemic effects of lactic acid bacteria and kimchi have been demonstrated previously. However, the kimchi fermentation process still relies on naturally present microorganisms. To obtain functional kimchi with consistent quality, we validated the capacity of Leuconostoc kimchii GJ2 as a starter culture to control kimchi fermentation. Moreover, cholesterol-lowering effects of starter kimchi as a health-promoting product were explored. Bacteriocin production by Lc. kimchii GJ2 was highly enhanced in the presence of 5% Lactobacillus sakei NJ1 cell fractions. When kimchi was fermented with bacteriocin-enhanced Lc. kimchii GJ2, Lc. kimchii GJ2 became overwhelmingly predominant (98.3%) at the end of fermentation and maintained its dominance (up to 82%) for 84 days. Growing as well as dead cells of Lc. kimchii GJ2 showed high cholesterol assimilation (in vitro). Rats were fed a high-fat and high-cholesterol diet supplemented with starter kimchi. The results showed that feeding of starter kimchi significantly reduced serum total cholesterol, triglyceride and low-density lipoprotein cholesterol levels. Additionally, atherogenic index, cardiac risk factor and triglyceride and total cholesterol levels in liver and epididymal adipose tissue decreased significantly in rats fed starter kimchi. Kimchi fermented with Lc. kimchii GJ2 as a starter culture has efficient cholesterol-lowering effects. © 2014 Society of Chemical Industry.

  15. Processing Environment and Ingredients Are Both Sources of Leuconostoc gelidum, Which Emerges as a Major Spoiler in Ready-To-Eat Meals.

    Science.gov (United States)

    Pothakos, Vasileios; Stellato, Giuseppina; Ercolini, Danilo; Devlieghere, Frank

    2015-05-15

    Mesophilic and psychrotrophic organism viable counts, as well as high-throughput 16S rRNA gene-based pyrosequencing, were performed with the aim of elucidating the origin of psychrotrophic lactic acid bacteria (LAB) in a ready-to-eat (RTE) meal manufacturing plant. The microbial counts of the products at the end of the shelf life were greatly underestimated when mesophilic incubation was implemented due to overlooked, psychrotrophic members of the LAB. Pseudomonas spp., Enterobacteriaceae, Streptococcaceae, and Lactobacillus spp. constituted the most widespread operational taxonomic units (OTUs), whereas Leuconostoc gelidum was detected as a minor member of the indigenous microbiota of the food ingredients and microbial community of the processing environment, albeit it colonized samples at almost every sampling point on the premises. However, L. gelidum became the most predominant microbe at the end of the shelf life. The ability of L. gelidum to outgrow notorious, spoilage-related taxa like Pseudomonas, Brochothrix, and Lactobacillus underpins its high growth dynamics and severe spoilage character under refrigeration temperatures. The use of predicted metagenomes was useful for observation of putative gene repertoires in the samples analyzed in this study. The end products grouped in clusters characterized by gene profiles related to carbohydrate depletion presumably associated with a fast energy yield, a finding which is consistent with the fastidious nature of highly competitive LAB that dominated at the end of the shelf life. The present study showcases the detrimental impact of contamination with psychrotrophic LAB on the shelf life of packaged and cold-stored foodstuffs and the long-term quality implications for production batches once resident microbiota are established in the processing environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Biodiversity of lactic acid bacteria in Moroccan soft white cheese (Jben).

    Science.gov (United States)

    Ouadghiri, Mouna; Amar, Mohamed; Vancanneyt, Marc; Swings, Jean

    2005-10-15

    The bacterial diversity occurring in traditional Moroccan soft white cheese, produced in eight different regions in Morocco, was studied. A total of 164 lactic acid bacteria were isolated, purified and identified by whole-cell protein fingerprinting and rep-PCR genomic fingerprinting. The majority of the strains belonged to the genera Lactobacillus, Lactococcus, Leuconostoc and Enterococcus. Sixteen species were identified: Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus buchneri, Lactococcus lactis, Lactococcus garvieae, Lactococcus raffinolactis, Leuconostoc pseudomesenteroides, Leuconostoc mesenteroides, Leuconostoc citreum, Eterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus saccharominimus and Streptococcus sp.

  17. A general method for selection of riboflavin-overproducing food grade micro-organisms

    OpenAIRE

    Burgess, Catherine M; Smid, Eddy J; Rutten, Ger; van Sinderen, Douwe

    2006-01-01

    Abstract Background This study describes a strategy to select and isolate spontaneous riboflavin-overproducing strains of Lactobacillus (Lb.) plantarum, Leuconostoc (Lc.) mesenteroides and Propionibacterium (P.) freudenreichii. Results The toxic riboflavin analogue roseoflavin was used to isolate natural riboflavin-overproducing variants of the food grade micro-organisms Lb. plantarum, Lc. mesenteroides and P. freudenreichii strains. The method was successfully employed for strains of all thr...

  18. Isolation and identification of lactic acid bacteria from koumiss in Eastern Inner Mongolia of China

    Science.gov (United States)

    Bai, Lijuan; Ji, Shujuan

    2017-01-01

    Koumiss is a traditional fermented dairy product and known as its unique physiological actions. Isolation and identification of LAB in it will yield valuable knowledge. In total, 55 LAB strains were isolated and identified of 12 koumiss samples collected in limited regions of Eastern Inner Mongolia. 16S rRNA sequence analysis results showed that were Lactobacillus helveticus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus delbrueckii, Enterococcus. durans, Leuconostoc lactis and Leuconostoc mesenteroides. It is benefit to further research on koumiss.

  19. Bacteria associated with cultures of psathyrella atroumbonata (Pleger)

    African Journals Online (AJOL)

    These bacteria include Bacillus licheniformis, Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. The average bacteria count was 1.0 x 106 cfu/ml and these bacteria grew within pH range of 5.0 and 9.0. the optimum temperature range of growth lied ...

  20. Lactic acid bacteria active during the fermentation of wheat silage in small scale silos

    Energy Technology Data Exchange (ETDEWEB)

    Moon, N.J.; Parker, J.A.; Moon, L.C.; Ely, L.O.

    1981-01-01

    Wheat was ensiled and periodically analyzed for lactic acid bacteria present. Initially Lactobacillus plantarum, Leuconostoc mesenteroides, Lactobacillus cellobiosus and Streptococcus lactis predominated. After two to four days enterococci including S. faecium and S. bovis were present in high populations as well as Lactobacillus plantarum. It was concluded that mixed populations of enterococci and L. plantarum are active in the successful fermentation of wheat silage.

  1. Antimicrobial activity of Xylopia aethiopica, Aframomum melegueta ...

    African Journals Online (AJOL)

    poisoning and/or food spoilage. The microorganisms were Bacillus subtilis IAM1069, Bacillus cereus IFO 13494, Staphylococcus aureus FDA 209p, Escherichia coli NRIC 1023, Salmonella typhimurium IFO12529, Lactobacillus plantarum IAM 1041, Pediococcus acidilactici-M, Leuconostoc mesenteroides- M, Lactobacillus ...

  2. (AJST) DETERMINATION DE LA QUALITÉ DU PAIN DE SUCRE A ...

    African Journals Online (AJOL)

    RÉFÉRENCES. Arguello-Morales, M., Sanchez-Gonzales, M., Canedo, M.,. Quirasco, M., Farres, A., Lopez-Munguia, A., (2005),. Proteolytic modification of Leuconostoc mesenteroides B-512F dextransucrase, Antonie Van. Leewenhoek, 87(2):131-141. Badui, J.D.S., (1995), Quimica de alimentos, 3a edicion,. 62-65, Edition ...

  3. Method for Rapid Purification of Class IIa Bacteriocins and Comparison of Their Activities

    OpenAIRE

    Guyonnet, D.; Fremaux, C.; Cenatiempo, Y.; Berjeaud, J. M.

    2000-01-01

    A three-step method was developed for the purification of mesentericin Y105 (60% yield) from the culture supernatant of Leuconostoc mesenteroides Y105. The same procedure was successfully applied to the purification of five other anti-Listeria bacteriocins identified by mass spectrometry. Specific activities of the purified bacteriocins were compared.

  4. Method for Rapid Purification of Class IIa Bacteriocins and Comparison of Their Activities

    Science.gov (United States)

    Guyonnet, D.; Fremaux, C.; Cenatiempo, Y.; Berjeaud, J. M.

    2000-01-01

    A three-step method was developed for the purification of mesentericin Y105 (60% yield) from the culture supernatant of Leuconostoc mesenteroides Y105. The same procedure was successfully applied to the purification of five other anti-Listeria bacteriocins identified by mass spectrometry. Specific activities of the purified bacteriocins were compared. PMID:10742275

  5. Microbiological and chemical properties of kefir manufactured by entrapped microorganisms isolated from kefir grains.

    Science.gov (United States)

    Chen, T-H; Wang, S-Y; Chen, K-N; Liu, J-R; Chen, M-J

    2009-07-01

    In this study, various yeasts (Kluyveromyces marxianus, Saccharomyces turicensis, Pichia fermentans) and lactic acid bacteria (Lactobacillus kefiranofaciens, Lactobacillus kefiri, Leuconostoc mesenteroides) were entrapped in 2 different microspheres using an entrapment ratio for the strains that was based on the distribution ratio of these organisms in kefir grains. The purpose of this study was to develop a new technique to produce kefir using immobilized starter cultures isolated from kefir grains. An increase in cell counts with fermentation cycles was observed for both the lactic acid bacteria (LAB) and yeasts, whereas the cell counts of kefir grains were very stable during cultivation. Scanning electron microscopy showed that the short-chain lactobacilli and lactococci occupied the surface of the LAB microspheres, whereas the long-chain lactobacilli were inside the microspheres. When the yeasts were analyzed, cells at a high density were entrapped in cracks on the surface and within the microspheres, where they were surrounded by the short-chain lactobacilli. The distribution of the LAB and yeast species in kefir produced from grains and microspheres showed that there was no significant difference between the kefirs produced by the 2 methods; moreover, Leu. mesenteroides and K. marxianus were the predominating microflora in both types of kefir. There was no significant difference in the ethanol and exopolysaccharide contents between the 2 kefirs, although the acidity was different.

  6. Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

    International Nuclear Information System (INIS)

    Martin del Campo, Julia S.; Patino, Rodrigo

    2011-01-01

    Research highlights: → The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. → A spectrophotometric method is proposed for kinetic and thermodynamic analysis. → The pH and the temperature influences are reported on physical chemical properties. → Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD ox ) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD ox as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, Δ f G o = -1784 ± 5 kJ mol -1 .

  7. Kinetic and thermodynamic study of the reaction catalyzed by glucose-6-phosphate dehydrogenase with nicotinamide adenine dinucleotide

    Energy Technology Data Exchange (ETDEWEB)

    Martin del Campo, Julia S. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico); Patino, Rodrigo, E-mail: rtarkus@mda.cinvestav.mx [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados - Unidad Merida, Carretera antigua a Progreso Km. 6, A.P. 73 Cordemex, 97310, Merida, Yucatan (Mexico)

    2011-04-20

    Research highlights: {yields} The reaction catalyzed by one enzyme of the pentose phosphate pathway was studied. {yields} A spectrophotometric method is proposed for kinetic and thermodynamic analysis. {yields} The pH and the temperature influences are reported on physical chemical properties. {yields} Relative concentrations of substrates are also important in the catalytic process. - Abstract: The enzyme glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from Leuconostoc mesenteroides has a dual coenzyme specificity with oxidized nicotinamide adenine dinucleotide (NAD{sub ox}) and oxidized nicotinamide adenine dinucleotide phosphate as electron acceptors. The G6PD coenzyme selection is determined by the metabolic cellular prevailing conditions. In this study a kinetic and thermodynamic analysis is presented for the reaction catalyzed by G6PD from L. mesenteroides with NAD{sub ox} as coenzyme in phosphate buffer. For this work, an in situ spectrophotometric technique was employed based on the detection of one product of the reaction. Substrate and coenzyme concentrations as well as temperature and pH effects were evaluated. The apparent equilibrium constant, the Michaelis constant, and the turnover number were determined as a function of each experimental condition. The standard transformed Gibbs energy of reaction was determined from equilibrium constants at different initial conditions. For the product 6-phospho-D-glucono-1,5-lactone, a value of the standard Gibbs energy of formation is proposed, {Delta}{sub f}G{sup o} = -1784 {+-} 5 kJ mol{sup -1}.

  8. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  9. Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

    Science.gov (United States)

    Cho, Gyu Sung; Do, Hyung Ki

    2006-06-01

    Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tent atively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

  10. Characterization of lactic acid bacteria isolated from Bosnian artisanal dry fermented sausage (sudžuk during fermentation

    Directory of Open Access Journals (Sweden)

    Čolo Josip

    2015-01-01

    Full Text Available Bosnian sudžuk is a dry fermented sausage produced in a rural household near the town of Visoko in central Bosnia and Herzegovina. This kind of sausage was manufactured only from beef and spices in a traditional way without the addition of a starter cultures. To identify lactic acid bacteria (LAB, a total number of 160 Lstrains were isolated from five samples of Bosnian sudžuk collected over 28 days of fermentation. Preliminary identification by phenotypic tests and 16S rDNA sequencing were performed for all 160 of the Lisolates. Identification of Lstrains from traditionally produced Bosnian sausage at the species level revealed the presence of six genera: Lactococcus sp., Enterococcus sp., Leuconostoc sp., Lactobacillus sp., Pediococcus sp. and Weissella sp.. Among the 15 distinct species identified, the species Lactobacillus plantarum, Leuconostoc mesenteroides, Lactococcus lactis, Enterococcus faecalis and Enterococcus durans were present throughout the entire process of fermentation. Leuconostoc mesenteroides, Lactobacillus plantarum and Lactococcus lactis prevailed, with 21.8%, 19.3% and 13.1%, respectively, of total Lstrains during the entire fermentation process. Significant negative correlations (r = 0.892 and r = 0.829, respectively between the presence of Weissella sp. and Lactobacillus sp., and between the presence of Weissella sp. and Lactococcus sp. were recorded. Lactobacillus plantarum, Enterococcus durans and Leuconostoc mesenteroides were the best producers of aromogenic compounds while 32.3% of Lactobacillus plantarum and 28.6% of Leuconostoc mesenteroides were produced exopolysaccharides. [Projekat Ministarstva nauke Republike Srbije, br. 173019

  11. DNA fingerprinting of lactic acid bacteria in sauerkraut fermentations.

    Science.gov (United States)

    Plengvidhya, Vethachai; Breidt, Fredrick; Lu, Zhongjing; Fleming, Henry P

    2007-12-01

    Previous studies using traditional biochemical identification methods to study the ecology of commercial sauerkraut fermentations revealed that four species of lactic acid bacteria, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis, were the primary microorganisms in these fermentations. In this study, 686 isolates were collected from four commercial fermentations and analyzed by DNA fingerprinting. The results indicate that the species of lactic acid bacteria present in sauerkraut fermentations are more diverse than previously reported and include Leuconostoc citreum, Leuconostoc argentinum, Lactobacillus paraplantarum, Lactobacillus coryniformis, and Weissella sp. The newly identified species Leuconostoc fallax was also found. Unexpectedly, only two isolates of P. pentosaceus and 15 isolates of L. brevis were recovered during this study. A better understanding of the microbiota may aid in the development of low-salt fermentations, which may have altered microflora and altered sensory characteristics.

  12. Efecto inhibidor del ácido jasmónico sobre el crecimiento de bacterias y hongos

    OpenAIRE

    Georgina Michelena; Giselle Almeida; Beatriz Altuna; Felipe Eng; Silvano Legrá; Maité Oliveros; Silvia Armenteros

    2005-01-01

    Se determinó el efecto de inhibición del AJ sobre el crecimiento del hongo Sclerotium rolfsii y de las bacterias Leuconostoc mesenteroides, Echerichia coli y Bacillus subtilis, con la técnica de envenenamiento de medio trabajando en placa Petri. Se obtuvieron inhibiciones del 70 % del S. rolfsii a concentraciones inferiores de AJ de 200 ppm y 100 % de inhibición del L. mesenteroides. Estos resultados mostraron la actividad antimicrobiana del AJ frente al hongo Sclerotium rolfsii, abriendo pos...

  13. Electronic technology

    International Nuclear Information System (INIS)

    Kim, Jin Su

    2010-07-01

    This book is composed of five chapters, which introduces electronic technology about understanding of electronic, electronic component, radio, electronic application, communication technology, semiconductor on its basic, free electron and hole, intrinsic semiconductor and semiconductor element, Diode such as PN junction diode, characteristic of junction diode, rectifier circuit and smoothing circuit, transistor on structure of transistor, characteristic of transistor and common emitter circuit, electronic application about electronic equipment, communication technology and education, robot technology and high electronic technology.

  14. Lactic acid bacteria from Sheep's Dhan, a traditional butter from sheep's milk: Isolation, identification and major technological traits

    Energy Technology Data Exchange (ETDEWEB)

    Idoui, T.; Boudjerda, J.; Leghouchi, E.; Karam, N. E.

    2009-07-01

    Twenty six lactic acid bacteria were isolated from sheep's Dhan, a traditional butter made from sheep's milk in Jijel (East of Algeria). These strains belong to three genera: Lactococcus, Leuconostoc and Lactobacillus. The results showed that Lactococcus lactic ssp diacetylactis was the predominant species in this traditional butter. The results of the assessment of the technological aptitude indicate that a major strain has a good acidification aptitude, some of them show good proteolytic activity and only Leuconostoc mesenteroides ssp. dextranicum isolates were able to produce exo polysaccharide. (Author) 42 refs.

  15. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  16. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  17. Electron radiography

    Science.gov (United States)

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  18. Analysis of the lactic acid bacteria microflora in traditional Caucasus cow's milk cheeses

    Directory of Open Access Journals (Sweden)

    Terzić-Vidojević Amarela

    2009-01-01

    Full Text Available A total of 157 lactic acid bacteria (LAB were isolated from three hand-made cheeses taken from different households in the region of the Caucasus Mountains. The cheeses were manufactured from cow's milk without the addition of a starter culture. The isolates of LAB were characterized by subjecting them to phenotypic and genotypic tests. The results of identification of LAB indicate that the examined cheeses contained 10 species, viz., Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus arizonensis, Lactobacillus farciminis, Lactobacillus brevis, Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc pseudomesenteroides, Enterococcus faecium, and Enterococcus faecalis. The strains within the species L. plantarum, L. arizonensis, L. paraplantarum, L. farciminis, and L. pseudomesenteroides showed good proteolytic activity.

  19. Fermentation of Prefermented and Extruded Rice Flour by Lactic Acid Bacteria from Sikhae

    DEFF Research Database (Denmark)

    Lee, C. H.; Min, K. C.; Souane, M.

    1992-01-01

    of prefermentation of rice flour in solid-state with Bacillus laevolacticus and Saccharomyces cerevisiae, extrusion cooking and addition of soymilk as the substrate of lactic acid fermentation were tested. Extrusion cooking and prefermentation of rice increased the soluble solid and sugar contents before malt......The acid- and flavor-forming properties of Lactobacillus plantarum and Leuconostoc mesenteroides isolated from Sikhae, a Korean traditional lactic acid fermented fish product, were examined and compared to those of Lactobacillus casei and Lactococcus lactis subsp. diacetylactis DRC3. The effects...... digestion. The amount of sugar consumption during lactic fermentation varied with the type of bacteria. Leuconostoc mesenteroides(sikhae) and Lactobacillus plantarum(sikhae) increased up to 6 times of original cell number by 24 hrs of fermentation in rice + soymilk substrate, but Lactococcus lactis...

  20. Summaries of Research - Fiscal Year 1981

    Science.gov (United States)

    1981-11-01

    w. ml U.- C.)L 011L r 0: w W 0 > z 0 z4 z.’.0- W 2 2 z0 ww2 U. z z z hi h MC w z 4 0h 2 z 0 C t Z Z 2_w20 w hi 0> 4.) Z -l 111 xI MISSION COMMAND The...Transform, Infrared Difference- Spectrometry: Correlation between Structures of Dextrans from Strains of Leuconostoc mesenteroides and of D-glunans

  1. Study of physiological properties of some probiotics in multiple cultures with mesophilic lactic acid bacteria by Flora Danica Ch. Hansen commercial starter

    OpenAIRE

    DANIELA PARASCHIV; AIDA VASILE; MADALINA CONSTANTIN; ALEXANDRU CIOBANU; GABRIELA BAHRIM

    2011-01-01

    The aim of this study was to establish the growth ability and stability of probiotic strains Lactobacillus acidophilus (commercial code La-5®), Lactobacillus casei ssp. paracasei (commercial code L. casei 431®) and Bifidobacterium bifidus (commercial code BB-12®) in multiple cultures with mesophilic lactic bacteria, Lactococcus lactis ssp. cremoris, Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. diacetylactis and Leuconostoc mesenteroides spp. cremoris, as Flora Danica Chr. Hansen co...

  2. Lactic acid bacteria active during the fermentation of wheat silage in small scale silos

    Energy Technology Data Exchange (ETDEWEB)

    Moon, N.J.; Moon, L.C.; Ely, L.O.; Parker, J.A.

    1981-01-01

    Wheat was ensiled and periodically analyzed for lactic acid bacteria present. Initially Lactobacillus plantarum, Leuconostoc mesenteroides, Lactobacillus cellobiosus and Streptococcus lactis predominated. After two to four days enterococci including S. faecium and S. bovis were present in high populations as well as Lactobacillus plantarum. It was concluded that mixed populations of enterococci and L. plantarum are active in the successful fermentation of wheat silage. (Refs. 5).

  3. Electrons, Electronic Publishing, and Electronic Display.

    Science.gov (United States)

    Brownrigg, Edwin B.; Lynch, Clifford A.

    1985-01-01

    Provides a perspective on electronic publishing by distinguishing between "Newtonian" publishing and "quantum-mechanical" publishing. Highlights include media and publishing, works delivered through electronic media, electronic publishing and the printed word, management of intellectual property, and recent copyright-law issues…

  4. Caracterização preliminar de bacteriocinas produzidas por seis cepas de bactérias láticas isoladas de produtos cárneos embalados a vácuo Preliminary characterization of bacteriocins produced by six lactic acid bacteria strains isolated from vacuum-packaged meat products

    Directory of Open Access Journals (Sweden)

    Elaine C. P. de Martinis

    2003-08-01

    Full Text Available No presente trabalho, foram estudadas as bacteriocinas produzidas por seis linhagens bacterianas: duas culturas Lactobacillus sake, duas de Lactobacillus curvatus, uma de Leuconostoc mesenteroides, uma de Leuconostoc sp 12. As atividades inibitórias foram quantificadas pelo método da diluição crítica, utilizando-se os indicadores Lactobacillus sake ATCC 15521 e Listeria monocytogenes. As bacteriocinas produzidas foram caracterizadas também quanto à sensibilidade a enzimas, faixa de temperatura na produção, termoestabilidade, estabilidade em diferentes pHs e modo de ação (bactericida ou bacteriostático frente a Listeria monocytogenes. Nenhuma bacteriocina foi destruída pela pepsina, mas todas foram sensíveis à proteinase K, tripsina e alfa-amilase (exceto a bacteriocina produzida por Leuconostoc sp 12, que foi insensível a alfa-amilase. Lactobacillus sake 1, Leuconostoc mesenteroides 11 e Lactobacillus sake 16 apresentaram atividade antilisterial, sendo a maior inibição observada para Lactobacillus sake 1 e Leuconostoc mesenteroides 11 (12.800UA/mL. Lactobacillus sake 1 e Lactobacillus curvatus 5 produziram as bacteriocinas mais termoestáveis. Lactobacillus sake 1 produziu a bacteriocina com maior estabilidade a variações de pH. Todas as bactérias láticas produziram bacteriocina entre 4ºC e 30ºC, sendo esta propriedade muito interessante para futuras aplicações em produtos cárneos refrigerados.In this work, the bacteriocins produced by six bacterial strains were studied (Lactobacillus sake 1, Lactobacillus curvatus 5, Leuconostoc mesenteroides 11, Leuconostoc sp 12, Lactobacillus curvatus 14 and Lactobacillus sake 16. Title of inhibitory activity was determined by critical dilution assay, using Lactobacillus sake ATCC 15521 and Listeria monocytogenes as indicator microorganisms. The inhibitory compounds were also characterized with respect to stability to the action of enzymes, thermostability, stability in several p

  5. Electron detector

    International Nuclear Information System (INIS)

    Hashimoto, H.; Mogami, A.

    1975-01-01

    A device for measuring electron densities at a given energy level in an electron beam or the like having strong background noise, for example, in the detection of Auger electric energy spectrums is described. An electron analyzer passes electrons at the given energy level and at the same time electrons of at least one adjacent energy level. Detecting means associated therewith produce signals indicative of the densities of the electrons at each energy level and combine these signals to produce a signal indicative of the density of the electrons of the given energy level absent background noise

  6. Electron/electron acoustic instability

    International Nuclear Information System (INIS)

    Gary, S.P.

    1987-01-01

    The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

  7. Electronic emission and electron guns

    International Nuclear Information System (INIS)

    Roy, Amitava

    2010-01-01

    This paper reviews the process of electron emission from metal surface. Although electrons move freely in conductors like metals, they normally do not leave the metal without some manipulation. In fact, heating and bombardment are the two primary ways in which electrons are emitted through the use of a heating element behind the cathode (termed thermionic emission) or as a result of bombardment with a beam of electrons, ions, or metastable atoms (termed secondary emission). Another important emission mechanism called Explosive Electron Emission (EEE) is also often used in various High Voltage Pulse Power Systems to generate very high current (few hundreds of kA) pulsed electron beams. The electron gun is the device in that it shoots off a continuous (or pulsed) stream of electrons. A brief idea about the evolution of the electron gun components and their basis of functioning are also discussed. (author)

  8. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa; Torres Sevilla, Galo Andres; Diaz Cordero, Marlon Steven

    2017-01-01

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces

  9. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    "[to] promote the understanding and, acceptance of and growth in the number of electronic transactions .... Chapter III of the ECT Act is based on the UNCITRAL Model Law on Electronic. Commerce ... Communications Technology Law 146. 22.

  10. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  11. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  12. Electronic Commerce

    OpenAIRE

    Slavko Đerić

    2016-01-01

    Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks...

  13. Electronic Publishing.

    Science.gov (United States)

    Lancaster, F. W.

    1989-01-01

    Describes various stages involved in the applications of electronic media to the publishing industry. Highlights include computer typesetting, or photocomposition; machine-readable databases; the distribution of publications in electronic form; computer conferencing and electronic mail; collaborative authorship; hypertext; hypermedia publications;…

  14. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-09-08

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces. The stickers can be wrappable, placed on surfaces, glued on walls or mirrors or wood or stone, and have electronics (112, 122, 132) which may or may not be ultrathin. Packaging for the electronic sticker can use polymer on cellulose manufacturing and/or three dimensional (3-D) printing. The electronic stickers may provide lighting capability, sensing capability, and/or recharging capabilities.

  15. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  16. Electronic Commerce and Electronic Business

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    This special issue is motivated by the recent upsurge of research activity in the areas of electronic commerce and electronic business both in India and all over the world. The current ... Monte Carlo methods for pricing financial options are then.

  17. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K; Gascó, M; Klievink, A.J.; Lindgren, I; Milano, M; Panagiotopoulos, P; Pardo, T.A.; Parycek, P; Sæbø, Ø

    2016-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies.This book presents papers from the 14th International Federation for Information

  18. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information

  19. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  20. `Twisted' electrons

    Science.gov (United States)

    Larocque, Hugo; Kaminer, Ido; Grillo, Vincenzo; Leuchs, Gerd; Padgett, Miles J.; Boyd, Robert W.; Segev, Mordechai; Karimi, Ebrahim

    2018-04-01

    Electrons have played a significant role in the development of many fields of physics during the last century. The interest surrounding them mostly involved their wave-like features prescribed by the quantum theory. In particular, these features correctly predict the behaviour of electrons in various physical systems including atoms, molecules, solid-state materials, and even in free space. Ten years ago, new breakthroughs were made, arising from the new ability to bestow orbital angular momentum (OAM) to the wave function of electrons. This quantity, in conjunction with the electron's charge, results in an additional magnetic property. Owing to these features, OAM-carrying, or twisted, electrons can effectively interact with magnetic fields in unprecedented ways and have motivated materials scientists to find new methods for generating twisted electrons and measuring their OAM content. Here, we provide an overview of such techniques along with an introduction to the exciting dynamics of twisted electrons.

  1. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  2. Advanced Electronics

    Science.gov (United States)

    2017-07-21

    AFRL-RV-PS- AFRL-RV-PS- TR-2017-0114 TR-2017-0114 ADVANCED ELECTRONICS Ashwani Sharma 21 Jul 2017 Interim Report APPROVED FOR PUBLIC RELEASE...NUMBER Advanced Electronics 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62601F 6. AUTHOR(S) 5d. PROJECT NUMBER 4846 Ashwani Sharma 5e. TASK NUMBER...Approved for public release; distribution is unlimited. (RDMX-17-14919 dtd 20 Mar 2018) 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Space Electronics

  3. Electron spectroscopy

    International Nuclear Information System (INIS)

    Hegde, M.S.

    1979-01-01

    An introduction to the various techniques in electron spectroscopy is presented. These techniques include: (1) UV Photoelectron spectroscopy, (2) X-ray Photoelectron spectroscopy, (3) Auger electron spectroscopy, (4) Electron energy loss spectroscopy, (5) Penning ionization spectroscopy and (6) Ion neutralization spectroscopy. The radiations used in each technique, the basis of the technique and the special information obtained in structure determination in atoms and molecules by each technique are summarised. (A.K.)

  4. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  5. Electronics Industry

    National Research Council Canada - National Science Library

    Bell, Robert; Carroll-Garrison, Martina; Donovan, Daniel; Fisher, John; Guemmer, Paul; Harms, Robert; Kelly, Timothy; Love, Mattie; McReynolds, James; Ward, Ralph

    2006-01-01

    .... Government action to preserve strategic access to semiconductor producers is clearly needed to ensure DoD electronic systems can be built without compromising sensitive technology, though every...

  6. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  7. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

  8. The electron

    International Nuclear Information System (INIS)

    Hestenes, David; Weingartshofer, Antonio

    1991-01-01

    The stupendous successes of the Dirac equation and quantum electro-dynamics have established the electron as the best understood of the fundamental constituents of matter. Nevertheless, physicists agree that the electron still has secrets to reveal. Moreover, powerful new theoretical and experimental tools for probing those secrets have been sharpened during the last decade. This workshop was organized to bring theorists and experimentalists together to discuss their common goal of knowing the electron. Present state and future prospects for progress toward that goal are here described. The theoretical papers encompass a wide range of views on the electron. Several argue that the 'Zitter-bewegung' is more than a mathematical peculiarity of the Dirac equation, that it may well be a real physical phenomenon and worthy of serious study, theoretically and experimentally. Besides generating the electron spin and magnetic moment, the 'Zitterbewegung' may be a vital clue to electron structure and self-interaction. Some of the papers employ a radical new formulation of the Dirac theory which reveals a hidden geo-metric structure in the theory that supports a 'Zitterbewegung' inter-pretation. For the last half century the properties of electrons have been probed primarily by scattering experiments at ever higher energies. Recently, however, two powerful new experimental techniques have emerged capable of giving alternative experimental views of the electron. First, techniques for confining single electrons for long term study have led to the most accurate measurements of the electron magnetic moment. Second, the interaction of high intensity laser fields with atoms and electrons have revealed striking new phenomena such as multiphoton ionization. refs.; figs.; tabs

  9. Printed Electronics

    Science.gov (United States)

    Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Crain, John M. (Inventor); Aksay, Ilhan A. (Inventor); Lettow, John S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2018-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  10. Estudio microbiológico de ajo(Allium sativum L. y cebolla (Allium cepa L. deshidratados Microbiological study of garlic (Allium sativum L. and onion (Allium cepaL. dehydrated

    Directory of Open Access Journals (Sweden)

    S.R. Fuselli

    2004-09-01

    Full Text Available En este trabajo se efectuó un estudio microbiológico durante la deshidratación y el almacenamiento de ajo (Allium sativum L. y de cebolla (Allium cepa L.. Al ajo se le efectuó un proceso de escaldado y a la cebolla un salmuereado previo a la deshidratación. En las materias primas los recuentos promedio expresados en UFC/g fueron: bacterias aerobias mesófilas entre 1,2 x 102y 1,6 x 103, mohos y levaduras entre 60 y 1,6 x 103, Lactobacillus spp. y Leuconostocmesenteroidessubesp. mesenteroides entre 10 y 50.Se identificaron: Penicillium spp., Monilia spp. Lactobacillus brevis,Leuconostoc mesenteroides subesp. mesenteroides y levaduras en ajo; Mucor spp., Penicillium spp., Monilia spp., Lactobacillus brevis y levaduras en dos tipos de cebolla. Leuconostoc mesenteroides subesp. mesenteroides sólo se detectó en un tipo de cebolla. En ajos deshidratados y durante el almacenamiento se hallaron Penicillium spp., Monilia spp., Lactobacillus brevis y levaduras mientras que los mismos con escaldado no presentaron desarrollo. Mucor spp., Penicillium spp., Monilia spp. y Lactobacillus brevis se identificaron en los dos tipos de cebolla deshidratadas. Con la incorporación del salmuereado la microflora se redujo significativamente hallándose solamente Penicillium spp. La utilización de barreras adicionales de control microbiano tales como escaldado y salmuereado produce un aporte importante a la estabilidad microbiológica de los productos.A microbiological study during the process and the storage of garlic (Allium sativum L. and onion (Allium cepa L. dehydrated, with the additional barriers of blanching or brine immersion, was made. In all raw materials the average counts of aerobic mesophilic bacteria expressed in CFU/g ranged from 1.2 x 102to 1.6 x 103, molds and yeasts from 60 to 1.6 x 103, Lactobacillus spp. and Leuconostocmesenteroides subsp. mesenteroides between 10 and 50. Microorganisms identified were Penicillium spp., Monilia spp

  11. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  12. Electronic diagrams

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

  13. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  14. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  15. Stretchable electronics

    CERN Document Server

    Someya, Takao

    2012-01-01

    With its comprehensive coverage this handbook and ready reference brings together some of the most outstanding scientists in the field to lay down the undisputed knowledge on how to make electronics stretchable.As such, it focuses on gathering and evaluating the materials, designs, models and technologies that enable the fabrication of fully elastic electronic devices which can sustain high strain. Furthermore, it provides a review of those specific applications that directly benefit from highly compliant electronics, including transistors, photonic devices and sensors. In addition to stre

  16. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  17. Electronic identity

    CERN Document Server

    de Andrade, Norberto Nuno Gomes; Argles, David

    2014-01-01

    With the increasing availability of electronic services, security and a reliable means by which identity is verified is essential.Written by Norberto Andrade the first chapter of this book provides an overview of the main legal and regulatory aspects regarding electronic identity in Europe and assesses the importance of electronic identity for administration (public), business (private) and, above all, citizens. It also highlights the role of eID as a key enabler of the economy.In the second chapter Lisha Chen-Wilson, David Argles, Michele Schiano di Zenise and Gary Wills discuss the user-cent

  18. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  19. Paper electronics.

    Science.gov (United States)

    Tobjörk, Daniel; Österbacka, Ronald

    2011-05-03

    Paper is ubiquitous in everyday life and a truly low-cost substrate. The use of paper substrates could be extended even further, if electronic applications would be applied next to or below the printed graphics. However, applying electronics on paper is challenging. The paper surface is not only very rough compared to plastics, but is also porous. While this is detrimental for most electronic devices manufactured directly onto paper substrates, there are also approaches that are compatible with the rough and absorptive paper surface. In this review, recent advances and possibilities of these approaches are evaluated and the limitations of paper electronics are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Electron Microprobe

    Data.gov (United States)

    Federal Laboratory Consortium — The JEOL JXA-8600 is a conventional hairpin filament thermal emission electron microprobe that is more than 20 years old. It is capable of performing qualitative and...

  1. Electronic Aggression

    Centers for Disease Control (CDC) Podcasts

    Aggression is no longer limited to the school yard. New forms of electronic media, such as blogs, instant messaging, chat rooms, email, text messaging, and the internet are providing new arenas for youth violence to occur.

  2. Electron Emitters

    National Research Council Canada - National Science Library

    Tzeng, Yonhua

    2002-01-01

    When two carbon-nanotube coated electrodes are placed at a small distance from each other, electron emission from carbon nanotubes allows a DC or AC electrical current to flow between these two electrodes...

  3. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  4. Electronic Elections

    DEFF Research Database (Denmark)

    Schürmann, Carsten

    2009-01-01

    Electronic voting technology is a two edged sword. It comes with many risks but brings also many benefits. Instead of flat out rejecting the technology as uncontrollably dangerous, we advocate in this paper a different technological angle that renders electronic elections trustworthy beyond...... the usual levels of doubt. We exploit the trust that voters currently have into the democratic process and model our techniques around that observation accordingly. In particular, we propose a technique of trace emitting computations to record the individual steps of an electronic voting machine...... for a posteriori validation on an acceptably small trusted computing base. Our technology enables us to prove that an electronic elections preserves the voter’s intent, assuming that the voting machine and the trace verifier are independent....

  5. Electronic commerce

    OpenAIRE

    Zvolánková, Pavla

    2010-01-01

    The thesis deals with a description of electronic commerce from its beginning up to present situation in this area. It explains basic terms connected with electronic commerce and it summarizes the relevant legislation. Moreover it describes e-contracts and rights and duties of both contractual parties. The main view is the view of Internet retailer, which is reflected in the practical part focused on concrete problems of retailers.

  6. Printed Electronics

    Science.gov (United States)

    Wade, Jessica; Hollis, Joseph Razzell; Wood, Sebastian

    2018-04-01

    The combination of printing technology with manufacturing electronic devices enables a new paradigm of printable electronics, where 'smart' functionality can be readily incorporated into almost any product at low cost. Over recent decades, rapid progress has been made in this field, which is now emerging into the industrial andcommercial realm. However, successful development and commercialisation on a large scale presents some significant technical challenges. For fully-printable electronic systems, all the component parts must be deposited from solutions (inks), requiring the development of new inorganic, organic and hybrid materials.A variety of traditional printing techniques are being explored and adapted forprinting these new materials in ways that result in the best performing electronicdevices. Whilst printed electronics research has initially focused on traditional typesof electronic device such as light-emitting diodes, transistors, and photovoltaics, it is increasingly apparent that a much wider range of applications can be realised. The soft and stretchable nature of printable materials makes them perfect candidates forbioelectronics, resulting in a wealth of research looking at biocompatible printable inks and biosensors. Regardless of application, the properties of printed electronicmaterials depend on the chemical structures, processing conditions, device architecture,and operational conditions, the complex inter-relationships of which aredriving ongoing research. We focus on three particular 'hot topics', where attention is currently focused: novel materials, characterisation techniques, and device stability. With progress advancing very rapidly, printed electronics is expected to grow over the next decade into a key technology with an enormous economic and social impact.

  7. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  8. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  9. Electron tube

    Science.gov (United States)

    Suyama, Motohiro [Hamamatsu, JP; Fukasawa, Atsuhito [Hamamatsu, JP; Arisaka, Katsushi [Los Angeles, CA; Wang, Hanguo [North Hills, CA

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  10. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  11. Electronic Commerce

    Energy Technology Data Exchange (ETDEWEB)

    Laird, N. [NRG Information Services Inc., Calgary, AB (Canada)

    1995-11-01

    The concept of electronic commerce in the gas industry was discussed. It was defined as the integration of communication technology, advanced information processing capability and business standards, to improve effectiveness of the business process. Examples of electronic data interchange from the automotive, airline, and banking industry were given. The objective of using this technology in the gas industry was described as the provision of one electronic facility to make seamless contractual and operational arrangements for moving natural gas across participating pipelines. The benefit of seamless integration - one readily available standard system used by several companies - was highlighted. A list of value-added services such as the free movement of bulletins, directories, nominations,and other documents was provided.

  12. Electron accelerator

    International Nuclear Information System (INIS)

    Abramyan.

    1981-01-01

    The USSR produces an electron accelerator family of a simple design powered straight from the mains. The specifications are given of accelerators ELITA-400, ELITA-3, ELT-2, TEUS-3 and RIUS-5 with maximum electron energies of 0.3 to 5 MeV, a mean power of 10 to 70 kW operating in both the pulsed and the continuous (TEUS-3) modes. Pulsed accelerators ELITA-400 and ELITA-3 and RIUS-5 in which TESLA resonance transformers are used are characterized by their compact size. (Ha)

  13. Electronic cigarette

    OpenAIRE

    Wang, Tao

    2016-01-01

    As we know E-cigarette is becoming increasingly popular all over the world. It is a new product that the most of smoking people would like to buy and use. However, we are not realizing advantages and disadvantages of e-cigarette clearly. My objective was to research the development of electronic cigarette whether it is under control or a good way of marketing. The thesis has two main parts. They include answers to questions what is electronic cigarette and how to manage the whole industry...

  14. The inhibitory activity of Lactic acid bacteria isolated from fresh cow cheese

    Directory of Open Access Journals (Sweden)

    Nevijo Zdolec

    2007-04-01

    Full Text Available Lactic acid bacteria are the constituent part of milk microbial flora that could influence the safety of dairy products due production of organic acids, hydrogen peroxide, carbon dioxide and bacteriocins. Taking this in consideration, the objective of this study was to investigate the composition of lactic acid bacteria population in fresh cow cheeses taken from local markets, as well as their antimicrobial capacity. Lactic acid bacteria counts were determined according to ISO 1524:1998 method, biochemical determination using API 50 CHL system, and inhibitory activity against L. monocytogenes NCTC 10527 by agar well diffusion assay. Lactic acid bacteria count in fresh cow cheeses (n=10 ranged from 5.87 to 8.38 log10 CFU g-1. Among 52 MRS isolates collected, 61.54 % were assigned to the Lactococcus lactis subsp. Lactis species, 23.07 % Lactobacillus helveticus, 11.54 % Leuconostoc mesenteroides subsp. cremoris and 3.85 % Leuconostoc mesenteroides subsp. mesenteroides. Antilisterial activity was found in 18 isolates.

  15. Electronic School.

    Science.gov (United States)

    Executive Educator, 1994

    1994-01-01

    This issue of "The Electronic School" features a special forum on computer networking. Articles specifically focus on network operating systems, cabling requirements, and network architecture. Tom Wall argues that virtual reality is not yet ready for classroom use. B.J. Novitsky profiles two high schools experimenting with CD-ROM…

  16. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e-government/e-governance...

  17. Electronics department

    International Nuclear Information System (INIS)

    1979-01-01

    This report summarizes the activities in 1978 of some of the groups within the Electronics Department. The work covered includes plant protection and operator studies, reliability techniques, application of nuclear techniques to mineral exploration, applied laser physics, computing and, lastly, research instrumentation. (author)

  18. Power electronics

    Indian Academy of Sciences (India)

    Kishore Chatterjee

    This special issue of Sadhana is a compilation of papers selected from those presented at the 7th National Power. Electronics Conference (NPEC), held at the Indian Institute of Technology, Bombay, on 21–23 December 2015. From among the papers presented in NPEC-2017, selected papers were peer-reviewed for ...

  19. Electron linacs

    Energy Technology Data Exchange (ETDEWEB)

    Loew, G A; Schriber, S O [ed.

    1976-11-01

    A study was made of the present status of the thousand or so electron linacs in the world, and future trends in the field. These machines were classified according to their use: medical, industrial, and nuclear physics. In the medical category, two types of electron linacs are discussed: the conventional ones which are used for x-ray and electron therapy, and those which may in the future be used for negative pion therapy. Industrial machines discussed include linacs for radiographic and other specialized applications. In the nuclear physics category, the status of conventional low- and medium-energy as well as high duty cycle linacs is reviewed. The question of how one might obtain a c-w, 1 GeV, 100..mu..A electron linac is raised, and various options using recirculation and stretchers are examined. In this connection, the status of rf superconductivity is summarized. A review is given of linacs for injectors into synchrotrons and e/sup +-/ storage rings, and recent work done to upgrade the only multi-GeV linac, namely SLAC, is described.

  20. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due...

  1. Electronic seal

    International Nuclear Information System (INIS)

    Musyck, E.

    1981-01-01

    An electronic seal is presented for a volume such as container for fissile materials. The seal encloses a lock for barring the space as well as a device for the detection and the recording of the intervention of the lock. (AF)

  2. Nuclear electronics

    International Nuclear Information System (INIS)

    Friese, T.

    1981-09-01

    A short survey is given on nuclear radiation detectors and nuclear electronics. It is written for newcomers and those, who are not very familiar with this technique. Some additional information is given on typical failures in nuclear measurement systems. (orig.) [de

  3. Electron linacs

    International Nuclear Information System (INIS)

    Loew, G.A.

    1976-01-01

    To study the present status of the thousand or so electron linacs in the world, and future trends in the field, we have classified these machines according to their use: medical, industrial, and nuclear physics. In the medical category, two types of electron linacs are discussed: the conventional ones which are used for X-ray and electron therapy, and those which may in the future be used for negative pion therapy. The section on industrial machines includes linacs for radiographic and other specialized applications. In the nuclear physics category, the status of conventional low- and medium-energy as well as high duty cycle linacs is reviewed. The question of how one might obtain a C.W., 1 GeV, 100 μA electron linac is raised and various options using recirculation and stretchers are examined. In this connection, the status of RF superconductivity is summarized. Following, there is a review of linacs for injectors into synchrotrons and e +- storage rings. The paper ends with a description of recent work done to upgrade the only multi-GeV linac, namely SLAC. (author)

  4. Identification, stress tolerance, and antioxidant activity of lactic acid bacteria isolated from tropically grown fruits and leaves.

    Science.gov (United States)

    Fessard, Amandine; Bourdon, Emmanuel; Payet, Bertrand; Remize, Fabienne

    2016-07-01

    From 6 samples of tropically grown fruits and leaves, 10 lactic acid bacteria belonging Leuconostoc, Weissella, and Lactobacillus species were isolated and identified by 16S rRNA gene sequencing and (GTG)5 fingerprinting. Acidification kinetics determined from BHI broth cultures showed genus-related patterns. In particular, Weissella cibaria appeared to act as a potent acidifier. Tolerance of isolates to acid, oxidative, or salt stress was highly variable and strain dependent. Isolate S14 (Leuconostoc pseudomesenteroides) growth was not affected by the presence of 0.05% H2O2, while Lactobacillus spp. isolates (S17 and S29) were the most tolerant to pH 4.5. The growth of 4 isolates, S5 (Leuconostoc mesenteroides), S14 and S10 (Leuconostoc pseudomesenteroides), and S27 (W. cibaria), was not affected by 5% NaCl. Nutritional beneficial properties were examined through measurement of antioxidant activities of short-term fermented pineapple juice, such as LDL oxidation and polyphenol content, and through exopolysaccharide formation from sucrose. Two isolates, S14 and S27, increased the antioxidant capacity of pineapple juice. The robust capacity of W. cibaria and of Leuconostoc pseudomesenteroides for vegetable lactic fermentation aimed to ameliorate food nutritional and functional quality was highlighted.

  5. Electronic Nose and Electronic Tongue

    Science.gov (United States)

    Bhattacharyya, Nabarun; Bandhopadhyay, Rajib

    Human beings have five senses, namely, vision, hearing, touch, smell and taste. The sensors for vision, hearing and touch have been developed for several years. The need for sensors capable of mimicking the senses of smell and taste have been felt only recently in food industry, environmental monitoring and several industrial applications. In the ever-widening horizon of frontier research in the field of electronics and advanced computing, emergence of electronic nose (E-Nose) and electronic tongue (E-Tongue) have been drawing attention of scientists and technologists for more than a decade. By intelligent integration of multitudes of technologies like chemometrics, microelectronics and advanced soft computing, human olfaction has been successfully mimicked by such new techniques called machine olfaction (Pearce et al. 2002). But the very essence of such research and development efforts has centered on development of customized electronic nose and electronic tongue solutions specific to individual applications. In fact, research trends as of date clearly points to the fact that a machine olfaction system as versatile, universal and broadband as human nose and human tongue may not be feasible in the decades to come. But application specific solutions may definitely be demonstrated and commercialized by modulation in sensor design and fine-tuning the soft computing solutions. This chapter deals with theory, developments of E-Nose and E-Tongue technology and their applications. Also a succinct account of future trends of R&D efforts in this field with an objective of establishing co-relation between machine olfaction and human perception has been included.

  6. Electronics Industry

    Science.gov (United States)

    2007-01-01

    countries in developing market nations in Asia (such as Korea, Taiwan, Singapore, Malaysia , China and Vietnam). The competition for the knowledge, economic...Intel, Infineon Technologies, STMicroelectronics, Samsung Electronics, Texas Instruments, AMD Spansion, Philips Semiconductor, Freescale... Samsung ($19.7B), #5 Toshiba ($9.8B), #6 TSMC ($9.7B), #7 Hynix ($8.0B) and #8 Renesas ($7.9B) (McGrath, 2007, p. 3). Samsung , headquartered in

  7. Electronic banking

    OpenAIRE

    Gradišnik, Monika

    2017-01-01

    The development of information and communication technology is one of the most important reasons for the incredibly fast changes in business. Electronic commerce is spreading unstoppably in the operations of companies. The creation of new models, such as online banking, online shopping and the like, has sped up the development of the World Wide Web. Owing to the rapid progress of the World Wide Web and technologies for secure business operations, we can barely imagine life today without e...

  8. Electronic Aggression

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Aggression is no longer limited to the school yard. New forms of electronic media, such as blogs, instant messaging, chat rooms, email, text messaging, and the internet are providing new arenas for youth violence to occur.  Created: 11/20/2007 by National Center for Injury Prevention and Control, Division of Violence Prevention.   Date Released: 11/28/2007.

  9. ELECTRON GUN

    Science.gov (United States)

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  10. Electronic sputtering

    International Nuclear Information System (INIS)

    Johnson, R.E.

    1989-01-01

    Electronic sputtering covers a range of phenomena from electron and photon stimulated desorption from multilayers to fast heavy ion-induced desorption (sputtering) of biomolecules. In this talk the author attempted. Therefore, to connect the detailed studies of argon ejection from solid argon by MeV ions and keV electrons to the sputtering of low temperatures molecular ices by MeV ions then to biomolecule ejection from organic solids. These are related via changing (dE/dx) e , molecular size, and transport processes occurring in materials. In this regard three distinct regions of (dE/dx) e have been identified. Since the talk this picture has been made explicit using a simple spike model for individual impulsive events in which spike interactions are combined linearly. Since that time also the molecular dynamics programs (at Virginia and Uppsala) have quantified both single atom and dimer processes in solid Ar and the momentum transport in large biomolecule sputtering. 5 refs

  11. Inhibitory Activity of Lactid Acid Bacteria Isolated from Tape Waterlily Seed to Enteric Pathogenic Bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, and E.coli and Its’ Susceptibility to Antibiotic, Bile Salt and Acidic Condition

    Directory of Open Access Journals (Sweden)

    Iin Khusnul Khotimah

    2012-03-01

    Full Text Available The aim of this research was to observe inhibitory activity of LAB isolated from tape waterlily seed to enteric pathogenic bacteria (Vibrio cholera, Salmonella typhi, Shigella disentri, E.coli ATCC 25922 and it’s susceptibility to antibiotic, in bile salt and under acidic condition. Microbia in the tape ( a fermented product of waterlily seed to showed were Streptococcus thermophilus (IKH-1, Pediococcus pentosaceus (IKH-2 and Leuconostoc mesentroides (IKH-8. Streptococcus thermophillus showed inhibition against the growth of Shigella disentri with inhibition zones 16,28 mm, but did not against the growth of V. Cholera, S. typhi, E.coli. Pediococcus pentosaceus inhibit Vibrio cholera, dan Salmonella thypi with inhibition zones 18,59 mm dan 7,91 mm. So that, Leuconostoc mesenteroides inhibit Salmonella thypi with zones inhibits average 8,25 mm. Chloramfenicol at 0.05 mg concentrations did not show inhibition against the growth of isolated Streptococcus thermophillus, Pediococcus pentosaceus and Leuconostoc mesentroides. These isolates could survive too in bile salt (2% and acidified media (pH 3.   Keyword : The tape of  waterlily seed, LAB, probiotic and enteric pathogenic   KEMAMPUAN PENGHAMBATAN BAKTERI ASAM LAKTAT DARI TAPE BIJI TERATAI TERHADAP PATOGENIK ENTERIK (VIBRIO CHOLERA, SALMONELLA THYPI, SHIGELLA DISENTRI, E. COLI, ANTIBIOTIK, KETAHANANNYA TERHADAP BILE SALT DAN ASAM   ABSTRAK   Penelitian ini bertujuan untuk menguji kemampuan penghambatan bakteri asam laktat yang diisolasi dari tape biji teratai terhadap patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, E. Coli ATCC 25922, antibiotik, bile salt dan asam. Jenis bakteri yang diketahui tumbuh selama fermentasi tape biji teratai adalah Streptococcus thermopilus (IKH-1, Pediococcus pentosaceus(IKH-2, dan Leuconostoc mesentroides (IKH-8. Pengamatan terhadap uji penghambatan patogenik enterik (Vibrio cholera, Salmonella thypi, Shigella disentri, dan E. Coli ATCC

  12. Detectors - Electronics

    International Nuclear Information System (INIS)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J.

    1998-01-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X → e - converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the 3 He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  13. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  14. Electronic wastes

    Science.gov (United States)

    Regel-Rosocka, Magdalena

    2018-03-01

    E-waste amount is growing at about 4% annually, and has become the fastest growing waste stream in the industrialized world. Over 50 million tons of e-waste are produced globally each year, and some of them end up in landfills causing danger of toxic chemicals leakage over time. E-waste is also sent to developing countries where informal processing of waste electrical and electronic equipment (WEEE) causes serious health and pollution problems. A huge interest in recovery of valuable metals from WEEE is clearly visible in a great number of scientific, popular scientific publications or government and industrial reports.

  15. Electron gun

    International Nuclear Information System (INIS)

    Chen, H.-Y.; Hughes, R.H.

    1979-01-01

    The invention described relates to cathode ray tubes, and particularly to color picture tubes of the type useful in home television receivers and therefore to electron guns. The invention is especially applicable to self-converging tube-yoke combinations with shadow mask tubes of the type having plural-beam in-line guns disposed in a horizontal plane, an apertured mask with vertically oriented slit-shaped apertures, and a screen with vertically oriented phosphor stripes. The invention is not, however, limited to use in such tubes and may in fact be used, e.g., in dot-type shadow mask tubes and index-type tubes. (Auth.)

  16. Bolometer electronics

    International Nuclear Information System (INIS)

    Groenig, D.E.

    1981-01-01

    High quality is required to the electronic which works with bolometer made of metal for measuring the radiation power in plasmaphysical experiments. If the bandwidth is to be 1 kHz, and the time constant of the bolometer is about 160 ms by high overall gain the critical parameters are the noise of the amplifier, pick up to the system, stability and decoupling of common mode signals. The high overall gain is necessary to be able to measure lowest radiation power. The design made is a good approach to the desired property. (orig.) [de

  17. Basic electronics

    CERN Document Server

    Tayal, DC

    2010-01-01

    The second edition of this book incorporates the comments and suggestions of my friends and students who have critically studied the first edition. In this edition the changes and additions have been made and subject matter has been rearranged at some places. The purpose of this text is to provide a comprehensive and up-to-date study of the principles of operation of solid state devices, their basic circuits and application of these circuits to various electronic systems, so that it can serve as a standard text not only for universities and colleges but also for technical institutes. This book

  18. Nuclear electronics

    International Nuclear Information System (INIS)

    Lucero B, E.

    1989-01-01

    The rapid technical development of Colombia over the past years, resulted among others, a considerable increase in the number of measuring instrumentation and testing laboratories, scientific research and metrology centers, in industry, agriculture, public health, education on the nuclear field, etc. IAN is a well organized institution with qualified management, trained staff and reasonably equipped laboratories to carry out tasks as: Metrology, standardization, quality control and maintenance and repair of nuclear instruments. The government of Colombia has adopted a policy to establish and operate through the country maintenance and repair facilities for nuclear instrumentation. This policy is reflected in the organization of electronic laboratories in Bogota-IAN

  19. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    2013-01-01

    Practical Electronics Handbook, Third Edition provides the frequently used and highly applicable principles of electronics and electronic circuits.The book contains relevant information in electronics. The topics discussed in the text include passive and active discrete components; linear and digital I.C.s; microprocessors and microprocessor systems; digital-analogue conversions; computer aids in electronics design; and electronic hardware components.Electronic circuit constructors, service engineers, electronic design engineers, and anyone with an interest in electronics will find the book ve

  20. Electron foreshock

    International Nuclear Information System (INIS)

    Klimas, A.J.

    1985-01-01

    ISEE particle and wave data are noted to furnish substantial support for the basic features of the velocity dispersed model at the foreshock boundary that was proposed by Filbert and Kellogg (1979). Among many remaining discrepancies between this model and observation, it is noted that unstable reduced velocity distributions have been discovered behind the thin boundary proposed by the model, and that these are at suprathermal energies lying far below those explainable in terms of an oscillating, two-stream instability. Although the long-theorized unstable beam of electrons has been found in the foreshock, there is still no ready explanation of the means by which it could have gotten there. 16 references

  1. Characterization of non-starter lactic acid bacteria in traditionally produced home-made Radan cheese during ripening

    Directory of Open Access Journals (Sweden)

    Jokovic Natasa

    2011-01-01

    Full Text Available Two hundred thirteen non-starter lactic acid bacteria isolated from Radan cheese during ripening were identified with both a classical biochemical test and rep-PCR with (GTG5 primer. For most isolates, which belong to the Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus paraplantarum and Enterococcus faecium, a phenotypic identification was in good agreement with rep-PCR identification. Lactococeus lactis subsp. lactis, Enterococcus faecium and subspecies from the Lenconostoc mesenteroides group were the dominant population of lactic acid bacteria in cheese until 10 days of ripening and only one Streptococcus thermophilus strain was isolated from the 5-day-old cheese sample. As ripening progressed, Lactobacillus plantarum became the predominant species together with the group of heterofermentative species of lactobacilli that could not be precisely identified with rep-PCR.

  2. Biochemical Factors Influencing Autolysis Of Leuconostocs in Buffer

    OpenAIRE

    ÇIBIK, Recep

    2010-01-01

    Orta ve daha yüksek oranda otolitik özelliğe sahip olan süt orjinli iki adet leukonostok susunun otolizine etki eden biyokimyasal faktörler tamponlanmış ortamda test edildi. Logoritmik büyüme fazının erken safhasında tampon ortamına alınan bakterilerin daha yüksek litik özelliğe sahip oldukları gözlendi. Asidik ve bazik ortamlarda aktivitenin azaldığı gözlenirken optimal aktivite için gerekli pH ortamının 6 ile 7 değerleri arasında olduğu saptandı. En uygun inkübasyon ısısı da yine leukonosto...

  3. Sustainable Management of Electronics

    Science.gov (United States)

    To provide information on EPAs strategy for electronics stewardship, certified electronics recyclers and the Challenge; as well as where to donate unwanted electronics, how to calculate benefits, and what's going on with electronics mgmt in their states.

  4. Advanced electron beam techniques

    International Nuclear Information System (INIS)

    Hirotsu, Yoshihiko; Yoshida, Yoichi

    2007-01-01

    After 100 years from the time of discovery of electron, we now have many applications of electron beam in science and technology. In this report, we review two important applications of electron beam: electron microscopy and pulsed-electron beam. Advanced electron microscopy techniques to investigate atomic and electronic structures, and pulsed-electron beam for investigating time-resolved structural change are described. (author)

  5. EDITORIAL: Synaptic electronics Synaptic electronics

    Science.gov (United States)

    Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

    2013-09-01

    Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

  6. Probiotic capacity of lactic acid bacteria isolated from chicha of molle

    OpenAIRE

    Rodríguez Carrasco, Jhanina; García-Godos Alcázar, Paula

    2017-01-01

    La investigación tuvo como objetivos aislar e identificar bacterias lácticas (BAL), evaluar la capacidad probiótica in vitro e in vivo de bacterias lácticas aisladas de chicha de molle, para ello se muestreó chichas de molle elaboradas artesanalmente de las provincias de Huanta y Huamanga, aislando 55 cepas BAL e identificando a Lactobacillus plantarum, Lactobacillus maltaromicus y Leuconostoc mesenteroides en base a la coloración Gram, producción de gas, gluconato y fermentación de azúcares....

  7. Produção de ácido lático e dextrana utilizando suco de caju como substrato

    OpenAIRE

    Honorato,Talita Lopes; Rabelo,Maria Cristiane; Pinto,Gustavo Adolfo Saavedra; Rodrigues,Sueli

    2007-01-01

    O presente trabalho teve como objetivo estudar a utilização de excedentes agrícolas como substrato para produção de dextrana e ácido lático. As fermentações foram conduzidas com o microorganismo Leuconostoc mesenteroides B512F, em meio contendo suco de caju e sacarose. As concentrações de açúcar redutor e sacarose foram variadas de acordo com um planejamento experimental. No final da fermentação foram quantificados a dextrana, o ácido lático e a biomassa produzida. Os resultados foram avaliad...

  8. Estudo de produção enzimatica da dextrana clinica

    OpenAIRE

    Juan Heraldo Viloche Bazan

    1993-01-01

    Resumo: Este trabalho consiste na obtenção "in vitro" de dextrana clínica a partir da sacarose utilizando a enzima dextrana-sacarase obtida pela fermentação do Leuconostoc mesenteroides linhagem NRRL B512-F. A dextrana clínica, de peso molecular médio 40.000 daltons, tem sua aplicação consagrada como expansor volumétrico de sangue humano. A enzima foi produzida por fermentação e purificada usando ultrafiltração, separada com o uso de polietilenoglicol de peso molecular 1500 daltons e estocada...

  9. Production of lactic acid and dextran using cashew apple juice as a substrate

    OpenAIRE

    Honorato, Talita Lopes; Rabelo, Maria Cristiane; Pinto, Gustavo Adolfo Saavedra; Rodrigues, Sueli

    2007-01-01

    O presente trabalho teve como objetivo estudar a utilização de excedentes agrícolas como substrato para produção de dextrana e ácido lático. As fermentações foram conduzidas com o microorganismo Leuconostoc mesenteroides B512F, em meio contendo suco de caju e sacarose. As concentrações de açúcar redutor e sacarose foram variadas de acordo com um planejamento experimental. No final da fermentação foram quantificados a dextrana, o ácido lático e a biomassa produzida. Os resultados foram avaliad...

  10. Estudo da recuperação de frutose produzida na sintese enzimatica "in vitro" de dextrana

    OpenAIRE

    Maria Eugenia Cavenaghi

    1999-01-01

    Resumo: A dextrana é um biopolímero, com grande potencial industrial, produzido principalmente pelo microorganismo Leuconostoc mesenteroides e formado por resíduos de glicose unidos por ligações a-1,6. Este polissacarídeo apresenta hoje diversas aplicações em alimentos, produtos farmacêuticos, cosméticos, indústrias química e fotográfica, devido provavelmente às inúmeras pesquisas realizadas. As características e propriedades da dextrana são muito específicas e seu uso é diferenciado de acord...

  11. Estimation of antibodies specific for dextran

    International Nuclear Information System (INIS)

    Matsuuchi, L.; Morrison, S.L.

    1978-01-01

    Methods are described for the isolation and characterization of picogram quantities of anti-dextran antibodies. 14 C-dextrans produced by using the dextransucrases of Leuconostoc mesenteroides strains B1355 and B512 were used in a radioimmunoassay. The specificity of this assay was verified by using cell cytoplasmic lysates from mouse plasmacytomas, J558 (anti-α 1 → 3 dextran) and W3129 (anti-α 1 → 6 dextran). Dextran produced by strain B1355 and insolubilized with epichlorohydrin was used as an immunoabsorbent

  12. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  13. Electron-electron Bremsstrahlung for bound target electrons

    International Nuclear Information System (INIS)

    Haug, E.

    2008-01-01

    For the process of electron-electron (e-e) Bremsstrahlung the momentum and energy distributions of the recoiling electrons are calculated in the laboratory frame. In order to get the differential cross section and the photon spectrum for target electrons which are bound to an atom, these formulae are multiplied by the incoherent scattering function and numerically integrated over the recoil energy. The effect of atomic binding is most pronounced at low energies of the incident electrons and for target atoms of high atomic numbers. The results are compared to those of previous calculations. (authors)

  14. Electron Beam Generation in Tevatron Electron Lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  15. Electron beam generation in Tevatron electron lenses

    International Nuclear Information System (INIS)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

    2006-01-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

  16. Interplay between electron-phonon and electron-electron interactions

    International Nuclear Information System (INIS)

    Roesch, O.; Gunnarsson, O.; Han, J.E.; Crespi, V.H.

    2005-01-01

    We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  18. Electronics for LHC Experiments

    International Nuclear Information System (INIS)

    2004-01-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance

  19. Electronics and Information

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Previously founded as CCPITMachinery and Electronics Sub-council and CCOIC Machinery and Electronics Chamber of Corn-merce in June, 1988, CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were established in May, 1993, and then renamed as CCPIT Electronics and Information Industry Sub-council and CCOIC Electronics and Infor-mation Industry Chamber of Commerce (CCPITECC) in September 1999.

  20. Electron-electron coincidence spectroscopies at surfaces

    International Nuclear Information System (INIS)

    Stefani, G.; Iacobucci, S.; Ruocco, A.; Gotter, R.

    2002-01-01

    In the past 20 years, a steadily increasing number of electron-electron coincidence experiments on atoms and molecules have contributed to a deeper understanding of electron-electron correlation effects. In more recent years this technique has been extended to the study of solid surfaces. This class of one photon IN two electrons OUT experiments will be discussed with an emphasis on grazing incidence geometry, that is expected to be particularly suited for studying surfaces. The crucial question of which is the dominant mechanism that leads to ejection of pairs of electron from the surface will be addressed. It will be shown that, depending on the kinematics chosen, the correlated behaviour of the pairs of electrons detected might be singled out from independent particle one

  1. Electron Microscopy Center (EMC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

  2. Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach.

    Science.gov (United States)

    Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco

    2008-05-31

    In this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional Mexican alcoholic beverage from maguey (Agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. The work included the isolation of lactic acid bacteria (LAB), aerobic mesophiles, and 16S rDNA clone libraries from total DNA extracted from the maguey sap (aguamiel) used as substrate, after inoculation with a sample of previously produced pulque and followed by 6-h fermentation. Microbiological diversity results were correlated with fermentation process parameters such as sucrose, glucose, fructose and fermentation product concentrations. In addition, medium rheological behavior analysis and scanning electron microscopy in aguamiel and during pulque fermentation were also performed. Our results showed that both culture and non-culture dependent approaches allowed the detection of several new and previously reported species within the alpha-, gamma-Proteobacteria and Firmicutes. Bacteria diversity in aguamiel was composed by the heterofermentative Leuconostoc citreum, L. mesenteroides, L. kimchi, the gamma-Proteobacteria Erwinia rhapontici, Enterobacter spp. and Acinetobacter radioresistens. Inoculation with previously fermented pulque incorporated to the system microbiota, homofermentative lactobacilli related to Lactobacillus acidophilus, several alpha-Proteobacteria such as Zymomonas mobilis and Acetobacter malorum, other gamma-Proteobacteria and an important amount of yeasts, creating a starting metabolic diversity composed by homofermentative and heterofermentative LAB, acetic and ethanol producing microorganisms. At the end of the fermentation process, the bacterial diversity was mainly composed by the homofermentative Lactobacillus acidophilus, the heterofermentative L. mesenteroides, Lactococcus lactis subsp. lactis and the alpha-Proteobacteria A. malorum. After

  3. Plasmaspheric electron content

    International Nuclear Information System (INIS)

    Hartmann, G.K.

    1978-01-01

    Measurements of the plasmaspheric electron content are reviewed with particular reference to the ATS-6 radio beacon experiment. From the review, it appears likely that measurement of the plasmaspheric electron content is the only one capable of monitoring electron fluxes continuously between L 1 and L 2. Some recent important results deduced from plasmaspheric electron content measurements are discussed

  4. Introduction to electronics

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  5. Introduction to Electronics course

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  6. Electronics engineer's reference book

    CERN Document Server

    Mazda, F F

    1989-01-01

    Electronics Engineer's Reference Book, Sixth Edition is a five-part book that begins with a synopsis of mathematical and electrical techniques used in the analysis of electronic systems. Part II covers physical phenomena, such as electricity, light, and radiation, often met with in electronic systems. Part III contains chapters on basic electronic components and materials, the building blocks of any electronic design. Part IV highlights electronic circuit design and instrumentation. The last part shows the application areas of electronics such as radar and computers.

  7. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  8. Electron-electron interactions in artificial graphene

    Science.gov (United States)

    Rasanen, Esa

    2013-03-01

    Recent advances in the creation and modulation of graphenelike systems are introducing a science of ``designer Dirac materials.'' In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional electron gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its electronic properties, including the effects of electron-electron interactions. Here we determine those effects on the band structure and on the emergence of Dirac points, and discuss future investigations and challenges in this field.

  9. Electronic payment systems

    OpenAIRE

    Mláka, Michal

    2010-01-01

    This bachelor thesis analysis issue of electronic payment systems. It discusses their use for payments on the internet and sending funds via e-mail. The first part is devoted to the theoretical definition and legislation of the issuance of electronic money and activities of electronic money institutions. The main part of the work clearly focuses on the use of e-wallets, which is an integral part of electronic payment systems. E-wallet of electronic payment system Moneybookers is considered as...

  10. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  11. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  12. Neutrinos in the Electron

    International Nuclear Information System (INIS)

    Koschmieder, E. L.

    2007-01-01

    I will show that one half of the rest mass of the electron consists of electron neutrinos and that the other half of the rest mass of the electron consists of the mass in the energy of electric oscillations. With this composition we can explain the rest mass of the electron, its charge, its spin and its magnetic moment We have also determined the rest masses of the muon neutrino and the electron neutrino

  13. Electron-electron interactions in disordered systems

    CERN Document Server

    Efros, AL

    1985-01-01

    ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

  14. VIRTUAL ELECTRONIC COMPONENTS OF THE ELECTRONIC EQUIPMENT

    Directory of Open Access Journals (Sweden)

    E. Lazarevich

    2013-01-01

    Full Text Available The article is present new idea of the creation, developments and improvements of the electronic equipment of complex systems by means of the virtual electronic components. The idea of the virtual electronic components is a presentation and perception of the creation and developments of the equipment on two forming: real – in the manner of standard marketed block of the intellectual property and image – in the manner of virtual component. The real component in most cases slows the development of the electronic equipment. The imaginary component is the «locomotive» of development of the electronic equipment. The Imaginary component contains the scientific has brushed against developer. The scientific has brushed against developer reveals of itself in the manner of virtual component on the modern level of the design rates of microelectronics.

  15. Practical XHV electron gun

    International Nuclear Information System (INIS)

    Urata, Tomohiro; Ishikawa, Tsuyoshi; Cho, Boklae; Oshima, Chuhei

    2008-01-01

    We have developed practical XHV chambers of a electron gun, of which the operating pressures are 1x10 -9 Pa in a stainless-steel one and 4x10 -9 Pa in a permalloy one. By mounting a noble single-atom electron source with high brightness and high spatial coherence on the electron gun including electron optics, we demonstrated highly collimated electron-beam emission: ∼80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources. In XHV, in addition, we confirmed stable electron emission up to 20 nA, which results in the specimen current high enough for scanning electron microscopes. (author)

  16. Fate of Escherichia coli O26 in Corn Silage Experimentally Contaminated at Ensiling, at Silo Opening, or after Aerobic Exposure, and Protective Effect of Various Bacterial Inoculants▿

    Science.gov (United States)

    Dunière, Lysiane; Gleizal, Audrey; Chaucheyras-Durand, Frédérique; Chevallier, Isabelle; Thévenot-Sergentet, Delphine

    2011-01-01

    Shiga toxin-producing Escherichia coli (STEC) strains are responsible for human illness. Ruminants are recognized as a major reservoir of STEC, and animal feeds, such as silages, have been pointed out as a possible vehicle for the spread of STEC. The present study aimed to monitor the fate of pathogenic E. coli O26 strains in corn material experimentally inoculated (105 CFU/g) during ensiling, just after silo opening, and after several days of aerobic exposure. The addition of 3 bacterial inoculants, Propionibacterium sp., Lactobacillus buchneri, and Leuconostoc mesenteroides (106 CFU/g), was evaluated for their abilities to control these pathogens. The results showed that E. coli O26 could not survive in corn silage 5 days postensiling, and the 3 inoculants tested did not modify the fate of pathogen survival during ensiling. In the case of direct contamination at silo opening, E. coli O26 could be totally eradicated from corn silage previously inoculated with Leuconostoc mesenteroides. The combination of proper ensiling techniques and the utilization of selected bacterial inoculants appears to represent a good strategy to guarantee nutritional qualities of cattle feed while at the same time limiting the entry of pathogenic E. coli into the epidemiological cycle to improve the microbial safety of the food chain. PMID:21984243

  17. Probiotic properties of lactic acid bacteria isolated from water-buffalo mozzarella cheese.

    Science.gov (United States)

    Jeronymo-Ceneviva, Ana Beatriz; de Paula, Aline Teodoro; Silva, Luana Faria; Todorov, Svetoslav Dimitrov; Franco, Bernadette Dora G Mello; Penna, Ana Lúcia B

    2014-12-01

    This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.

  18. Water Kefir grain as a source of potent dextran producing lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Davidović Slađana Z.

    2015-01-01

    Full Text Available Water kefir is abeverage fermented by a microbial consortium captured in kefir grains. The kefir grains matrix is composed of polysaccharide, primarily dextran, whichis produced by members of the microbial consortium. In this study, we have isolated lactic acid bacteria (LAB from non-commercial water kefir grains (from Belgrade, Serbia and screened for dextran production. Among twelve Lisolates threeproduced slime colonies on modified MRS (mMRS agar containing sucrose instead of glucoseand were presumed to produce dextran. Three LABwere identified based on morphological, physiological and biochemical characteristics and 16S rRNA sequencing as Leuconostoc mesenteroides(strains T1 and T3 and Lactobacillus hilgardii (strain T5. The isolated strains were able to synthesize a substantial amount of dextran in mMRS broth containing 5% sucrose. Maximal yields (11.56, 18.00 and 18.46 g/l were obtained after 16h, 20h and 32h for T1, T3 and T5, respectively. Optimal temperature for dextran production was 23oC for two Leuconostoc mesenteroides strains and 30oC for Lactobacillus hilgardii strain. The produced dextrans were identified based on paper chromatography while the main structure characteristics of purified dextranwere observed by FT-IR spectroscopy. Our study shows that water kefir grains are a natural source of potent dextranproducing LAB. [Projekat Ministarstva nauke Republike Srbije, br. TR 31035

  19. Identification of Coccoidal Bacteria in Traditional Fermented Milk Products from Mongolia, and the Fermentation Properties of the Predominant Species, Streptococcus thermophilus

    Science.gov (United States)

    2015-01-01

    The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production. PMID:26761898

  20. A superconducting electron spectrometer

    International Nuclear Information System (INIS)

    Guttormsen, M.; Huebel, H.; Grumbkow, A. von

    1983-03-01

    The set-up and tests of an electron spectrometer for in-beam conversion electron measurements are described. A superconducting solenoid is used to transport the electrons from the target to cooled Si(Li) detectors. The solenoid is designed to produce either a homogeneous axially symmetric field of up to 2 Tesla or a variety of field profiles by powering the inner and outer set of coils of the solenoid separately. The electron trajectories resulting for various field profiles are discussed. In-beam electron spectra taken in coincidence with electrons, gammas and alpha-particles are shown. (Auth.)

  1. Electronics for dummies

    CERN Document Server

    Shamieh

    2015-01-01

    Explore the basic concepts of electronics, build your electronics workbench, and begin creating fun electronics projects right away! Electronics For Dummies, 3rd Edition is your guide to the world of electronics. Spanning circuitry, wiring, robotics, transmitters, amplifiers, and more, this book demystifies electricity basics and beyond. The third edition offers new content revised to reflect the latest advancements in the electronics field, and it offers full color project examples to spark your creativity and inspire you to put your new skills to use! Packed with projects that can be comple

  2. RHIC electron lenses upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Bruno, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Binello, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Costanzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Drees, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hock, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Marusic, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mi, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Pikin, A. I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Robert-Demolaize, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Samms, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Shrey, T. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tan, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Thieberger, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; White, S. M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2015-05-03

    In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.

  3. Electron emitting filaments for electron discharge devices

    International Nuclear Information System (INIS)

    Leung, K.N.; Pincosy, P.A.; Ehlers, K.W.

    1988-01-01

    This patent describes an electron emitting device for use in an electron discharge system. It comprises: a filament having a pair of terminal ends, electrical supply means for supplying electrical power to the terminal ends of the filament for directly heating the filament by the passage of an electrical current along the filament between the terminal ends, the filament being substantially tapered in cross section continuously in one direction from one of its pair of terminal ends to another of its pair of terminal ends to achieve uniform heating of the filament along the length thereof by compensating for the nonuniform current along the filament due to the emission of electrons therefrom

  4. Narrow electron injector for ballistic electron spectroscopy

    International Nuclear Information System (INIS)

    Kast, M.; Pacher, C.; Strasser, G.; Gornik, E.

    2001-01-01

    A three-terminal hot electron transistor is used to measure the normal energy distribution of ballistic electrons generated by an electron injector utilizing an improved injector design. A triple barrier resonant tunneling diode with a rectangular transmission function acts as a narrow (1 meV) energy filter. An asymmetric energy distribution with its maximum on the high-energy side with a full width at half maximum of ΔE inj =10 meV is derived. [copyright] 2001 American Institute of Physics

  5. Electronic Submission of Labels

    Science.gov (United States)

    Pesticide registrants can provide draft and final labels to EPA electronically for our review as part of the pesticide registration process. The electronic submission of labels by registrants is voluntary but strongly encouraged.

  6. Electron scattering from pyrimidine

    International Nuclear Information System (INIS)

    Colmenares, Rafael; Fuss, Martina C; García, Gustavo; Oller, Juan C; Muñoz, Antonio; Blanco, Francisco; Almeida, Diogo; Limão-Vieira, Paulo

    2014-01-01

    Electron scattering from pyrimidine (C 4 H 4 N 2 ) was investigated over a wide range of energies. Following different experimental and theoretical approaches, total, elastic and ionization cross sections as well as electron energy loss distributions were obtained.

  7. THE ELECTRONIC SIGNATURE

    Directory of Open Access Journals (Sweden)

    Voiculescu Madalina Irena

    2009-05-01

    Full Text Available Article refers to significance and the digital signature in electronic commerce. Internet and electronic commerce open up many new opportunities for the consumer, yet, the security (or perceived lack of security of exchanging personal and financial data

  8. Laboratory Handbook Electronics

    CERN Multimedia

    1966-01-01

    Laboratory manual 1966 format A3 with the list of equipment cables, electronic tubes, chassis, diodes transistors etc. One of CERN's first material catalogue for construction components for mechanical and electronic chassis.

  9. Presidential Electronic Records Library

    Data.gov (United States)

    National Archives and Records Administration — PERL (Presidential Electronic Records Library) used to ingest and provide internal access to the Presidential electronic Records of the Reagan, Bush, and Clinton...

  10. Chapter 9: Electronics

    International Nuclear Information System (INIS)

    Grupen, Claus; Shwartz, Boris A.

    2006-01-01

    Sophisticated front-end electronics are a key part of practically all modern radiation detector systems. This chapter introduces the basic principles and their implementation. Topics include signal acquisition, electronic noise, pulse shaping (analog and digital), and data readout techniques

  11. Certified Electronics Recyclers

    Science.gov (United States)

    Learn how EPA encourages all electronics recyclers become certified by demonstrating to an accredited, independent third-party auditor and that they meet specific standards to safely recycle and manage electronics.

  12. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-01-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent

  13. Electronic Signature Policy

    Science.gov (United States)

    Establishes the United States Environmental Protection Agency's approach to adopting electronic signature technology and best practices to ensure electronic signatures applied to official Agency documents are legally valid and enforceable

  14. Electronics Industry Study Report

    National Research Council Canada - National Science Library

    Belt, David; Fellows, John R; Kameru, Philip; Nazaroff, Boris-Frank A; Pauroso, Anthony; Schulz, Frederick; Ballew, Bob; Bond, Thomas; Demers, Stephy; Kirkpatrick, Steve

    2005-01-01

    This paper provides a national strategy for the US electronics industry. Electronics is one of the largest industries in the US and plays a critical role in almost every aspect of national security...

  15. Electron microscopy for Engineers

    International Nuclear Information System (INIS)

    Jones, I P

    2009-01-01

    This paper reviews the application of (mainly) Transmission Electron Microscopy (TEM) in an engineering context. The first two sections are TEM and chemical in nature; the final three sections are more general and include aspects of Scanning Electron Microscopy (SEM).

  16. ELSA electron stretcher devices

    International Nuclear Information System (INIS)

    1979-10-01

    The use of an electron stretcher ring at the Bonn electron synchrotron is discussed. The construction of the proposed ring is described, and the costs are estimated. Possible experiments using this ring are discussed. (HSI)

  17. Electron shuttles in biotechnology.

    Science.gov (United States)

    Watanabe, Kazuya; Manefield, Mike; Lee, Matthew; Kouzuma, Atsushi

    2009-12-01

    Electron-shuttling compounds (electron shuttles [ESs], or redox mediators) are essential components in intracellular electron transfer, while microbes also utilize self-produced and naturally present ESs for extracellular electron transfer. These compounds assist in microbial energy metabolism by facilitating electron transfer between microbes, from electron-donating substances to microbes, and/or from microbes to electron-accepting substances. Artificially supplemented ESs can create new routes of electron flow in the microbial energy metabolism, thereby opening up new possibilities for the application of microbes to biotechnology processes. Typical examples of such processes include halogenated-organics bioremediation, azo-dye decolorization, and microbial fuel cells. Herein we suggest that ESs can be applied widely to create new microbial biotechnology processes.

  18. Electronic Science Seminar

    Directory of Open Access Journals (Sweden)

    Geidarov P.Sh.

    2015-09-01

    Full Text Available The structure of electronic scientific seminar, which provides a high level of quality of the objectivity in the evaluation of scientific papers, including dissertations, is described. Conditions for the implementation of electronic scientific seminar are also considered.

  19. Copyright of Electronic Publishing.

    Science.gov (United States)

    Dong, Elaine; Wang, Bob

    2002-01-01

    Analyzes the importance of copyright, considers the main causes of copyright infringement in electronic publishing, discusses fair use of a copyrighted work, and suggests methods to safeguard copyrighted electronic publishing, including legislation, contracts, and technology. (Author/LRW)

  20. Paleoclassical electron heat transport

    International Nuclear Information System (INIS)

    Callen, J.D.

    2005-01-01

    Radial electron heat transport in low collisionality, magnetically-confined toroidal plasmas is shown to result from paleoclassical Coulomb collision processes (parallel electron heat conduction and magnetic field diffusion). In such plasmas the electron temperature equilibrates along magnetic field lines a long length L, which is the minimum of the electron collision length and a maximum effective half length of helical field lines. Thus, the diffusing field lines induce a radial electron heat diffusivity M ≅ L/(πR 0q ) ∼ 10 >> 1 times the magnetic field diffusivity η/μ 0 ≅ ν e (c/ω p ) 2 . The paleoclassical electron heat flux model provides interpretations for many features of 'anomalous' electron heat transport: magnitude and radial profile of electron heat diffusivity (in tokamaks, STs, and RFPs), Alcator scaling in high density plasmas, transport barriers around low order rational surfaces and near a separatrix, and a natural heat pinch (or minimum temperature gradient) heat flux form. (author)

  1. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  2. Electronic theodolite intersection systems

    OpenAIRE

    Bingley, R. M.

    1990-01-01

    The development of electronic surveying instruments, such as electronic theodolites, and concurrent advances in computer technology, has revolutionised engineering surveying; one of the more recent examples being the introduction of Electronic Theodolite Intersection Systems (ETISs). An ETIS consists of two or more electronic theodolites and a computer, with peripheral hardware and suitable software. The theoretical principles on which they are based have been known for a long time, but ...

  3. Electron-attachment processes

    International Nuclear Information System (INIS)

    Christophorou, L.G.; McCorkle, D.L.; Christodoulides, A.A.

    1982-01-01

    Topics covered include: (1) modes of production of negative ions, (2) techniques for the study of electron attachment processes, (3) dissociative electron attachment to ground-state molecules, (4) dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), (5) molecular parent negative ions, and (6) negative ions formed by ion-pair processes and by collisions of molecules with ground state and Rydberg atoms

  4. Handbook on electronic commerce

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M. [Illinois Univ., Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology; Blanning, R. [Vanderbilt Univ., Nashville, TN (United States). Owen Graduate School of Management; Strader, T. [Iowa State Univ., Ames, IA (United States). Management Information Systems; Whinston, A. [eds.] [Texas Univ., Austin, TX (United States). Dept. of Management Science and Information Systems

    2000-07-01

    The world is undergoing a revolution to a digital economy, with pronounced implications for corporate strategy, marketing, operations, information systems, customer services, global supply-chain management, and product distribution. This handbook examines the aspects of electronic commerce, including electronic storefront, on-line business, consumer interface, business-to-business networking, digital payment, legal issues, information product development, and electronic business models. Indispensable for academics, students and professionals who are interested in Electronic Commerce and Internet Business. (orig.)

  5. Electron Cyclotron Resonances in Electron Cloud Dynamics

    International Nuclear Information System (INIS)

    Celata, Christine; Celata, C.M.; Furman, Miguel A.; Vay, J.-L.; Yu, Jennifer W.

    2008-01-01

    We report a previously unknown resonance for electron cloud dynamics. The 2D simulation code 'POSINST' was used to study the electron cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. An electron equilibrium density enhancement of up to a factor of 3 was found at magnetic field values for which the bunch frequency is an integral multiple of the electron cyclotron frequency. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ∼(2 pi mec/(elb)), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics are discussed

  6. Syringe injectable electronics

    Science.gov (United States)

    Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-01-01

    Seamless and minimally-invasive three-dimensional (3D) interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with > 90% device yield. We demonstrate several applications of syringe injectable electronics as a general approach for interpenetrating flexible electronics with 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, delivery of large volume flexible electronics that can fill internal cavities and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics. PMID:26053995

  7. Syringe-injectable electronics.

    Science.gov (United States)

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  8. Electrons in Condensed Matter

    Indian Academy of Sciences (India)

    three freely moving electrons. The value at room temperature is 3.1 k B; the electronic specific heat is missing! The next stage in the electronic theory of solids clears up ..... a big dog? We do not know the reasons yet. As it turns out for many fundamentally interesting phenomena, colossal magneto- resistance may also find ...

  9. Arduino electronics blueprints

    CERN Document Server

    Wilcher, Don

    2015-01-01

    This book is intended for those who want to learn about electronics and coding by building amazing devices and gadgets with Arduino. If you are an experienced developer who understands the basics of electronics, then you can quickly learn how to build smart devices using Arduino. The only experience needed is a desire to learn about electronics, circuit breadboarding, and coding.

  10. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  11. Embracing Electronic Publishing.

    Science.gov (United States)

    Wills, Gordon

    1996-01-01

    Electronic publishing is the grandest revolution in the capture and dissemination of academic and professional knowledge since Caxton developed the printing press. This article examines electronic publishing, describes different electronic publishing scenarios (authors' cooperative, consolidator/retailer/agent oligopsony, publisher oligopoly), and…

  12. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  13. Quantitative secondary electron detection

    Science.gov (United States)

    Agrawal, Jyoti; Joy, David C.; Nayak, Subuhadarshi

    2018-05-08

    Quantitative Secondary Electron Detection (QSED) using the array of solid state devices (SSD) based electron-counters enable critical dimension metrology measurements in materials such as semiconductors, nanomaterials, and biological samples (FIG. 3). Methods and devices effect a quantitative detection of secondary electrons with the array of solid state detectors comprising a number of solid state detectors. An array senses the number of secondary electrons with a plurality of solid state detectors, counting the number of secondary electrons with a time to digital converter circuit in counter mode.

  14. Electron distribution function in electron-beam-excited plasmas

    International Nuclear Information System (INIS)

    Brau, C.A.

    1976-01-01

    In monatomic plasmas excited by high-intensity relativistic electron beams, the electron secondary distribution function is dominated by elastic electron-electron collisions at low electron energies and by inelastic electron-atom collisions at high electron energies (above the excitation threshold). Under these conditions, the total rate of excitation by inelastic collisions is limited by the rate at which electron-electron collisions relax the distribution function in the neighborhood of the excitation threshold. To describe this effect quantitatively, an approximate analytic solution of the electron Boltzmann equation is obtained, including both electron-electron and inelastic collisions. The result provides a simple formula for the total rate of excitation

  15. Molecular electron affinities

    International Nuclear Information System (INIS)

    Fukuda, E.K.

    1983-01-01

    Molecular electron affinities have historically been difficult quantities to measure accurately. These difficulties arise from differences in structure between the ion and neutral as well as the existence of excited negative ion states. To circumvent these problems, relative electron affinities were determined in this dissertation by studying equilibrium electron transfer reactions using a pulsed ion cyclotron resonance (ICR) spectrometer. Direct measurement of ion and neutral concentrations for reactions of the general type, A - + B = B - + A, allow calculation of the equilibrium constant and, therefore, the free energy change. The free energy difference is related to the difference in electron affinities between A and B. A relative electron affinity scale covering a range of about 45 kcal/mol was constructed with various substituted p-benzoquinones, nitrobenzenes, anhydrides, and benzophenones. To assign absolute electron affinities, various species with accurately known electron affinities are tied to the scale via ion-cyclotron double resonance bracketing techniques. After the relative scale is anchored to these species with well-known electron affinities, the scale is then used as a check on other electron affinity values as well as generating new electron affinity values. Many discrepancies were found between the electron affinities measured using the ICR technique and previous literature determinations

  16. Nonambipolar electron source

    International Nuclear Information System (INIS)

    Longmier, B.; Baalrud, S.; Hershkowitz, N.

    2006-01-01

    A radio frequency (rf) plasma-based electron source that does not rely on electron emission at a cathode surface has been constructed. All of the random electron flux incident on an exit aperture is extracted through an electron sheath resulting in total nonambipolar flow within the device when the ratio of the ion loss area to the electron loss area is approximately equal to the square root of the ratio of the ion mass to the electron mass, and the ion sheath potential drop at the chamber walls is much larger than T e /e. The nonambipolar electron source (NES) has an axisymmetric magnetic field of 100 G at the extraction aperture that results in a uniform plasma potential across the aperture, allowing the extraction of all the incident electron flux without the use of grids. A prototype NES has produced 15 A of continuous electron current, using 15 SCCM (SCCM denotes cubic centimeter per minute at STP) Ar, 1200 W rf power at 13.56 MHz, and 6 times gas utilization. Alternatively 8 A of electron current can be produced, using 3 SCCM Ar at 1200 W rf and 20 times gas utilization. NES could replace hollow cathode electron sources in a wide variety of applications

  17. High brightness electron accelerator

    International Nuclear Information System (INIS)

    Sheffield, R.L.; Carlsten, B.E.; Young, L.M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of accelerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity. 5 figs

  18. Electronic equipment packaging technology

    CERN Document Server

    Ginsberg, Gerald L

    1992-01-01

    The last twenty years have seen major advances in the electronics industry. Perhaps the most significant aspect of these advances has been the significant role that electronic equipment plays in almost all product markets. Even though electronic equipment is used in a broad base of applications, many future applications have yet to be conceived. This versatility of electron­ ics has been brought about primarily by the significant advances that have been made in integrated circuit technology. The electronic product user is rarely aware of the integrated circuits within the equipment. However, the user is often very aware of the size, weight, mod­ ularity, maintainability, aesthetics, and human interface features of the product. In fact, these are aspects of the products that often are instrumental in deter­ mining its success or failure in the marketplace. Optimizing these and other product features is the primary role of Electronic Equipment Packaging Technology. As the electronics industry continues to pr...

  19. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  20. Ion plasma electron gun

    International Nuclear Information System (INIS)

    Wakalopulos, G.

    1976-01-01

    In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode

  1. Seeing with electrons

    International Nuclear Information System (INIS)

    Nellist, P.

    2006-01-01

    Commercially available lens correctors are extending the reach of electron microscopes to unprecedented atomic scales, as Peter Nellist describes. The electron microscope was invented in 1933 and is based on the principle that electrons have a wavelength that is inversely proportional to their momentum. There are two basic types: transmission electron microscopes and scanning electron microscopes, plus a hybrid of the two. The lenses in an electron microscope are provided by electromagnetic fields, but they suffer from spherical aberration. The addition of octupole and quadrupole corrector fields has improved the resolution of the electron microscope to better than 0.1 nm in the last decade. The next step is to correct for chromatic aberration, after which the resolution of the microscope will probably be limited by the size of the atom itself. (U.K.)

  2. Engineered phages for electronics.

    Science.gov (United States)

    Cui, Yue

    2016-11-15

    Phages are traditionally widely studied in biology and chemistry. In recent years, engineered phages have attracted significant attentions for functionalization or construction of electronic devices, due to their specific binding, catalytic, nucleating or electronic properties. To apply the engineered phages in electronics, these are a number of interesting questions: how to engineer phages for electronics? How are the engineered phages characterized? How to assemble materials with engineered phages? How are the engineered phages micro or nanopatterned? What are the strategies to construct electronics devices with engineered phages? This review will highlight the early attempts to address these questions and explore the fundamental and practical aspects of engineered phages in electronics, including the approaches for selection or expression of specific peptides on phage coat proteins, characterization of engineered phages in electronics, assembly of electronic materials, patterning of engineered phages, and construction of electronic devices. It provides the methodologies and opens up ex-cit-ing op-por-tu-ni-ties for the development of a variety of new electronic materials and devices based on engineered phages for future applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Decal electronics for printed high performance cmos electronic systems

    KAUST Repository

    Hussain, Muhammad Mustafa; Sevilla, Galo Torres; Cordero, Marlon Diaz; Kutbee, Arwa T.

    2017-01-01

    High performance complementary metal oxide semiconductor (CMOS) electronics are critical for any full-fledged electronic system. However, state-of-the-art CMOS electronics are rigid and bulky making them unusable for flexible electronic applications

  4. Electronic Publishing or Electronic Information Handling?

    Science.gov (United States)

    Heck, A.

    The current dramatic evolution in information technology is bringing major modifications in the way scientists communicate. The concept of 'electronic publishing' is too restrictive and has often different, sometimes conflicting, interpretations. It is thus giving way to the broader notion of 'electronic information handling' encompassing the diverse types of information, the different media, as well as the various communication methodologies and technologies. New problems and challenges result also from this new information culture, especially on legal, ethical, and educational grounds. The procedures for validating 'published material' and for evaluating scientific activities will have to be adjusted too. 'Fluid' information is becoming a common concept. Electronic publishing cannot be conceived without link to knowledge bases nor without intelligent information retrieval tools.

  5. Electron transfer in proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1991-01-01

    Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable...... specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition......-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function....

  6. Electrons in Nanostructures

    DEFF Research Database (Denmark)

    Flindt, Christian

    2007-01-01

    in the possibilities o®ered by the quantum mechanical behavior of electrons when it comes to informa- tion processing. This branch of research is also concerned with fundamental questions in physics. Besides an introduction to the above-mentioned subjects, the thesis con- tains a number of contributions to the ¯elds...... of coherent electron manip- ulation and the statistical description of electron transport through nano- devices. The physics of the electrons are described with a combination of numerical methods, developed and applied in the thesis, and more analytical approaches, which are also discussed. The thesis......-based communication. The statistical description of electron transport through nanostructures is based on rate equations, and the primary contribution of the thesis in that respect is the development of a method that allows for the calculation of the distribution of electrons passing through a device. The method...

  7. Transition to electronic publishing

    Science.gov (United States)

    Bowning, Sam

    Previous communications have described some of the many changes that will occur in the next few months as AGU makes the transition to fully electronic publishing. With the advent of the new AGU electronic publishing system, manuscripts will be submitted, edited, reviewed, and published in electronic formats. This piece discusses how the electronic journals will differ from the print journals. Electronic publishing will require some adjustments to the ways we currently think about journals from our perspective of standard print versions. Visiting the Web site of AGU's Geochemistry, Geophysics, Geosystems (G-Cubed) is a great way to get familiar with the look and feel of electronic publishing. However, protocols, especially for citations of articles, are still evolving. Some of the biggest changes for users of AGU publications may be the lack of page numbers, the use of a unique identifier (DOI),and changes in citation style.

  8. Characterisation and biochemical properties of predominant lactic acid bacteria from fermenting cassava for selection as starter cultures.

    Science.gov (United States)

    Kostinek, M; Specht, I; Edward, V A; Pinto, C; Egounlety, M; Sossa, C; Mbugua, S; Dortu, C; Thonart, P; Taljaard, L; Mengu, M; Franz, C M A P; Holzapfel, W H

    2007-03-20

    A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, beta-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H(2)O(2)-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of

  9. Electron microscopy of surfaces

    International Nuclear Information System (INIS)

    Venables, J.A.

    1981-01-01

    Electron beam techniques used to study clean surfaces and surface processes on a microscopic scale are reviewed. Recent experimental examples and possible future developments are discussed. Special emphasis is given to (i) transmission diffraction and microscopy techniques, including atomic imaging; (ii) Auger microscopy on bulk and thin film samples; (iii) secondary electron microscopy, especially low energy secondaries for work-function imaging and photoelectron imaging; and (iv) reflection electron microscopy and diffraction. (orig.)

  10. New electronics stuff chemistry

    International Nuclear Information System (INIS)

    Byeon, Su Il

    2003-04-01

    The first part of this book is about equilibrium electrochemistry on electric thermo dynamic equilibrium state of electrochemistry, crystal defect of solid, thermodynamics on defect electron and election in semiconductor, Gawani potential, volta potential and equilibrium potential and thermodynamics application in Gawani battery. The second part deals with dynamic electrochemistry electrode reaction kinetics and corrosion potential in normal state, diffusion and transport of ion and electron and current impedance spectroscopy. It also mentions industrial electrochemistry and laboratory works in electronics chemistry course.

  11. Ceramic Electron Multiplier

    International Nuclear Information System (INIS)

    Comby, G.

    1996-01-01

    The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

  12. Organizing the Electronic Century

    OpenAIRE

    Richard N. Langlois

    2007-01-01

    This paper's title is an echo of Alfred Chandler's (2001) chronicle of the electronics industry, Inventing the Electronic Century. The paper attempts (A) a general reinterpretation of the pattern of technological advance in (American) electronics over the twentieth century and (B) a somewhat revisionist account of the role of organization and institution in that advance. The paper stresses the complex effects of product architecture and intellectual property regime on industrial organization ...

  13. Introduction to printed electronics

    CERN Document Server

    Suganuma, Katsuaki

    2014-01-01

    This book describes in detail modern technologies for printed electronics, explaining how nanotechnology and modern printing technology are merging to revolutionize electronics fabrication of thin, lightweight, large, and inexpensive products. Readers will benefit from the explanations of materials, devices and circuits used to design and implement the latest applications of printed electronics, such as thin flexible OLED displays, organic solar cells, OLED lighting, smart wallpaper, sensors, logic, memory and more.

  14. Interoperability for electronic ID

    OpenAIRE

    Zygadlo, Zuzanna

    2009-01-01

    Electronic Business, including eBanking, eCommerce and eGovernmental services, is today based on a large variety of security solutions, comprising electronic IDs provided by a broad community of Public Key Infrastructure (PKI) vendors. Significant differences in implementations of those solutions introduce a problem of lack of interoperability in electronic business, which have not yet been resolved by standardization and interoperability initiatives based on existing PKI trust models. It i...

  15. TRANSIENT ELECTRONICS CATEGORIZATION

    Science.gov (United States)

    2017-08-24

    AFRL-RY-WP-TR-2017-0169 TRANSIENT ELECTRONICS CATEGORIZATION Dr. Burhan Bayraktaroglu Devices for Sensing Branch Aerospace Components & Subsystems...SUBTITLE TRANSIENT ELECTRONICS CATEGORIZATION 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) Dr. Burhan...88ABW-2017-3747, Clearance Date 31 July 2017. Paper contains color. 14. ABSTRACT Transient electronics is an emerging technology area that lacks proper

  16. Introduction to electronics

    CERN Document Server

    Korneff, Theodore

    1966-01-01

    Introduction to Electronics focuses on the study of electronics and electronic devices. Composed of 14 chapters, the book starts with discussions on dc circuits, including resistance, voltmeter, ammeter, galvanometer, internal resistance, and positive and negative currents. This topic is followed by discussions on ac circuits, particularly addressing voltage and current, average power, resistive load, complex plane, and parallel circuits. Discussions also focus on filters and tuned circuits, diodes, and power supplies. Particularly given attention are the processes, diagrams, and analyses

  17. Modern electronic materials

    CERN Document Server

    Watkins, John B

    2013-01-01

    Modern Electronic Materials focuses on the development of electronic components. The book first discusses the history of electronic components, including early developments up to 1900, developments up to World War II, post-war developments, and a comparison of present microelectric techniques. The text takes a look at resistive materials. Topics include resistor requirements, basic properties, evaporated film resistors, thick film resistors, and special resistors. The text examines dielectric materials. Considerations include basic properties, evaporated dielectric materials, ceramic dielectri

  18. Electron-beam lithography

    International Nuclear Information System (INIS)

    Harriott, L.; Liddle, A.

    1997-01-01

    As part of a commemorative series of articles to mark the hundredth anniversary of the discovery of the electron, this article describes the use of electron beams to write features on silicon wafers. Recent advances in electron beam lithography, as it is known, could enable this technology to be used for the mass manufacture of silicon chips. The validation of space-charge optimization and evaluation of printing techniques is underway. (UK)

  19. Electron beam lithography

    International Nuclear Information System (INIS)

    Harriott, L.; Liddle, A.

    1997-01-01

    As part of a commemorative series of articles to mark the hundredth anniversary of the discovery of the electron, this article describes the use of electron beams to write features on silicon wafers. Recent advances in electron beam lithography, as it is known, could enable this technology to be used for the mass manufacture of silicon chips. The validation of space-charge optimization and evaluation of printing techniques is underway. 5 figs

  20. Electron microscopy and diffraction

    International Nuclear Information System (INIS)

    Gjoennes, J.; Olsen, A.

    1986-01-01

    This report is a description of research activities and plans at the electron microscopy laboratorium, Physics Department, University of Oslo. Since the first electron microscope was installed in 1968, the research has covered inorganic structures, physical metallurgy, as well as theory of electron scattering and the development of methods in this field. The current plans involve efforts in the development of crystallographic and spectroscopic methods

  1. The Electronic Notebook Ontology

    OpenAIRE

    Chalk, Stuart

    2016-01-01

    Science is rapidly being brought into the electronic realm and electronic laboratory notebooks (ELN) are a big part of this activity. The representation of the scientific process in the context of an ELN is an important component to making the data recorded in ELNs semantically integrated. This presentation will outline initial developments of an Electronic Notebook Ontology (ENO) that will help tie together the ExptML ontology, HCLS Community Profile data descriptions, and the VIVO-ISF ontol...

  2. Electronics Environmental Benefits Calculator

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Electronics Environmental Benefits Calculator (EEBC) was developed to assist organizations in estimating the environmental benefits of greening their purchase,...

  3. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  4. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  5. The auroral electron accelerator

    International Nuclear Information System (INIS)

    Bryant, D.A.; Hall, D.S.

    1989-01-01

    A model of the auroral electron acceleration process is presented in which the electrons are accelerated resonantly by lower-hybrid waves. The essentially stochastic acceleration process is approximated for the purposes of computation by a deterministic model involving an empirically derived energy transfer function. The empirical function, which is consistent with all that is known of electron energization by lower-hybrid waves, allows many, possibly all, observed features of the electron distribution to be reproduced. It is suggested that the process occurs widely in both space and laboratory plasmas. (author)

  6. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  7. Two electron Rydberg states

    International Nuclear Information System (INIS)

    Cooke, W.E.

    1981-01-01

    This paper addresses the study of two-electron Rydberg atoms. With Multichannel Quantum Defect Theory (MQDT), there is a technique for characterizing a spectra in terms of a small number of parameters. A survey of some important effects specific to two-electon Rydberg states, using primarily the alkaline earth atoms for examples, is made. The remainder of the paper deals with a discussion of the electron-electron interaction, including some of the basic points of MQDT. Energy exchange between two electrons is also addressed

  8. Fundamentals of electronics

    CERN Document Server

    Schubert, Thomas F

    2015-01-01

    This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

  9. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  10. Electronics pocket book

    CERN Document Server

    Parr, E A

    1981-01-01

    Electronics Pocket Book, Fourth Edition is a nonmathematical presentation of the many varied topics covered by electronics. The book tackles electron physics, electronic components (i.e. resistors, capacitors, and conductors), integrated circuits, and the principles of a.c. and d.c. amplifiers. The text also discusses oscillators, digital circuits, digital computers, and optoelectronics (i.e., sensors, emitters, and devices that utilize light). Communications (such as line and radio communications, transmitters, receivers, and digital techniques); the principles and examples of servosystems; a

  11. Electron beam welding

    International Nuclear Information System (INIS)

    Schwartz, M.M.

    1974-01-01

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  12. Flying Electronic Warfare Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides NP-3D aircraft host platforms for Effectiveness of Navy Electronic Warfare Systems (ENEWS) Program antiship missile (ASM) seeker simulators used...

  13. Free electron laser

    International Nuclear Information System (INIS)

    Ortega, J.M.; Billardon, M.

    1986-01-01

    Operation principle of a laser and an oscillator are recalled together with the klystron one. In the free electron laser, electrons go through an undulator or an optical klystron. Principles of the last one are given. The two distinct ways of producing coherent radiation with an undulator and an optical klystron are presented. The first one is the use of the free electron laser, the second is to make use of the spontaneous emission generation (harmonics generation). The different current types of free electron lasers are presented (Stanford, Los Alamos, Aco at Orsay). Prospects and applications are given in conclusion [fr

  14. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  15. Flexible Electronics Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Flexible Electronics Research Facility designs, synthesizes, tests, and fabricates materials and devices compatible with flexible substrates for Army information...

  16. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  17. Electrons in water radiolysis

    International Nuclear Information System (INIS)

    Laverne, J.A.; Pimblott, S.M.

    2006-01-01

    The hydrated electron is the main reducing species produced in the radiolysis of water. Many studies have examined its reactivity using pulsed radiolysis techniques and competition kinetics. Data bases list hundreds of rate coefficients for reaction of the hydrated electron with substances ranging from inorganic ions like nitrate to biopolymers like DNA. Although the chemistry of the hydrated electron is often examined, its mechanism of formation and variation in yield are considerable less known, especially under extreme conditions such as in high temperature water or with heavy ion radiolysis. This work will examine various aspects of the radiation chemistry of the hydrated electron beginning with the generation of secondary electrons in primary energy loss events during the passage of ionizing radiation to the radiolytic yields of the hydrated electron produced by different types of radiation. Ion radiation is a 'white light source.' Energy losses range from the minimum excitation energy of the medium up to the kinematic maximum determined by the collision parameters. However, certain energy loss events are more probable than others. The dipole oscillator strength distributions of media essentially give the probability of energy loss events in collisions with no momentum transfer. Dipole oscillator distributions have been constructed from experimental data for a wide variety of materials including all the phases of water. Calculations using cross sections based on dipole oscillator distributions show that the most probable energy loss event in water is only about 20 eV with an average value closer to 60 eV. The preponderance of energy loss events of less than 100 eV means that many low energy electrons are formed by the passage of a single ion. Low energy electrons have short mean free paths and they remain in the vicinity of the primary energy loss events. The spatial distribution of these low energy electrons defines the radial track structure of the incident

  18. INDRA. Electronic Architecture

    International Nuclear Information System (INIS)

    Ganil Team.

    1993-01-01

    The INDRA multidetector electronics is described. The system is a set of 17 rings consisting of 96 ionization chambers and 180 silicon detectors plus 324 cesium iodide and 12 Phoswich scintillators. Their integrated electronic lines, the trigger modules, the control and data acquisition units are presented briefly. (R.P.) 6 figs

  19. Recycling of electronic scrap

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech

    This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...

  20. Cooling of electronic equipment

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    2003-01-01

    Cooling of electronic equipment is studied. The design size of electronic equipment decrease causing the thermal density to increase. This affect the cooling which can cause for example failures of critical components due to overheating or thermal induced stresses. Initially a pin fin heat sink...

  1. Scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    1970-05-15

    The JSM-11 scanning electron microscope at CRNL has been used extensively for topographical studies of oxidized metals, fracture surfaces, entomological and biological specimens. A non-dispersive X-ray attachment permits the microanalysis of the surface features. Techniques for the production of electron channeling patterns have been developed. (author)

  2. Electron scattering from tetrahydrofuran

    International Nuclear Information System (INIS)

    Fuss, M C; Sanz, A G; García, G; Muñoz, A; Oller, J C; Blanco, F; Do, T P T; Brunger, M J; Almeida, D; Limão-Vieira, P

    2012-01-01

    Electron scattering from Tetrahydrofuran (C 4 H 8 O) was investigated over a wide range of energies. Following a mixed experimental and theoretical approach, total scattering, elastic scattering and ionization cross sections as well as electron energy loss distributions were obtained.

  3. Paradoxes of unstable electron

    International Nuclear Information System (INIS)

    Okun, L.B.; Zeldovich, Ya.B.

    1978-01-01

    The hypothesis that electron is unstable - when it is consistent with the vanishing mass of the photon- leads to a number of paradoxical statements. The lifetime of the electron is determined by emission of a huge number of longitudinal photons and exponentially depends on the amount of emitted energy. This suggests to discuss searches for charge nonconservation in experiments with high energy particles

  4. Electron scattering violates parity

    CERN Multimedia

    2004-01-01

    Parity violation has been observed in collisions between electrons at the Stanford Linear Accelerator Center (SLAC) in the US. The resuls, which are in agreement with the Stanford Model of particle physics, also provide a new measurement of the weak charge of the electron (½ page)

  5. Electronically Controlled Resistor Bank

    Science.gov (United States)

    Ross, Walter L.

    1987-01-01

    Resistance quickly varied in small steps over wide range. Device with no moving parts provides variable electrical resistance. Used with analog or digital circuity to provide electronic selection of large number of resistance values for testing, simulation, control, or other purposes. Nearest electromechanical equivalent of all-electronic device is potentiometer driven by servomotor.

  6. Voltmeter with Compton electrons

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, N R; Gorbics, S G; Weidenheimer, D M [Berkeley Research Associates, Springfield, VA (United States)

    1997-12-31

    A technique to measure the electron end point energy of bremsstrahlung in the MV regime using only two detectors is described. One of the detector measures the total radiation, the other filters out all except the hardest photons by looking only at their Compton electrons, whose average energy is determined with a magnetic field. (author). 4 figs., 2 refs.

  7. Advances in Opto Electronics

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Advances in Opto Electronics. Optoelectronics is where electronics was 15 years back. All Optical Amplifiers and Semiconductor Amplifiers. Fastest Semiconductor (InP) switch is at 170GHz- where is terrabit ? MEMS based switches that route traffic at wavelength level ...

  8. Electron beam welding

    International Nuclear Information System (INIS)

    Gabbay, M.

    1972-01-01

    The bead characteristics and the possible mechanisms of the electron beam penetration are presented. The different welding techniques are exposed and the main parts of an electron beam welding equipment are described. Some applications to nuclear, spatial and other industries are cited [fr

  9. Electron beam simulation applicators

    International Nuclear Information System (INIS)

    Purdy, J.A.

    1983-01-01

    A system for simulating electron beam treatment portals using low-temperature melting point alloy is described. Special frames having the same physical dimensions as the electron beam applicators used on the Varian Clinac 20 linear accelerator were designed and constructed

  10. Radiative electron capture

    International Nuclear Information System (INIS)

    Biggerstaff, J.A.; Appleton, B.R.; Datz, S.; Moak, C.D.; Neelavathi, V.N.; Noggle, T.S.; Ritchie, R.H.; VerBeek, H.

    1975-01-01

    Some data are presented for radiative electron capture by fast moving ions. The radiative electron capture spectrum is shown for O 8+ in Ag, along with the energy dependence of the capture cross-section. A discrepancy between earlier data, theoretical prediction, and the present data is pointed out. (3 figs) (U.S.)

  11. Electronics and Lithuanian Terminology

    Directory of Open Access Journals (Sweden)

    Stasys Zajankauskas

    2011-04-01

    Full Text Available It is found that the vacuum triode, transistor, monolithic circuit and microprocessor were the most important inventions of traditional electronics. Thus, the origins of the traditional electronics should be associated with the invention of the vacuum triode, but not with the invention of vacuum diode. It is shown that the science of electronics is not as young as computer science or up-to-date information technologies: electronics, including active electronics, had already celebrated the centenary, and the period of 2004–2008 is the period of numerous already solid jubilees. Thus, the terminology of electronics is not at initial stage of evolution as well – general terms should be already systematized and normalized. However, Lithuanian terms for electronic devices invented before tens of years and terms for old-defined notions associated with these devices are still varying, some are worsened. Especially, the incorrectly motivated terms used for variations of transistors and microcircuits are analyzed in the article. It is motivated which terms are preferable, systematic and exact. The paper is dedicated to the 50th anniversary of monolithic circuit, as well as the 60th anniversary of transistor, the 40th jubilee of microprocessor and centenary of electronics.

  12. Electron tunneling in chemistry

    International Nuclear Information System (INIS)

    Zamaraev, K.I.; Khajrutdinov, R.F.; Zhdanov, V.P.; Molin, Yu.N.

    1985-01-01

    Results of experimental and theoretical investigations are outlined systematically on electron tunnelling in chemical reactions. Mechanism of electron transport to great distances is shown to be characteristic to chemical compounds of a wide range. The function of tunnel reactions is discussed for various fields of chemistry, including radiation chemistry, electrochemistry, chemistry of solids, chemistry of surface and catalysis

  13. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  14. ELECTRON COOLING FOR RHIC

    International Nuclear Information System (INIS)

    BEN-ZVI, I.; AHRENS, L.; BRENNAN, M.; HARRISON, M.; KEWISCH, J.; MACKAY, W.; PEGGS, S.; ROSER, T.; SATOGATA, T.; TRBOJEVIC, D.; YAKIMENKO, V.

    2001-01-01

    We introduce plans for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This project has a number of new features as electron coolers go: It will cool 100 GeV/nucleon ions with 50 MeV electrons; it will be the first attempt to cool a collider at storage-energy; and it will be the first cooler to use a bunched beam and a linear accelerator as the electron source. The linac will be superconducting with energy recovery. The electron source will be based on a photocathode gun. The project is carried out by the Collider-Accelerator Department at BNL in collaboration with the Budker Institute of Nuclear Physics

  15. Electron - proton colliders

    International Nuclear Information System (INIS)

    Wiik, B.H.

    1985-01-01

    Electron-proton storage rings allow us to study the interaction between the two basic constituents of matter, electrons and quarks at very short distances. Such machines were first discussed in connection with the ISR but the idea was abandoned because of the anticipated low counting rate. The interest in electron-proton storage rings was rekindeled by the discovery of large pointlike cross sections in lepton-hardon interactions and several/sup 2-15/ projects have been discussed during the past decade. However, despite a glorious past, which includes the discovery of quarks and neutral currents, and a multitude of proposals no electron-proton storage ring has ever been built. What we might learn by studying electron-proton collisions at high energies is discussed. After some brief comments on present proposals the proposed DESY ep project HERA is described as an example of how to realize such a machine

  16. Electron: Cluster interactions

    International Nuclear Information System (INIS)

    Scheidemann, A.A.; Knight, W.D.

    1994-02-01

    Beam depletion spectroscopy has been used to measure absolute total inelastic electron-sodium cluster collision cross sections in the energy range from E ∼ 0.1 to E ∼ 6 eV. The investigation focused on the closed shell clusters Na 8 , Na 20 , Na 40 . The measured cross sections show an increase for the lowest collision energies where electron attachment is the primary scattering channel. The electron attachment cross section can be understood in terms of Langevin scattering, connecting this measurement with the polarizability of the cluster. For energies above the dissociation energy the measured electron-cluster cross section is energy independent, thus defining an electron-cluster interaction range. This interaction range increases with the cluster size

  17. Practical electronics for inventors

    CERN Document Server

    Scherz, Paul

    2013-01-01

    Spark your creativity and gain the electronics skills required to transform your innovative ideas into functioning gadgets. This hands-on, updated guide outlines electrical principles and provides thorough, easy-to-follow instructions, schematics, and illustrations. Findout how to select components, safely assemble circuits, perform error tests, and build plug-and-play prototypes. Practical Electronics for Inventors, Third Edition, features all-new chapters on sensors, microcontrollers, modular electronics, and the latest software tools. Coverage includes: Resistors, capacitors, inductors, and transformers Diodes, transistors, and integrated circuits Optoelectronics, solar cells, and phototransistors Sensors, GPS modules, and touch screens Op amps, regulators, and power supplies Digital electronics, LCD displays, and logic gates Microcontrollers and prototyping platforms, including Arduino DC motors, RC servos, and stepper motors Microphones, audio amps, and speakers Modular electronics and prototyping.

  18. Characterization of lactic acid bacteria from musts and wines of three consecutive vintages of Ribeira Sacra.

    Science.gov (United States)

    Mesas, J M; Rodríguez, M C; Alegre, M T

    2011-03-01

    This study was designed to isolate and characterize the lactic acid microbiota of the musts and wines of a young denomination of origin area, Ribeira Sacra in north-west Spain. Over three consecutive years (2007, 2008 and 2009), we examined musts and wines from four cellars in different zones of the region. Through biochemical and genetic tests, 459 isolates of lactic acid bacteria (LAB) were identified as the following species: Lactobacillus alvei (0·7%), Lactobacillus brevis (1·7%), Lactobacillus frumenti (0·9%), Lactobacillus kunkeei (12%), Lactobacillus plantarum (6·5%), Lactobacillus pentosus (0·9%), Lactococcus lactis ssp. lactis (3%), Leuconostoc citreum (0·7%), Leuconostoc fructosum (synon. Lactobacillus fructosum) (3·7%), Leuconostoc mesenteroides ssp. mesenteroides (2·8%), Leuconostoc pseudomesenteroides (0·2%), Oenococcus oeni (59%), Pediococcus parvulus (7%) and Weisella paramesenteroides (synon. Leuconostoc paramesenteroides) (0·9%). Of these species, O. oeni was the main one responsible for malolactic fermentation (MLF) in all cellars and years with the exception of Lact. plantarum, predominant in 2007, in one cellar, and Lact. brevis, Lact. frumenti and Ped. parvulus coexisting with O. oeni in one cellar in 2009. Different strains (84) of LAB species (14) were identified by biochemical techniques (API strips, the presence of plasmids, enzyme activities and MLF performance) and molecular techniques (PCR). All assays were carried out with every one of the 459 isolates. To select candidates for use as culture starters, we assessed malolactic, β-glucosidase and tannase activities, the presence of genes involved in biogenic amine production and plasmid content. A high diversity of LAB is present in the grape musts of Ribeira Sacra but few species are responsible for MLF; however, different strains of such species are involved in the process. As far as we are aware, this is the first report of Lact. frumenti thriving in wine. Information on LAB

  19. Lactic acid bacteria in dried vegetables and spices.

    Science.gov (United States)

    Säde, Elina; Lassila, Elisa; Björkroth, Johanna

    2016-02-01

    Spices and dried vegetable seasonings are potential sources of bacterial contamination for foods. However, little is known about lactic acid bacteria (LAB) in spices and dried vegetables, even though certain LAB may cause food spoilage. In this study, we enumerated LAB in 104 spices and dried vegetables products aimed for the food manufacturing industry. The products were obtained from a spice wholesaler operating in Finland, and were sampled during a one-year period. We picked isolates (n = 343) for species identification based on numerical analysis of their ribotyping patterns and comparing them with the corresponding patterns of LAB type strains. We found LAB at levels >2 log CFU/g in 68 (65%) of the samples, with the highest counts detected from dried onion products and garlic powder with counts ranging from 4.24 to 6.64 log CFU/g. The LAB identified were predominantly Weissella spp. (61%) and Pediococcus spp. (15%) with Weissella confusa, Weissella cibaria, Weissella paramesenteroides, Pediococcus acidilactici and Pediococcus pentosaceus being the species identified. Other species identified belonged to the genera of Enterococcus spp. (8%), Leuconostoc spp. (6%) and Lactobacillus spp. (2%). Among the LAB identified, Leuconostoc citreum, Leuconostoc mesenteroides and W. confusa have been associated with food spoilage. Our findings suggest that spices and dried vegetables are potential sources of LAB contamination in the food industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Electronically cloaked nanoparticles

    Science.gov (United States)

    Shen, Wenqing

    The concept of electronic cloaking is to design objects invisible to conduction electrons. The approach of electronic cloaking has been recently suggested to design invisible nanoparticle dopants with electronic scattering cross section smaller than 1% of the physical cross section (pi a2), and therefore to enhance the carrier mobility of bulk materials. The proposed nanoparticles have core-shell structures. The dopants are incorporated inside the core, while the shell layer serves both as a spacer to separate the charge carriers from their parent atoms and as a cloaking shell to minimize the scattering cross section of the electrons from the ionized nanoparticles. Thermoelectric materials are usually highly doped to have enough carrier density. Using invisible dopants could achieve larger thermoelectric power factors by enhancing the electronic mobility. Core-shell nanoparticles show an advantage over one-layer nanoparticles, which are proposed in three-dimensional modulation doping. However designing such nanoparticles is not easy as there are too many parameters to be considered. This thesis first shows an approach to design hollow nanoparticles by applying constrains on variables. In the second part, a simple mapping approach is introduced where one can identify possible core-shell particles by comparing the dimensionless parameters of chosen materials with provided maps. In both parts of this work, several designs with realistic materials were made and proven to achieve electronic cloaking. Improvement in the thermoelectric power factor compared to the traditional impurity doping method was demonstrated in several cases.

  1. Electron Cooling of RHIC

    CERN Document Server

    Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

    2005-01-01

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

  2. Coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.

    2009-05-04

    Cooling intense high-energy hadron beams remains a major challenge in modern accelerator physics. Synchrotron radiation is still too feeble, while the efficiency of two other cooling methods, stochastic and electron, falls rapidly either at high bunch intensities (i.e. stochastic of protons) or at high energies (e-cooling). In this talk a specific scheme of a unique cooling technique, Coherent Electron Cooling, will be discussed. The idea of coherent electron cooling using electron beam instabilities was suggested by Derbenev in the early 1980s, but the scheme presented in this talk, with cooling times under an hour for 7 TeV protons in the LHC, would be possible only with present-day accelerator technology. This talk will discuss the principles and the main limitations of the Coherent Electron Cooling process. The talk will describe the main system components, based on a high-gain free electron laser driven by an energy recovery linac, and will present some numerical examples for ions and protons in RHIC and the LHC and for electron-hadron options for these colliders. BNL plans a demonstration of the idea in the near future.

  3. Dose calculation for electrons

    International Nuclear Information System (INIS)

    Hirayama, Hideo

    1995-01-01

    The joint working group of ICRP/ICRU is advancing the works of reviewing the ICRP publication 51 by investigating the data related to radiation protection. In order to introduce the 1990 recommendation, it has been demanded to carry out calculation for neutrons, photons and electrons. As for electrons, EURADOS WG4 (Numerical Dosimetry) rearranged the data to be calculated at the meeting held in PTB Braunschweig in June, 1992, and the question and request were presented by Dr. J.L. Chartier, the responsible person, to the researchers who are likely to undertake electron transport Monte Carlo calculation. The author also has carried out the requested calculation as it was the good chance to do the mutual comparison among various computation codes regarding electron transport calculation. The content that the WG requested to calculate was the absorbed dose at depth d mm when parallel electron beam enters at angle α into flat plate phantoms of PMMA, water and ICRU4-element tissue, which were placed in vacuum. The calculation was carried out by the versatile electron-photon shower computation Monte Carlo code, EGS4. As the results, depth dose curves and the dependence of absorbed dose on electron energy, incident angle and material are reported. The subjects to be investigated are pointed out. (K.I.)

  4. Polarized electron sources

    International Nuclear Information System (INIS)

    Prepost, R.

    1994-01-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented

  5. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  6. Electron collisions with biomolecules

    International Nuclear Information System (INIS)

    McKoy, V; Winstead, C

    2008-01-01

    We report on results of recent studies of collisions of low-energy electrons with nucleobases and other DNA constituents. A particular focus of these studies has been the identification and characterization of resonances that play a role in electron attachment leading to strand breaks in DNA. Comparison of the calculated resonance positions with results of electron transmission measurements is quite encouraging. However, the higher-lying π* resonances of the nucleobases appear to be of mixed elastic and core-excited character. Such resonant channel coupling raises the interesting possibility that the higher π*resonances in the nucleobases may promote dissociation of DNA by providing doorway states to triplet excited states.

  7. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  8. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  9. Power Electronics for Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Blaabjerg, Frede

    2016-01-01

    A microgrid (MG) is a stand-alone or grid-connected hybrid renewable system that uses distributed renewable and nonrenewable energy sources and energy storage systems (ESSs) to supply power to local loads. The system is ordinarily based on power electronics, with interface converters allowing...... a continuous supply of power in the presence of variable RES production. This chapter describes some specific features of DC MGs in terms of power architecture, control, and protection. It also reviews several uncommon power electronic interfaces. Regarding control, operation without critical communication...... are explained in this chapter. The chapter concludes with a review of power electronic intensive protection solutions for DC MGs....

  10. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  11. BEPCII electronic logbook system

    International Nuclear Information System (INIS)

    Liu Shu; Zhao Jijiu; Wang Chunhong

    2007-01-01

    According to demands of BEPCII construction and future operation, we are going to supply an open electronic logbook platform for people to record their message in developing and running BEPCII, and browse the log-book on website. That gives people an open and transparent logbook, rather than traditional paper notebook. With the template of DESY's Elogbook, the BEPCII electronic logbook was developed, using the popular JSP technology to develop dynamic Web applications. This paper will introduce the development of BEPCII electronic logbook system. (authors)

  12. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  13. A simple electron multiplexer

    International Nuclear Information System (INIS)

    Dobrzynski, L; Akjouj, A; Djafari-Rouhani, B; Al-Wahsh, H; Zielinski, P

    2003-01-01

    We present a simple multiplexing device made of two atomic chains coupled by two other transition metal atoms. We show that this simple atomic device can transfer electrons at a given energy from one wire to the other, leaving all other electron states unaffected. Closed-form relations between the transmission coefficients and the inter-atomic distances are given to optimize the desired directional electron ejection. Such devices can be adsorbed on insulating substrates and characterized by current surface technologies. (letter to the editor)

  14. Electron paramagnetic resonance

    CERN Document Server

    Al'tshuler, S A

    2013-01-01

    Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

  15. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  16. Auger electron spectroscopy

    International Nuclear Information System (INIS)

    Gopalaraman, C.P.

    1975-01-01

    General features of electron excited Auger electron spectroscopy (AES) which is a nondestructive technique for the analysis of surfaces upto about 15 Adeg depth with a detection limit of about 0.1% of a monolayer. Methods of measuring the Auger electron energies and recent improvements in the instrumentation are reviewed. Typical energy resolution is found to be about 0.5% which is specially suited for the detection of light elements. It is widely used in metallurgy, surface chemistry and thin film studies. (K.B.)

  17. Modern dictionary of electronics

    CERN Document Server

    Graf, Rudolf F

    1999-01-01

    Included in this fully revised classic are well over 28,000 terms, phrases, acronyms, and abbreviations from the ever-expanding worlds of consumer electronics, optics, microelectronics, computers, communications, and medical electronics. From the basic elements of theory to the most cutting-edge circuit technology, this book explains it all in both words and pictures.For easy reference, the author has provided definitions for standard abbreviations and equations as well as tables of SI (International System of Units) units, measurements, and schematic symbolsModern Dictionary of Electronics is

  18. VLSI electronics microstructure science

    CERN Document Server

    1982-01-01

    VLSI Electronics: Microstructure Science, Volume 4 reviews trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the silicon-on-insulator for VLSI and VHSIC, X-ray lithography, and transient response of electron transport in GaAs using the Monte Carlo method. The technology and manufacturing of high-density magnetic-bubble memories, metallic superlattices, challenge of education for VLSI, and impact of VLSI on medical signal processing are also elaborated. This text likewise covers the impact of VLSI t

  19. Single Electron Tunneling

    International Nuclear Information System (INIS)

    Ruggiero, Steven T.

    2005-01-01

    Financial support for this project has led to advances in the science of single-electron phenomena. Our group reported the first observation of the so-called ''Coulomb Staircase'', which was produced by tunneling into ultra-small metal particles. This work showed well-defined tunneling voltage steps of width e/C and height e/RC, demonstrating tunneling quantized on the single-electron level. This work was published in a now well-cited Physical Review Letter. Single-electron physics is now a major sub-field of condensed-matter physics, and fundamental work in the area continues to be conducted by tunneling in ultra-small metal particles. In addition, there are now single-electron transistors that add a controlling gate to modulate the charge on ultra-small photolithographically defined capacitive elements. Single-electron transistors are now at the heart of at least one experimental quantum-computer element, and single-electron transistor pumps may soon be used to define fundamental quantities such as the farad (capacitance) and the ampere (current). Novel computer technology based on single-electron quantum dots is also being developed. In related work, our group played the leading role in the explanation of experimental results observed during the initial phases of tunneling experiments with the high-temperature superconductors. When so-called ''multiple-gap'' tunneling was reported, the phenomenon was correctly identified by our group as single-electron tunneling in small grains in the material. The main focus throughout this project has been to explore single electron phenomena both in traditional tunneling formats of the type metal/insulator/particles/insulator/metal and using scanning tunneling microscopy to probe few-particle systems. This has been done under varying conditions of temperature, applied magnetic field, and with different materials systems. These have included metals, semi-metals, and superconductors. Amongst a number of results, we have

  20. Consulting in Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Florentina Loredana Tache

    2010-10-01

    Full Text Available Economic development of electronic services provide advice and many agents of existingreferral systems to recommend and provide products, information and customized views of thecommunity through a personalized interaction in real time. Distributed systems of autonomous agentsare becoming increasingly important in electronic comet because the basic decisions of agents adviceon trust and reputation are taken in a similar way human society. If these decisions will be as a realconsumer protection, when new aspects of online consumer legislation will become usefulinformation in advice and consulting of electronic commerce.

  1. Coding for Electronic Mail

    Science.gov (United States)

    Rice, R. F.; Lee, J. J.

    1986-01-01

    Scheme for coding facsimile messages promises to reduce data transmission requirements to one-tenth current level. Coding scheme paves way for true electronic mail in which handwritten, typed, or printed messages or diagrams sent virtually instantaneously - between buildings or between continents. Scheme, called Universal System for Efficient Electronic Mail (USEEM), uses unsupervised character recognition and adaptive noiseless coding of text. Image quality of resulting delivered messages improved over messages transmitted by conventional coding. Coding scheme compatible with direct-entry electronic mail as well as facsimile reproduction. Text transmitted in this scheme automatically translated to word-processor form.

  2. The art of electronics

    CERN Document Server

    Horowitz, Paul

    2015-01-01

    At long last, here is the thoroughly revised and updated third edition of the hugely successful Art of Electronics. It is widely accepted as the best single authoritative book on electronic circuit design. In addition to new or enhanced coverage of many topics, the Third Edition includes: 90 oscilloscope screenshots illustrating the behavior of working circuits; dozens of graphs giving highly useful measured data of the sort that's often buried or omitted in datasheets but which you need when designing circuits; 80 tables (listing some 1650 active components), enabling intelligent choice of circuit components by listing essential characteristics (both specified and measured) of available parts. The new Art of Electronics ​​retains the feeling of informality and easy access that helped make the earlier editions so successful and popular. It is an indispensable reference and the gold standard​​ for anyone, student or researcher, professional or amateur, who works with electronic circuits.

  3. Electron and Photon ID

    CERN Document Server

    Hryn'ova, Tetiana; The ATLAS collaboration

    2017-01-01

    The identification of prompt photons and the rejection of background coming mostly from photons from hadron decays relies on the high granularity of the ATLAS calorimeter. The electron identification used in ATLAS for run 2 is based on a likelihood discrimination to separate isolated electron candidates from candidates originating from photon conversions, hadron misidentification and heavy flavor decays. In addition, isolation variables are used as further handles to separate signal and background. Several methods are used to measure with data the efficiency of the photon identification requirements, to cover a broad energy spectrum. At low energy, photons from radiative Z decays are used. In the medium energy range, similarities between electrons and photon showers are exploited using Z->ee decays. At high energy, inclusive photon samples are used. The measurement of the efficiencies of the electron identification and isolation cuts are performed with the data using tag and probe techniques with large statis...

  4. Channel electron multipliers

    International Nuclear Information System (INIS)

    Seidman, A.; Avrahami, Z.; Sheinfux, B.; Grinberg, J.

    1976-01-01

    A channel electron multiplier is described having a tubular wall coated with a secondary-electron emitting material and including an electric field for accelerating the electrons, the electric field comprising a plurality of low-resistive conductive rings each alternating with a high-resistive insulating ring. The thickness of the low-resistive rings is many times larger than that of the high-resistive rings, being in the order of tens of microns for the low-resistive rings and at least one order of magnitude lower for the high-resistive rings; and the diameter of the channel tubular walls is also many times larger than the thickness of the high-resistive rings. Both single-channel and multiple-channel electron multipliers are described. A very important advantage, particularly in making multiple-channel multipliers, is the simplicity of the procedure that may be used in constructing such multipliers. Other operational advantages are described

  5. Typewriting by Electronics

    Science.gov (United States)

    Etier, Faborn

    1971-01-01

    By using the electronic typewriting teaching aid, it is believed by those closely associated with its use in teaching typing that as much can be accomplished in one semester as in two semesters using the conventional method of teaching. (Editor)

  6. Electron identification at CDF

    International Nuclear Information System (INIS)

    Kim, Shinhong

    1990-01-01

    Electron identification at CDF is performed using the information of lateral and longitudinal shower spread, the track-cluster position match and the energy-momentum match. The tracking chamber with a solenoidal magnetic field at CDF is powerful for rejecting the backgrounds such as the π ± - π 0 overlaps, the π 0 /γ conversions and interactive π ± in electromagnetic calorimeter: The energy- momentum match cut can decrease the background due to the π ± - π 0 overlaps for non-isolated electrons with Et above 10 GeV by a factor of 20. The conversion electrons are identified using track information with an efficiency of 80 ± 3%. The charge of electrons from W decay can be determined in the pseudorapidity range of |η| < 1.7 at CDF. The charge determination is useful for background estimation of Drell-Yan physics and heavy flavor physics. 5 refs., 5 figs

  7. The electron accelerator Ridgetron

    International Nuclear Information System (INIS)

    Hayashizaki, N.; Hattori, T.; Odera, M.; Fujisawa, T.

    1999-01-01

    Many electron accelerators of DC or RF type have been widely used for electron beam irradiation (curing, crosslinking of polymers, sterilization of medical disposables, preservation of food, etc.). Regardless of the acceleration energy, the accelerators to be installed in industrial facilities, have to satisfy the requires of compact size, low power consumption and stable operation. The DC accelerator is realized very compact in the energy under 300 keV, however, it is large to prevent the discharge of an acceleration column in the energy over 300 keV. The RF electron accelerator Ridgetron has been developed to accelerate the continuous beam of the 0.5-10 MeV range in compact space. It is the first example as an electron accelerator incorporated a ridged RF cavity. A prototype system of final energy of 2.5 MeV has been studied to confirm the feasibility at present

  8. Advanced Electron Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Siemann, R.

    2005-02-14

    The research into advanced acceleration concepts for electron linear accelerators being pursued at SLAC is reviewed. This research includes experiments in laser acceleration, plasma wakefield acceleration, and mmwavelength RF driven accelerators.

  9. Electronic Universal Vote

    Directory of Open Access Journals (Sweden)

    Cristian USCATU

    2008-01-01

    Full Text Available In the days of informational society everything is going online. Most aspects of our lives have online components. Since democracy is a big issue, it could not escape this trend. Governments themselves are moving to the online environment for the purpose of improving their internal efficiency and their availability to the citizens, businesses and other parties interested. Since governments are the result of elections, elections have also been touched by the electronic fever. New electronic voting solutions arise and each one brings new debates with many arguments in their favor and against them. Accessibility and ease of use leads the arguments in favor of electronic voting over the internet, while fear of fraud is the main reason people are avoiding electronics and clinging on classic paper ballots.

  10. ORELA electron guns

    International Nuclear Information System (INIS)

    Christian, O.W.; Lewis, T.A.

    1981-09-01

    The most recent information concerning the production and performance of ORELA electron guns is presented. Included are descriptions of procedures for gun fabrication, cathode conditioning and high voltage processing. Highlights of the performance characteristics are also included

  11. Corrosion in Electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan; Gudla, Helene Virginie Conseil; Verdingovas, Vadimas

    2017-01-01

    Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together...... and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due...... to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion...

  12. Paper based electronics platform

    KAUST Repository

    Nassar, Joanna Mohammad; Sevilla, Galo Andres Torres; Hussain, Muhammad Mustafa

    2017-01-01

    A flexible and non-functionalized low cost paper-based electronic system platform fabricated from common paper, such as paper based sensors, and methods of producing paper based sensors, and methods of sensing using the paper based sensors

  13. Electronic personal dosemeters

    International Nuclear Information System (INIS)

    Marshall, T.O.; Bartlett, D.T.; Burgess, P.H.; Cranston, C.S.; Higginbottom, D.J.; Sutton, K.W.

    1990-01-01

    Personal dosimetry services approved by their national authorities for category A workers, invariably use passive dosemeters incorporating photographic film or thermoluminescent detectors. However, the performance characteristics of electronic dosemeters has improved substantially over the past decade to such an extent that in the opening lecture of the Solid State Dosimetry Conference at Oxford in 1986 the development of an electronic 'smart card' based on a silicon detector was briefly discussed. This idea has been taken up and at least one development programme is in progress aimed at the production of an electronic dosemeter suitable for use as a legal device. The more important performance requirements of personal dosemeters for this purpose are discussed and the earlier electronic dosemeter designs and the latest devices under development to meet this specification are compared. (author)

  14. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  15. Issues in Electronic Publishing.

    Science.gov (United States)

    Meadow, Charles T.

    1997-01-01

    Discusses issues related to electronic publishing. Topics include writing; reading; production, distribution, and commerce; copyright and ownership of intellectual property; archival storage; technical obsolescence; control of content; equality of access; and cultural changes. (Author/LRW)

  16. Modular Lego-Electronics

    KAUST Repository

    Shaikh, Sohail F.; Ghoneim, Mohamed T.; Bahabry, Rabab R.; Khan, Sherjeel M.; Hussain, Muhammad Mustafa

    2017-01-01

    . Here, a generic manufacturable method of converting state-of-the-art complementary metal oxide semiconductor-based ICs into modular Lego-electronics is shown with unique geometry that is physically identifiable to ease manufacturing and enhance

  17. Electron linac injector developments

    International Nuclear Information System (INIS)

    Fraser, J.S.

    1986-01-01

    There is a continuing demand for improved injectors for electron linacs. Free-electron laser (FEL) oscillators require pulse trains of high brightness and, in some applications, high average power at the same time. Wakefield-accelerator and laser-acceleration experiments require isolated bunches of high peak brightness. Experiments with alkali-halide photoemissive and thermionic electron sources in rf cavities for injector applications are described. For isolated pulses, metal photocathodes (illuminated by intense laser pulses) are being employed. Reduced emittance growth in high-peak-current electron injectors may be achieved by linearizing the cavity electric field's radial component and by using high field strengths at the expense of lower shunt impedance. Harmonically excited cavities have been proposed for enlarging the phase acceptance of linac cavities and thereby reducing the energy spread produced in the acceleration process. Operation of injector linacs at a subharmonic of the main linac frequency is also proposed for enlarging the phase acceptance

  18. Electronics for guitarists

    CERN Document Server

    Dailey, Denton J

    2014-01-01

    Electronics for Guitarists focuses on analog circuitry, and is written for the guitarist interested in transistor and vacuum tube-based amplifiers. Topics include discrete transistors and diodes, classical filter circuits, and vacuum tube-based amplifiers.

  19. Nemo-3 calorimeter electronics

    International Nuclear Information System (INIS)

    Bernaudin, P.; Cheikali, C.; Lavigne, B.; Richard, A.; Lebris, J.

    2000-11-01

    The calorimeter electronics of the NEMO-3 double beta decay experiment fulfills three functions: -energy measurement of the electrons by measuring the charge of the pulses, - time measurement, - fast first level triggering. The electronics of the 1940 Scintillator-PM modules is implemented as 40 '9U x 400 mm VME' boards of up to 51 channels. For each channel the analog signals conditioning is implemented as one SMD daughter board. Each board performs 12 bit charge measurements with 0.35 pC charge resolution, 12 bit time measurements with 50 ps time resolution and a fast analog multiplicity level for triggering. The total handling and conversion time for all the channels is less than 100 μs. The electronics will be presented as well as the test system. (authors)

  20. Novel electron gas systems

    International Nuclear Information System (INIS)

    Senatore, G.; Rapisarda, F.; Conti, S.

    1998-01-01

    We review recent progress on the physics of electrons in the bilayered electron gas, relevant to coupled quantum wells in GaAs/AIGaAs heterostructures. First we focus on the phase diagram of a symmetric bilayer at T = B = 0, obtained by diffusion Monte Carlo (DMC) simulations. It is found that inter-layer correlations stabilize crystalline structures at intermediate inter-layer separation, while favoring a liquid phase at smaller distance. Also, the available DMC evidence is in contrast with the recently (Hartree-Fock) predicted total charge transfer (TCT), whereby all the electron spontaneously jump in one layer. In fact, one can show that such a TCT state is never stable in the ideal bilayer with no tunneling. We finally comment on ongoing DMC investigations on the electron-hole bilayer, where excitonic condensation is expected to take place. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)

  1. Improved electron transport layer

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution......; a method of preparing a zinc oxide electron transporting layer, which method comprises: i) coating a substrate with the coating ink of the present invention to form a film; ii) drying the film; and iii) heating the dry film to convert the zinc acetate substantially to ZnO; a method of preparing an organic...... photovoltaic device or an organic LED having a zinc oxide electron transport layer, the method comprising, in this order: a) providing a substrate bearing a first electrode layer; b) forming an electron transport layer according to the following method: i) coating a coating ink comprising an ink according...

  2. Magnetic electron scattering

    International Nuclear Information System (INIS)

    Peterson, G.A.

    1989-01-01

    We briefly review some of the motivations, early results, and techniques of magnetic elastic and inelastic electron-nucleus scattering. We then discuss recent results, especially those acquired at high momentum transfers. 50 refs., 19 figs

  3. Advances in electron dosimetry

    International Nuclear Information System (INIS)

    Harder, D.

    1980-04-01

    Starting from the two most important interactions of electrons with matter, energy loss and scattering, a review is given of a number of effects which are important in electron dosimetry. For determining the absorbed dose in a phantom by means of ionization chambers, imformation is required on the electron spectrum at the location of the measurement, on the stopping powers of different materials and on disturbances such as the displacement of the effective point of measurements from the centre of the chamber. By means of figures and photographs of electron traces in bubble chambers, the origin of the formation of the absorbed dose maximum in a phantom is explained. It is shown, how by multiple scattering, the similarity of dose distributions in different media can be explained and how by Monte-Carlo calculations absorbed dose distributions in the surroundings of inhomogeneities (e.g. cavities) in a phantom can be determined. (orig.) [de

  4. Electron gun for SSRF

    International Nuclear Information System (INIS)

    Sheng Shugang; Lin Guoqiang; Gu Qiang; Li Deming

    2003-01-01

    A 100 kV triode-electron-gun has been designed and manufactured for the Linac of Shanghai Synchrotron Radiation Facility (SSRF). In this paper the performance of the gun and some key components are described

  5. PREFACE: Spin Electronics

    Science.gov (United States)

    Dieny, B.; Sousa, R.; Prejbeanu, L.

    2007-04-01

    Conventional electronics has in the past ignored the spin on the electron, however things began to change in 1988 with the discovery of giant magnetoresistance in metallic thin film stacks which led to the development of a new research area, so called spin-electronics. In the last 10 years, spin-electronics has achieved a number of breakthroughs from the point of view of both basic science and application. Materials research has led to several major discoveries: very large tunnel magnetoresistance effects in tunnel junctions with crystalline barriers due to a new spin-filtering mechanism associated with the spin-dependent symmetry of the electron wave functions new magnetic tunnelling barriers leading to spin-dependent tunnelling barrier heights and acting as spin-filters magnetic semiconductors with increasingly high ordering temperature. New phenomena have been predicted and observed: the possibility of acting on the magnetization of a magnetic nanostructure with a spin-polarized current. This effect, due to a transfer of angular momentum between the spin polarized conduction electrons and the local magnetization, can be viewed as the reciprocal of giant or tunnel magnetoresistance. It can be used to switch the magnetization of a magnetic nanostructure or to generate steady magnetic excitations in the system. the possibility of generating and manipulating spin current without charge current by creating non-equilibrium local accumulation of spin up or spin down electrons. The range of applications of spin electronics materials and phenomena is expanding: the first devices based on giant magnetoresistance were the magnetoresistive read-heads for computer disk drives. These heads, introduced in 1998 with current-in plane spin-valves, have evolved towards low resistance tunnel magnetoresistice heads in 2005. Besides magnetic recording technology, these very sensitive magnetoresistive sensors are finding applications in other areas, in particular in biology. magnetic

  6. ELECTRONIC BANKING AND ELECTRONIC COMMERCE IN SERBIA

    Directory of Open Access Journals (Sweden)

    Ivana B. Petrevska

    2014-10-01

    Full Text Available Nowadays, we may witness to dramatic and visible changes in our life environment. Business ambient for companies is different every day, and it is very hard to predict a direction of future changes. There is an environment characterized by sharp competition and increasing number of competitors, fast technological improvements and highly sophisticated and informed costumers. Technological process influences the humanity strongly, changing the way that people live, work and spend. Electronic commerce and electronic banking has become incontinent, and makes a great part of today's total transactions. There are an increasing number of companies that perform their business that way and make profit. Social networks are proven to be the least expensive way of information exchange, and they are present in almost every part of the world. The globalization has reached the most distant parts of the Earth. Every resistance to new technologies is dangerous and may lead to bankruptcy. Due to the EU expansion, Internet users are to be expected, and prosperity of the e-commerce business models at the same time. In Serbia, electronic commerce is present, but not as developed as in EU countries. E-commerce, however it might be successful throughout the world, it is somewhat slow in its growth in Serbia. The reasons are numerous, and main obstacles are the lack of trust, still limited usage of banking cards, avoiding of e-payments by older population etc. Also, the recent scandals over the misuse of personal data, and e-crime are discouraging factors for the growth of e-trade and ebanking. The younger generations are ever more ready to use e-commerce, since they are open to new technologies and do not have the defensive attitude towards it. E-commerce and e-banking has growing potential even among older population, if the society prevents them from fear and mistrust.

  7. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W

    2013-01-01

    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  8. Low emittance thermionic electron guns

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1989-01-01

    The author discusses self-field effects and external field effects for electron guns. He also discusses designs of electron guns and their uses in electron cooling systems and as an injector for electrostatic free electron lasers. He closes by looking at electron guns for linear accelerators. 20 references, 3 figures

  9. A new stage of nuclear electronics-particle electronics

    International Nuclear Information System (INIS)

    Xi Deming

    1987-01-01

    The rapid development of high energy physics experiments has pushed the nuclear electronics to a new stage, i.e. the particle electronics. In this paper the background, main features and recent trends of the particle electronics are expounded

  10. Electron attachment cross sections obtained from electron attachment spectroscopy

    International Nuclear Information System (INIS)

    Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.

    1988-01-01

    Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)

  11. Auroal electron distribution function

    International Nuclear Information System (INIS)

    Kaufmann, R.L.; Dusenbery, P.B.; Thomas, B.J.; Arnoldy, R.L.

    1978-01-01

    The electron velocity distribution function is presented in the energy range 25 eV 8 cm/s (E=300 eV) are nearly isotropic in pitch angle throughout the flight. Upgoing electrons show almost no pitch angle dependence beyond 120 0 , and their fluxes decline smoothly as energy increases, with little or no evidence of a plateau. Preliminary results of numerical integrations, to study bulk properties and stability of the plasma are presented

  12. Mathematics for electronic technology

    CERN Document Server

    Howson, D P

    1975-01-01

    Mathematics for Electronic Technology is a nine-chapter book that begins with the elucidation of the introductory concepts related to use of mathematics in electronic engineering, including differentiation, integration, partial differentiation, infinite series, vectors, vector algebra, and surface, volume and line integrals. Subsequent chapters explore the determinants, differential equations, matrix analysis, complex variable, topography, graph theory, and numerical analysis used in this field. The use of Fourier method for harmonic analysis and the Laplace transform is also described. The ma

  13. Electricity electron measurement

    International Nuclear Information System (INIS)

    Kim, Sang Jin; Sung, Rak Jin

    1985-11-01

    This book deals with measurement of electricity and electron. It is divided into fourteen chapters, which depicts basic of electricity measurement, unit and standard, important electron circuit for measurement, instrument of electricity, impedance measurement, power and power amount measurement, frequency and time measurement, waveform measurement, record instrument and direct viewing instrument, super high frequency measurement, digital measurement on analog-digital convert, magnetic measurement on classification by principle of measurement, measurement of electricity application with principle sensors and systematization of measurement.

  14. Electron affinities: theoretical

    International Nuclear Information System (INIS)

    Kaufman, J.J.

    1976-01-01

    A brief description is given of the conceptual background and formalism of the various ab-initio and semi-ab-initio quantum computational techniques for calculating atomic and molecular electron affinities: Hartree--Fock--Roothaan SCF, configuration interaction (CI), multiconfiguration SCF (MC-SCF), Bethe--Goldstone, superposition of configurations (SOC), ab-initio effective core model potentials, Xα-MS, plus other less common methods. Illustrative and comparative examples of electron affinities calculated by these various methods are presented

  15. Electronics practice technology

    International Nuclear Information System (INIS)

    1995-01-01

    This book concentrates on electronic technology. It deals with kinds of terminal and mounting such as teflon terminal, steatite terminal, and harmonica terminal, small parts like connector, plug jack, vernier dial, and coupling, termination of wiring, kinds of switch and mounting, a condenser, fixed resistor, trance coil, loading of semiconductor, mounting of high input impedance circuit, mounting of electric power circuit, manufacturing of print substrate and practice of manufacturing for print substrate. This is one of series books on electronic technology.

  16. Electron-ion collisions

    International Nuclear Information System (INIS)

    Crandall, D.H.

    1982-01-01

    This discussion concentrates on basic physics aspects of inelastic processes of excitation, ionization, and recombination that occur during electron-ion collisions. Except for cases of illustration along isoelectronic sequences, only multicharged (at least +2) ions will be specifically discussed with some emphasis of unique physics aspects associated with ionic charge. The material presented will be discussed from a primarily experimental viewpoint with most attention to electron-ion interacting beams experiments

  17. Newnes electronics toolkit

    CERN Document Server

    Phillips, Geoff

    2013-01-01

    Newnes Electronics Toolkit brings together fundamental facts, concepts, and applications of electronic components and circuits, and presents them in a clear, concise, and unambiguous format, to provide a reference book for engineers. The book contains 10 chapters that discuss the following concepts: resistors, capacitors, inductors, semiconductors, circuit concepts, electromagnetic compatibility, sound, light, heat, and connections. The engineer's job does not end when the circuit diagram is completed; the design for the manufacturing process is just as important if volume production is to be

  18. Electronic states of myricetin

    DEFF Research Database (Denmark)

    Vojta, Danijela; Karlsen, Eva; Spanget-Larsen, Jens

    2017-01-01

    Myricetin (3,3',4',5,5',7'-hexahydroxyflavone) was investigated by linear dichroism spectroscopy on molecular samples partially aligned in stretched poly(vinyl alcohol) (PVA). At least five electronic transitions in the range 40000 – 20000 cm–1 were characterized with respect to their wavenumbers......, relative intensities, and transition moment directions. The observed bands were assigned to electronic transitions predicted with TD-B3LYP/6-31+G(d,p)....

  19. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  20. The Recycler Electron Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Prost, L. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-19

    The Recycler Electron cooler was the first (and so far, the only) cooler working at a relativistic energy (γ = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005-2011, providing cooling of antiprotons in the Recycler ring. This paper describes the cooler, difficulties in achieving the required electron beam parameters and the ways to overcome them, cooling measurements, and details of operation.

  1. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  2. Electronics 3 checkbook

    CERN Document Server

    Knight, S A; May, A J C

    2013-01-01

    Electronics 3 Checkbook provides a concise coverage of the theories and definitions of concepts in electronics. The book provides problems and worked examples to supplement fuller textbooks of the same subject. The coverage of the text includes decibel measurement, operational amplifiers, DA and AD converters, controlled rectifiers, triggering devices, optoelectronic devices, fiber optics, and power amplifiers. The text will be of great use to electrical engineering students who wish to enhance their understanding of the basics of mechanical and electrical science.

  3. Antifragile Electronic Warfare

    OpenAIRE

    Lichtman, Marc

    2014-01-01

    This letter introduces the concept of antifragile electronic warfare (EW), which we define as the ability to allow a communications link to improve performance due to the presence of a jammer. This concept should not be confused with jamming countermeasures (a.k.a. anti-jamming or electronic protection). Rather, antifragile EW can be thought of as the next step beyond simply avoiding or mitigating jamming. After introducing the concept we narrow down the subset of jammers this concept can be ...

  4. Electrical and electronic principles

    CERN Document Server

    Knight, SA

    1988-01-01

    Electrical and Electronic Principles, 3 focuses on the principles involved in electrical and electronic circuits, including impedance, inductance, capacitance, and resistance.The book first deals with circuit elements and theorems, D.C. transients, and the series circuits of alternating current. Discussions focus on inductance and resistance in series, resistance and capacitance in series, power factor, impedance, circuit magnification, equation of charge, discharge of a capacitor, transfer of power, and decibels and attenuation. The manuscript then examines the parallel circuits of alternatin

  5. Nuclear electronics laboratory manual

    International Nuclear Information System (INIS)

    1984-05-01

    The Nuclear Electronics Laboratory Manual is a joint product of several electronics experts who have been associated with IAEA activity in this field for many years. The manual does not include experiments of a basic nature, such as characteristics of different active electronics components. It starts by introducing small electronics blocks, employing one or more active components. The most demanding exercises instruct a student in the design and construction of complete circuits, as used in commercial nuclear instruments. It is expected that a student who completes all the experiments in the manual should be in a position to design nuclear electronics units and also to understand the functions of advanced commercial instruments which need to be repaired or maintained. The future tasks of nuclear electronics engineers will be increasingly oriented towards designing and building the interfaces between a nuclear experiment and a computer. The manual pays tribute to this development by introducing a number of experiments which illustrate the principles and the technology of interfacing

  6. Auroral electron energies

    International Nuclear Information System (INIS)

    McEwan, D.J.; Duncan, C.N.; Montalbetti, R.

    1981-01-01

    Auroral electron characteristic energies determined from ground-based photometer measurements of the ratio of 5577 A OI and 4278 A N 2 + emissions are compared with electron energies measured during two rocket flights into pulsating aurora. Electron spectra with Maxwellian energy distributions were observed in both flights with an increase in characteristic energy during each pulsation. During the first flight on February 15, 1980 values of E 0 ranging from 1.4 keV at pulsation minima to 1.8 keV at pulsation maxima were inferred from the 5577/4278 ratios, in good agreement with rocket measurements. During the second flight on February 23, direct electron energy measurements yielded E 0 values of 1.8 keV rising to 2.1 keV at pulsation maxima. The photometric ratio measurements in this case gave inferred E 0 values about 0.5 keV lower. This apparent discrepancy is considered due to cloud cover which impaired the absolute emission intensity measurements. It is concluded that the 5577/4278 ratio does yield a meaningful measure of the characteristic energy of incoming electrons. This ratio technique, when added to the more sensitive 6300/4278 ratio technique usable in stable auroras can now provide more complete monitoring of electron influx characteristics. (auth)

  7. Netiquette in Electronic Communication

    Directory of Open Access Journals (Sweden)

    Tomáš Kozík

    2014-06-01

    Full Text Available Electronic mail and electronic communications systems are considered significant and effective tools of communication. One of the most widespread electronic communication tools is e - mail communication. In order to avoid misinterpretation of the report on the side of the recipient, it is need to pay attention to the writing of e - mail messages as well as to their content. With the continuous expansion of the use of electronic communication there have gradually developed certain rules of etiquette in electronic communications. The existing rules of the propriety ones are expressed in the term " etiqutte " and are not automatically applied in the new communications environment - media. For electronic communication, the new rules of etiquette have been stabilised into a term NETIQUETTE. The word netiquette was created by combining words NET (net and ETIKETA (a set of rules of social behavior and habits. Netiquette constitutes the rules of the behavior of users on a network. Although the netiquette is merely "an unwritten set of rules", their not using can be understood as a type of disrespect. Analysis of knowledge of domestic and foreign sources as well as results of a survey confirmed the justification of paying attention to the education of individuals in NETIQUETTE, irrespective of the degree of education.

  8. HDTV versus electronic cinema

    Science.gov (United States)

    Tinker, Michael

    1998-12-01

    We are on the brink of transforming the movie theatre with electronic cinema. Technologies are converging to make true electronic cinema, with a 'film look,' possible for the first time. In order to realize the possibilities, we must leverage current technologies in video compression, electronic projection, digital storage, and digital networks. All these technologies have only recently improved sufficiently to make their use in the electronic cinema worthwhile. Video compression, such as MPEG-2, is designed to overcome the limitations of video, primarily limited bandwidth. As a result, although HDTV offers a serious challenge to film-based cinema, it falls short in a number of areas, such as color depth. Freed from the constraints of video transmission, and using the recently improved technologies available, electronic cinema can move beyond video; Although movies will have to be compressed for some time, what is needed is a concept of 'cinema compression,' rather than video compression. Electronic cinema will open up vast new possibilities for viewing experiences at the theater, while at the same time offering up the potential for new economies in the movie industry.

  9. Transformational III-V Electronics

    KAUST Repository

    Nour, Maha A.

    2014-01-01

    Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS

  10. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  11. Electron Accumulative Molecules.

    Science.gov (United States)

    Buades, Ana B; Sanchez Arderiu, Víctor; Olid-Britos, David; Viñas, Clara; Sillanpää, Reijo; Haukka, Matti; Fontrodona, Xavier; Paradinas, Markos; Ocal, Carmen; Teixidor, Francesc

    2018-02-28

    With the goal to produce molecules with high electron accepting capacity and low reorganization energy upon gaining one or more electrons, a synthesis procedure leading to the formation of a B-N(aromatic) bond in a cluster has been developed. The research was focused on the development of a molecular structure able to accept and release a specific number of electrons without decomposing or change in its structural arrangement. The synthetic procedure consists of a parallel decomposition reaction to generate a reactive electrophile and a synthesis reaction to generate the B-N(aromatic) bond. This procedure has paved the way to produce the metallacarboranylviologen [M(C 2 B 9 H 11 )(C 2 B 9 H 10 )-NC 5 H 4 -C 5 H 4 N-M'(C 2 B 9 H 11 )(C 2 B 9 H 10 )] (M = M' = Co, Fe and M = Co and M' = Fe) and semi(metallacarboranyl)viologen [3,3'-M(8-(NC 5 H 4 -C 5 H 4 N-1,2-C 2 B 9 H 10 )(1',2'-C 2 B 9 H 11 )] (M = Co, Fe) electron cumulative molecules. These molecules are able to accept up to five electrons and to donate one in single electron steps at accessible potentials and in a reversible way. By targeted synthesis and corresponding electrochemical tests each electron transfer (ET) step has been assigned to specific fragments of the molecules. The molecules have been carefully characterized, and the electronic communication between both metal centers (when this situation applies) has been definitely observed through the coplanarity of both pyridine fragments. The structural characteristics of these molecules imply a low reorganization energy that is a necessary requirement for low energy ET processes. This makes them electronically comparable to fullerenes, but on their side, they have a wide range of possible solvents. The ET from one molecule to another has been clearly demonstrated as well as their self-organizing capacity. We consider that these molecules, thanks to their easy synthesis, ET, self-organizing capacity, wide range of solubility, and easy processability, can

  12. Electronic Submissions of Pesticide Applications

    Science.gov (United States)

    Applications for pesticide registration can be submitted electronically, including forms, studies, and draft product labeling. Applicants need not submit multiple electronic copies of any pieces of their applications.

  13. Electron beams and applications

    International Nuclear Information System (INIS)

    Haouat, G.; Couillaud, C.

    1998-01-01

    Studies of the physical properties of the ELSA-linac electron beam are presented. They include measurements of the characteristic beam parameter and analyzes of the beam transport using simulation codes. The aim of these studies is to determine the best conditions for production of intense and very short electron bunches and to optimize the transport of space-charge dominated beams. Precise knowledge of the transport dynamics allows to produce beams with the required characteristics for light production in Free-Electron Laser (FEL), and to give a good description of energy-transfer phenomena between electrons and photons in the wriggler. The particular features of ELSA authorize studies of high-intensity, high-brightness beam properties, especially the halo surrounding the dense core of the electron bunches, which is formed by the space charge effects. It is also shown that the ELSA facility is well suited for the fabrication of very short γ and X-rays sources for applied research in nuclear and plasma physics, or for time response studies of fast detectors. (author)

  14. Auroral electron time dispersion

    International Nuclear Information System (INIS)

    Kletzing, C.A.

    1989-01-01

    A sounding rocket flight was launched from Greenland in 1985 to study high latitude, early morning auroral physics. The payload was instrumented with electron and ion detectors, AC and DC electric field experiments, a plasma density experiment, and a magnetometer to measure the ambient field. The rocket was launched during disturbed conditions, when the polar cap was in a contracted state with visible aurora overhead. The electron data contained numerous signatures indicative of time-of-flight energy dispersion characterized by a coherent structure in which lower energy electrons arrived at the rocket after higher energy electrons. A model was constructed to explain this phenomena by the sudden application of a region of parallel electric field along a length of magnetic field line above the rocket. The model incorporates detector response and uses an altitudinal density profile based on auroral zone measurements. Three types of potential structures were tried: linear, quadratic and cubic. Of the three it was found that the cubic (electric field growing in a quadratic manner moving up the field line) produced the best fit to the data. The potential region was found to be approximately 1-2 R e in extent with the lower edge 3000-4000 km away from the rocket. The background electron temperature in the model which produced the best fit to the data was of the order of 15 eV

  15. Electron irradiation of zeolites

    International Nuclear Information System (INIS)

    Wang, S.X.; Wang, L.M.; Ewing, R.C.

    1999-01-01

    Three different zeolites (analcime, natrolite, and zeolite-Y) were irradiated with 200 keV and 400 keV electrons. All zeolites amorphized under a relatively low electron fluence. The transformation from the crystalline-to-amorphous state was continuous and homogeneous. The electron fluences for amorphization of the three zeolites at room temperature were: 7.0 x 10 19 e - /cm 2 (analcime), 1.8 x 10 20 e - /cm 2 (natrolite), and 3.4 x 10 20 e - /cm 2 (zeolite-Y). The different susceptibilities to amorphization are attributed to the different channel sizes in the structures which are the pathways for the release of water molecules and Na + . Natrolite formed bubbles under electron irradiation, even before complete amorphization. Analcime formed bubbles after amorphization. Zeolite-Y did not form bubbles under irradiation. The differences in bubble formation are attributed to the different channel sizes of the three zeolites. The amorphization dose was also measured at different temperatures. An inverse temperature dependence of amorphization dose was observed for all three zeolites: electron dose for amorphization decreased with increasing temperature. This unique temperature effect is attributed to the fact that zeolites are thermally unstable. A semi-empirical model was derived to describe the temperature effect of amorphization in these zeolites

  16. Politics Under Electronic Simultaneity

    Directory of Open Access Journals (Sweden)

    Valery P. Terin

    2014-01-01

    Full Text Available In contradistinction to the book and the other typographic products, the electronic media operates on a 24-hour-a-day basis evoking simultaneity as the guiding mode of perception and thinking for all those under its influence. The discovery of this fact manifested itself in the formation and development of the managerial technologies operating by means of the electronic information environment and following the principle of simultaneity in the first place. Thus, at the end of the 1960s already the election campaigns in the U.S.A. began to operate on the basis of the final cause as the guiding principle of the country's mass consciousness motivating to carry out each particular event as if already rejoicing at the victory. With this in mind, there emerged a problem of applying this approach with its enormous managerial potential elsewhere. To add, simultaneity as a norm of perception and thinking turned out to be increasingly important with the advent of the electrical telegraph and the press relying on its short disconnected messages instantaneously arriving from all parts of the world. All the other media, which emerged in the wake of this development, has served to fortify this mode of thought as governing in the electronic information environment. The potential of the electronically operating global managerial technologies is quickly growing. The article also deals with the information overload and pattern recognition problem understood in managerial terms as well as mythologization and demythologization processes as they are necessitated by the electronic media coverage worldwide.

  17. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-05-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

  18. Theory of runaway electrons

    Energy Technology Data Exchange (ETDEWEB)

    Dreicer, H [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1958-07-01

    This paper treats the problem of electrons moving through an infinite gas of positive ions under the influence of a static uniform electric field of arbitrary strength. In evaluating the electrical conductivity of such a gas the conventional treatment involves a perturbation solution of the time-independent Boltzmann equation, and results in the well-known (temperature){sup 3/2} law. Two assumptions are basic to these treatments: 1) that a steady state electron velocity distribution is attained several mean-free collision times after the electric field is applied, and 2) that the terminal electron drift velocity is small compared to the average random electron speed. Both assumptions are avoided in this paper. In the next section the problem is formulated starting with the Boltzmann equation and a review of approximate analytic solutions appropriate to the weak and strong electric field cases is presented. We then describe a time-dependent numerical solution to the Boltzmann equation and compare these results with the approximate solutions. All of these treatments lead to the conclusion that this problem does not admit a time-independent solution. Because of the strong energy dependence of the Rutherford scattering law, the electron drift velocity is not bounded by a terminal value, rather it grows monotonically with time. This is the so-called runaway effect predicted by Giovanelli. Collective effects, or plasma oscillations, are ignored in this work, although these undoubtedly play an important role in the conduction of electricity through the plasma.

  19. Microfluidic stretchable RF electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2010-12-07

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  20. Electron guns for accelerators

    International Nuclear Information System (INIS)

    Rangarajan, L.M.; Mahadevan, S.; Ramamurthi, S.S.

    1995-01-01

    The high voltage, high current electron guns developed elsewhere for Linacs are based on cathode pulsing with direct emitting cathodes. Our grid pulsed triode gun employs indirect emitting cathode pellet under electron bombardment or a direct cathode emitter. Electron beam from the gun is injected to the accelerator guide at 40 kV and pulse duration is 2.8μsec. The gun is limited to axially symmetric geometry and electron optical design is optimized by computer programming. The gun with a water cooled Faraday cup is connected to a vacuum system comprising of a sputter ion pump and sorption pump. Working pressure is 1x10 -6 Pa. Gun is designed to be baked as an assembly at temperatures of 400 degC while vacuum processing. Materials are therefore restricted to refractory metals, SS, OFHC copper and all the electrodes are housed inside a ceramic tube. Lower Z graphite is used as a base material of Faraday cup. Grid is non-intercepting modulator anode, a new feature introduced, as compared to meshed grid system by others. CAT gun delivers 160 mA current pulses at 40 kV and its working characteristics such as perveance, emittance and beam radius compare well with SLAC and Hermosa guns. The above guns can be used for electron beam machines such as medical Linacs, industrial accelerators and EB welding equipment. (author). 2 refs., 2 figs

  1. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  2. Electron-molecule collisions

    International Nuclear Information System (INIS)

    Shimamura, I.; Takayanagi, K.

    1984-01-01

    The study of collision processes plays an important research role in modern physics. Many significant discoveries have been made by means of collision experiments. Based on theoretical, experimental, and computational studies, this volume presents an overview detailing the basic processes of electron-molecule collisions. The editors have collected papers-written by a group of international experts-that consider a diverse range of phenomena occurring in electronmolecule collisions. The volume discusses first the basic formulation for scattering problems and then gives an outline of the physics of electron-molecule collisions. The main topics covered are rotational transitions, vibrational transitions, dissociation of molecules in slow collisions, the electron-molecule collision as a spectroscopic tool for studying molecular electronic structures, and experimental and computational techniques for determining the cross sections. These well-referenced chapters are self-contained and can be read independently or consecutively. Authoritative and up-to-date, Electron-Molecule Collisions is a useful addition to the libraries of students and researchers in the fields of atomic, molecular, and chemical physics, and physical chemistry

  3. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD`s Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases & Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  4. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD's Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  5. Electronic Materials Science

    Science.gov (United States)

    Irene, Eugene A.

    2005-02-01

    A thorough introduction to fundamental principles and applications From its beginnings in metallurgy and ceramics, materials science now encompasses such high- tech fields as microelectronics, polymers, biomaterials, and nanotechnology. Electronic Materials Science presents the fundamentals of the subject in a detailed fashion for a multidisciplinary audience. Offering a higher-level treatment than an undergraduate textbook provides, this text benefits students and practitioners not only in electronics and optical materials science, but also in additional cutting-edge fields like polymers and biomaterials. Readers with a basic understanding of physical chemistry or physics will appreciate the text's sophisticated presentation of today's materials science. Instructive derivations of important formulae, usually omitted in an introductory text, are included here. This feature offers a useful glimpse into the foundations of how the discipline understands such topics as defects, phase equilibria, and mechanical properties. Additionally, concepts such as reciprocal space, electron energy band theory, and thermodynamics enter the discussion earlier and in a more robust fashion than in other texts. Electronic Materials Science also features: An orientation towards industry and academia drawn from the author's experience in both arenas Information on applications in semiconductors, optoelectronics, photocells, and nanoelectronics Problem sets and important references throughout Flexibility for various pedagogical needs Treating the subject with more depth than any other introductory text, Electronic Materials Science prepares graduate and upper-level undergraduate students for advanced topics in the discipline and gives scientists in associated disciplines a clear review of the field and its leading technologies.

  6. Need for accelerating electrons

    International Nuclear Information System (INIS)

    Kerst, D.W.

    1987-01-01

    Photons for nuclear disintegration experiments were not abundantly available in the early days of nuclear physics, whereas accelerated ions led the way. When electrons could be accelerated into the 20--30 MeV range, they found application not only to nuclear disintegration of the elements of the periodic table but also to x-ray radiography and to deep therapy. Energies of interest for probing nuclear structure by electron scattering and for meson production followed soon after. The elementary nature of the electron has now made it a valuable tool for present day particle physics; and the synchrotron radiation, which is an obstacle for some accelerating processes, has become a much sought after source of photons for experiments at atomic structure energies

  7. Electronic structure of silicene

    International Nuclear Information System (INIS)

    Voon, L. C. Lew Yan

    2015-01-01

    In this topical review, we discuss the electronic structure of free-standing silicene by comparing results obtained using different theoretical methods. Silicene is a single atomic layer of silicon similar to graphene. The interest in silicene is the same as for graphene, in being two-dimensional and possessing a Dirac cone. One advantage of silicene is due to its compatibility with current silicon electronics. Both empirical and first-principles techniques have been used to study the electronic properties of silicene. We will provide a brief overview of the parameter space for first-principles calculations. However, since the theory is standard, no extensive discussion will be included. Instead, we will emphasize what empirical methods can provide to such investigations and the current state of these theories. Finally, we will review the properties computed using both types of theories for free-standing silicene, with emphasis on areas where we have contributed. Comparisons to graphene is provided throughout. (topical review)

  8. Electron microscopy in metallurgy

    International Nuclear Information System (INIS)

    Loretto, M.H.

    1980-01-01

    The aim of this paper is to review briefly the contribution which (TEM) transmission electron microscopy (including high voltage electron microscopy (HVEM)) has made to metallurgy. Since it is straightforward with modern electron microscopes to extract the crystallographic information which provides the basis for any interpretation, the major problem in most metallurgical work lies in assessing how the structure (which TEM has characterised) has arisen and which properties of the specimen can be understood in terms of this structure. Radiation damage, quenching, phase transformations, grain boundaries and plastic deformation have been the main fields in which TEM has contributed significantly. After briefly summarising the role of TEM in each field, examples of recent work will be used to indicate current TEM activity in physical metallurgy. (author)

  9. Wireless Biological Electronic Sensors.

    Science.gov (United States)

    Cui, Yue

    2017-10-09

    The development of wireless biological electronic sensors could open up significant advances for both fundamental studies and practical applications in a variety of areas, including medical diagnosis, environmental monitoring, and defense applications. One of the major challenges in the development of wireless bioelectronic sensors is the successful integration of biosensing units and wireless signal transducers. In recent years, there are a few types of wireless communication systems that have been integrated with biosensing systems to construct wireless bioelectronic sensors. To successfully construct wireless biological electronic sensors, there are several interesting questions: What types of biosensing transducers can be used in wireless bioelectronic sensors? What types of wireless systems can be integrated with biosensing transducers to construct wireless bioelectronic sensors? How are the electrical sensing signals generated and transmitted? This review will highlight the early attempts to address these questions in the development of wireless biological electronic sensors.

  10. Beam electron microprobe

    CERN Document Server

    Stoller, D; Muterspaugh, M W; Pollock, R E

    1999-01-01

    A beam profile monitor based on the deflection of a probe electron beam by the electric field of a stored, electron-cooled proton beam is described and first results are presented. Electrons were transported parallel to the proton beam by a uniform longitudinal magnetic field. The probe beam may be slowly scanned across the stored beam to determine its intensity, position, and size. Alternatively, it may be scanned rapidly over a narrow range within the interior of the stored beam for continuous observation of the changing central density during cooling. Examples of a two dimensional charge density profile obtained from a raster scan and of a cooling alignment study illustrate the scope of measurements made possible by this device.

  11. Noncovalent Molecular Electronics.

    Science.gov (United States)

    Gryn'ova, G; Corminboeuf, C

    2018-05-03

    Molecular electronics covers several distinctly different conducting architectures, including organic semiconductors and single-molecule junctions. The noncovalent interactions, abundant in the former, are also often found in the latter, i.e., the dimer junctions. In the present work, we draw the parallel between the two types of noncovalent molecular electronics for a range of π-conjugated heteroaromatic molecules. In silico modeling allows us to distill the factors that arise from the chemical nature of their building blocks and from their mutual arrangement. We find that the same compounds are consistently the worst and the best performers in the two types of electronic assemblies, emphasizing the universal imprint of the underlying chemistry of the molecular cores on their diverse charge transport characteristics. The interplay between molecular and intermolecular factors creates a spectrum of noncovalent conductive architectures, which can be manipulated using the design strategies based upon the established relationships between chemistry and transport.

  12. PHERMEX electron gun development

    International Nuclear Information System (INIS)

    Builta, L.A.; Elliott, J.C.; Moir, D.C.; Starke, T.P.; Vecere, C.A.

    1983-01-01

    The PHERMEX facility is a 50-MHz standing-wave linear accelerator. Electrons are injected, accelerated, and transported to a tungsten target where bremsstrahlung x rays are generated for flash radiography of hydrodynamic systems. The purpose of this article is to describe the progress of PHERMEX electron gun development. The goal of this program is to generate and transport a 200-ns, 1-MV, 1-kA electron beam into the first PHERMEX accelerating cavity. The standard gun is operated at a pulse voltage of 550 kV, which is the limit determined by internal breakdown of the vacuum insulator. This insulator has been redesigned, and the gun has been pulsed at 750 kV without internal breakdown. At present, the current output is not limited by voltage but by a phenomenon called pulse shortening, which occurs at a pulse voltage of approximately 650 kV. The phenomenon has been investigated and the results are presented

  13. Phasor power electronics

    CERN Document Server

    Rim, Chun T

    2016-01-01

    This book presents a comprehensive introduction to the principles of power electronics, focusing on the switched transformer concept and phasor transformation techniques as employed in the analysis and design of power electronic circuits. Phasor transformations, as introduced in this book, make the time-varying nature of a switching converter simple and easy to handle, transforming it into an equivalent time-invariant circuit. The book starts with an introduction to the philosophy and fundamental principles of power electronics. The switched transformer concept, which is applicable to any switching converter, is introduced, and it is shown how DC-DC converters analyses are then so straightforward that very little equational manipulation is needed. Then the phasor transformation techniques are comprehensively explained over three parts. Single phase and multi-phase AC systems are dealt with through the single phase phasor transformation and circuit DQ transformation, respectively. A general unified phasor tran...

  14. Polarized electron sources

    International Nuclear Information System (INIS)

    Clendenin, J.E.

    1995-05-01

    Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with ∼99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the possibilities for producing highly polarized electron beams for high-duty-factor accelerators are discussed

  15. Plasma relativistic microwave electronics

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.

    2001-01-01

    One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru

  16. 4D Electron Tomography

    Science.gov (United States)

    Kwon, Oh-Hoon; Zewail, Ahmed H.

    2010-06-01

    Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

  17. Electronics a systems approach

    CERN Document Server

    Storey, Neil

    2017-01-01

    Electronics plays a central role in our everyday lives. It is at the heart of almost all of today's essential technology, from mobile phones to computers and from cars to power stations. As such, all engineers, scientists and technologists need to have a fundamental understanding of this exciting subject, and for many this will just be the beginning. Now in its sixth edition, Electronics: A Systems Approach provides an outstanding introduction to this fast-moving and important field. Comprehensively revised and updated to cover the latest developments in the world of electronics, the text continues to use Neil Storey's established and well-respected systems approach. It introduces the basic concepts first before progressing to a more advanced analysis, enabling you to contextualise what a system is designed to achieve before tackling the intricacies of designing or analysing its various components with confidence. This book is accompanied by a website which contains over 100 video tutorials to help explain ke...

  18. Electron Technology: ELTE 2016

    Science.gov (United States)

    Pisarkiewicz, Tadeusz; Kucewicz, Wojciech

    2016-12-01

    In this paper we present a review of research results and technical accomplishments presented by researchers from technical universities, governmental institutes and research companies during the XIIth Scientific Conference Electron Technology, ELTE 2016. This review is based on materials presented at four topical conference sessions: Microelectronics and Nanoelectronics, Photonics, Materials and Technologies, and Microsystems and also on materials presented by invited speakers at two dedicated sessions. Oral sessions were accompanied by the poster sessions. In effect about 50 papers gathered in this volume reflect the topics discussed at the Conference. A short description of technological and measurement possibilities in the laboratories of Academic Centre for Materials and Nanotechnology and also in the Department of Electronics of the Faculty of Computer Science, Electronics and Telecommunications AGH UST are given.

  19. Electron microscopy of boron carbide before and after electron irradiation

    International Nuclear Information System (INIS)

    Stoto, T.; Zuppiroli, L.; Beauvy, M.; Athanassiadis, T.

    1984-06-01

    The microstructure of boron carbide has been studied by electron microscopy and related to the composition of the material. After electron irradiations in an usual transmission electron microscope and in a high voltage electron microscope at different temperatures and fluxes no change of these microstructures have been observed but a sputtering of the surface of the samples, which has been studied quantitatively [fr

  20. Precision electron polarimetry

    International Nuclear Information System (INIS)

    Chudakov, E.

    2013-01-01

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. Mo/ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at 300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100%-polarized electron target for Mo/ller polarimetry

  1. Electronics 2 checkbook

    CERN Document Server

    Knight, S A

    2013-01-01

    Electronics 2 Checkbook is an 11-chapter text that presents problems and worked examples to establish and exemplify the theory contained in technical syllabuses, with a particular emphasis on electronics.The introductory chapters review the elementary theory of semiconductors and the p-n junction diode. The subsequent chapters deal with the applications of diode, the characteristics of bipolar transistors, and the mode of operation of small signal amplifiers. These topics are followed by discussions of the function of the field-effect transistor and power supplies. The concluding chapters expl

  2. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    1988-01-01

    Practical Electronics Handbook, Second Edition covers information useful in electronics, with focus on mathematical conventions. The handbook discusses the passive (resistors, capacitors, band coding, and inductors) and active discrete (diodes, transistors and negative feedback) components; discrete component circuits; and transferring digital data. Linear I.C.s, which are the single-chip arrangements of amplifier circuits that are intended to be biased and operated in a linear way, and digital I.C.s, which process signals and consist of two significant voltage levels, are also considered. T

  3. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  4. Innovations in electronic services

    Directory of Open Access Journals (Sweden)

    Dagmara Wach

    2011-12-01

    Full Text Available Summarry Existence in electronic business has become increasingly difficult. High competition and considerable financial resources needed to enter electronic market are the problems of most micro and small sized enterprises, starting or developing their business. Nevertheless, there is a market niche for them, which can ensure success and grant partial financing of the business. This niche are small web projects, providing the customer with personalized service, hitting his tastes and meeting immediate needs. A projects that large websites are unable to perform. Financial sourcing of those projects comes from EU subsidies, in the framework of the Działanie 8.1. PO IG, 2007-2013.

  5. Electronic components and technology

    CERN Document Server

    Sangwine, Stephen

    2007-01-01

    Most introductory textbooks in electronics focus on the theory while leaving the practical aspects to be covered in laboratory courses. However, the sooner such matters are introduced, the better able students will be to include such important concerns as parasitic effects and reliability at the very earliest stages of design. This philosophy has kept Electronic Components and Technology thriving for two decades, and this completely updated third edition continues the approach with a more international outlook.Not only does this textbook introduce the properties, behavior, fabrication, and use

  6. Pulsed Plasma Electron Sources

    Science.gov (United States)

    Krasik, Yakov

    2008-11-01

    Pulsed (˜10-7 s) electron beams with high current density (>10^2 A/cm^2) are generated in diodes with electric field of E > 10^6 V/cm. The source of electrons in these diodes is explosive emission plasma, which limits pulse duration; in the case E Saveliev, J. Appl. Phys. 98, 093308 (2005). Ya. E. Krasik, A. Dunaevsky, and J. Felsteiner, Phys. Plasmas 8, 2466 (2001). D. Yarmolich, V. Vekselman, V. Tz. Gurovich, and Ya. E. Krasik, Phys. Rev. Lett. 100, 075004 (2008). J. Z. Gleizer, Y. Hadas and Ya. E. Krasik, Europhysics Lett. 82, 55001 (2008).

  7. Advances in quantum electronics

    CERN Document Server

    Goodwin, D W

    1974-01-01

    Advances in Quantum Electronics, Volume 2 deals with the effects of quantum mechanics on the behavior of electrons in matter. This book is divided into three chapters. Chapter 1 reviews the statistical properties of optical fields and spectral processing techniques, including the use of photon correlation techniques to measure scattering effects in a number of different media. The use of optical E.P.R. and excitation spectroscopic techniques and techniques for establishing the location of impurity ions in the chalcogenides are describe in Chapter 2. The last chapter surveys the field of mode l

  8. Modern electronic maintenance principles

    CERN Document Server

    Garland, DJ

    2013-01-01

    Modern Electronic Maintenance Principles reviews the principles of maintaining modern, complex electronic equipment, with emphasis on preventive and corrective maintenance. Unfamiliar subjects such as the half-split method of fault location, functional diagrams, and fault finding guides are explained. This book consists of 12 chapters and begins by stressing the need for maintenance principles and discussing the problem of complexity as well as the requirements for a maintenance technician. The next chapter deals with the connection between reliability and maintenance and defines the terms fai

  9. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  10. Auroral electron acceleration

    International Nuclear Information System (INIS)

    Bryant, D.A.

    1989-10-01

    Two theories of auroral electron acceleration are discussed. Part 1 examines the currently widely held view that the acceleration is an ordered process in a quasi-static electric field. It is suggested that, although there are many factors seeming to support this theory, the major qualifications and uncertainties that have been identified combine to cast serious doubt over its validity. Part 2 is devoted to a relatively new interpretation in terms of stochastic acceleration in turbulent electric fields. This second theory, which appears to account readily for most known features of the electron distribution function, is considered to provide a more promising approach to this central question in magnetospheric plasma physics. (author)

  11. Advances in electronic materials

    CERN Document Server

    Kasper, Erich; Grimmeiss, Hermann G

    2008-01-01

    This special-topic volume, Advances in Electronic Materials, covers various fields of materials research such as silicon, silicon-germanium hetero-structures, high-k materials, III-V semiconductor alloys and organic materials, as well as nano-structures for spintronics and photovoltaics. It begins with a brief summary of the formative years of microelectronics; now the keystone of information technology. The latter remains one of the most important global technologies, and is an extremely complex subject-area. Although electronic materials are primarily associated with computers, the internet

  12. Electronics for technicians

    CERN Document Server

    Crane, P W

    2013-01-01

    Electronics for Technicians covers the basic fundamentals of electronics, including the operation of devices and circuits. The book is meant to help the technician to obtain numerical answers to actual circuit problems. This volume consists of seven chapters, the first of which introduces the reader to the basic rules for circuits containing resistive and reactive elements. Charge and discharge of a capacitor through a resistor is discussed, along with charge and discharge of an inductance through a resistance, application of sinusoidal voltages to simple networks, and series and parallel LCR

  13. Superconducting quantum electronics

    International Nuclear Information System (INIS)

    Kose, V.

    1989-01-01

    This book reviews recent accomplishments, presents new results and discusses possible future developments of superconducting quantum electronics and high T c superconductivity. The three main parts of the book deal with fundamentals, sensitive detectors, and precision metrology. New results reported include: correct equivalent circuits modelling superconducting electronic devices; exact solution of the Mattis-Bardeen equations describing various experiments for thin films; complete theoretical description and experimental results for a new broad band spectrum analyzer; a new Josephson junction potentiometer allowing tracing of unknown voltage ratios back to well-known frequency ratios; and fast superconducting SQUID shift registers enabling the production of calculable noise power spectra in the microwave region

  14. VLSI electronics microstructure science

    CERN Document Server

    1981-01-01

    VLSI Electronics: Microstructure Science, Volume 3 evaluates trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the impact of VLSI on computer architectures; VLSI design and design aid requirements; and design, fabrication, and performance of CCD imagers. The approaches, potential, and progress of ultra-high-speed GaAs VLSI; computer modeling of MOSFETs; and numerical physics of micron-length and submicron-length semiconductor devices are also elaborated. This text likewise covers the optical linewi

  15. Electronic health records

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross......-border and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increase the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...... of the personal data concerning health, from different sources, and throughout a lifetime....

  16. Electron transfer from electronic excited states to sub-vacuum electron traps in amorphous ice

    International Nuclear Information System (INIS)

    Vichnevetski, E.; Bass, A.D.; Sanche, L.

    2000-01-01

    We investigate the electron stimulated yield of electronically excited argon atoms (Ar * ) from monolayer quantities of Ar deposited onto thin films of amorphous ice. Two peaks of narrow width ( - electron-exciton complex into exciton states, by the transfer of an electron into a sub-vacuum electron state within the ice film. However, the 10.7 eV feature is shifted to lower energy since electron attachment to Ar occurs within small pores of amorphous ice. In this case, the excess electron is transferred into an electron trap below the conduction band of the ice layer

  17. Electron localization in water clusters

    International Nuclear Information System (INIS)

    Landman, U.; Barnett, R.N.; Cleveland, C.L.; Jortner, J.

    1987-01-01

    Electron attachment to water clusters was explored by the quantum path integral molecular dynamics method, demonstrating that the energetically favored localization mode involves a surface state of the excess electron, rather than the precursor of the hydrated electron. The cluster size dependence, the energetics and the charge distribution of these novel electron-cluster surface states are explored. 20 refs., 2 figs., 1 tab

  18. Analyser of sweeping electron beam

    International Nuclear Information System (INIS)

    Strasser, A.

    1993-01-01

    The electron beam analyser has an array of conductors that can be positioned in the field of the sweeping beam, an electronic signal treatment system for the analysis of the signals generated in the conductors by the incident electrons and a display for the different characteristics of the electron beam

  19. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  20. The electronic neighbourhood

    DEFF Research Database (Denmark)

    Rüdiger, Bjarne; Tournay, Bruno

    2004-01-01

    This paper presents the results of a 3-year research project. The Electronic Neighbourhood (2000-2004). Researchers have developed and tested a digital model of the urban area and other digital tools for supporting the dialogue and cooperation between professionals and citizens in an urban...

  1. The Electronic Game Gambit.

    Science.gov (United States)

    Bing, Jon

    1982-01-01

    The rapid evolution of today's video games now fills arcades, snack bars, and homes with an array of highly interactive, graphically vivid technical devices. This electronic environment is creating a worldwide communication network. Developments in this area will be beneficial provided that appropriate media policies can be framed. (Author/JN)

  2. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1990-01-01

    Our laboratory has made significant progress this year in devising improved electron-optical systems, in studying invertebrate hemoglobins with the STEM, and in achieving a workable sub-angstrom STEM. Our goal in electron optics is to improve resolution by producing spherical and chromatic aberration coefficients with signs opposite those of magnetic lenses. We have progressed toward this goal through calculations that explore the addition of electrodes to electron mirrors to reduce these two geometric aberrations and by devising a beam separation system that won't introduce asymmetrical aberrations. Some promising new designs of magnetic lenses for SEM applications have also been investigated. We have continued our exploration of the quaternary structure of the invertebrate hemoglobins and are now among the top laboratories in this area of expertise. In addition, we have overcome many of our electronic difficulties on the sub-angstrom STEM and have made significant progress toward achieving an operational system. The addition of an IBM RISC-6000 workstation to our lab has significantly increased our image processing capabilities

  3. The electron foreshock

    Science.gov (United States)

    Fitzenreiter, R. J.

    1995-01-01

    An overview of the observations of backstreaming electrons in the foreshock and the mechanisms that have been proposed to explain their properties will be presented. A primary characteristic of observed foreshock electrons is that their velocity distributions are spatially structured in a systematic way depending on distance from the magnetic field line which is tangent to the shock. There are two interrelated aspects to explaining the structure of velocity distributions in the foreshock, one involving the acceleration mechanism and the other, propagation from the source to the observing point. First, the source distribution of electrons energized by the shock must be determined along the shock surface. Proposed acceleration mechanisms include magnetic mirroring of incoming solar wind particles and mechanisms involving transmission of particles through the shock. Secondly, the kinematics of observable electrons streaming away from a curved shock with an initial parallel velocity and a downstream perpendicular velocity component due to the motional electric field must be determined. This is the context in which the observations and their explanations will be reviewed.

  4. Using Electronic Portfolios

    Science.gov (United States)

    Page, Deb

    2012-01-01

    The digitized collections of artifacts known as electronic portfolios are creating solutions to a variety of performance improvement needs in ways that are cost-effective and improve both individual and group learning and performance. When social media functionality is embedded in e-portfolios, the tools support collaboration, social learning,…

  5. Electronic procedure distribution

    International Nuclear Information System (INIS)

    Slone, B.J. III; Richardson, C.E.

    1993-01-01

    Printed procedures can offer a mix of text and graphic information that improves readability and increases understanding. A typical procedure uses illustrations and graphics to clarify concepts, a variety of type styles and weights to make it easier to find different topics and sections, white space to improve readability, and familiar navigational clues such as page numbers and topic headers. Initially, electronic procedure systems had limited typeface options, often only a single typeface, with no capability for enhancing readability by varying type size bolding, italicizing, or underlining, and no ability to include graphics. Even recently, many text-only electronic procedures were originally created in a modern What-You-See-Is-What-You-Get (WYSI-WYG) document authoring system, only to be converted to pages and pages of plain type for electronic distribution. Given the choice of paper or on-line producers, most users have chosen paper for its readability. But current-generation electronic document systems that use formatted text and embedded graphics offer users vastly improved readability. Further, they are offering ever-better search tools to enable rapid location of material of interest

  6. International Competitiveness in Electronics.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Office of Technology Assessment.

    This assessment continues the Office of Technology Assessment's (OTA) exploration of the meaning of industrial policy in the United States context, while also examining the industrial policies of several U.S. economic rivals. The major focus is on electronics, an area which virtually defines "high technology" of the 1980's. The…

  7. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  8. Electron injection in microtron

    International Nuclear Information System (INIS)

    Axinescu, S.

    1977-01-01

    A review of the methods of injecting electrons in the microtron is presented. A special attention is paid to efficient injection systems developed by Wernholm and Kapitza. A comparison of advantages and disadvantages of both systems is made in relation to the purpose of the microtron. (author)

  9. Transformational silicon electronics

    KAUST Repository

    Rojas, Jhonathan Prieto; Sevilla, Galo T.; Ghoneim, Mohamed T.; Inayat, Salman Bin; Ahmed, Sally; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2014-01-01

    In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100

  10. ELECTRON COOLING FOR RHIC

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    2001-01-01

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling

  11. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.

    2001-05-13

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling.

  12. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  13. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Electron Paramagnetic Resonance Spectroscopy: Biological Applications. B G Hegde. General Article Volume 20 Issue 11 November 2015 pp 1017-1032. Fulltext. Click here to view fulltext PDF. Permanent link:

  14. Quantum Hall Electron Nematics

    Science.gov (United States)

    MacDonald, Allan

    In 2D electron systems hosted by crystals with hexagonal symmetry, electron nematic phases with spontaneously broken C3 symmetry are expected to occur in the quantum Hall regime when triplets of Landau levels associated with three different Fermi surface pockets are partially filled. The broken symmetry state is driven by intravalley Coulombic exchange interactions that favor spontaneously polarized valley occupations. I will discuss three different examples of 2D electron systems in which this type of broken symmetry state is expected to occur: i) the SnTe (111) surface, ii) the Bi (111) surface. and iii) unbalanced bilayer graphene. This type of quantum Hall electron nematic state has so far been confirmed only in the Bi (111) case, in which the anisotropic quasiparticle wavefunctions of the broken symmetry state were directly imaged. In the SnTe case the nematic state phase boundary is controlled by a competition between intravalley Coulomb interactions and intervalley scattering processes that increase in relative strength with magnetic field. An in-plane Zeeman field alters the phase diagram by lifting the three-fold Landau level degeneracy, yielding a ground state energy with 2 π/3 periodicity as a function of Zeeman-field orientation angle. I will comment on the possibility of observing similar states in the absence of a magnetic field. Supported by DOE Division of Materials Sciences and Engineering Grant DE-FG03-02ER45958.

  15. Spaceradiation effects on electronics

    International Nuclear Information System (INIS)

    Salminen, Arto.

    1989-01-01

    The failure mechanisms and radiation hardening of electronic devices in spaceborne environment are considered. Radiation hardened components and radiation shielding of electronics are described. Because of the radiation belts and particle radiation from the Sun, the near earth space is hostile to electronics. Besides cosmic radiation represents fully random failure source, against which redundant methods have to be applied. Failures caused by absorbed doses can be dealt with component selection, layout adjustment and addition of absorber. Prepairing for radiation damage presupposes the calculation of absorbed doses and SEU-cross sections from flight parameters. Thus the expected lifetime for spacecraft can be estimated. The above observations belong to the domain of normal routine operation in space electronic engineering and product assurance, which has a crucial meaning in space technology. Devices are to operate years without failure in demanding conditions. The reliable products are result of careful consideration of space environment from the beginning of device design. This applies especially to component selection and circuit design

  16. Wavepacket electron scattering

    International Nuclear Information System (INIS)

    Marks, L.D.

    1986-01-01

    In this note, the formal analysis of the electron wavepacket produced by a STEM instrument is sketched, and some of the diffraction effects briefly described. It is hoped that this will encourage some needed analysis of the complicated inelastic processes occurring in this experimental geometry. 21 references, 3 figures

  17. Inventing the Electronic University

    Science.gov (United States)

    Lewis, David W.

    2015-01-01

    Higher education is confronting a fundamental change. The transition from print on paper to digital and electronic technologies is transforming instruction, scholarly communication, and the storage and preservation of knowledge. What is required is not the automation of old systems, but the restructuring of institutions. The drive for autonomy,…

  18. The electronic stethoscope.

    Science.gov (United States)

    Leng, Shuang; Tan, Ru San; Chai, Kevin Tshun Chuan; Wang, Chao; Ghista, Dhanjoo; Zhong, Liang

    2015-07-10

    Most heart diseases are associated with and reflected by the sounds that the heart produces. Heart auscultation, defined as listening to the heart sound, has been a very important method for the early diagnosis of cardiac dysfunction. Traditional auscultation requires substantial clinical experience and good listening skills. The emergence of the electronic stethoscope has paved the way for a new field of computer-aided auscultation. This article provides an in-depth study of (1) the electronic stethoscope technology, and (2) the methodology for diagnosis of cardiac disorders based on computer-aided auscultation. The paper is based on a comprehensive review of (1) literature articles, (2) market (state-of-the-art) products, and (3) smartphone stethoscope apps. It covers in depth every key component of the computer-aided system with electronic stethoscope, from sensor design, front-end circuitry, denoising algorithm, heart sound segmentation, to the final machine learning techniques. Our intent is to provide an informative and illustrative presentation of the electronic stethoscope, which is valuable and beneficial to academics, researchers and engineers in the technical field, as well as to medical professionals to facilitate its use clinically. The paper provides the technological and medical basis for the development and commercialization of a real-time integrated heart sound detection, acquisition and quantification system.

  19. Electron beam processing system

    International Nuclear Information System (INIS)

    Kashiwagi, Masayuki

    2004-01-01

    Electron beam Processing Systems (EPS) are used as useful and powerful tools in many industrial application fields such as the production of cross-linked wire, rubber tire, heat shrinkable film and tubing, curing, degradation of polymers, sterilization and environmental application. In this paper, the feature and application fields, the selection of machine ratings and safety measures of EPS will be described. (author)

  20. Atom electron scattering

    International Nuclear Information System (INIS)

    Santoso, B.

    1976-01-01

    Green Lippmann-Schwinger functions operator representations, derivation of perturbation method using Green function and atom electron scattering, are discussed. It is concluded that by using complex coordinate places where resonances occur, can be accurately identified. The resonance can be processed further for practical purposes, for example for the separation of atom. (RUW)

  1. Electron-Cyclotron Waves

    NARCIS (Netherlands)

    Westerhof, E.

    1994-01-01

    The essential elements of the theory of electron cyclotron waves are reviewed, The two main electro-magnetic modes of propagation are identified and their dispersion and absorption properties are discussed. The importance of the use of the relativistic resonance condition is stressed.

  2. Superconductivity and electron microscopy

    International Nuclear Information System (INIS)

    Hawkes, P.W.; Valdre, U.

    1977-01-01

    In this review article, two aspects of the role of superconductivity in electron microscopy are examined: (i) the development of superconducting devices (mainly lenses) and their incorporation in electron microscopes; (ii) the development of electron microscope techniques for studying fundamental and technological problems associated with superconductivity. The first part opens with a brief account of the relevant properties of conventional lenses, after which the various types of superconducting lenses are described and their properties compared. The relative merits and inconveniences of superconducting and conventional lenses are examined, particular attention being paid to the spherical and chromatic aberration coefficients at accelerating voltages above a megavolt. This part closes with a survey of the various microscope designs that have been built or proposed, incorporating superconducting components. In the second part, some methods that have been or might be used in the study of superconductivity in the electron microscope are described. A brief account of the types of application for which they are suitable is given. (author)

  3. Scanning electron microscope

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The principle underlying the design of the scanning electron microscope (SEM), the design and functioning of SEM are described. Its applications in the areas of microcircuitry and materials science are outlined. The development of SEM in India is reviewed. (M.G.B.)

  4. Electron Scattering on deuterium

    International Nuclear Information System (INIS)

    Platchkov, S.

    1987-01-01

    Selected electron scattering experiments on the deuteron system are discussed. The main advantages of the electromagnetic probe are recalled. The deuteron A(q 2 ) structure function is analyzed and found to be very sensitive to the neutron electric form factor. Electrodisintegration of the deuteron near threshold is presented as evidence for the importance of meson exchange currents in nuclei [fr

  5. Adaptive municipal electronic forms

    NARCIS (Netherlands)

    Kuiper, Pieternel; van Dijk, Elisabeth M.A.G.; Bondarouk, Tatiana; Ruel, Hubertus Johannes Maria; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    Adaptation of electronic forms (e-forms) seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer e-forms online that can be used by citizens to request a municipal product or service or by municipal employees to place a request on behalf of a

  6. Electronic structure of superlattices

    International Nuclear Information System (INIS)

    Altarelli, M.

    1987-01-01

    Calculations of electronic states in semiconductor superlattices are briefly reviewed, with emphasis on the envelope-function method and on comparison with experiments. The energy levels in presence of external magnetic fields are discussed and compared to magneto-optical experiments. (author) [pt

  7. Japan's electronic packaging technologies

    Science.gov (United States)

    Tummala, Rao R.; Pecht, Michael

    1995-02-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  8. Parity violating electron scattering

    International Nuclear Information System (INIS)

    McKeown, R.D.

    1990-01-01

    Previous measurements of parity violation in electron scattering are reviewed with particular emphasis on experimental techniques. Significant progress in the attainment of higher precision is evident in these efforts. These pioneering experiments provide a basis for consideration of a future program of such measurements. In this paper some future plans and possibilities in this field are discussed

  9. Electron hopping through proteins

    Czech Academy of Sciences Publication Activity Database

    Warren, J. J.; Ener, M. E.; Vlček, Antonín; Winkler, J. R.; Gray, H. B.

    2012-01-01

    Roč. 256, 21-22 (2012), s. 2478-2487 ISSN 0010-8545 R&D Projects: GA MŠk(CZ) ME10124 Institutional support: RVO:61388955 Keywords : electron transfer * multistep tunneling * hopping maps Subject RIV: CG - Electrochemistry Impact factor: 11.016, year: 2012

  10. MODULATED PLASMA ELECTRON BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, L. H.

    1963-08-15

    Techniques have been developed for producing electron beams of two amperes or more, from a plasma within a hollow cathode. Electron beam energies of 20 kilovolts are readily obtained and power densities of the order of 10,000 kilowatts per square inch can be obtained with the aid of auxiliary electromagnetic focusing. An inert gas atmosphere of a few microns pressure is used to initiate and maintain the beam. Beam intensity increases with both gas pressure and cathode potential but may be controlled by varying the potential of an internal electrode. Under constant pressure and cathode potential the beam intensity may be varied over a wide range by adjusting the potential of the internal control electrode. The effects of cathode design on the volt-ampere characteristics of the beam and the design of control electrodes are described. Also, performance data in both helium and argon are given. A tentative theory of the origin of electrons and of beam formation is proposed. Applications to vacuum metallurgy and to electron beam welding are described and illustrated. (auth)

  11. Accessing Electronic Journals.

    Science.gov (United States)

    McKay, Sharon Cline

    1999-01-01

    Discusses issues librarians need to consider when providing access to electronic journals. Topics include gateways; index and abstract services; validation and pay-per-view; title selection; integration with OPACs (online public access catalogs)or Web sites; paper availability; ownership versus access; usage restrictions; and services offered…

  12. Microchannel electron multiplier

    International Nuclear Information System (INIS)

    Beranek, I.; Janousek, L.; Vitovsky, O.

    1981-01-01

    A microchannel electron multiplier is described for detecting low levels of alpha, beta, soft X-ray and UV radiations. It consists of a glass tube or a system of tubes of various shapes made of common technological glass. The inner tube surface is provided with an active coat with photoemitter and secondary emitter properties. (B.S.)

  13. Electronic Mentoring of Research.

    Science.gov (United States)

    Gregory, Vicki L.

    On July 1, 1991, the ACRL (Association of College and Research Libraries) Research Committee launched a pilot project to mentor academic librarians in their conduct of research. Since the mentors and protegees were potentially from all over the United States, the decision was made to mentor using the electronic conferencing capability of BITNET…

  14. Electronics Book II.

    Science.gov (United States)

    Johnson, Dennis; And Others

    This manual, the second of three curriculum guides for an electronics course, is intended for use in a program combining vocational English as a second language (VESL) with bilingual vocational education. Ten units cover the electrical team, Ohm's law, Watt's law, series resistive circuits, parallel resistive circuits, series parallel circuits,…

  15. Electronic waste recycling techniques

    CERN Document Server

    Bernardes, Andréa

    2015-01-01

    This book presents an overview of the characterization of electronic waste. In addition, processing techniques for the recovery of metals, polymers and ceramics are described. This book serves as a source of information and as an educational technical reference for practicing scientists and engineers, as well as for students.

  16. Electronic Journalism: More Fear?

    Science.gov (United States)

    Terry, Carolyn

    2002-01-01

    Considers how the same First Amendment protections that govern print journalism apply to electronic practitioners. Discusses how the number of broadcast and online journalism classes at the nation's high schools demonstrate steady growth, according to a survey conducted in the fall of 2001 for the Radio and Television News Directors Foundation.…

  17. Interatomic Coulombic electron capture

    International Nuclear Information System (INIS)

    Gokhberg, K.; Cederbaum, L. S.

    2010-01-01

    In a previous publication [K. Gokhberg and L. S. Cederbaum, J. Phys. B 42, 231001 (2009)] we presented the interatomic Coulombic electron capture process--an efficient electron capture mechanism by atoms and ions in the presence of an environment. In the present work we derive and discuss the mechanism in detail. We demonstrate thereby that this mechanism belongs to a family of interatomic electron capture processes driven by electron correlation. In these processes the excess energy released in the capture event is transferred to the environment and used to ionize (or to excite) it. This family includes the processes where the capture is into the lowest or into an excited unoccupied orbital of an atom or ion and proceeds in step with the ionization (or excitation) of the environment, as well as the process where an intermediate autoionizing excited resonance state is formed in the capturing center which subsequently deexcites to a stable state transferring its excess energy to the environment. Detailed derivation of the asymptotic cross sections of these processes is presented. The derived expressions make clear that the environment assisted capture processes can be important for many systems. Illustrative examples are presented for a number of model systems for which the data needed to construct the various capture cross sections are available in the literature.

  18. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    Twentieth century bore witness to remarkable scientists whohave advanced our understanding of the brain. Among them,EPR (Electron Paramagnetic Resonance) imaging is particularlyuseful in monitoring hypoxic zones in tumors which arehighly resistant to radiation and chemotherapeutic treatment.This first part of the ...

  19. Electronic transport properties

    International Nuclear Information System (INIS)

    Young, W.H.

    1985-01-01

    The theory of the electron transport properties of liquid alkali metals is described. Conductivity coefficients, Boltzmann theory, Ziman theory, alkali form factors, Ziman theory and alkalis, Faber-Ziman alloy theory, Faber-Ziman theory and alkali-alkali methods, status of Ziman theory, and other transport properties, are all discussed. (UK)

  20. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.