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Sample records for repeated vacuum fermentation

  1. Dynamic lipidomic insights into the adaptive responses of Saccharomyces cerevisiae to the repeated vacuum fermentation.

    Science.gov (United States)

    Zhou, Xiao; Zhou, Jian; Tian, Hongchi; Yuan, Yingjin

    2010-10-01

    Vacuum fermentation is utilized in a wide range of life science industries and biomedical R&D. Little is known, however, on the effects of the vacuum on the yeast, and in particular, on the yeast lipidome that plays a central role in maintaining cell membrane and other vital (yeast) cell functions. The present study evaluated the adaptive responses of Saccharomyces cerevisiae to repeated vacuum fermentation by lipidomic analysis. We employed gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI/MS(n)) to quantify a total of 13 intermediate sterols and 139 phospholipid species of yeast cells. Principal components analysis found that the PI (phosphatidylinositol) 26:0, PI 28:0, PE (phosphatidylethanolamine) 32:1, and PE 34:1 were potential biomarkers to distinguish the vacuum fermentation process. Quantitative analysis showed that vacuum fermentation increased the synthesis of PI and the PC (phosphatidylcholine) species with short saturated acyl chains. The synthesis of PC via CDP-choline and turnover of PC were enhanced, instead of formation via methylation of PE. Additionally, increased PI at the expense of PE and PG (phosphatidylglycerol) was associated with enhancement of ethanol productivity. Vacuum fermentation caused eburicol accumulation, suggesting that vacuum can activate the branch of the ergosterol biosynthesis pathway. Eburicol decrease and PI increase contributed to recovery of cellular activities with oxygenating treatment. Ethanol productivity was increased by sixfold in vacuum-treated cells. These observations may allow the development of future mechanistic approaches to optimization of yeast fermentation under vacuum for bioindustry and life science applications. In particular, our findings on changes in lipid molecular species and the ergosterol biosynthesis pathway elucidate the defense responses of yeast cell membranes during the repeated

  2. Vacuum stripping of ethanol during high solids fermentation of corn.

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    Shihadeh, Jameel K; Huang, Haibo; Rausch, Kent D; Tumbleson, Mike E; Singh, Vijay

    2014-05-01

    In corn-ethanol industry, yeast stress inducing glucose concentrations produced during liquefaction and subsequent high ethanol concentrations produced during fermentation restrict slurry solids to 32 % w/w. These limits were circumvented by combining two novel technologies: (1) granular starch hydrolyzing enzyme (GSHE) to break down starch simultaneously with fermentation and (2) vacuum stripping to remove ethanol. A vacuum stripping system was constructed and applied to fermentations at 30, 40, and 45 % solids. As solids increased from 30 to 40 %, ethanol yield decreased from 0.35 to 0.29 L/kg. Ethanol yield from 45 % solids was only 0.18 L/kg. An improvement was conducted by increasing enzyme dose from 0.25 to 0.75 g/g corn and reducing yeast inoculum by half. After improvement, ethanol yield from 40 % solids vacuum treatment increased to 0.36 L/kg, comparable to ethanol yield from 30 % solids (control).

  3. Vacuum packing: a model system for laboratory-scale silage fermentations.

    Science.gov (United States)

    Johnson, H E; Merry, R J; Davies, D R; Kell, D B; Theodorou, M K; Griffith, G W

    2005-01-01

    To determine the utility of vacuum-packed polythene bags as a convenient, flexible and cost-effective alternative to fixed volume glass vessels for lab-scale silage studies. Using perennial ryegrass or red clover forage, similar fermentations (as assessed by pH measurement) occurred in glass tube and vacuum-packed silos over a 35-day period. As vacuum-packing devices allow modification of initial packing density, the effect of four different settings (initial packing densities of 0.397, 0.435, 0.492 and 0.534 g cm(-3)) on the silage fermentation over 16 days was examined. Significant differences in pH decline and lactate accumulation were observed at different vacuum settings. Gas accumulation was apparent within all bags and changes in bag volume with time was observed to vary according to initial packing density. Vacuum-packed silos do provide a realistic model system for lab-scale silage fermentations. Use of vacuum-packed silos holds potential for lab-scale evaluations of silage fermentations, allowing higher throughput of samples, more consistent packing as well as the possibility of investigating the effects of different initial packing densities and use of different wrapping materials.

  4. 2,3-Butanediol recovery from fermentation broth by alcohol precipitation and vacuum distillation.

    Science.gov (United States)

    Jeon, Sangjun; Kim, Duk-Ki; Song, Hyohak; Lee, Hee Jong; Park, Sunghoon; Seung, Doyoung; Chang, Yong Keun

    2014-04-01

    This study presents a new and effective downstream process to recover 2,3-butanediol (2,3-BD) from fermentation broth which is produced by a recombinant Klebsiella pneumoniae strain. The ldhA-deficient K. pneumoniae strain yielded about 90 g/L of 2,3-BD, along with a number of by-products, such as organic acids and alcohols, in a 65 h fed-batch fermentation. The pH-adjusted cell-free fermentation broth was firstly concentrated until 2,3-BD reached around 500 g/L by vacuum evaporation at 50°C and 50 mbar vacuum pressure. The concentrated solution was further treated using light alcohols, including methanol, ethanol, and isopropanol, for the precipitation of organic acids and inorganic salts. Isopropanol showed the highest removal efficiency, in which 92.5% and 99.8% of organic acids and inorganic salts were precipitated, respectively. At a final step, a vacuum distillation process enabled the recovery of 76.2% of the treated 2,3-BD, with 96.1% purity, indicating that fermentatively produced 2,3-BD is effectively recovered by a simple alcohol precipitation and vacuum distillation. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Production of ethyl alcohol by a repeated batch fermentation method. Kurikaeshi kaibun hakkoho ni yoru arukoru no seizoho

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, T. (Tokyo (Japan)); Takagi, Y. (Chiba (Japan)); Shiba, M. (Kagoshima (Japan))

    1994-01-11

    This invention relates to a production method of ethyl alcohol from sugar and starch raw materials by a repeated batch fermentation method and aims to provide a method to produce ethyl alcohol efficiently by accurate repetition. Conventional batch fermentation methods require the experiences and skill to confirm an end point of the fermentation and have a problem in a control of repeated batch fermentation. This invention uses a gas flow meter of a velocity head measurement type and judges an end point of fermentation at a time when the amount of the exhaust gas flow from the fermentation is 0.35 to 0.1 m[sup 3] per hour and per 1 kl fermentation liquid or below and the next batch fermentation is started. By this invention, ethyl alcohol is produced efficiently from the raw materials with less damage of the yeast and efficient repeated batch fermentation is realized. 6 figs., 1 tab.

  6. Repeated batch fermentation from raw starch using a maltose transporter and amylase expressing diploid yeast strain.

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    Yamakawa, Syun-ichi; Yamada, Ryosuke; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

    2010-06-01

    We successfully demonstrated batch ethanol fermentation repeated ten times from raw starch with high ethanol productivity. We constructed a yeast diploid strain coexpressing the maltose transporter AGT1, alpha-amylase, and glucoamylase. The introduction of AGT1 allows maltose and maltotriose fermentation as well as the improvement of amylase activities. We also found that alpha-amylase activity during fermentation was retained by the addition of 10 mM calcium ion and that the highest alpha-amylase activity was 9.26 U/ml during repeated fermentation. The highest ethanol productivity was 2.22 g/l/h at the fourth batch, and after ten cycles, ethanol productivity of more than 1.43 g/l/h was retained, as was alpha-amylase activity at 6.43 U/ml.

  7. COMPARISON OF VACUUM AND HIGH PRESSURE EVAPORATED WOOD HYDROLYZATE FOR ETHANOL PRODUCTION BY REPEATED FED-BATCH USING FLOCCULATING SACCHAROMYCES CEREVISIAE

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    Anahita Dehkhoda

    2009-02-01

    Full Text Available With the aim of increasing the sugars concentration in dilute-acid ligno-cellulosic hydrolyzate to more than 100 g/l for industrial applications, the hydrolyzate from spruce was concentrated about threefold by high-pressure or vacuum evaporations. It was then fermented by repeated fed-batch cultivation using flocculating Saccharomyces cerevisiae with no prior detoxification. The sugars and inhibitors concentrations in the hydrolyzates were compared after the evaporations and also fermenta-tion. The evaporations were carried out either under vacuum (VEH at 0.5 bar and 80°C or with 1.3 bar pressure (HPEH at 107.5°C, which resulted in 153.3 and 164.6 g/l total sugars, respectively. No sugar decomposition occurred during either of the evaporations, while more than 96% of furfural and to a lesser extent formic and acetic acids disappeared from the hydrolyzates. However, HMF and levulinic acid remained in the hydrolyzates and were concentrated proportionally. The concentrated hydrolyzates were then fermented in a 4 l bioreactor with 12-22 g/l yeast and 0.14-0.22 h-1 initial dilute rates (ID. More than 84% of the fermentable sugars present in the VEH were fermented by fed-batch cultivation using 12 g/l yeast and initial dilution rate (ID of 0.22 h-1, and resulted in 0.40±0.01 g/g ethanol from the fermentable sugars in one cycle of fermentation. Fermentation of HPEH was as successful as VEH and resulted in more than 86% of the sugar consumption under the corresponding conditions. By lowering the initial dilution rate to 0.14 h-1, more than 97% of the total fermentable sugars were consumed, and ethanol yield was 0.44±0.01 g/g in one cycle of fermentation. The yeast was able to convert or assimilate HMF, levulinic, acetic, and formic acids by 96, 30, 43, and 74%, respectively.

  8. Improving cellulase productivity of Penicillium oxalicum RE-10 by repeated fed-batch fermentation strategy.

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    Han, Xiaolong; Song, Wenxia; Liu, Guodong; Li, Zhonghai; Yang, Piao; Qu, Yinbo

    2017-03-01

    Medium optimization and repeated fed-batch fermentation were performed to improve the cellulase productivity by P. oxalicum RE-10 in submerged fermentation. First, Plackett-Burman design (PBD) and central composite design (CCD) were used to optimize the medium for cellulase production. PBD demonstrated wheat bran and NaNO3 had significant influences on cellulase production. The CCD results showed the maximum filter paper activity (FPA) production of 8.61U/mL could be achieved in Erlenmeyer flasks. The maximal FPA reached 12.69U/mL by submerged batch fermentation in a 7.5-L stirred tank, 1.76-fold higher than that on the original medium. Then, the repeated fed-batch fermentation strategy was performed successfully for increasing the cellulase productivity from 105.75U/L/h in batch fermentation to 158.38U/L/h. The cellulase activity and the glucan conversion of delignined corn cob residue hydrolysis had no significant difference between the enzymes sampled from different cycles of the repeated fed-batch fermentation and that from batch culture.

  9. The morphology of Ganoderma lucidum mycelium in a repeated-batch fermentation for exopolysaccharide production

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    Wan Abd Al Qadr Imad Wan-Mohtar

    2016-09-01

    Full Text Available The morphology of Ganoderma lucidum BCCM 31549 mycelium in a repeated-batch fermentation (RBF was studied for exopolysaccharide (EPS production. RBF was optimised for time to replace and volume to replace. G. lucidum mycelium showed the ability to self-immobilise and exhibited high stability for repeated use in RBF with engulfed pellets. Furthermore, the ovoid and starburst-like pellet morphology was disposed to EPS production in the shake flask and bioreactor, respectively. Seven RBF could be carried out in 500 mL flasks, and five repeated batches were performed in a 2 L bioreactor. Under RBF conditions, autolysis of pellet core in the shake flask and shaving off of the outer hairy region in the bioreactor were observed at the later stages of RBF (R4 for the shake flask and R6 for the bioreactor. The proposed strategy showed that the morphology of G. lucidum mycelium can withstand extended fermentation cycles.

  10. Butanol production from lignocellulose by simultaneous fermentation, saccharification, and pervaporation or vacuum evaporation.

    Science.gov (United States)

    Díaz, Víctor Hugo Grisales; Tost, Gerard Olivar

    2016-10-01

    Techno-economic study of acetone, butanol and ethanol (ABE) fermentation from lignocellulose was performed. Simultaneous saccharification, fermentation and vacuum evaporation (SFS-V) or pervaporation (SFS-P) were proposed. A kinetic model of metabolic pathways for ABE fermentation with the effect of phenolics and furans in the growth was proposed based on published laboratory results. The processes were optimized in Matlab®. The end ABE purification was carried out by heat-integrated distillation. The objective function of the minimization was the total annualized cost (TAC). Fuel consumption of SFS-P using poly[1-(trimethylsilyl)-1-propyne] membrane was between 13.8 and 19.6% lower than SFS-V. Recovery of furans and phenolics for the hybrid reactors was difficult for its high boiling point. TAC of SFS-P was increased 1.9 times with supplementation of phenolics and furans to 3g/l each one for its high toxicity. Therefore, an additional detoxification method or an efficient pretreatment process will be necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Repeated fermentation from raw starch using Saccharomyces cerevisiae displaying both glucoamylase and α-amylase.

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    Yamakawa, Syun-ichi; Yamada, Ryosuke; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

    2012-05-10

    A diploid yeast strain displaying both α-amylase and glucoamylase was developed for repeated fermentation from raw starch. First, the construct of α-amylase was optimized for cell surface display, as there have been no reports of α-amylase-displaying yeast. The modified yeast displaying both glucoamylase and α-amylase produced 46.5 g/l of ethanol from 200 g/l of raw corn starch after 120 h of fermentation, and this was 1.5-fold higher when compared to native α-amylase-displaying yeast. Using the glucoamylase and modified α-amylase co-displaying diploid strain, we repeated fermentation from 100g/l of raw starch for 23 cycles without the loss of α-amylase or glucoamylase activity. The average ethanol productivity and yield during repeated fermentation were 1.61 g/l/h and 76.6% of the theoretical yield, respectively. This novel yeast may be useful for reducing the cost of bio-ethanol production and may be suitable for industrial-scale bio-ethanol production.

  12. Repeating Pulsed Magnet System for Axion-like Particle Searches and Vacuum Birefringence Experiments

    CERN Document Server

    Yamazaki, T; Namba, T; Asai, S; Kobayashi, T; Matsuo, A; Kindo, K; Nojiri, H

    2016-01-01

    We have developed a repeating pulsed magnet system which generates magnetic fields of about 10 T in a direction transverse to an incident beam over a length of 0.8 m with a repetition rate of 0.2 Hz. Its repetition rate is by two orders of magnitude higher than usual pulsed magnets. It is composed of four low resistance racetrack coils and a 30 kJ transportable capacitor bank as a power supply. The system aims at axion-like particle searches with a pulsed light source and vacuum birefringence measurements. We report on the details of the system and its performances.

  13. Repeating pulsed magnet system for axion-like particle searches and vacuum birefringence experiments

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    Yamazaki, T.; Inada, T.; Namba, T.; Asai, S.; Kobayashi, T.; Matsuo, A.; Kindo, K.; Nojiri, H.

    2016-10-01

    We have developed a repeating pulsed magnet system which generates magnetic fields of about 10 T in a direction transverse to an incident beam over a length of 0.8 m with a repetition rate of 0.2 Hz. Its repetition rate is by two orders of magnitude higher than usual pulsed magnets. It is composed of four low resistance racetrack coils and a 30 kJ transportable capacitor bank as a power supply. The system aims at axion-like particle searches with a pulsed light source and vacuum birefringence measurements. We report on the details of the system and its performances.

  14. Butanol production by immobilised Clostridium acetobutylicum in repeated batch, fed-batch, and continuous modes of fermentation.

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    Dolejš, Igor; Krasňan, Vladimír; Stloukal, Radek; Rosenberg, Michal; Rebroš, Martin

    2014-10-01

    Clostridium acetobutylicum immobilised in polyvinylalcohol, lens-shaped hydrogel capsules (LentiKats(®)) was studied for production of butanol and other products of acetone-butanol-ethanol fermentation. After optimising the immobilisation protocol for anaerobic bacteria, continuous, repeated batch, and fed-batch fermentations in repeated batch mode were performed. Using glucose as a substrate, butanol productivity of 0.41 g/L/h and solvent productivity of 0.63 g/L/h were observed at a dilution rate of 0.05 h(-1) during continuous fermentation with a concentrated substrate (60 g/L). Through the process of repeated batch fermentation, the duration of fermentation was reduced from 27.8h (free-cell fermentation) to 3.3h (immobilised cells) with a solvent productivity of 0.77 g/L/h (butanol 0.57 g/L/h). The highest butanol and solvent productivities of 1.21 and 1.91 g/L/h were observed during fed-batch fermentation operated in repeated batch mode with yields of butanol (0.15 g/g) and solvents (0.24 g/g), respectively, produced per gram of glucose.

  15. Aroma improvement by repeated freeze-thaw treatment during Tuber melanosporum fermentation

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    Xiao, Deng-Rong; Liu, Rui-Sang; He, Long; Li, Hong-Mei; Tang, Ya-Ling; Liang, Xin-Hua; Chen, Tao; Tang, Ya-Jie

    2015-01-01

    The aroma attributes of sulfurous, mushroom and earthy are the most important characteristics of the aroma of Tuber melanosporum. However, these three aroma attributes are absent in the T. melanosporum fermentation system. To improve the quality of the aroma, repeated freeze-thaw treatment (RFTT) was adopted to affect the interplay of volatile organic compounds (VOCs). Using RFTT, not only was the score on the hedonic scale of the aroma increased from the “liked slightly” to the “liked moderately” grade, but the aroma attributes of sulfurous, mushroom and earthy could also be smelled in the T. melanosporum fermentation system for the first time. A total of 29 VOCs were identified, and 9 compounds were identified as the key discriminative volatiles affected by RFTT. Amino acid analysis revealed that methionine, valine, serine, phenylalanine, isoleucine and threonine were the key substrates associated with the biosynthesis of the 9 key discriminative VOCs. This study noted that amino acid metabolism played an important role in the regulation of the aroma of the T. melanosporum fermentation system. PMID:26607288

  16. Aroma improvement by repeated freeze-thaw treatment during Tuber melanosporum fermentation.

    Science.gov (United States)

    Xiao, Deng-Rong; Liu, Rui-Sang; He, Long; Li, Hong-Mei; Tang, Ya-Ling; Liang, Xin-Hua; Chen, Tao; Tang, Ya-Jie

    2015-11-26

    The aroma attributes of sulfurous, mushroom and earthy are the most important characteristics of the aroma of Tuber melanosporum. However, these three aroma attributes are absent in the T. melanosporum fermentation system. To improve the quality of the aroma, repeated freeze-thaw treatment (RFTT) was adopted to affect the interplay of volatile organic compounds (VOCs). Using RFTT, not only was the score on the hedonic scale of the aroma increased from the "liked slightly" to the "liked moderately" grade, but the aroma attributes of sulfurous, mushroom and earthy could also be smelled in the T. melanosporum fermentation system for the first time. A total of 29 VOCs were identified, and 9 compounds were identified as the key discriminative volatiles affected by RFTT. Amino acid analysis revealed that methionine, valine, serine, phenylalanine, isoleucine and threonine were the key substrates associated with the biosynthesis of the 9 key discriminative VOCs. This study noted that amino acid metabolism played an important role in the regulation of the aroma of the T. melanosporum fermentation system.

  17. Improvement of l-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation.

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    Wang, Yong; Meng, Hongyu; Cai, Di; Wang, Bin; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-07-01

    In order to efficiently produce l-lactic acid from non-food feedstocks, sweet sorghum juice (SSJ), which is rich of fermentable sugars, was directly used for l-lactic acid fermentation by Lactobacillus rhamnosus LA-04-1. A membrane integrated repeated batch fermentation (MIRB) was developed for productivity improvement. High-cell-density fermentation was achieved with a final cell density (OD620) of 42.3, and the CCR effect was overcomed. When SSJ (6.77gL(-1) glucose, 4.51gL(-1) fructose and 50.46gL(-1) sucrose) was used as carbon source in MIRB process, l-lactic acid productivity was increased significantly from 1.45gL(-1)h(-1) (batch 1) to 17.55gL(-1)h(-1) (batch 6). This process introduces an effective way to produce l-lactic acid from SSJ.

  18. Efficient production of bioactive metabolites from Antrodia camphorata ATCC 200183 by asexual reproduction-based repeated batch fermentation.

    Science.gov (United States)

    Li, Hua-Xiang; Lu, Zhen-Ming; Geng, Yan; Gong, Jin-Song; Zhang, Xiao-Juan; Shi, Jin-Song; Xu, Zheng-Hong; Ma, Yan-He

    2015-10-01

    Large-scale submerged fermentation (SmF) of Antrodia camphorata (A. camphorata) usually encounters challenges including tedious preparation of mycelial inoculum, long fermentation period (10-14 d), and poor repeatability. Here we developed an asexual reproduction-based repeated batch fermentation (RBF) process for bioactive metabolites production by A. camphorata ATCC 200183. Compared with traditional batch fermentation, production time was shortened to 58 d from 80 d (overall time for eight cycles) using the RBF process established in this study, and accordingly, the productivities of bioactive metabolites (including antrodins) were improved by 40-60%. Kinetic parameters (α is 2.1-18.7 times as β) indicated that the cell growth was the major contribution for bioactive metabolites production. The RBF shows excellent batch-repeatability (Pearson correlation coefficient of 0.998±0.001), together with advantages of energy-efficient, low cost, and labor-saving, RBF process can be implemented to SmF by other filamentous fungi.

  19. Survival of experimentally induced Toxoplasma gondii tissue cysts in vacuum packed goat meat and dry fermented goat meat sausages.

    Science.gov (United States)

    Neumayerová, Helena; Juránková, Jana; Saláková, Alena; Gallas, Leo; Kovařčík, Kamil; Koudela, Břetislav

    2014-05-01

    Ingestion of raw or undercooked meat is a potential source of human toxoplasmosis. The aim of this study was to determine the viability of Toxoplasma gondii cysts in vacuum packed (VP) goat meat and in dry fermented sausages (DFS), and evaluate certain physical and chemical parameters, like water activity (aw), pH value, content of salt, dry matter and fat. A portion of muscle tissue from experimentally infected animals was used for production of VP meat with or without addition of 2.5% curing salt, and stored at 4 °C or at -20 °C. Results of bioassay showed that, samples of vacuum packed Toxoplasma positive meat without salt addition were alive after six weeks at 4 °C. Incubation at -20 °C supported the viability after 3 h, but not after 4 h. After 7 days in 2.5% of curing salt, samples of T. gondii VP goat meat were still viable, but not after 14 days at 4 °C. All the DFS samples were not positive for infective cysts which mean that, they do not pose a risk of T. gondii transmission. These data suggest that vacuum packaging increases the survival of T. gondii cysts.

  20. Microencapsulation of Baker’s Yeast in Gellan Gum Beads Used in Repeated Cycles of Glucose Fermentation

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    Camelia Elena Iurciuc (Tincu

    2017-01-01

    Full Text Available The purpose of this work is to prepare ionically cross-linked (with CaCl2 gellan particles with immobilized yeast cells for their use in repeated fermentation cycles of glucose. The study investigates the influence of ionic cross-linker concentration on the stability and physical properties of the particles obtained before extrusion and during time in the coagulation bath (the cross-linker solution with different CaCl2 concentrations. It was found that by increasing the amount of the cross-linker the degree of cross-linking in the spherical gellan matrix increases, having a direct influence on the particle morphology and swelling degree in water. These characteristics were found to be very important for diffusion of substrate, that is, the glucose, into the yeast immobilized cells and for the biocatalytic activity of the yeast immobilized cells in gellan particles. These results highlight the potential of these bioreactors to be used in repeated fermentation cycles (minimum 10 without reducing their biocatalytic activity and maintaining their productivity at similar parameters to those obtained in the free yeast fermentation. Encapsulation of Saccharomyces cerevisiae into the gellan gum beads plays a role in the effective application of immobilized yeast for the fermentation process.

  1. Effect of the ripening time under vacuum and packaging film permeability on processing and quality characteristics of low-fat fermented sausages.

    Science.gov (United States)

    Liaros, N G; Katsanidis, E; Bloukas, J G

    2009-12-01

    The effect of vacuum ripening of low-fat fermented sausages packaged in films with different permeabilities on their microbiological, physicochemical and sensorial characteristics was studied. High-fat control sausages were produced with 30% initial fat and low-fat sausages with 10% initial fat. The low-fat sausages were separated into: (a) non-packaged (control) and (b) packaged under vacuum on 7th, 12th and 17th day of processing, remaining under vacuum during the ripening period for 21, 16 and 11days, respectively, in three different oxygen (100, 38 and⩽5cm(3)/m(2)/24h/1atm) and water vapour (4.5, sausages, increased (p0.05) on the redness, compared to the control sausages. Packaging low-fat fermented sausages under vacuum for the last 11days of ripening in packaging film with high permeability increased (p0.05) hardness and overall acceptability as the high-fat control sausages. A ripening time of 11days and the medium packaging film permeability were the most appropriate conditions for the vacuum packaging of low-fat fermented sausages.

  2. Long-term production of bioethanol in repeated-batch fermentation of microalgal biomass using immobilized Saccharomyces cerevisiae.

    Science.gov (United States)

    El-Dalatony, Marwa M; Kurade, Mayur B; Abou-Shanab, Reda A I; Kim, Hoo; Salama, El-Sayed; Jeon, Byong-Hun

    2016-11-01

    Separate hydrolysis fermentation (SHF) and simultaneous saccharification fermentation (SSF) processes were studied for bioethanol production from microalgal biomass. SSF was selected as an efficient process to enhance the bioethanol yield through repeated-batches using immobilized yeast cells. Combined sonication and enzymatic hydrolysis of Chlamydomonas mexicana generated 10.5 and 8.48g/L of ethanol in SSF and SHF, respectively. Yeast utilized maximum portion of total reducing sugar (TRS) reaching a consumption efficiency of 91-98%. A bioethanol yield of 0.5g/g (88.2% of theoretical yield) and volumetric productivity of 0.22g/L/h was obtained after 48h of SSF. Immobilized yeast cells enabled repetitive production of ethanol for 7 cycles displaying a fermentation efficiency up to 79% for five consecutive cycles. The maximum ethanol production was 9.7g/L in 2nd-4th cycles. A total energy recovery of 85.81% was achieved from microalgal biomass in the form of bioethanol. Repeated-batch SSF demonstrated the possibility of cost-effective bioethanol production.

  3. Dynamics of hydrogen-producing bacteria in a repeated batch fermentation process using lake sediment as inoculum.

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    Romano, Stefano; Paganin, Patrizia; Varrone, Cristiano; Tabacchioni, Silvia; Chiarini, Luigi

    2014-02-01

    In this study, we evaluated the effectiveness of lake sediment as inoculum for hydrogen production through dark fermentation in a repeated batch process. In addition, we investigated the effect of heat treatment, applied to enrich hydrogen-producing bacteria, on the bacterial composition and metabolism. Denaturing gradient gel electrophoresis and molecular cloning, both performed using the 16S rDNA gene as target gene, were used to monitor the structure of the bacterial community. Hydrogen production and bacterial metabolism were analysed via gas chromatography and high-performance liquid chromatography. Both treated and non-treated inocula were able to produce high amounts of hydrogen. However, statistical analysis showed a clear difference in their bacterial composition and metabolism. The heat treatment favoured the growth of different Clostridia sp., in particular of Clostridium bifermentans, allowing the production of a constant amount of hydrogen over prolonged time. These cultures showed both butyrate and ethanol fermentation types. Absence of heat treatment allowed species belonging to the genera Bacillus, Sporolactobacillus and Massilia to outgrow Clostridia sp. with a reduction in hydrogen production and a significant metabolic change. Our data indicate that lake sediment harbours bacteria that can efficiently produce hydrogen over prolonged fermentation time. Moreover, we could show that the heat treatment stabilizes the bacterial community composition and the hydrogen production.

  4. [A comparison of the rates of hemolysis and repeated blood sampling using syringe needles versus vacuum tube needles in the emergency department].

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    Sung, Young Hee; Hwang, Moon Sook; Lee, Jee Hyang; Park, Hyung Doo; Ryu, Kwang Hyun; Cho, Myung Sook; Yi, Young Hee; Song, S

    2012-06-01

    This study was done to compare the rates of hemolysis and repeated sampling in blood samples obtained by a syringe needle versus a vacuum tube needle. A randomized, prospective study was used to evaluate the differences between the two blood sampling methods. The study group consisted of patients seen in the emergency department (ED) for blood sampling to determine electrolyte level. ED patients were randomly assigned to either the syringe group or the vacuum tube group. All blood samples were collected by experienced ED nurses and hemolysis was determined by experienced laboratory technologists. Data were analyzed using Fisher's exact test and binary logistic regression. One hundred forty-five valid samples were collected (74 in the syringe group versus 71 in the vacuum tube group). 5 of 74 (6.8%) blood samples in the syringe group and 8 of 71 (11.3%) in the vacuum tube group hemolyzed. Repeated blood sampling occurred for 2 of 74 (2.7%) and 3 of 71 (4.2%) in each group respectively. There were no significant differences in rates of hemolysis and repeated sampling between two groups (B=1.97, p=.204; B=2.36, p=.345). Venipuncture with syringe needles can be recommended for ED nurses to obtain blood samples.

  5. One Approach for Dynamic L-lysine Modelling of Repeated Fed-batch Fermentation

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    Kalin Todorov

    2007-03-01

    Full Text Available This article deals with establishment of dynamic unstructured model of variable volume fed-batch fermentation process with intensive droppings for L-lysine production. The presented approach of the investigation includes the following main procedures: description of the process by generalized stoichiometric equations; preliminary data processing and calculation of specific rates for main kinetic variables; identification of the specific rates as a second-order non-linear dynamic models; establishment and optimisation of dynamic model of the process; simulation researches. MATLAB is used as a research environment.

  6. L-Lactic acid production by combined utilization of agricultural bioresources as renewable and economical substrates through batch and repeated-batch fermentation of Enterococcus faecalis RKY1.

    Science.gov (United States)

    Reddy, Lebaka Veeranjaneya; Kim, Young-Min; Yun, Jong-Sun; Ryu, Hwa-Won; Wee, Young-Jung

    2016-06-01

    Enterococcus faecalis RKY1 was used to produce l-lactic acid from hydrol, soybean curd residues (SCR), and malt. Hydrol was efficiently metabolized to l-lactic acid with optical purity of >97.5%, though hydrol contained mixed sugars such as glucose, maltose, maltotriose, and maltodextrin. Combined utilization of hydrol, SCR, and malt was enough to sustain lactic acid fermentation by E. faecalis RKY1. In order to reduce the amount of nitrogen sources and product inhibition, cell-recycle repeated-batch fermentation was employed, where a high cell mass (26.3g/L) was obtained. Lactic acid productivity was improved by removal of lactic acid from fermentation broth by membrane filtration and by linearly increased cell density. When the total of 10 repeated-batch fermentations were carried out using 100g/L hydrol, 150g/L SCR hydrolyzate, and 20g/L malt hydrolyzate as the main nutrients, lactic acid productivity was increased significantly from 3.20g/L/h to 6.37g/L/h.

  7. Enhancement of fermentative hydrogen production in an extreme-thermophilic (70°C) mixed-culture environment by repeated batch cultivation.

    Science.gov (United States)

    Lu, Wenjing; Fan, Gaoyuan; Zhao, Chenxi; Wang, Hongtao; Chi, Zifang

    2012-05-01

    Repeated batch cultivation was applied to enrich hydrogen fermentative microflora under extreme-thermophilic (70°C) environment. Initial inoculums received from a hydrogen producing reactor fed with organic fraction of household solid wastes. In total seven transfers was conducted and maximum hydrogen yield reached 296 ml H(2)/g (2.38 mol/mol) glucose and 252 ml H(2)/g (2.03 mol/mol) for 1 and 2 g/l glucose medium, respectively. It was found that hydrogen production was firstly decreased and got increased gradually from third generation. Acetate was found to be the main metabolic by-product in all batch cultivation. Furthermore, the diversity of bacterial community got decreased after repeated batch cultivation. It was proved that repeated batch cultivation was a good method to enhance the hydrogen production by enriching the mixed cultures of dominant species.

  8. Improving lactic acid productivity from wheat straw hydrolysates by membrane integrated repeated batch fermentation under non-sterilized conditions

    DEFF Research Database (Denmark)

    Zhang, Yuming; Chen, Xiangrong; Qi, Benkun

    2014-01-01

    Bacillus coagulans IPE22 was used to produce lactic acid (LA) from mixed sugar and wheat straw hydrolysates, respectively. All fermentations were conducted under non-sterilized conditions and sodium hydroxide was used as neutralizing agent to avoid the production of insoluble CaSO4. In order to e...

  9. Modelling of L-valine Repeated Fed-batch Fermentation Process Taking into Account the Dissolved Oxygen Tension

    Directory of Open Access Journals (Sweden)

    Tzanko Georgiev

    2009-03-01

    Full Text Available This article deals with synthesis of dynamic unstructured model of variable volume fed-batch fermentation process with intensive droppings for L-valine production. The presented approach of the investigation includes the following main procedures: description of the process by generalized stoichiometric equations; preliminary data processing and calculation of specific rates for main kinetic variables; identification of the specific rates takes into account the dissolved oxygen tension; establishment and optimisation of dynamic model of the process; simulation researches. MATLAB is used as a research environment.

  10. Repeated-batch fermentation of lignocellulosic hydrolysate to ethanol using a hybrid Saccharomyces cerevisiae strain metabolically engineered for tolerance to acetic and formic acids.

    Science.gov (United States)

    Sanda, Tomoya; Hasunuma, Tomohisa; Matsuda, Fumio; Kondo, Akihiko

    2011-09-01

    A major challenge associated with the fermentation of lignocellulose-derived hydrolysates is improved ethanol production in the presence of fermentation inhibitors, such as acetic and formic acids. Enhancement of transaldolase (TAL) and formate dehydrogenase (FDH) activities through metabolic engineering successfully conferred resistance to weak acids in a recombinant xylose-fermenting Saccharomyces cerevisiae strain. Moreover, hybridization of the metabolically engineered yeast strain improved ethanol production from xylose in the presence of both 30 mM acetate and 20mM formate. Batch fermentation of lignocellulosic hydrolysate containing a mixture of glucose, fructose and xylose as carbon sources, as well as the fermentation inhibitors, acetate and formate, was performed for five cycles without any loss of fermentation capacity. Long-term stability of ethanol production in the fermentation phase was not only attributed to the coexpression of TAL and FDH genes, but also the hybridization of haploid strains.

  11. Drying performance of fermented cassava (fercaf) using a convective multiple flash dryer

    Science.gov (United States)

    Handojo, Lienda A.; Zefanya, Samuel; Christanto, Yohanes

    2017-05-01

    Fermented cassava (fercaf) is a tropical versatile carbohydrate source flour which is produced by modifying the characteristics of cassava. Drying process is one of the processes that could influence the quality of fercaf. In general, for food application, convective and vacuum drying were used, however recently another advanced method using combination of both convective and vacuum, i.e. convective multiple flash drying (CMFD), was proposed. This method is conducted by repeating cycles of convective and vacuum drying in intermittent manner. Cassava chips with thickness of 0.1-0.2 cm were fermented for 24 hours at room condition. Then, the drying process was conducted by using 3 techniques, i.e. convective, vacuum, and combined method (CMFD), with operation temperatures between 50 and 70°C for 10 hours or until fermented cassava reached a moisture content of less than 20%. The study shows that CMFD was the fastest drying method with only 5-6 hours period compared to 8-10 hours using vacuum and more than 10 hours using convective method. CMFD also produces harder fercaf chips than those of vacuum and convective methods. Moreover, this research also proves that the operating pressure and temperature influence the moisture content.

  12. Stable high-titer n-butanol production from sucrose and sugarcane juice by Clostridium acetobutylicum JB200 in repeated batch fermentations.

    Science.gov (United States)

    Jiang, Wenyan; Zhao, Jingbo; Wang, Zhongqiang; Yang, Shang-Tian

    2014-07-01

    The production of n-butanol, a widely used industrial chemical and promising transportation fuel, from abundant, low-cost substrates, such as sugarcane juice, in acetone-butanol-ethanol (ABE) fermentation was studied with Clostridium acetobutylicum JB200, a mutant with high butanol tolerance and capable of producing high-titer (>20 g/L) n-butanol from glucose. Although JB200 is a favorable host for industrial bio-butanol production, its fermentation performance with sucrose and sugarcane juice as substrates has not been well studied. In this study, the long-term n-butanol production from sucrose by JB200 was evaluated with cells immobilized in a fibrous-bed bioreactor (FBB), showing stable performance with high titer (16-20 g/L), yield (∼ 0.21 g/g sucrose) and productivity (∼ 0.32 g/Lh) for 16 consecutive batches over 800 h. Sugarcane thick juice as low-cost substrate was then tested in 3 consecutive batches, which gave similar n-butanol production, demonstrating that JB200 is a robust and promising strain for industrial ABE fermentation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. VACUUM TRAP

    Science.gov (United States)

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  14. Vacuum Technology

    Energy Technology Data Exchange (ETDEWEB)

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  15. Vacuum mechatronics

    Science.gov (United States)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  16. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  17. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  18. Gravitational vacuum

    Science.gov (United States)

    Grigoryan, L. S.; Saakyan, G. S.

    1984-09-01

    The existence of a special gravitational vacuum is considered in this paper. A phenomenological method differing from the traditional Einsteinian formalization is utilized. Vacuum, metric and matter form a complex determined by field equations and at great distances from gravitational masses vacuum effects are small but could be large in powerful fields. Singularities and black holes justify the approach as well as the Ambartsmyan theory concerning the existence of supermassive and superdense prestallar bodies that then disintegrate. A theory for these superdense bodies is developed involving gravitational field equations that describe the vacuum by an energy momentum tensor and define the field and mass distribution. Computations based on the theory for gravitational radii with incompressible liquid models adequately reflecting real conditions indicate that a gravitational vacuum could have considerable effects on superdense stars and could have radical effects for very large masses.

  19. Manufacturing Ethyl Acetate From Fermentation Ethanol

    Science.gov (United States)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  20. Pilot scale repeated fed-batch fermentation processes of the wine yeast Dekkera bruxellensis for mass production of resveratrol from Polygonum cuspidatum.

    Science.gov (United States)

    Kuo, Hsiao-Ping; Wang, Reuben; Lin, Yi-Sheng; Lai, Jinn-Tsyy; Lo, Yi-Chen; Huang, Shyue-Tsong

    2017-11-01

    Resveratrol has long been used as an ingredient in functional foods. Currently, Polygonum cuspidatum extract is the greatest natural source for resveratrol because of high concentrations of glycosidic-linked resveratrol. Thus, developing a cost-effective procedure to hydrolyze glucoside could substantially enhance resveratrol production from P. cuspidatum. This study selected Dekkera bruxellensis from several microorganisms based on its bioconversion and enzyme-specific activities. We demonstrated that the cells could be reused at least nine times while maintaining an average of 180.67U/L β-glucosidase activity. The average resveratrol bioconversion efficiency within five rounds of repeated usage was 108.77±0.88%. This process worked effectively when the volume was increased to 1200L, a volume at which approximately 35mgL(-1)h(-1) resveratrol per round was produced. This repeated fed-batch bioconversion process for resveratrol production is comparable to enzyme or cell immobilization strategies in terms of reusing cycles, but without incurring additional costs for immobilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Vacuum Incalescence

    CERN Document Server

    Intravaia, F

    2016-01-01

    In quantum theory the vacuum is defined as a state of minimum energy that is devoid of particles but still not completely empty. It is perhaps more surprising that its definition depends on the geometry of the system and on the trajectory of an observer through space-time. Along these lines we investigate the case of an atom flying at constant velocity near a planar surface. Using general concepts of statistical mechanics it is shown that the motion-modified interaction with the electromagnetic vacuum is formally equivalent to the interaction with a thermal field having an effective temperature determined by the atom's velocity and distance from the surface. This result suggests new ways to experimentally investigate the properties of the quantum vacuum in non-equilibrium systems and effects such as quantum friction.

  2. Vacuum Valve

    CERN Multimedia

    1974-01-01

    This valve was used in the Intersecting Storage Rings (ISR) to protect against the shock waves that would be caused if air were to enter the vacuum tube. Some of the ISR chambers were very fragile, with very thin walls - a design required by physicists on the lookout for new particles.

  3. Vacuum measurement on vacuum packaged MEMS devices

    Energy Technology Data Exchange (ETDEWEB)

    Gan Zhiyin; Lin Dong; Wang Xuefang; Chenggang; Zhang Honghai; Liu Sheng [Institute of Microsystems and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China, 430074 (China)

    2007-07-15

    This paper investigates the relationship between the resonance impedance of a tuning fork quartz oscillator and the small size cavity vacuum pressure and develops an on-line vacuum measurement system to track real-time vacuum pressure in MEMS devices. Furthermore, authors completely analyze all facts that affect the resonance impedance. A set of metal vacuum packaged devices have been monitored for more than 10 months using this on-line vacuum measurement system. The results indicate that it is very critical to investigate vacuum packaging processes, reliability and durability of the vacuum devices by using this on-line vacuum measurement system.

  4. Ethanol production from food waste at high solids content with vacuum recovery technology.

    Science.gov (United States)

    Huang, Haibo; Qureshi, Nasib; Chen, Ming-Hsu; Liu, Wei; Singh, Vijay

    2015-03-18

    Ethanol production from food wastes does not only solve environmental issues but also provides renewable biofuels. This study investigated the feasibility of producing ethanol from food wastes at high solids content (35%, w/w). A vacuum recovery system was developed and applied to remove ethanol from fermentation broth to reduce yeast ethanol inhibition. A high concentration of ethanol (144 g/L) was produced by the conventional fermentation of food waste without a vacuum recovery system. When the vacuum recovery is applied to the fermentation process, the ethanol concentration in the fermentation broth was controlled below 100 g/L, thus reducing yeast ethanol inhibition. At the end of the conventional fermentation, the residual glucose in the fermentation broth was 5.7 g/L, indicating incomplete utilization of glucose, while the vacuum fermentation allowed for complete utilization of glucose. The ethanol yield for the vacuum fermentation was found to be 358 g/kg of food waste (dry basis), higher than that for the conventional fermentation at 327 g/kg of food waste (dry basis).

  5. Vacuum phenomenon.

    Science.gov (United States)

    Yanagawa, Youichi; Ohsaka, Hiromichi; Jitsuiki, Kei; Yoshizawa, Toshihiko; Takeuchi, Ikuto; Omori, Kazuhiko; Oode, Yasumasa; Ishikawa, Kouhei

    2016-08-01

    This article describes the theory of the formation of the vacuum phenomenon (VP), the detection of the VP, the different medical causes, the different locations of the presentation of the VP, and the differential diagnoses. In the human body, the cavitation effect is recognized on radiological studies; it is called the VP. The mechanism responsible for the formation of the VP is as follows: if an enclosed tissue space is allowed to expand as a rebound phenomenon after an external impact, the volume within the enclosed space will increase. In the setting of expanding volume, the pressure within the space will decrease. The solubility of the gas in the enclosed space will decrease as the pressure of the space decreases. Decreased solubility allows a gas to leave a solution. Clinically, the pathologies associated with the VP have been reported to mainly include the normal joint motion, degeneration of the intervertebral discs or joints, and trauma. The frequent use of CT for trauma patients and the high spatial resolution of CT images might produce the greatest number of chances to detect the VP in trauma patients. The VP is observed at locations that experience a traumatic impact; thus, an analysis of the VP may be useful for elucidating the mechanism of an injury. When the VP is located in the abdomen, it is important to include perforation of the digestive tract in the differential diagnosis. The presence of the VP in trauma patients does not itself influence the final outcome.

  6. Vacuum mechatronics. Proceedings.

    Science.gov (United States)

    Belinski, S. E.; Shirazi, M.; Hackwood, S.; Beni, G.

    The discipline of vacuum mechatronics is the design and development of vacuum-compatible, computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. Vacuum mechantronics is relevant to research engineers in integrated circuit manufacturing, surface physics, food processing, biotechnology, materials handling, space sciences and manufacturing.

  7. Indian Vacuum Society: The Indian Vacuum Society

    Science.gov (United States)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  8. Fermentation Industry.

    Science.gov (United States)

    Grady, C. P. L., Jr.; Grady, J. K.

    1978-01-01

    Presents a literature review of wastes from the fermentation industry, covering publications of 1976-77. This review focuses on: (1) alcoholic beverage production; (2) pharmaceuticals and biochemicals production; and (3) biomass production. A list of 62 references is also presented. (HM)

  9. Fermentation Industry.

    Science.gov (United States)

    Grady, C. P. L., Jr.; Grady, J. K.

    1978-01-01

    Presents a literature review of wastes from the fermentation industry, covering publications of 1976-77. This review focuses on: (1) alcoholic beverage production; (2) pharmaceuticals and biochemicals production; and (3) biomass production. A list of 62 references is also presented. (HM)

  10. Food Fermentation

    NARCIS (Netherlands)

    Nout, M.J.R.; Vos, de W.M.; Zwietering, M.H.

    2005-01-01

    The focus of this book is on state of the art technologies and scientific developments in academia and industry that contribute to the characterization and specification of fermentation starter microorganisms, to the present-day experimental approaches in product and process development and control,

  11. Vacuum level effects on gait characteristics for unilateral transtibial amputees with elevated vacuum suspension.

    Science.gov (United States)

    Xu, Hang; Greenland, Kasey; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew

    2017-03-01

    The elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees. Three-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20inHg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups. The effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables. There was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20inHg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15inHg is suggested for unilateral transtibial amputees with elevated vacuum suspension. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Study of Vacuum Energy Physics for Breakthrough Propulsion

    Science.gov (United States)

    Millis, Marc G. (Technical Monitor); Maclay, G. Jordan; Hammer, Jay; Clark, Rod; George, Michael; Kim, Yeong; Kir, Asit

    2004-01-01

    This report summarizes the accomplishments during a three year research project to investigate the use of surfaces, particularly in microelectromechanical systems (MEMS), to exploit quantum vacuum forces. During this project, we developed AFM instrumentation to repeatably measure Casimir forces in the nanoNewton range at 10 6 torr, designed an experiment to measure attractive and repulsive quantum vacuum forces, developed a QED based theory of Casimir forces that includes non-ideal material properties for rectangular cavities and for multilayer slabs, developed theoretical models for a variety of microdevices utilizing vacuum forces, applied vacuum physics to a gedanken spacecraft, and investigated a new material with a negative index of refraction.

  13. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  14. Fermentation to ethanol of pentose-containing spent sulphite liquor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Wayman, M.; Parekh, S.K.

    1987-06-01

    Ethanolic fermentation of spent sulphite liquor with ordinary bakers' yeast is incomplete because this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem. By using the yeast Candida shehatae (R) for fermentation of the spent sulphite liquor from a large Canadian alcohol-producing sulphite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose:xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly. Present indications are that it is well suited to industrial operations wherever hexoses and pentoses are both to be fermented to ethanol, for example, in wood hydrolysates. (Refs. 6).

  15. Vacuum Energy: Myths and Reality

    OpenAIRE

    Volovik, G. E.

    2006-01-01

    We discuss the main myths related to the vacuum energy and cosmological constant, such as: ``unbearable lightness of space-time''; the dominating contribution of zero point energy of quantum fields to the vacuum energy; non-zero vacuum energy of the false vacuum; dependence of the vacuum energy on the overall shift of energy; the absolute value of energy only has significance for gravity; the vacuum energy depends on the vacuum content; cosmological constant changes after the phase transition...

  16. Physical Vacuum in Superconductors

    CERN Document Server

    de Matos, Clovis Jacinto

    2009-01-01

    Although experiments carried out by Jain et al. showed that the Cooper pairs obey the strong equivalence principle, The measurement of the Cooper pairs inertial mass by Tate et al. revealed an anomalous excess of mass. In the present paper we interpret these experimental results in the framework of an electromagnetic model of dark energy for the superconductors' vacuum. We argue that this physical vacuum is associated with a preferred frame. Ultimately from the conservation of energy for Cooper pairs we derive a model for a variable vacuum speed of light in the superconductors physical vacuum in relation with a possible breaking of the weak equivalence principle for Cooper pairs.

  17. Vacuum Birefringence as a Vacuum Emission Process

    CERN Document Server

    Karbstein, Felix

    2015-01-01

    We argue that the phenomenon of vacuum birefringence in strong inhomogeneous electromagnetic fields can be most efficiently analyzed in terms of a vacuum emission process. In this contribution, we exemplarily stick to the case of vacuum birefringence in a stationary perpendicularly directed, purely magnetic background field extending over a finite spatial extent. Similar field configurations are realized in the BMV and PVLAS experiments. We demonstrate that we can reproduce the conventional constant field result. Our focus is on effects which arise when the probe photons originate in the field free region, are directed towards the magnetic field region, and detected well after the interaction with the magnetic field has taken place, again at zero field.

  18. Cervical spine annulus vacuum.

    Science.gov (United States)

    Bohrer, S P; Chen, Y M

    1988-01-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  19. ELETTRA vacuum system

    Science.gov (United States)

    Bernardini, M.

    1991-08-01

    A status report of the vacuum system of ELETTRA, the 2 GeV, 400 mA light source under construction in Trieste, will be described. The Vacuum project, presented at ``Synchrotron Radiation Vacuum Workshop'' at Riken (Japan 22-24 March 1990) and more recently at EVC-2, the European Vacuum Conference at Trieste (Italy 21-26 May 1990), is now in the phase of testing a prototype sector, which is 1/24 of the ring circumference. Details and some technological aspects of the fabrication will be reviewed together with the vacuum performances. Results of laboratory experiments on components, standard or not, allowed us to finalize the main choices in light of the general philosophy of the project and will be properly summarized.

  20. Cervical spine annulus vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, S.P.; Chen, Y.M.

    1988-07-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  1. Vacuum controls and interlocks

    CERN Document Server

    Strubin, P

    2007-01-01

    The vacuum control system is, in most cases, a subset of the general control system of an accelerator. As such, it shares the architecture and communication infrastructure of the main control system. Considered as a ‘slow process’ to control in the frame of accelerators, the vacuum control system can be built using commercial industrial controllers (PLCs). A data driven approach allows for changes in configuration without changing the software code but at the expense of a solid database. Modelling the equipment allows for easy adaptation of a variety of control units with the same functionality but different physical interfaces. It also allows for a uniform display of the available data and status values. Interlocks are required to protect the vacuum equipment itself against abnormal conditions, but also to protect other systems, like RF, which need a good vacuum to operate. They are an integral part of any vacuum control system.

  2. Microfabricated triggered vacuum switch

    Science.gov (United States)

    Roesler, Alexander W.; Schare, Joshua M.; Bunch, Kyle

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  3. Fermentation to ethanol of pentose-containing spent sulfite liquor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.; Wayman, M.; Parekh, S.K.

    1987-01-01

    Ethanolic fermentation of spent sulfite liquor with ordinary bakers' yeast is incomplete because of this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem. By using the yeast Candida shehatae (R) for fermentation of the spent sulfite liquor from a large Canadian alcohol-producing sulfite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose:xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached over 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly.

  4. Thermophoretic vacuum wand

    Science.gov (United States)

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2000-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  5. Evading death by vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, A. [Universidade de Lisboa, Centro de Fisica Teorica e Computacional, Faculdade de Ciencias, Lisboa (Portugal); Ferreira, P.M.; Santos, Rui [Universidade de Lisboa, Centro de Fisica Teorica e Computacional, Faculdade de Ciencias, Lisboa (Portugal); Instituto Superior de Engenharia de Lisboa, Lisboa (Portugal); Ivanov, I.P. [Universite de Liege, IFPA, Liege (Belgium); Sobolev Institute of Mathematics, Novosibirsk (Russian Federation); Silva, Joao P. [Instituto Superior de Engenharia de Lisboa, Lisboa (Portugal); Universidade Tecnica de Lisboa, Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, Lisboa (Portugal)

    2013-09-15

    In the Standard Model, the Higgs potential allows only one minimum at tree level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that we might now be in a metastable state, which we dub the panic vacuum. Current experiments at the LHC are probing the Higgs particle predicted as a result of the spontaneous symmetry breaking. Remarkably, in the two Higgs model with a softly broken U(1) symmetry, the LHC experiments already allow to exclude many panic vacuum solutions. (orig.)

  6. Vacuum mechatronics first international workshop

    Energy Technology Data Exchange (ETDEWEB)

    Belinski, S.E.; Shirazi, M.; Hackwood, S.; Beni, G. (eds.) (California Univ., Santa Barbara, CA (USA))

    1989-01-01

    This report contains papers on the following topics: proposed epitaxial thin film growth in the ultra-vacuum of space; particle monitoring and control in vacuum processing equipment; electrostatic dust collector for use in vacuum systems; materials evaluation of an electrically noisy vacuum slip ring assembly; an overview of lubrication and associated materials for vacuum service; the usage of lubricants in a vacuum environment; guidelines and practical applications for lubrication in vacuum; recent development in leak detector and calibrator designs; the durability of ballscrews for ultrahigh vacuum; vacuum-compatible robot for self-contained manufacturing systems; the design, fabrication, and assembly of an advanced vacuum robotics system for space payload calibration; design criteria for mechanisms used in space; and concepts and requirements for semiconductor multiprocess integration in vacuum. These papers are indexed separately elsewhere.

  7. Cold Vacuum Drying Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Located near the K-Basins (see K-Basins link) in Hanford's 100 Area is a facility called the Cold Vacuum Drying Facility (CVDF).Between 2000 and 2004, workers at the...

  8. Cosmology of gravitational vacuum

    CERN Document Server

    Burdyuzha, V; Pacheco, J

    2008-01-01

    Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing" when a gravitational vacuum condensate has appeared. They must be isotropically distributed over the isotropic expanding Universe. After Universe inflation these microdefects are smoothed, stretched and broken up. A part of them could survive and now they are perceived as the structures of Lambda-term and an unclustered dark matter. It is shown that the parametrization noninvariance of the Wheeler-De Witt equation can be used to describe phenomenologically vacuum topological defects of different dimensions (worm-holes, micromembranes, microstrings and monopoles). The mathematical illustration of these processes may be the spontaneous breaking of the local Lorentz-invariance of the quasi-classical equations of gravity. Probably the gravitational vacuum condensate has fixed tim...

  9. Handbook of vacuum technology

    CERN Document Server

    2016-01-01

    This comprehensive, standard work has been updated to remain an important resource for all those needing detailed knowledge of the theory and applications of vacuum technology. With many numerical examples and illustrations to visualize the theoretical issues.

  10. Vacuum Camera Cooler

    Science.gov (United States)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  11. ISR Intersection Vacuum Chamber

    CERN Multimedia

    1975-01-01

    This special vacuum chamber presenting a lateral opening at the beam crossing point is one of the many chambers specifically designed for a particular experiment. Here it is shown during assembly at the ISR mechanical worshop.

  12. A Planck Vacuum Cosmology

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-04-01

    Full Text Available Both the big-bang and the quasi-steady-state cosmologies originate in some type of Planck state. This paper presents a new cosmological theory based on the Planck- vacuum negative-energy state, a state consisting of a degenerate collection of negative- energy Planck particles. A heuristic look at the Einstein field equation provides a con- vincing argument that such a vacuum state could provide a theoretical explanation for the visible universe.

  13. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  14. Calibrating System for Vacuum Gauges

    Institute of Scientific and Technical Information of China (English)

    MengJun; YangXiaotian; HaoBinggan; HouShengjun; HuZhenjun

    2003-01-01

    In order to measure the vacuum degree, a lot of vacuum gauges will be used in CSR vacuum system. We bought several types of vacuum gauges. We know that different typos of vacuum gauges or even one type of vacuum gauges have different measure results in same condition, so they must be calibrated. But it seems impossible for us to send so many gauges to the calibrating station outside because of the high price. So the best choice is to build a second class calibrating station for vacuum gauges by ourselves (Fig.l).

  15. LER Vacuum Studies

    Energy Technology Data Exchange (ETDEWEB)

    Matter, Regina S.

    2000-06-27

    During the Summer of 1999 the vacuum in LER was studied in order to answer a few questions: (1) how fast is the vacuum system cleaning; (2) when will the required operating pressure 10 nTorr be reached; (3) how fast do the TSP's saturate; and (4) what is the present average pressure in LER and what is the corresponding beam lifetime? Once {Delta}P/I, the coefficient relating the pressure to beam current and the base pressure is calculated, it is easy to find the time constants associated with the cleaning of the vacuum system and the saturation of the TSP's. In addition, these calculations showed that vertical steering of the LER orbit affects the vacuum and that leaks cause the TSP's to saturate. It is difficult to calculate the average pressure in the ring because most of the ion pumps in the straight sections do not read pressure accurately. Secondly, how do you calculate the conductance between the chamber and the anti-chamber? Thirdly, the gas load is unevenly distributed along the ring because of photon stops and leaks. However, the average vacuum pressure seen by the beam in the arcs is roughly three times higher than the pressure measured at the ion pumps, according to Artem Kulikov. Instead of calculating the average pressure in the ring, the author has calculated the coefficient relating the inverse beam lifetime to the beam current to see the long term improvement of the LER beam lifetime as the vacuum system is scrubbed. These calculations showed that the lifetime, including the low intensity lifetime, is limited by the vacuum pressure. The results reported here are obtained from numerical calculations.

  16. Probiotic fermented dairy products

    Directory of Open Access Journals (Sweden)

    Adnan Tamime

    2003-04-01

    Full Text Available Fermented dairy products are the most popular vehicle used in theindustry for the implantation of the probiotic microflora in humans. Therefore this paper provides an overview of new knowledge on probiotic fermented dairy products. It involves historical developments, commercial probiotic microorganisms and products, and their therapeutic properties, possibilities of quality improvement of different types of newly developed fermented dairy products together with fermented goat’s milk products.

  17. Fermented milk for hypertension

    DEFF Research Database (Denmark)

    Usinger, Lotte; Reimer, Christina; Ibsen, Hans

    2012-01-01

    Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle...... interventions, such as fermented milk, would be of great importance....

  18. Acetylene Vacuum Carburizing

    Institute of Scientific and Technical Information of China (English)

    Hitoshi Iwata

    2004-01-01

    Almost 30 years has passed since the publication of materials on vacuum carburizing technology, and is attracting a great deal of attention as a technology capable of being used as a substitute for gas carburizing technology.However, the technology was not popular except in specific fields. The main reason for this is due to a variety of harmful influences accompanying the sooting problems caused by CH4 or C3H8. We have succeeded in that the occurrence of sooting was suppressed by utilizing acetylene, at extremely low pressure for carburizing (below 1 kPa). This process is now showing the excellent quality and prospects for this technology in terms of quality, economy and safety. At present almost 70 practical mass production furnaces are used in production lines, in Japan and abroad. At this time, we will report summary of the present acetylene vacuum carbufizing process and the actual results obtained by these acetylene vacuum carbufizing furnaces for mass production.

  19. Handbook of vacuum physics

    CERN Document Server

    1964-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is a handbook of vacuum physics, with emphasis on the properties of miscellaneous materials such as mica, oils, greases, waxes, and rubber. Accurate modern tables of physical constants, properties of materials, laboratory techniques, and properties of commercial pumps, gauges, and leak detectors are presented. This volume is comprised of 12 chapters and begins with a discussion on pump oils, divided into rotary pump oils and vapor pump oils. The next chapter deals with the properties and applications of greases, including outgassing and vapor pr

  20. Baryogenesis in false vacuum

    CERN Document Server

    Hamada, Yuta

    2016-01-01

    The null result in the LHC may indicate that the standard model is not drastically modified up to very high scale such as the GUT/string scale. Having this in the mind, we suggest a novel leptogenesis scenario realized in the false vacuum of the Higgs field. If the Higgs field develops the large vacuum expectation value in the early universe, the lepton number violating process is enhanced, which we use for baryogenesis. To demonstrate the scenario, several models are discussed. For example, we show that the observed baryon asymmetry is successfully generated in the standard model with a second Higgs doublet and a singlet scalar.

  1. New Vacuum Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With its pure aperture up to 985mm, the New Vacuum Solar Telescope of China (NVST) has become the world's biggest vacuum solar telescope. The main science task of NVST is the high-resolution observation of photosphere and chromosphere including their fine structure of magnetic field on the sun. The NVST was equipped with many new technologies and powerful instruments, such as an adaptive optical system, a polarization analyzer, two vertical spectrographs, a high-resolution image system and a very narrow Ha filter (0.125A).

  2. A rotating quantum vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Lorenci, V.A. de; Svaiter, N.F. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-11-01

    It was investigated which mapping has to be used to compare measurements made in a rotating frame to those made in an inertial frame. Using a non-Galilean coordinate transformation, the creation-annihilation operators of a massive scalar field in the rotating frame are not the same as those of an inertial observer. This leads to a new vacuum state(a rotating vacuum) which is a superposition of positive and negative frequency Minkowski particles. Polarization effects in circular accelerators in the proper frame of the electron making a connection with the inertial frame point of view were analysed. 65 refs.

  3. Superoleophobicity under vacuum

    Science.gov (United States)

    Liu, Xinjie; Wang, Xiaolong; Liang, Yongmin; Bell, Steven E. J.; Liu, Weimin; Zhou, Feng

    2011-05-01

    By using superoleophobic alumina and low vapor pressure oils we have been able to study wetting behavior at high vacuum. Here, we show that a superoleophobic state can exist for some probe liquids, even under high vacuum. However, with other liquids the surfaces are only superoloephobic because air is trapped beneath the droplet and the contact angle decreases dramatically (150°-120°) if this air is removed. These observations open up the possibility of designing materials which fully exploit the potential of physically trapped air to achieve extreme oleophobicity and/or hydrophobicity.

  4. Technology handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 3: Technology is part of a series of publications that presents articles featuring the whole spectrum of vacuum physics. This particular volume presents materials that deal with technology concerns in vacuum mechanics. The first material talks about the utilization of ceramic materials in the construction of vacuum devices. The next paper details the application of vacuum physics in soldering and brazing process. The last article deals with the utilization of vacuum technology in high frequency heating. The book will be of great use to professionals involved

  5. The vacuum strikes back

    CERN Multimedia

    2007-01-01

    "Modern physics has shown that the vacuum, previously thought of as a stated of total nothingness, is really a seething background of virtual particles springing in and out of eixstence until they can seize enough energy to materialize as "real" particles." (1,5 page)

  6. ISR vacuum system

    CERN Multimedia

    1971-01-01

    Some of the most important components of the vacuum system are shown. At the left, the rectangular box is a sputter-ion pump inside its bake-out oven. The assembly in the centre includes a sector valve, three roughing valves, a turbomolecular pump, a rotary backing pump and auxiliary equipment. At the right, the small elbow houses a Bayard-

  7. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  8. Vacuum-assisted delivery

    Science.gov (United States)

    ... a handle on the cup to move the baby through the birth canal. When is Vacuum-assisted Delivery Needed? Even after your cervix is fully dilated ( ... delivers the baby's head, you will push the baby the rest of the way out. After delivery, you can hold your baby on your tummy ...

  9. ISR vacuum system

    CERN Multimedia

    1970-01-01

    A pressure of 5 x 10-11 Torr has been obtained repreatedly in this pilot section of the ISR vacuum system. The pilot section is 45 m long is pumped by 9 sputter-ion pumps pf 350 l/s pumping speed, and is baked out at 200 degrees C before each pump down.

  10. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  11. The rotating quantum vacuum

    CERN Document Server

    Davies, Paul Charles William; Manogue, C A; Davies, Paul C W; Dray, Tevian; Manogue, Corinne A

    1996-01-01

    We derive conditions for rotating particle detectors to respond in a variety of bounded spacetimes and compare the results with the folklore that particle detectors do not respond in the vacuum state appropriate to their motion. Applications involving possible violations of the second law of thermodynamics are briefly addressed.

  12. Optimization of Fermentation Conditions for the Production of Bacteriocin Fermentate

    Science.gov (United States)

    2015-03-30

    FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ” by Anthony Sikes Wayne Muller and Claire Lee March 2015...From - To) October 2010 – November 2013 4. TITLE AND SUBTITLE OPTIMIZATION OF FERMENTATION CONDITIONS FOR THE PRODUCTION OF BACTERIOCIN “ FERMENTATE ...nisin and pediocin. Whey + yeast extract was the best performing whey fermentation media. The nisin producer strain Lactococcus. lactis ssp. lactis was

  13. Sugaring-out extraction of acetoin from fermentation broth by coupling with fermentation.

    Science.gov (United States)

    Dai, Jian-Ying; Ma, Lin-Hui; Wang, Zhuang-Fei; Guan, Wen-Tian; Xiu, Zhi-Long

    2017-03-01

    Acetoin is a natural flavor and an important bio-based chemical which could be separated from fermentation broth by solvent extraction, salting-out extraction or recovered in the form of derivatives. In this work, a novel method named as sugaring-out extraction coupled with fermentation was tried in the acetoin production by Bacillus subtilis DL01. The effects of six solvents on bacterial growth and the distribution of acetoin and glucose in different solvent-glucose systems were explored. The operation parameters such as standing time, glucose concentration, and volume ratio of ethyl acetate to fermentation broth were determined. In a system composed of fermentation broth, glucose (100%, m/v) and two-fold volume of ethyl acetate, nearly 100% glucose was distributed into bottom phase, and 61.2% acetoin into top phase without coloring matters and organic acids. The top phase was treated by vacuum distillation to remove solvent and purify acetoin, while the bottom phase was used as carbon source to produce acetoin in the next batch of fermentation.

  14. Batchwise ethanol fermentation with shochu distillery waste

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, S.; Teramoto, Y.; Oba, R.; Ueki, T.; Kimura, K. (Kumamoto Institute of Technology, Kumamoto (Japan)); Shiota, S. (Tohi Jozo Co. Ltd., Kumamoto (Japan))

    1991-10-25

    In order to produce a shochu with a mild aroma, a new vacuum distillation precedure at low temperature of 35 to 40 centigrade was applied to shochu distillation. The resulting rice shochu distillery waste contained a large amount of viable yeast glucoamylase activity, acid protease activity, and neutral protease activity. About 10% of ethanol was produced in the fermented mash at 30 centigrade within three days. In contrast, distillery waste discharged by conventional distillation at high temperature of 55 to 60 centigrade could not be used for secondary ethanol fermentation at all. It was provided that the filtrate of secondarily-fermented distillery waste, which is containing ethanol and possessing a fine aroma fortified with higher alcohols and volatile esters during ethanol fermentation, can be useful for the production of a mirin-like liquor for cooking, Akazake,'' a characteristic red-colored, sweet alcoholic beverage produced in Kumamoto prefecture only, and a bath additive containing ethanol, a fine aroma, and enzymes. 15 refs, 2 figs., 3 tabs.

  15. Study on the Quality Control of Chinese Jujube Wine Fermentation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bao-shan; CHEN Jin-ping; LI Hui-yun

    2004-01-01

    Fermentation processes were studied,with an aim of improving the quality of Chinese jujube wine.Results showed the quality of the wine made from fresh Chinese jujube and dried Chinese jujube were similar,but wine made from excessively dried Chinese jujube showed decreased quality.The reducing sugar content in Chinese jujube juice extracted by pectic enzymes was higher than the reducing sugar content extracted by hot water,however,methanol content in wine extracted by pectic enzymes also increased.Therefore the hot water extraction method is recommended for fermentation of Chinese jujube wine.Fermentation using vacuum concentrated Chinese jujube juice was more effective than that using filtered juice readjusted to 20% soluble solid content .(SSC) with sucrose or glucose.The inoculation of 0.3% Saccharomyces ellipsodieus Strain was suitable for fermentation of Chinese jujube wine.Fermentation was carried out at 21-25℃.The concentration of SO2 in wine affected fermentation time and the optimum additional amount was 40 mg L-1.Post fermentation storage in oak barrel improved the quality of Chinese jujube wine,as did 4.5% diatomite filtration.

  16. Gas bearing operates in vacuum

    Science.gov (United States)

    Perkins, G. S.

    1975-01-01

    Bearing has restrictions to reduce air leaks and is connected to external pumpout facility which removes exhausted air. Token amount of air which is lost to vacuum is easily removed by conventional vacuum pump.

  17. Tritium handling in vacuum systems

    Energy Technology Data Exchange (ETDEWEB)

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  18. Enhanced ethanol fermentation by engineered Saccharomyces cerevisiae strains with high spermidine contents.

    Science.gov (United States)

    Kim, Sun-Ki; Jo, Jung-Hyun; Jin, Yong-Su; Seo, Jin-Ho

    2017-05-01

    Construction of robust and efficient yeast strains is a prerequisite for commercializing a biofuel production process. We have demonstrated that high intracellular spermidine (SPD) contents in Saccharomyces cerevisiae can lead to improved tolerance against various fermentation inhibitors, including furan derivatives and acetic acid. In this study, we examined the potential applicability of the S. cerevisiae strains with high SPD contents under two cases of ethanol fermentation: glucose fermentation in repeated-batch fermentations and xylose fermentation in the presence of fermentation inhibitors. During the sixteen times of repeated-batch fermentations using glucose as a sole carbon source, the S. cerevisiae strains with high SPD contents maintained higher cell viability and ethanol productivities than a control strain with lower SPD contents. Specifically, at the sixteenth fermentation, the ethanol productivity of a S. cerevisiae strain with twofold higher SPD content was 31% higher than that of the control strain. When the SPD content was elevated in an engineered S. cerevisiae capable of fermenting xylose, the resulting S. cerevisiae strain exhibited much 40-50% higher ethanol productivities than the control strain during the fermentations of synthetic hydrolysate containing high concentrations of fermentation inhibitors. These results suggest that the strain engineering strategy to increase SPD content is broadly applicable for engineering yeast strains for robust and efficient production of ethanol.

  19. Coproduction of acetic acid and electricity by application of microbial fuel cell technology to vinegar fermentation.

    Science.gov (United States)

    Tanino, Takanori; Nara, Youhei; Tsujiguchi, Takuya; Ohshima, Takayuki

    2013-08-01

    The coproduction of a useful material and electricity via a novel application of microbial fuel cell (MFC) technology to oxidative fermentation was investigated. We focused on vinegar production, i.e., acetic acid fermentation, as an initial and model useful material that can be produced by oxidative fermentation in combination with MFC technology. The coproduction of acetic acid and electricity by applying MFC technology was successfully demonstrated by the simultaneous progress of acetic acid fermentation and electricity generation through a series of repeated batch fermentations. Although the production rate of acetic acid was very small, it increased with the number of repeated batch fermentations that were conducted. We obtained nearly identical (73.1%) or larger (89.9%) acetic acid yields than that typically achieved by aerated fermentation (75.8%). The open-cycle voltages measured before and after fermentation increased with the total fermentation time and reached a maximum value of 0.521 V prior to the third batch fermentation. The maximum current and power densities measured in this study (19.1 μA/cm² and 2.47 μW/cm², respectively) were obtained after the second batch fermentation.

  20. Vacuum grasping as a manipulation technique for minimally invasive surgery

    Science.gov (United States)

    Goossens, R. H. M.; van Eijk, D. J.; de Hingh, I. H. J. T.; Jakimowicz, J. J.

    2010-01-01

    Background Laparoscopic surgery requires specially designed instruments. Bowel tissue damage is considered one of the most serious forms of lesion, specifically perforation of the bowel. Methods An experimental setting was used to manipulate healthy pig bowel tissue via two vacuum instruments. During the experiments, two simple manipulations were performed for both prototypes by two experienced surgeons. Each manipulation was repeated 20 times for each prototype at a vacuum level of 60 kPa and 20 times for each prototype at a vacuum level of 20 kPa. All the manipulations were macroscopically assessed by two experienced surgeons in terms of damage to the bowel. Results In 160 observations, 63 ecchymoses were observed. All 63 ecchymoses were classified as not relevant and negligible. No serosa or seromuscular damages and no perforations were observed. Conclusion Vacuum instruments such as the tested prototypes have the potential to be used as grasper instruments in minimally invasive surgery. PMID:20195640

  1. Surge-damping vacuum valve

    Science.gov (United States)

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  2. Repeat-until-success quantum repeaters

    Science.gov (United States)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  3. A Rotating Quantum Vacuum

    CERN Document Server

    De Lorenci, V A

    1996-01-01

    We investigate which mapping we have to use to compare measurements made in a rotating frame to those made in an inertial frame. Using a "Lorentz-like" coordinate transformation we obtain that creation-anihilation operators of a massless scalar field in the rotating frame are not the same as those of an inertial observer. This leads to a new vacuum state (a rotating vacuum) which is a superposition of positive and negative frequency Minkowski particles. After this, introducing an apparatus device coupled linearly with the field we obtain that there is a strong correlation between number of rotating particles (in a given state) obtained via canonical quantization and via response function of the rotating detector. Finally, we analyse polarization effects in circular accelerators in the proper frame of the electron making a connection with the inertial frame point of view.

  4. Dry vacuum pumps

    Science.gov (United States)

    Sibuet, R.

    2008-05-01

    For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R&D/industries, merits over conventional pumps and future growth scope will be discussed.

  5. PARAFFIN SEPARATION VACUUM DISTILLATION

    Directory of Open Access Journals (Sweden)

    Zaid A. Abdulrahman

    2013-05-01

    Full Text Available Simulated column performance curves were constructed for existing paraffin separation vacuum distillation column in LAB plant (Arab Detergent Company/Baiji-Iraq. The variables considered in this study are the thermodynamic model option, top vacuum pressure, top and bottom temperatures, feed temperature, feed composition & reflux ratio. Also simulated columns profiles for the temperature, vapor & liquid flow rates composition were constructed. Four different thermodynamic model options (SRK, TSRK, PR, and ESSO were used, affecting the results within 1-25% variation for the most cases.The simulated results show that about 2% to 8 % of paraffin (C10, C11, C12, & C13 present at the bottom stream which may cause a problem in the LAB plant. The major variations were noticed for the top temperature & the  paraffin weight fractions at bottom section with top vacuum pressure. The bottom temperature above 240 oC is not recommended because the total bottom flow rate decreases sharply, where as  the weight fraction of paraffins decrease slightly. The study gives evidence about a successful simulation with CHEMCAD

  6. Food Technologies: Fermentation

    NARCIS (Netherlands)

    Nout, M.J.R.

    2014-01-01

    Fermentation refers to the use of microorganisms to achieve desirable food properties in the fermented food or beverage. Although the word ‘fermentation’ indicates ‘anaerobic metabolism,’ it is also used in a broader sense to indicate all anaerobic and aerobic microbiological and biochemical

  7. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds,

  8. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds, vegeta

  9. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  10. Asian fungal fermented food

    NARCIS (Netherlands)

    Nout, M.J.R.; Aidoo, K.E.

    2010-01-01

    In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds, vegeta

  11. Food Technologies: Fermentation

    NARCIS (Netherlands)

    Nout, M.J.R.

    2014-01-01

    Fermentation refers to the use of microorganisms to achieve desirable food properties in the fermented food or beverage. Although the word ‘fermentation’ indicates ‘anaerobic metabolism,’ it is also used in a broader sense to indicate all anaerobic and aerobic microbiological and biochemical modific

  12. Pure Culture Fermentation of Brined Cucumbers.

    Science.gov (United States)

    Etchells, J L; Costilow, R N; Anderson, T E; Bell, T A

    1964-11-01

    , pure culture fermentor which was suitable for gamma radiation, resistant to salt and acid, and which permitted repeated aseptic sampling of the fermenting brine, is illustrated and the specifications are given.

  13. Vacuum bell therapy

    Science.gov (United States)

    Sesia, Sergio

    2016-01-01

    Background For specific therapy to correct pectus excavatum (PE), conservative treatment with the vacuum bell (VB) was introduced more than 10 years ago in addition to surgical repair. Preliminary results using the VB were encouraging. We report on our 13-year experience with the VB treatment including the intraoperative use during the Nuss procedure and present some technical innovations. Methods A VB with a patient-activated hand pump is used to create a vacuum at the anterior chest wall. Three different sizes of vacuum bells, as well as a model fitted for young women, exist. The appropriate size is selected according to the individual patient’s age and ventral surface. The device should be used at home for a minimum of 30 minutes (twice a day), and may be used up to a maximum of several hours daily. The intensity of the applied negative pressure can be evaluated with an integrated pressure gauge during follow-up visits. A prototype of an electronic model enables us to measure the correlation between the applied negative pressure and the elevation of the anterior chest wall. Results Since 2003, approx. 450 patients between 2 to 61 years of age started the VB therapy. Age and gender specific differences, depth of PE, symmetry or asymmetry, and concomitant malformations such as scoliosis and/or kyphosis influence the clinical course and success of VB therapy. According to our experience, we see three different groups of patients. Immediate elevation of the sternum was confirmed thoracoscopically during the Nuss procedure in every patient. Conclusions The VB therapy has been established as an alternative therapeutic option in selected patients suffering from PE. The initial results up to now are encouraging, but long-term results comprising more than 15 years are so far lacking, and further evaluation and follow-up studies are necessary. PMID:27747177

  14. Effects of yeast, fermentation time, and preservation methods on tarhana.

    Science.gov (United States)

    Gurbuz, Ozan; Gocmen, Duygu; Ozmen, Nese; Dagdelen, Fatih

    2010-01-01

    The physicochemical properties of tarhana soup produced with different dough treatments, fermentation times, and preservation methods were examined. Tarhana doughs were prepared with yogurt (control) or baker's yeast (Saccharomyces cerevisiae) and fermented for 3 days. Samples were taken at 24, 48, and 72 hr. Samples were then preserved via one of four methods: sun dried, dried in the shade, vacumn dried, and frozen. Frozen samples produced lower organic acid levels after 72 hr of fermentation in both control (0.68 g/100 g) and yeast (0.61 g/100 g) applications than samples that were dried (0.94 g/100 g control samples; 0.81 g/100 g samples with yeast). Increasing fermentation time resulted in a significant effect on the formation of organic acid in the tarhana (p .01). However, sensory scores for tarhana prepared from the samples dried in a sheltered area showed a reduction in color desireablilty as the fermentation time increased. The soup prepared from frozen tarhana (72 hr fermentation, with yeast) had the highest scores with respect to color, mouth feel, flavor, and overall acceptability. Vacuum-dried samples' scores in these areas were also high in comparison to the two other drying methods.

  15. Plasmons in QED vacuum

    Science.gov (United States)

    Petrov, E. Yu.; Kudrin, A. V.

    2016-09-01

    The problem of longitudinal oscillations of an electric field and a charge polarization density in a quantum electrodynamics (QED) vacuum is considered. Within the framework of semiclassical analysis, we calculate time-periodic solutions of bosonized (1 +1 )-dimensional QED (massive Schwinger model). Applying the Bohr-Sommerfeld quantization condition, we determine the mass spectrum of charge-zero bound states (plasmons) which correspond in quantum theory to the found classical solutions. We show that the existence of such plasmons does not contradict any fundamental physical laws and study qualitatively their excitation in a (3 +1 )-dimensional real world.

  16. Vacuum ultraviolet spectroscopy I

    CERN Document Server

    Samson, James A; Lucatorto, Thomas

    1998-01-01

    This volume is for practitioners, experimentalists, and graduate students in applied physics, particularly in the fields of atomic and molecular physics, who work with vacuum ultraviolet applications and are in need of choosing the best type of modern instrumentation. It provides first-hand knowledge of the state-of-the-art equipment sources and gives technical information on how to use it, along with a broad reference bibliography.Key Features* Aimed at experimentalists who are in need of choosing the best type of modern instrumentation in this applied field* Contains a detailed chapter on la

  17. Fermented milk for hypertension.

    Science.gov (United States)

    Usinger, Lotte; Reimer, Christina; Ibsen, Hans

    2012-04-18

    Fermented milk has been suggested to have a blood pressure lowering effect through increased content of proteins and peptides produced during the bacterial fermentation. Hypertension is one of the major risk factors for cardiovascular disease world wide and new blood pressure reducing lifestyle interventions, such as fermented milk, would be of great importance. To investigate whether fermented milk or similar products produced by lactobacilli fermentation of milk proteins has any blood pressure lowering effect in humans when compared to no treatment or placebo. The Cochrane Central Register of Controlled Trials (CENTRAL), English language databases, including MEDLINE (1966-2011), EMBASE (1974-2011), Cochrane Complementary Medicine Trials Register, Allied and Complementary Medicine (AMED) (1985-2011), Food science and technology abstracts (1969-2011). Randomised controlled trials; cross over and parallel studies evaluating the effect on blood pressure of fermented milk in humans with an intervention period of 4 weeks or longer. Data was extracted individually by two authors, afterwards agreement had to be obtained before imputation in the review. A modest overall effect of fermented milk on SBP was found (MD -2.45; 95% CI -4.30 to -0.60), no effect was evident on DBP (MD -0.67; 95% CI -1.48, 0.14). The review does not support an effect of fermented milk on blood pressure. Despite the positive effect on SBP the authors conclude, for several reasons, that fermented milk has no effect on blood pressure. The effect found was very modest and only on SBP, the included studies were very heterogeneous and several with weak methodology. Finally, sensitivity and subgroup analyses could not reproduce the antihypertensive effect. The results do not give notion to the use of fermented milk as treatment for hypertension or as a lifestyle intervention for pre-hypertension nor would it influence population blood pressure.

  18. R&D ERL: Vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

    2010-01-01

    The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The

  19. Of vacuum and gas

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    A new LHCb programme is delving into uncharted waters for the LHC: exploring how protons interact with noble gases inside the machine pipe. While, at first glance, it may sound risky for the overall quality of the vacuum in the machine, the procedure is safe and potentially very rich in rewards. The results could uncover the high-energy helium-proton cross-section (with all the implications thereof), explore new boundaries of the quark-gluon plasma and much more.   As the beam passes through LHCb, interactions with neon gas allow the experiment to measure the full beam profile. In this diagram, beam 1 (blue) and beam 2 (red) are measured by the surrounding VELO detector. It all begins with luminosity. In 2011, LHCb set out to further improve its notoriously precise measurements of the beam profile, using the so-called Beam-Gas Imaging (BGI) method. BGI does exactly what it says on the tin: a small amount of gas is inserted into the vacuum, increasing the rate of collisions around the interaction ...

  20. LHC vacuum system

    CERN Document Server

    Gröbner, Oswald

    1999-01-01

    The Large Hadron Collider (LHC) project, now in the advanced construction phase at CERN, comprises two proton storage rings with colliding beams of 7-TeV energy. The machine is housed in the existing LEP tunnel with a circumference of 26.7 km and requires a bending magnetic field of 8.4 T with 14-m long superconducting magnets. The beam vacuum chambers comprise the inner 'cold bore' walls of the magnets. These magnets operate at 1.9 K, and thus serve as very good cryo-pumps. In order to reduce the cryogenic power consumption, both the heat load from synchrotron radiation emitted by the proton beams and the resistive power dissipation by the beam image currents have to be absorbed on a 'beam screen', which operates between 5 and 20 K and is inserted inside the vacuum chamber. The design of this beam screen represents a technological challenge in view of the numerous and often conflicting requirements and the very tight mechanical tolerances imposed. The synchrotron radiation produces strong outgassing from the...

  1. Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.

    Science.gov (United States)

    Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

    2013-09-01

    In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Vacuum metastability with black holes

    Energy Technology Data Exchange (ETDEWEB)

    Burda, Philipp [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Gregory, Ruth [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Perimeter Institute, 31 Caroline Street North,Waterloo, ON, N2L 2Y5 (Canada); Moss, Ian G. annd [School of Mathematics and Statistics, Newcastle University,Newcastle Upon Tyne, NE1 7RU (United Kingdom)

    2015-08-24

    We consider the possibility that small black holes can act as nucleation seeds for the decay of a metastable vacuum, focussing particularly on the Higgs potential. Using a thin-wall bubble approximation for the nucleation process, which is possible when generic quantum gravity corrections are added to the Higgs potential, we show that primordial black holes can stimulate vacuum decay. We demonstrate that for suitable parameter ranges, the vacuum decay process dominates over the Hawking evaporation process. Finally, we comment on the application of these results to vacuum decay seeded by black holes produced in particle collisions.

  3. Rumen microorganisms and fermentation

    Directory of Open Access Journals (Sweden)

    AR Castillo-González

    2014-01-01

    Full Text Available The rumen consists of a complex ecosystem where nutrients consumed by ruminants are digested by fermentation process, which is executed by diverse microorganisms such as bacteria, protozoa, and fungi. A symbiotic relationship is found among different groups of microorganisms due to the diverse nature of these microbial species and their adaptability and interactions also coexist. The ruminant provides the necessary environment for the establishment of such microorganisms, while the microorganisms obtain energy from the host animal from microbial fermentation end products. Within the ruminal ecosystem, the microorganisms coexist in a reduced environment and pH remains close to neutral. Rumen microorganisms are involved in the fermentation of substrates contained in thedietof the animals (carbohydrates, proteins and lipids. However, the fermentation process is not 100% effective because there are energy losses mainly in the form of methane gas (CH4, which is a problem for the environment since it is a greenhouse gas. In order to improve the efficiency of ruminant production systems, nutritional strategies that aim to manipulate ruminal fermentation using additives in the diet such as monensin, tallow, buffers, nitrogen compounds, probiotics, and others have been used. These additives allow changing the ruminal fermentation process in ways that produce better growth efficiency while decreasing energy loss. The purpose of this review is to contribute to a better understanding of the fermentation processes taking place in the rumen, providing information that can be applied in the development of new nutritional strategies for the improvement of the digestion process to achieve maximum production.

  4. Variation among Dairy Cows in Rumen Liquid Fermentation Characteristics

    DEFF Research Database (Denmark)

    Lassen, Jan; Løvendahl, Peter; Kristensen, Lise

    Volatile fatty acids are the main energy product from rumen fermentation. This study investigated the individuality of VFA concentrations in samples of rumen fluid obtained from 10 Holstein cows using a esophageal probe to take samples repeatedly over a 7 week period. Systematic changes were seen...

  5. Ethanol by continuous fermentation

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    EtOH is produced by continuous fermentation of molasses. Thus, molasses diluted to 20/sup 0/ Brix was inoculated with bakers' yeast and fermented at 32/sup 0/. When the medium reached 4% EtOH, it was circulated through a centrifuge. The concentrated yeast was recycled to the fermentor and the supernatant was sent to a still. After distillation, the still residue was returned to the fermentor. When the initial charge was entirely fermented, 13 kg molasses of 40/sup 0/ Brix was added to the fermentor per hour, and the yield of EtOH was 1.7 kg/100 L-hour.

  6. Protein modification by fermentation

    DEFF Research Database (Denmark)

    Barkholt, Helle Vibeke; Jørgensen, P.B.; Sørensen, Anne Dorthe

    1998-01-01

    The effect of fermentation on components of potential significance for the allergenicity of pea was analyzed. Pea flour was fermented with three lactic acid bacteria, Pediococcus pentosaceus, Lactococcus raffinolactis, and Lactobacillus plantarum, and two fungi, Rhizopus microsporus, var....... oligosporus and Geotrichum candidum. Residual antigenicity against antipea antibodies was reduced to 10% by the three lactic acid bacteria and R. microsporus. Reactions to anti-pea profilin and anti-Bet v I were still detectable after fermentation. The contents of lectin and pea protease inhibitor were...

  7. THERMOCOUPLE VACUUM GAUGE

    Science.gov (United States)

    Price, G.W.

    1954-08-01

    A protector device is described for use in controlling the pressure within a cyclotron. In particular, an electrical circuit functions to actuate a vacuum pump when a predetermined low pressure is reached and disconnect the pump when the pressure increases abcve a certain value. The principal feature of the control circuit lies in the use of a voltage divider network at the input to a relay control tube comprising two parallel, adjustable resistances wherein one resistor is switched into the circuit when the relay connects the pump to a power source. With this arrangement the relay is energized at one input level received from a sensing element within the cyclotron chamber and is de-energized when a second input level, representing the higher pressure limit, is reached.

  8. Vacuum Energy Sequestering and Graviton Loops

    CERN Document Server

    Kaloper, Nemanja

    2016-01-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  9. High Vacuum Furnace for HIRFL-CSR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to satisfy the requirement of ultra-high vacuum and low out-gassing rate of materials which are used to make HIIRFL-CSR vacuum chambers, a high vacuum furnace for degassing the beam chambers, flanges, and the other vacuum components has been designed and manufactured by IMP and Vacuum Equipment Factory in Lanzhou.

  10. Vacuum Energy Sequestering and Graviton Loops

    OpenAIRE

    Kaloper, Nemanja; Padilla, Antonio

    2016-01-01

    We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy sequestering mechanism to also cancel all the vacuum energy loops involving virtual gravitons, in addition to the vacuum energy generated by matter fields alone.

  11. Vacuum Gas Tungsten Arc Welding

    Science.gov (United States)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  12. Vacuum enhanced cutaneous biopsy instrument

    Science.gov (United States)

    Collins, Joseph

    2000-01-01

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  13. ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    1995-01-01

    A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at relati

  14. ULTRARAPID VACUUM-MICROWAVE HISTOPROCESSING

    NARCIS (Netherlands)

    KOK, LP; BOON, ME

    A novel histoprocessing method for paraffin sections is presented in which the combination of vacuum and microwave exposure is the key element. By exploiting the decrease in boiling temperature under vacuum, the liquid molecules in the tissues have been successfully extracted and exchanged at

  15. Breather cloth for vacuum curing

    Science.gov (United States)

    Reed, M. W.

    1979-01-01

    Finely-woven nylon cloth that has been treated with Teflon improves vacuum adhesive bonding of coatings to substrates. Cloth is placed over coating; entire assembly, including substrate, coating, and cloth, is placed in plastic vacuum bag for curing. Cloth allows coating to "breathe" when bag is evacuated. Applications include bonding film coatings to solar concentrators and collectors.

  16. GUT FERMENTATION SYNDROME

    African Journals Online (AJOL)

    boaz

    AFRICAN JOURNAL OF CLINICAL AND EXPERIMENTAL MICROBIOLOGY. JANUARY 2014 ISBN ... documented case of Gut Fermentation Syndrome verified with glucose and .... cerevisiae in Bone Marrow Transplant. Patients,” Journal of ...

  17. Hadron Contribution to Vacuum Polarisation

    Science.gov (United States)

    Davier, M.; Hoecker, A.; Malaescu, B.; Zhang, Z.

    2016-10-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle-antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e- annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingredients to high precision tests of the Standard Theory.

  18. Hadron Contribution to Vacuum Polarisation

    CERN Document Server

    Davier, M; Malaescu, B; Zhang, Z

    2016-01-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...

  19. Vacuum energy as dark matter

    Science.gov (United States)

    Albareti, F. D.; Cembranos, J. A. R.; Maroto, A. L.

    2014-12-01

    We consider the vacuum energy of massive quantum fields in an expanding universe. We define a conserved renormalized energy-momentum tensor by means of a comoving cutoff regularization. Using exact solutions for de Sitter space-time, we show that in a certain range of mass and renormalization scales there is a contribution to the vacuum energy density that scales as nonrelativistic matter and that such a contribution becomes dominant at late times. By means of the WKB approximation, we find that these results can be extended to arbitrary Robertson-Walker geometries. We study the range of parameters in which the vacuum energy density would be compatible with current limits on dark matter abundance. Finally, by calculating the vacuum energy in a perturbed Robertson-Walker background, we obtain the speed of sound of density perturbations and show that the vacuum energy density contrast can grow on sub-Hubble scales as in standard cold dark matter scenarios.

  20. Vacuum energy as dark matter

    CERN Document Server

    Albareti, F D; Maroto, A L

    2014-01-01

    We consider the vacuum energy of massive quantum fields in an expanding universe. We define a conserved renormalized energy-momentum tensor by means of a comoving cutoff regularization. Using exact solutions for de Sitter space-time, we show that in a certain range of mass and renormalization scales there is a contribution to the vacuum energy density that scales as non-relativistic matter and that such a contribution becomes dominant at late times. By means of the WKB approximation, we find that these results can be extended to arbitrary Robertson-Walker geometries. We study the range of parameters in which the vacuum energy density would be compatible with current limits on dark matter abundance. Finally, by calculating the vacuum energy in a perturbed Robertson-Walker background, we obtain the speed of sound of density perturbations and show that the vacuum energy density contrast can grow on sub-Hubble scales as in standard cold dark matter scenarios.

  1. Vacuum Energy and Its Consequences

    Science.gov (United States)

    Hewett, Lionel

    2009-10-01

    Intuitively one would think that a perfect vacuum should contain no energy. However, quantum mechanics asserts that virtual particles popping in and out of existence too fast to be observed directly should produce a non-zero average energy density for empty space. This presentation discusses how quantum mechanics predicts too large a value for this energy density, how the Casimir effect correctly predicts the measured value of the vacuum energy between closely spaced objects, how time-symmetric cosmology predicts the energy density of interstellar space, how vacuum energy produces negative pressure, how vacuum energy causes the current universe to accelerate its expansion, and why vacuum energy cannot be tapped so as to produce an inexhaustible source of energy for all mankind.

  2. Kinetics of methane fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y. R.; Hashimoto, A. G.

    1978-01-01

    The kinetics on methane fermentation are described using published data for livestock residue, sewage sludge, and municipal refuse. Methods are presented to determine the kinetic constants and the finally attainable methane production using steady-state methane production data. The effects of temperature, loading rate, and influent substrate concentration on methane fermentation kinetics are discussed. These relationships were used to predict the rate of methane production of a pilot-scale fermentor with excellent results.

  3. Vacuum fiber-fiber coupler

    Science.gov (United States)

    Heinrici, Axel; Bjelajac, Goran; Jonkers, Jeroen; Jakobs, Stefan; Olschok, Simon; Reisgen, Uwe

    2017-02-01

    Research and development carried out by the ISF Welding and Joining Institute of RWTH Aachen University has proven that combining high power laser and low vacuum atmosphere provides a welding performance and quality, which is comparable to electron beam welding. The developed welding machines are still using a beam forming which takes place outside the vacuum and the focusing laser beam has to be introduced to the vacuum via a suitable window. This inflexible design spoils much of the flexibility of modern laser welding. With the target to bring a compact, lightweight flying optics with flexible laser transport fibers into vacuum chambers, a high power fiber-fiber coupler has been adapted by II-VI HIGHYAG that includes a reliable vacuum interface. The vacuum-fiber-fiber coupler (V-FFC) is tested with up to 16 kW sustained laser power and the design is flexible in terms of a wide variety of laser fiber plug systems and vacuum flanges. All that is needed to implement the V-FFC towards an existing or planned vacuum chamber is an aperture of at least 100 mm (4 inch) diameter with any type of vacuum or pressure flange. The V-FFC has a state-of-the-art safety interface which allows for fast fiber breakage detection for both fibers (as supported by fibers) by electric wire breakage and short circuit detection. Moreover, the System also provides connectors for cooling and electric signals for the laser beam optics inside the vacuum. The V-FFC has all necessary adjustment options for coupling the laser radiation to the receiving fiber.

  4. Fermentation of cereals - Influence on digestibility of nutrients in growing pigs

    DEFF Research Database (Denmark)

    Jørgensen, Henry; Sholly, Danielle; Pedersen, Anni Øyan;

    2010-01-01

    A study was carried out to determine the impact of fermentation of two cereals, barley and wheat, on chemical composition and nutrient digestibility in the small intestine and the total tract of growing pigs. Fermented liquid cereals were prepared by mixing either barley or wheat and water (25 °C......) at a ratio of 1:2.75 (wt/wt). Four experimental diets consisting of either dry or fermented barley or wheat, supplemented with a protein mixture (not fermented) were formulated to contain recommended levels of nutrients. Eight pigs from two litters were surgically fitted with a T-cannula anterior to the ileo......-cecal junction and fed one of the four experimental diets according to a repeated 4 × 4 Latin-square design. The fermentation process was followed by measuring the changes in the major nutrients, microbial composition and organic acid concentrations. Fermentation caused a reduced concentration of carbohydrates...

  5. Effects of Shrimp Meal Fermented with Aspergillus niger On Physical Quality of Broiler Meat

    Directory of Open Access Journals (Sweden)

    Djalal Rosyidi

    2012-02-01

    Full Text Available The research materials were 75 broiler chickens of 1 day old and feeds. The research employed five treatments, namely (P0: feed without addition of fermented shrimp meal, P1: feed with 5 % addition of fermented shrimp meal, P2: feed with 7.5 % addition of fermented shrimp meal, P3: feed with 10 % addition of fermented shrimp meal, P4: feed with 12.5 % addition of fermented shrimp meal. Every treatment was repeated 3 times, with 5 chickens respectively. Variables of this research were Water Holding Capacity (WHC, cooking loss and tenderness of broiler meat. Data were analyzed by completely randomized design, if there was a significant effect, it was followed by Duncan’s Multiple Range Test (DMRT. The result of this research showed that the use of fermented shrimp meal in broiler feed can improve WHC, degrading cooking loss and improving tenderness of broiler meat.   Keywords : Water holding capacity, cooking loss, tenderness

  6. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems...

  7. Vacuum technology, thin films and sputtering an introduction

    CERN Document Server

    Stuart, R V

    1983-01-01

    Vacuum technology is advancing and expanding so rapidly that a major difficulty for most companies in the field is finding qualified technicians needed for expansion and as replacements. The only recourse for most companies is to hire capable, though untrained, people to train them in-house. One of the problems in this course of action is that it repeatedly draws on the valuable time of experienced personnel to explain fundamental concepts to a trainee.

  8. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  9. Applied in situ product recovery in ABE fermentation

    Science.gov (United States)

    Lalander, Carl‐Axel; Lee, Jonathan G. M.; Davies, E. Timothy; Harvey, Adam P.

    2017-01-01

    The production of biobutanol is hindered by the product's toxicity to the bacteria, which limits the productivity of the process. In situ product recovery of butanol can improve the productivity by removing the source of inhibition. This paper reviews in situ product recovery techniques applied to the acetone butanol ethanol fermentation in a stirred tank reactor. Methods of in situ recovery include gas stripping, vacuum fermentation, pervaporation, liquid–liquid extraction, perstraction, and adsorption, all of which have been investigated for the acetone, butanol, and ethanol fermentation. All techniques have shown an improvement in substrate utilization, yield, productivity or both. Different fermentation modes favored different techniques. For batch processing gas stripping and pervaporation were most favorable, but in fed‐batch fermentations gas stripping and adsorption were most promising. During continuous processing perstraction appeared to offer the best improvement. The use of hybrid techniques can increase the final product concentration beyond that of single‐stage techniques. Therefore, the selection of an in situ product recovery technique would require comparable information on the energy demand and economics of the process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:563–579, 2017 PMID:28188696

  10. Vacuum Brazing of Accelerator Components

    Science.gov (United States)

    Singh, Rajvir; Pant, K. K.; Lal, Shankar; Yadav, D. P.; Garg, S. R.; Raghuvanshi, V. K.; Mundra, G.

    2012-11-01

    Commonly used materials for accelerator components are those which are vacuum compatible and thermally conductive. Stainless steel, aluminum and copper are common among them. Stainless steel is a poor heat conductor and not very common in use where good thermal conductivity is required. Aluminum and copper and their alloys meet the above requirements and are frequently used for the above purpose. The accelerator components made of aluminum and its alloys using welding process have become a common practice now a days. It is mandatory to use copper and its other grades in RF devices required for accelerators. Beam line and Front End components of the accelerators are fabricated from stainless steel and OFHC copper. Fabrication of components made of copper using welding process is very difficult and in most of the cases it is impossible. Fabrication and joining in such cases is possible using brazing process especially under vacuum and inert gas atmosphere. Several accelerator components have been vacuum brazed for Indus projects at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore using vacuum brazing facility available at RRCAT, Indore. This paper presents details regarding development of the above mentioned high value and strategic components/assemblies. It will include basics required for vacuum brazing, details of vacuum brazing facility, joint design, fixturing of the jobs, selection of filler alloys, optimization of brazing parameters so as to obtain high quality brazed joints, brief description of vacuum brazed accelerator components etc.

  11. NCSX Vacuum Vessel Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Viola, M. E.; Brown, T.; Heitzenroeder, P.; Malinowski, F.; Reiersen, W.; Sutton, L.; Goranson, P.; Nelson, B.; Cole, M.; Manuel, M.; McCorkle, D.

    2005-10-07

    The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120º vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1" of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120º vessel segments are formed by welding two 60º segments together. Each 60º segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8" (20.3 cm) wide spacer "spool pieces." The vessel must have a total leak rate less than 5 X 10-6 t-l/s, magnetic permeability less than 1.02μ, and its contours must be within 0.188" (4.76 mm). It is scheduled for completion in January 2006.

  12. HIGH TEMPERATURE VACUUM MIXER

    Directory of Open Access Journals (Sweden)

    E. D. Chertov

    2015-01-01

    Full Text Available The work is devoted to the creation of a new type of mixer to produce homogeneous mixtures of dissimilar materials applied to recycling of housing and communal services waste. The article describes the design of a dual-chamber device of the original high-temperature vacuum mixer, there investigated the processes occurring in the chambers of such devices. The results of theoretical and experimental research of the process of mixing recycled polyethylene with a mixture of "grinded food waste – Eco wool” are presented. The problem of the optimum choice of bending the curvilinear blades in the working volume of the seal, which is achieved by setting their profile in the form of involute arc of several circles of different radii, is examined . The dependences, allowing to define the limits of the changes of the main mode parameters the angular velocity of rotation of the working body of the mixer using two ways of setting the profile of the curvilinear blade mixer are obtained. Represented design of the mixer is proposed to use for a wide range of tasks associated with the mixing of the components with a strongly pronounced difference of physic al chemical properties and, in particular, in the production of composites out of housing and communal services waste.

  13. Vacuum plasma spray coating

    Science.gov (United States)

    Holmes, Richard R.; Mckechnie, Timothy N.

    1989-01-01

    Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

  14. The vacuum universe the vacuum deposit and the dimensional hierarchy

    CERN Document Server

    Chung Ding Yu

    2001-01-01

    In this paper, it is proposed that the universe not only gains its existence from the vacuum but also fattens itself with the vacuum. It is the vacuum universe. The vacuum is deposited in the inflationary universe before the inflation. During the inflation, the deposited vacuum is spent to acquire space. In terms of elementary particles, the deposited vacuum is spent to dilute (fractionalize) the primordial high mass mixed 9-branes to form the low mass hierarchical mixed branes from 9 to 3 whose masses decrease with the space-time dimension numbers. This formation of the hierarchical mixed branes is followed by the internal empty space formation. The internal empty space is generate internally by the annihilation of some of the mixed branes through charge symmetry. The energy released is cosmic radiation. The inflationary emergence of the hierarchical mixed branes and the non-inflationary emergence of cosmic radiation after the inflation constitute the hybrid inflation. The mixed 3-brane is the mixture of lep...

  15. Quantum repeaters based on heralded qubit amplifiers

    CERN Document Server

    Minář, Jiří; Sangouard, Nicolas

    2011-01-01

    We present a quantum repeater scheme based on the recently proposed qubit amplifier [N. Gisin, S. Pironio and N. Sangouard, Phys. Rev. Lett. 105, 070501 (2010)]. It relies on a on-demand entangled-photon pair source which uses on-demand single-photon sources, linear optical elements and atomic ensembles. Interestingly, the imperfections affecting the states created from this source, caused e.g. by detectors with non-unit efficiencies, are systematically purified from an entanglement swapping operation based on a two-photon detection. This allows the distribution of entanglement over very long distances with a high fidelity, i.e. without vacuum components and multiphoton errors. Therefore, the resulting quantum repeater architecture does not necessitate final postselections and thus achieves high entanglement distribution rates. This also provides unique opportunities for device-independent quantum key distribution over long distances with linear optics and atomic ensembles.

  16. Xylose fermentation to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1993-01-01

    The past several years have seen tremendous progress in the understanding of xylose metabolism and in the identification, characterization, and development of strains with improved xylose fermentation characteristics. A survey of the numerous microorganisms capable of directly fermenting xylose to ethanol indicates that wild-type yeast and recombinant bacteria offer the best overall performance in terms of high yield, final ethanol concentration, and volumetric productivity. The best performing bacteria, yeast, and fungi can achieve yields greater than 0.4 g/g and final ethanol concentrations approaching 5%. Productivities remain low for most yeast and particularly for fungi, but volumetric productivities exceeding 1.0 g/L-h have been reported for xylose-fermenting bacteria. In terms of wild-type microorganisms, strains of the yeast Pichia stipitis show the most promise in the short term for direct high-yield fermentation of xylose without byproduct formation. Of the recombinant xylose-fermenting microorganisms developed, recombinant E. coli ATTC 11303 (pLOI297) exhibits the most favorable performance characteristics reported to date.

  17. Quantum Electrodynamics vacuum polarization solver

    CERN Document Server

    Carneiro, Pedro; Fonseca, Ricardo; Silva, Luís

    2016-01-01

    The self-consistent modeling of vacuum polarization due to virtual electron-positron fluctuations is of relevance for many near term experiments associated with high intensity radiation sources and represents a milestone in describing scenarios of extreme energy density. We present a generalized finite-difference time-domain solver that can incorporate the modifications to Maxwells equations due to virtual vacuum polarization. Our multidimensional solver reproduced in one dimensional configurations the results for which an analytic treatment is possible, yielding vacuum harmonic generation and birefringence. The solver has also been tested for two-dimensional scenarios where finite laser beam spot sizes must be taken into account. We employ this solver to explore different types of counter-propagating configurations that can be relevant for future planned experiments aiming to detect quantum vacuum dynamics at ultra-high electromagnetic field intensities.

  18. SILICON REFINING BY VACUUM TREATMENT

    Directory of Open Access Journals (Sweden)

    André Alexandrino Lotto

    2014-12-01

    Full Text Available This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi (98.5% to 99% Si. Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP, and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

  19. Inhomogeneous and interacting vacuum energy

    CERN Document Server

    De-Santiago, Josue; Wang, Yuting

    2012-01-01

    Vacuum energy is a simple model for dark energy driving an accelerated expansion of the universe. If the vacuum energy is inhomogeneous in spacetime then it must be interacting. We present the general equations for a spacetime-dependent vacuum energy in cosmology, including inhomogeneous perturbations. We show how any dark energy cosmology can be described by an interacting vacuum+matter. Different models for the interaction can lead to different behaviour (e.g., sound speed for dark energy perturbations) and hence could be distinguished by cosmological observations. As an example we present the cosmic microwave microwave background anisotropies and the matter power spectrum for two different versions of a generalised Chaplygin gas cosmology.

  20. APS storage ring vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, R.C.; Benaroya, R.; Choi, M.; Dortwegt, R.J.; Goeppner, G.A.; Gonczy, J.; Krieger, C.; Howell, J.; Nielsen, R.W.; Roop, B.; Wehrle, R.B.

    1990-01-01

    The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's experimental program. The Storage Ring's 1104 m circumference is divided into 40 functional sectors. The sectors include vacuum, beam transport, control, acceleration and insertion device components. The vacuum system, which is designed to operate at a pressure of 1 n Torr, consists of 240 connected sections, the majority of which are fabricated from an aluminum alloy extrusion. The sections are equipped with distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. The details of the vacuum system design, selected results of the development program and general construction plans are presented. 11 refs., 6 figs., 3 tabs.

  1. Fermentation, Effect on Textural Properties *

    African Journals Online (AJOL)

    Cyanide and pH decreased, while crude protein, acidity, and apparent amy tose content increased in the fermented ... Fresh cassava roots of the 'Red Skin' ... starch at 854] were measured by the .... fermentation, granule surface corrosion,.

  2. Vacuum production; Produccion de vacio

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, J. L. de

    2010-07-01

    Since the advent of ultra high vacuum in 1958 has been a great demand for new as means of production and to meet the process needs to be done: industry heavy, high technology and space research areas, large accelerator systems particles or nuclear fusion. In this paper we explore the modern media production: dry vacuum pumps, turbo pumps, pump status diffusion ion pumps and cryopumps. (Author)

  3. Decoherence delays false vacuum decay

    OpenAIRE

    Bachlechner, Thomas C.

    2012-01-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling $\\Gamma\\sim\\Gamma_{CDL}^{2}$, where $\\Gamma_{CDL}$ is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable i...

  4. ITER diagnostic system: Vacuum interface

    Energy Technology Data Exchange (ETDEWEB)

    Patel, K.M., E-mail: Kaushal.Patel@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Drevon, J.M. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Encheva, A. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Kashchuk, Y. [Institution “PROJECT CENTER ITER”, 1, Akademika Kurchatova pl., Moscow (Russian Federation); Maquet, Ph. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France)

    2013-10-15

    Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10{sup −7} Pa, irrespective of plasma operation, and a leak rate of less than 10{sup −10} Pa m{sup 3} s{sup −1}. In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions

  5. Vacuum Frying: A nutritional approach

    OpenAIRE

    Manuel Coronel

    2014-01-01

    (Received: 2014/08/07 - Accepted: 2014/09/22)One of the largest areas of the food industry is the production of snacks, but these have generally an inadequate nutritional profile in healthy eating. The vacuum frying technology is presented as a clear option processing for the development of new products and existing ones. This review article presents the advantages of using technology in Vacuum frying different types of food, especially in relation to the contents of some micronutrients and f...

  6. Vacuum-assisted cesarean section

    Directory of Open Access Journals (Sweden)

    McQuivey RW

    2017-03-01

    Full Text Available Ross W McQuivey,1 Jon E Block2 1Clinical Innovations, Salt Lake City, UT, 2Independent consultant, San Francisco, CA, USA Abstract: There has been a dramatic rise in the frequency of cesarean sections, surpassing 30% of all deliveries in the US. This upsurge, coupled with a decreasing willingness to allow vaginal birth after cesarean section, has resulted in an expansion of the use of vacuum assistance to safely extract the fetal head. By avoiding the use of a delivering hand or forceps blade, the volume being delivered through the uterine incision can be decreased when the vacuum is used properly. Reducing uterine extensions with their associated complications (eg, excessive blood loss in difficult cases is also a theoretical advantage of vacuum delivery. Maternal discomfort related to excessive fundal pressure may also be lessened. To minimize the risk of neonatal morbidity, proper cup placement over the “flexion point” remains essential to maintain vacuum integrity and reduce the chance of inadvertent detachment and uterine extensions. Based on the published literature and pragmatic clinical experience, utilization of the vacuum device is a safe and effective technique to assist delivery during cesarean section. Keywords: cesarean section, vacuum, forceps, birth, delivery

  7. Edge conduction in vacuum glazing

    Energy Technology Data Exchange (ETDEWEB)

    Simko, T.M.; Collins, R.E. [Sydney Univ., NSW (Australia). Dept. of Applied Physics; Beck, F.A.; Arasteh, D. [Lawrence Berkeley Lab., CA (United States)

    1995-03-01

    Vacuum glazing is a form of low-conductance double glazing using in internal vacuum between the two glass sheets to eliminate heat transport by gas conduction and convection. An array of small support pillars separates the sheets; fused solder glass forms the edge seal. Heat transfer through the glazing occurs by radiation across the vacuum gap, conduction through the support pillars, and conduction through the bonded edge seal. Edge conduction is problematic because it affects stresses in the edge region, leading to possible failure of the glazing; in addition, excessive heat transfer because of thermal bridging in the edge region can lower overall window thermal performance and decrease resistance to condensation. Infrared thermography was used to analyze the thermal performance of prototype vacuum glazings, and, for comparison, atmospheric pressure superwindows. Research focused on mitigating the edge effects of vacuum glazings through the use of insulating trim, recessed edges, and framing materials. Experimentally validated finite-element and finite-difference modeling tools were used for thermal analysis of prototype vacuum glazing units and complete windows. Experimental measurements of edge conduction using infrared imaging were found to be in good agreement with finite-element modeling results for a given set of conditions. Finite-element modeling validates an analytic model developed for edge conduction.

  8. Technical specification for vacuum systems

    Energy Technology Data Exchange (ETDEWEB)

    Khaw, J. (ed.)

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)

  9. Filamentous Fungi Fermentation

    DEFF Research Database (Denmark)

    Nørregaard, Anders; Stocks, Stuart; Woodley, John

    2014-01-01

    Filamentous fungi (including microorganisms such as Aspergillus niger and Rhizopus oryzae) represent an enormously important platform for industrial fermentation. Two particularly valuable features are the high yield coefficients and the ability to secrete products. However, the filamentous...... morphology, together with non-Newtonian rheological properties (shear thinning), result in poor oxygen transfer unless sufficient energy is provided to the fermentation. While genomic research may improve the organisms, there is no doubt that to enable further application in future it will be necessary...... to match such research with studies of oxygen transfer and energy supply to high viscosity fluids. Hence, the implementation of innovative solutions (some of which in principle are already possible) will be essential to ensure the further development of such fermentations....

  10. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  11. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  12. Recursive quantum repeater networks

    CERN Document Server

    Van Meter, Rodney; Horsman, Clare

    2011-01-01

    Internet-scale quantum repeater networks will be heterogeneous in physical technology, repeater functionality, and management. The classical control necessary to use the network will therefore face similar issues as Internet data transmission. Many scalability and management problems that arose during the development of the Internet might have been solved in a more uniform fashion, improving flexibility and reducing redundant engineering effort. Quantum repeater network development is currently at the stage where we risk similar duplication when separate systems are combined. We propose a unifying framework that can be used with all existing repeater designs. We introduce the notion of a Quantum Recursive Network Architecture, developed from the emerging classical concept of 'recursive networks', extending recursive mechanisms from a focus on data forwarding to a more general distributed computing request framework. Recursion abstracts independent transit networks as single relay nodes, unifies software layer...

  13. RFQ Vacuum brazing at CERN

    CERN Document Server

    Mathot, S

    2008-01-01

    The aim of this paper is to describe the vacuum brazing procedure used at CERN for the brazing of Radio Frequency Quadrupole (RFQ). The RFQ is made of high precision machined OFE copper pieces assembled together. Vacuum brazing is one of the most promising techniques used to join the individual components leading to vacuum tightness and high precision alignment. The RFQ modules brazed at CERN are made of four 100 or 120 cm long vanes (two major and two minor vanes). Our brazing procedure consists of two steps. The first step involves the brazing of the four vanes in a horizontal position. The second step consists of brazing the vacuum stainless steel flanges to the copper structure in a vertical position. The paper describes the problems encountered with the alignment and the vacuum tightness. The difficulties related to the stress relaxation of the machined copper pieces during the brazing heat treatment are discussed. In addition, the solutions developed to improve the alignment of the brazed RFQ’s are...

  14. The Light-Front Vacuum

    CERN Document Server

    Herrmann, Marc

    2015-01-01

    Background: The vacuum in the light-front representation of quantum field theory is trivial while vacuum in the equivalent canonical representation of the same theory is non-trivial. Purpose: Understand the relation between the vacuum in light-front and canonical representations of quantum field theory and the role of zero-modes in this relation. Method: Vacuua are defined as linear functionals on an algebra of field operators. The role of the algebra in the definition of the vacuum is exploited to understand this relation. Results: The vacuum functional can be extended from the light-front Fock algebra to an algebra of local observables. The extension to the algebra of local observables is responsible for the inequivalence. The extension defines a unitary mapping between the physical representation of the local algebra and a sub-algebra of the light-front Fock algebra. Conclusion: There is a unitary mapping from the physical representation of the algebra of local observables to a sub-algebra of the light-fro...

  15. Microscale Digital Vacuum Electronic Gates

    Science.gov (United States)

    Manohara, Harish (Inventor); Mojarradi, Mohammed M. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement microscale digital vacuum electronic gates. In one embodiment, a microscale digital vacuum electronic gate includes: a microscale field emitter that can emit electrons and that is a microscale cathode; and a microscale anode; where the microscale field emitter and the microscale anode are disposed within at least a partial vacuum; where the microscale field emitter and the microscale anode are separated by a gap; and where the potential difference between the microscale field emitter and the microscale anode is controllable such that the flow of electrons between the microscale field emitter and the microscale anode is thereby controllable; where when the microscale anode receives a flow of electrons, a first logic state is defined; and where when the microscale anode does not receive a flow of electrons, a second logic state is defined.

  16. Impedances of Laminated Vacuum Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A.; Lebedev, V.; /Fermilab

    2011-06-22

    First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

  17. Particle description of zero energy vacuum; 2, Basic vacuum systems

    CERN Document Server

    Grandpeix, J Y

    2002-01-01

    We describe vacuum as a system of virtual particles, some of which have negative energies. Any system of vacuum particles is a part of a keneme, i.e. of a system of n particles which can, without violating the conservation laws, annihilate in the strict sense of the word (transform into nothing). A keneme is a homogeneous system, i.e. its state is invariant by all transformations of the invariance group. But a homogeneous system is not necessarily a keneme. In the simple case of a spin system, where the invariance group is SU(2), a homogeneous system is a system whose total spin is unpolarized; a keneme is a system whose total spin is zero. The state of a homogeneous system is described by a statistical operator with infinite trace (von Neumann), to which corresponds a characteristic distribution. The characteristic distributions of the homogeneous systems of vacuum are defined and studied. Finally it is shown how this description of vacuum can be used to solve the frame problem posed in (I).

  18. The Pentapeptide Repeat Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Vetting,M.; Hegde, S.; Fajardo, J.; Fiser, A.; Roderick, S.; Takiff, H.; Blanchard, J.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S, T,A, V][D, N][L, F]-[S, T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Mycobacterium tuberculosis. The structure revealed that the pentapeptide repeats encode the folding of a novel right-handed quadrilateral {beta}-helix. MfpA binds to DNA gyrase and inhibits its activity. The rod-shaped, dimeric protein exhibits remarkable size, shape and electrostatic similarity to DNA.

  19. The Source of the Quantum Vacuum

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-01-01

    Full Text Available The quantum vacuum consists of virtual particles randomly appearing and disappearing in free space. Ordinarily the wavenumber (or frequency spectrum of the zero-point fields for these virtual particles is assumed to be unbounded. The unbounded nature of the spectrum leads in turn to an infinite energy density for the quantum vacuum and an infinite renormalization mass for the free particle. This paper argues that there is a more fundamental vacuum state, the Planck vacuum, from which the quantum vacuum emerges and that the "graininess" of this more fundamental vacuum state truncates the wavenumber spectrum and leads to a finite energy density and a finite renormalization mass.

  20. The Source of the Quantum Vacuum

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-01-01

    Full Text Available The quantum vacuum consists of virtual particles randomly appearing and disappearing in free space. Ordinarily the wavenumber (or frequency spectrum of the zero-point fields for these virtual particles is assumed to be unbounded. The unbounded nature of the spectrum leads in turn to an infinite energy density for the quantum vacuum and an infinite renormalization mass for the free particle. This paper argues that there is a more fundamental vacuum state, the Planck vacuum, from which the quantum vacuum emerges and that the “graininess” of this more fundamental vacuum state truncates the wavenumber spectrum and leads to a finite energy density and a finite renormalization mass.

  1. Gases and vacua handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 1: Gases and Vacua provides information on the many aspects of vacuum technology, from material on the quantum theoretical aspects of the complex semi-conductors used for thermionic and photo-electric emission to data on the performance of commercially available pumps, gauges, and high-vacuum materials. The handbook satisfies the need of workers using vacuum apparatuses or works on the diverse applications of high-vacuum technology in research and industry. The book is a compilation of long articles prepared by experts in vacuum technology. Sufficient theoret

  2. The Fate of the Higgs Vacuum

    CERN Document Server

    Gregory, Ruth

    2016-01-01

    This talk reviews our recent work showing how tiny black holes can act as nucleation sites for the decay of the metastable Higgs vacuum. We start by discussing the formation of thin wall bubbles of true vacuum inside a false vacuum, and show how adding a black hole lowers the action of the Euclidean tunneling solution, thus strongly enhancing the probability of vacuum decay. We then review numerical results for the Higgs vacuum showing that the decay rate is even higher for these "thick wall" bubbles. The results imply either tiny black holes are not a component of our universe, or BSM corrections to the Higgs potential must stabilise our vacuum.

  3. Repeating the Past

    Science.gov (United States)

    Moore, John W.

    1998-05-01

    As part of the celebration of the Journal 's 75th year, we are scanning each Journal issue from 25, 50, and 74 years ago. Many of the ideas and practices described are so similar to present-day "innovations" that George Santayana's adage (1) "Those who cannot remember the past are condemned to repeat it" comes to mind. But perhaps "condemned" is too strong - sometimes it may be valuable to repeat something that was done long ago. One example comes from the earliest days of the Division of Chemical Education and of the Journal.

  4. Vacuum arc localization in CLIC prototype radio frequency accelerating structures

    CERN Document Server

    AUTHOR|(CDS)2091976; Koivunen, Visa

    2016-04-04

    A future linear collider capable of reaching TeV collision energies should support accelerating gradients beyond 100 MV/m. At such high fields, the occurrence of vacuum arcs have to be mitigated through conditioning, during which an accelerating structure’s resilience against breakdowns is slowly increased through repeated radio frequency pulsing. Conditioning is very time and resource consuming, which is why developing more efficient procedures is desirable. At CERN, conditioning related research is conducted at the CLIC high-power X-band test stands. Breakdown localization is an important diagnostic tool of accelerating structure tests. Abnormal position distributions highlight issues in structure design, manufacturing or operation and may consequently help improve these processes. Additionally, positioning can provide insight into the physics of vacuum arcs. In this work, two established positioning methods based on the time-difference-ofarrival of radio frequency waves are extended. The first method i...

  5. Compression Responses of Preform in Vacuum Infusion Process

    Institute of Scientific and Technical Information of China (English)

    Duan Yuexin; Tan Zhaoyuan; Zhao Yan; Sun Jing

    2008-01-01

    The final thickness of a product after the vacuum infusion process (VIP), which is equal to the fiber volume fraction, depends in part on the compression responses of the preform because one of the mold faces is flexible in VIP. This study aims at investigating the compression responses of different fabrics under dry or wet conditions. The main factors affecting the compression response under investigation include, the vacuum pressure, the loading and unloading repeatability on the preform, the layup design, the kinds of fabrics,and the resin viscosity. Besides, the effects of some internal factors such as nesting and elastic recovery of fibers, lubrication of resin,friction between fibers, and so on, are also studied. In the end, this article expatiates the meaning of the matching requirements of the permeability of the preform and that of the distribution medium.

  6. Filling the vacuum at LHCb

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Last month, the Vacuum, Surfaces and Coatings (VSC) group was tasked with an unusually delicate operation in the LHCb experiment cavern: removing the LHC beam pipe while keeping the sensitive Vertex Locator vacuum vessel (VELO) completely isolated from the action.   The VSC group seal off the VELO beam pipe with a flange. Image: Gloria Corti. LHCb’s VELO detector is one of the crown jewels of the experiment. With detector elements surrounded by a vacuum, it gets as close as 5 cm from the beam. Fantastic for physics, but difficult for all-important access. “Because of the sensitivity of the VELO detector and its proximity to the beam, the collaboration decided not to bake (see box) its portion of the beam pipe,” says Giulia Lanza (TE-VSC-LBV), the expert in charge of the beam vacuum operation. “Our group was therefore asked to remove the rest of the LHC beam pipe while keeping the VELO portion of the pipe completely isolated. This work...

  7. Entanglement in the Bogoliubov vacuum

    DEFF Research Database (Denmark)

    Poulsen, Uffe Vestergaard; Meyer, T.; Lewenstein, M.

    2005-01-01

    We analyze the entanglement properties of the Bogoliubov vacuum, which is obtained as a second-order approximation to the ground state of an interacting Bose-Einstein condensate. We work in one- and two-dimensional lattices and study the entanglement between two groups of sites as a function...

  8. Vacuum assisted closure in coloproctology

    NARCIS (Netherlands)

    Bemelman, W.A.

    2009-01-01

    Vacuum-assisted closure has earned its indications in coloproctology. It has been described with variable results in the treatment of large perineal defects after abdominoperineal excision, in the treatment of stoma dehiscence and perirectal abscesses. The most promising indication for

  9. Vacuum barrier for excimer lasers

    Energy Technology Data Exchange (ETDEWEB)

    Shurter, Roger P. (Jemez Springs, NM)

    1992-01-01

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

  10. Vacuum barrier for excimer lasers

    Energy Technology Data Exchange (ETDEWEB)

    Shurter, R.P.

    1992-09-15

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput. 3 figs.

  11. Vacuum mounting for piezoelectric transducers

    Science.gov (United States)

    Tiede, D. A.

    1977-01-01

    Special housing couples piezoelectric transducers to nonporous surfaces for ultrasonic or acoustic-emission testing. Device, while providing sound isolation on flat or nonflat surfaces, can be attached and detached quickly. Vacuum sealing mechanism eliminates need for permanent or semipermanent bonds, viscous coupling liquids, weights, magnets, tape, or springs ordinarily used.

  12. Brine Distribution after Vacuum Saturation

    DEFF Research Database (Denmark)

    Hedegaard, Kathrine; Andersen, Bertel Lohmann

    1999-01-01

    Experiments with the vacuum saturation method for brine in plugs of chalk showed that a homogeneous distribution of brine cannot be ensured at saturations below 20% volume. Instead of a homogeneous volume distribution the brine becomes concentrated close to the surfaces of the plugs...

  13. Fermentation method producing ethanol

    Science.gov (United States)

    Wang, Daniel I. C.; Dalal, Rajen

    1986-01-01

    Ethanol is the major end product of an anaerobic, thermophilic fermentation process using a mutant strain of bacterium Clostridium thermosaccharolyticum. This organism is capable of converting hexose and pentose carbohydrates to ethanol, acetic and lactic acids. Mutants of Clostridium thermosaccharolyticum are capable of converting these substrates to ethanol in exceptionally high yield and with increased productivity. Both the mutant organism and the technique for its isolation are provided.

  14. All-optical repeater.

    Science.gov (United States)

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  15. Bidirectional Manchester repeater

    Science.gov (United States)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  16. Vacuum polarization and Hawking radiation

    Science.gov (United States)

    Rahmati, Shohreh

    Quantum gravity is one of the interesting fields in contemporary physics which is still in progress. The purpose of quantum gravity is to present a quantum description for spacetime at 10-33cm or find the 'quanta' of gravitational interaction.. At present, the most viable theory to describe gravitational interaction is general relativity which is a classical theory. Semi-classical quantum gravity or quantum field theory in curved spacetime is an approximation to a full quantum theory of gravity. This approximation considers gravity as a classical field and matter fields are quantized. One interesting phenomena in semi-classical quantum gravity is Hawking radiation. Hawking radiation was derived by Stephen Hawking as a thermal emission of particles from the black hole horizon. In this thesis we obtain the spectrum of Hawking radiation using a new method. Vacuum is defined as the possible lowest energy state which is filled with pairs of virtual particle-antiparticle. Vacuum polarization is a consequence of pair creation in the presence of an external field such as an electromagnetic or gravitational field. Vacuum polarization in the vicinity of a black hole horizon can be interpreted as the cause of the emission from black holes known as Hawking radiation. In this thesis we try to obtain the Hawking spectrum using this approach. We re-examine vacuum polarization of a scalar field in a quasi-local volume that includes the horizon. We study the interaction of a scalar field with the background gravitational field of the black hole in the desired quasi-local region. The quasi-local volume is a hollow cylinder enclosed by two membranes, one inside the horizon and one outside the horizon. The net rate of particle emission can be obtained as the difference of the vacuum polarization from the outer boundary and inner boundary of the cylinder. Thus we found a new method to derive Hawking emission which is unitary and well defined in quantum field theory.

  17. PILOT FERMENTERS OF CAPACITY TYPE

    National Research Council Canada - National Science Library

    Yu I Sidorov

    2012-01-01

      Basic information about modern pilot fermentation apparatus in sterile implementation used for the down-scaling of processes of cultivation of microorganisms, vegetable and animal cells, leading...

  18. A New Approach for Calculating Vacuum Susceptibility

    Institute of Scientific and Technical Information of China (English)

    宗红石; 平加伦; 顾建中

    2004-01-01

    Based on the Dyson-Schwinger approach, we propose a new method for calculating vacuum susceptibilities. As an example, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is presented.

  19. Improved vacuum evaporation unit for beryllium coating for biological X-ray microanalysis.

    Science.gov (United States)

    Marshall, A T; Carde, D; Kent, M

    1985-09-01

    An improved vacuum evaporator is described for coating frozen-hydrated biological samples with beryllium for X-ray microanalysis. The evaporator permits repeated coatings without bringing the main chamber to atmospheric pressure and ambient temperature. The use of a glass sleeve in the evaporation chamber facilitates cleaning.

  20. Polarizable vacuum analysis of electromagnetic fields

    CERN Document Server

    Ye, Xing-Hao

    2009-01-01

    By examining the electric displacement in a dielectric medium and in a vacuum, the polarization property of quantum vacuum is discussed. Both the electric and magnetic fields are analysed in the framework of polarizable vacuum. It is found that the energy and force generated by the electric and magnetic fields can then be understood in a natural way. As an application, the electromagnetic wave is also investigated, which reaches a polarizable vacuum interpretation of the energy and spin of a photon.

  1. The Dirac-Electron Vacuum Wave

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2016-07-01

    Full Text Available This paper argues that the Dirac equation can be interpreted as an interaction between the electron core and the Planck vacuum state, where the positive and negative solutions represent respectively the dynamics of the electron core and a vacuum wave propagating within the vacuum state. Results show that the nonrelativistic positive solution reduces to the Schrödinger wave equation

  2. Vacuum alignment with and without elementary scalars

    DEFF Research Database (Denmark)

    Alanne, Tommi; Gertov, Helene; Meroni, Aurora

    2016-01-01

    We systematically elucidate differences and similarities of the vacuum alignment issue in composite and renormalizable elementary extensions of the Standard Model featuring a pseudo-Goldstone Higgs. We also provide general conditions for the stability of the vacuum in the elementary framework......, thereby extending previous studies of the vacuum alignment....

  3. 14 CFR 29.1433 - Vacuum systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vacuum systems. 29.1433 Section 29.1433... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1433 Vacuum systems. (a... the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe...

  4. 14 CFR 25.1433 - Vacuum systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vacuum systems. 25.1433 Section 25.1433... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1433 Vacuum systems. There... discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe. ...

  5. Utilize Vacuum Forming to Make Interdisciplinary Connections

    Science.gov (United States)

    Love, Tyler S.; Valenza, Frank

    2011-01-01

    The concept of vacuum forming has been around since the 19th century, despite not being fully utilized in industry until the 1950s. In the past, industrial arts classes have used vacuum-forming projects to concentrate solely on the manufacturing process and the final product. However, vacuum forming is not just an old industrial arts activity; it…

  6. Vacuum alignment with and without elementary scalars

    DEFF Research Database (Denmark)

    Alanne, Tommi; Gertov, Helene; Meroni, Aurora;

    2016-01-01

    We systematically elucidate differences and similarities of the vacuum alignment issue in composite and renormalizable elementary extensions of the Standard Model featuring a pseudo-Goldstone Higgs. We also provide general conditions for the stability of the vacuum in the elementary framework......, thereby extending previous studies of the vacuum alignment....

  7. Vacuum alignment with(out) elementary scalars

    CERN Document Server

    Alanne, Tommi; Meroni, Aurora; Sannino, Francesco

    2016-01-01

    We systematically elucidate differences and similarities of the vacuum alignment issue in composite and renormalizable elementary extensions of the Standard Model featuring a pseudo-Goldstone Higgs. We also provide general conditions for the stability of the vacuum in the elementary framework, thereby extending previous studies of the vacuum alignment.

  8. Gravitational vacuum polarization; 2, energy conditions in the Boulware vacuum

    CERN Document Server

    Visser, M

    1996-01-01

    I show that in the Boulware vacuum (1) all standard (point-wise and averaged) energy conditions are violated throughout the exterior region---all the way from spatial infinity down to the event horizon, and (2) outside the event horizon the standard point-wise energy conditions are violated in a maximal manner: they are violated at all points and for all null/timelike vectors. (The region inside the event horizon is considerably messier, and of dubious physical relevance. Nevertheless the standard point-wise energy conditions also seem to be violated even inside the event horizon.) This is rather different from the case of the Hartle--Hawking vacuum, wherein violations of the energy conditions were confined to the region inside the unstable photon orbit. These calculations are for the quantum stress-energy tensor corresponding to a conformally-coupled massless scalar field in the Boulware vacuum. I work in the test-field limit, restrict attention to the Schwarzschild geometry, and invoke a mixture of analytic...

  9. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  10. Visualizing electromagnetic vacuum by MRI

    CERN Document Server

    Chandrashekar, Chandrika S; Chandrashekar, S; Taylor, Erika A; Taylor, Deanne M

    2016-01-01

    Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface decay exponentially inside the conductor, leading to a virtual EM vacuum at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present the first visualization of an EM vacuum inside a bulk metal strip by MRI, amongst several novel findings. We uncover unexpected MRI intensity patterns arising from two orthogonal pairs of faces of a metal strip, and derive formulae for their intensity ratios. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expe...

  11. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  12. Decoherence delays false vacuum decay

    Science.gov (United States)

    Bachlechner, Thomas C.

    2013-05-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling \\Gamma \\sim \\Gamma _{CDL}^{2}, where ΓCDL is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincaré recurrence in de Sitter space.

  13. Decoherence delays false vacuum decay

    CERN Document Server

    Bachlechner, Thomas C

    2012-01-01

    We show that gravitational interactions between thermal de Sitter photons and a nucleating Coleman-de Luccia bubble lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and photon interactions has the exponential scaling $\\Gamma\\sim \\Gamma_{0}^{2}$, where $\\Gamma_{0}$ is the Coleman-de Luccia decay rate neglecting photon interactions. This strong decoherence effect is a generic consequence of gravitational interactions with light external modes. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincare recurrence in de Sitter space.

  14. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  15. Low-Cost "Vacuum Desiccator"

    Science.gov (United States)

    Sweet, Frederick

    2004-10-01

    Described are individualized, low-cost, and safe desiccators that can be efficiently and rapidly made with an inexpensive kitchen aid sold for shrink-wrapping food. The device can be used for enclosing small vials or bottles and also jars that are too large to be placed in conventional glass or plastic desiccators. This shrink-wrapping device is proposed for producing "vacuum desiccators" in large undergraduate chemistry laboratories or in graduate and research laboratories.

  16. Improved Vacuum-Tight Connector

    Science.gov (United States)

    Rudin, Frank

    1989-01-01

    Simple reinforcing tube increases service life and improves seal. Short stainless-steel tube inserted in copper tube to reinforce against compression, preventing leaks due to thermal distortion or to collapse under squeeze of ferrule in compressure fitting. Several test specimens of improved connector constructed, tested, and evaluated. Fittings not only operated successfully at required operating conditions of vacuum and temperature but also consistently demonstrated high reliability after loosened and tightened many times.

  17. Vacuum barrier for excimer lasers

    Energy Technology Data Exchange (ETDEWEB)

    Shurter, R.P.

    1990-10-10

    This invention is comprised of a barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yearns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

  18. The statistics of vacuum geometry

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Melissa [Merton College, University of Oxford,OX1 4JD (United Kingdom); Gu, Wei [The Interdisciplinary Center for Theoretical Study,University of Science and Technology of China, Hefei, Anhui, 230026 (China); He, Yang-Hui [Merton College, University of Oxford,OX1 4JD (United Kingdom); Department of Mathematics, City University,London, EC1V 0HB (United Kingdom); School of Physics, NanKai University,Tianjin, 300071 (China); Zhou, Da [The Interdisciplinary Center for Theoretical Study,University of Science and Technology of China, Hefei, Anhui, 230026 (China)

    2014-06-09

    We investigate the vacuum moduli space of supersymmetric gauge theories en masse by probing the space of such vacua from a statistical standpoint. Using quiver gauge theories with N=1 supersymmetry as a testing ground, we sample over a large number of vacua as algebraic varieties, computing explicitly their dimension, degree and Hilbert series. We study the distribution of these geometrical quantities, and also address the question of how likely it is for the moduli space to be Calabi-Yau.

  19. Random numbers from vacuum fluctuations

    Science.gov (United States)

    Shi, Yicheng; Chng, Brenda; Kurtsiefer, Christian

    2016-07-01

    We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

  20. TRADITIONAL FERMENTED FOODS OF LESOTHO

    Directory of Open Access Journals (Sweden)

    Tendekayi H. Gadaga

    2013-06-01

    Full Text Available This paper describes the traditional methods of preparing fermented foods and beverages of Lesotho. Information on the preparation methods was obtained through a combination of literature review and face to face interviews with respondents from Roma in Lesotho. An unstructured questionnaire was used to capture information on the processes, raw materials and utensils used. Four products; motoho (a fermented porridge, Sesotho (a sorghum based alcoholic beverage, hopose (sorghum fermented beer with added hops and mafi (spontaneously fermented milk, were found to be the main fermented foods prepared and consumed at household level in Lesotho. Motoho is a thin gruel, popular as refreshing beverage as well as a weaning food. Sesotho is sorghum based alcoholic beverage prepared for household consumption as well as for sale. It is consumed in the actively fermenting state. Mafi is the name given to spontaneously fermented milk with a thick consistency. Little research has been done on the technological aspects, including the microbiological and biochemical characteristics of fermented foods in Lesotho. Some of the traditional aspects of the preparation methods, such as use of earthenware pots, are being replaced, and modern equipment including plastic utensils are being used. There is need for further systematic studies on the microbiological and biochemical characteristics of these these products.

  1. China's Fermentation Industry Develops Rapidly

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Output increases steadily The main products of China's fermen-tation industry include amino acid,organic acid, enzyme preparation,yeast, starch and starch sugar, spe-cial functional fermented products,etc. Monosodium glutamate is themain product of amino acid, and cit-ric acid is the main product of or-ganic acid.

  2. Hydrogen Production by Thermophilic Fermentation

    NARCIS (Netherlands)

    Niel, van E.W.J.; Willquist, K.; Zeidan, A.A.; Vrije, de T.; Mars, A.E.; Claassen, P.A.M.

    2012-01-01

    Of the many ways hydrogen can be produced, this chapter focuses on biological hydrogen production by thermophilic bacteria and archaea in dark fermentations. The thermophiles are held as promising candidates for a cost-effective fermentation process, because of their relatively high yields and broad

  3. Vacuum electronics applications at CERN

    CERN Document Server

    Jensen, E

    2009-01-01

    CERN operates a large number of vacuum electronics based RF power amplifiers covering a wide frequency range – over 300 sockets with 24 different grid tubes and klystrons are in use and require constant care to insure reliable operation of the accelerators. This is in particular true for the LHC and its injector chain, for which a program of improvement and stepwise upgrade has started. These include IOT’s for the SPS and klystrons and modulators for Linac4 and SPL. The CLIC study and the CTF3 facility are relevant to vacuum electronics in many ways: The CLIC primary RF power, to be provided at 1 GHz, requires highest possible efficiency and phase stability, MBK’s are likely candidates. The CLIC RF power source and CTF3 are themselves large vacuum electronics applications, consequently there are areas of common interest and concern, including fabrication techniques, pulse compression techniques, breakdown and multipactor theory and simulation, material fatigue, numerical analysis of slow-wave structures...

  4. Vacuum-Packaging Technology for IRFPAs

    Science.gov (United States)

    Matsumura, Takeshi; Tokuda, Takayuki; Tsutinaga, Akinobu; Kimata, Masafumi; Abe, Hideyuki; Tokashiki, Naotaka

    We developed vacuum-packaging equipment and low-cost vacuum packaging technology for IRFPAs. The equipment is versatile and can process packages with various materials and structures. Getters are activated before vacuum packaging, and we can solder caps/ceramic-packages and caps/windows in a high-vacuum condition using this equipment. We also developed a micro-vacuum gauge to measure pressure in vacuum packages. The micro-vacuum gauge uses the principle of thermal conduction of gases. We use a multi-ceramic package that consists of six packages fabricated on a ceramic sheet, and confirm that the pressure in the processed packages is sufficiently low for high-performance IRFPA.

  5. Vacuum Technology and Standardization-An Update

    Science.gov (United States)

    Akram, H. M.; Rashid, H.

    2011-06-01

    Vacuum technology has been vital for the progress in almost every field of modern industrial & scientific research and technological developments. Research in this field is therefore important for the rapid progress in other sophisticated technologies. The modern society require precise know-how of vacuum metrology for its complex and sophisticated manufacturing processes and research activities. Accuracy in vacuum measurements is therefore an essential need for every application. The required accuracy is achieved with the help of well-calibrated vacuum gauges and this is possible only, if there exist proper vacuum standards of required range and accuracy. In this paper, a brief review of recently developed different vacuum standards, namely Standard Mercury Manometer, Standard Volume Expansion System and Standard Orifice Flow System will be presented, employed for the calibration of low, medium and high vacuum gauges respectively. Our recently developed standards are simple in design, least in vibration & degassing rate with desired accuracy, ease of operation and cost effective.

  6. Lactose fermentation by engineered Saccharomyces cerevisiae capable of fermenting cellobiose.

    Science.gov (United States)

    Liu, Jing-Jing; Zhang, Guo-Chang; Oh, Eun Joong; Pathanibul, Panchalee; Turner, Timothy L; Jin, Yong-Su

    2016-09-20

    Lactose is an inevitable byproduct of the dairy industry. In addition to cheese manufacturing, the growing Greek yogurt industry generates excess acid whey, which contains lactose. Therefore, rapid and efficient conversion of lactose to fuels and chemicals would be useful for recycling the otherwise harmful acid whey. Saccharomyces cerevisiae, a popular metabolic engineering host, cannot natively utilize lactose. However, we discovered that an engineered S. cerevisiae strain (EJ2) capable of fermenting cellobiose can also ferment lactose. This finding suggests that a cellobiose transporter (CDT-1) can transport lactose and a β-glucosidase (GH1-1) can hydrolyze lactose by acting as a β-galactosidase. While the lactose fermentation by the EJ2 strain was much slower than the cellobiose fermentation, a faster lactose-fermenting strain (EJ2e8) was obtained through serial subcultures on lactose. The EJ2e8 strain fermented lactose with a consumption rate of 2.16g/Lh. The improved lactose fermentation by the EJ2e8 strain was due to the increased copy number of cdt-1 and gh1-1 genes. Looking ahead, the EJ2e8 strain could be exploited for the production of other non-ethanol fuels and chemicals from lactose through further metabolic engineering.

  7. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-01-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  8. Electroweak Vacuum Instability and Renormalized Higgs Field Vacuum Fluctuations in the Inflationary Universe

    CERN Document Server

    Kohri, Kazunori

    2016-01-01

    In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations $\\left$ enlarge in proportion to the Hubble scale $H^{2}$. Therefore, the large inflationary vacuum fluctuations of the Higgs field $\\left$ are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations $\\left$, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field $\\phi$ determined by the effective potential ${ V }_{\\rm eff}\\left( \\phi \\right)$ in curved space-time and the renormalized...

  9. Running vacuum cosmological models: linear scalar perturbations

    Science.gov (United States)

    Perico, E. L. D.; Tamayo, D. A.

    2017-08-01

    In cosmology, phenomenologically motivated expressions for running vacuum are commonly parameterized as linear functions typically denoted by Λ(H2) or Λ(R). Such models assume an equation of state for the vacuum given by bar PΛ = - bar rhoΛ, relating its background pressure bar PΛ with its mean energy density bar rhoΛ ≡ Λ/8πG. This equation of state suggests that the vacuum dynamics is due to an interaction with the matter content of the universe. Most of the approaches studying the observational impact of these models only consider the interaction between the vacuum and the transient dominant matter component of the universe. We extend such models by assuming that the running vacuum is the sum of independent contributions, namely bar rhoΛ = Σibar rhoΛi. Each Λ i vacuum component is associated and interacting with one of the i matter components in both the background and perturbation levels. We derive the evolution equations for the linear scalar vacuum and matter perturbations in those two scenarios, and identify the running vacuum imprints on the cosmic microwave background anisotropies as well as on the matter power spectrum. In the Λ(H2) scenario the vacuum is coupled with every matter component, whereas the Λ(R) description only leads to a coupling between vacuum and non-relativistic matter, producing different effects on the matter power spectrum.

  10. Gravitational vacuum polarization; 4, Energy conditions in the Unruh vacuum

    CERN Document Server

    Visser, M

    1997-01-01

    Building on a series of earlier papers [gr-qc/9604007, gr-qc/9604008, gr-qc/9604009], I investigate the various point-wise and averaged energy conditions in the Unruh vacuum. I consider the quantum stress-energy tensor corresponding to a conformally coupled massless scalar field, work in the test-field limit, restrict attention to the Schwarzschild geometry, and invoke a mixture of analytical and numerical techniques. I construct a semi-analytic model for the stress-energy tensor that globally reproduces all known numerical results to within 0.8%, and satisfies all known analytic features of the stress-energy tensor. I show that in the Unruh vacuum (1) all standard point-wise energy conditions are violated throughout the exterior region--all the way from spatial infinity down to the event horizon, and (2) the averaged null energy condition is violated on all outgoing radial null geodesics. In a pair of appendices I indicate general strategy for constructing semi-analytic models for the stress-energy tensor in...

  11. [The ultrastructure changes of rabbit retina after periodical vacuum suction].

    Science.gov (United States)

    Li, Shan-shan; Zhou, Xiao-dong; Chu, Ren-yuan

    2005-12-01

    To study the effects of periodical vacuum-suction of different pressures on the ultrastructure of rabbits' retina. Rabbits involved in the present study were divided into a control group and four treatment groups, which were treated with vacuum-suction of different pressures through scleral suction ring. The suction pressure was increased at a rate of 100 mm Hg/3 sec (1 mm Hg = 0.133 kPa) and reached (200 +/- 20) mm Hg (group I), (300 +/- 20) mm Hg (group II); (400 +/- 20) mm Hg (group III) and (500 +/- 20) mm Hg (group IV). The suction pressure was maintained for 5 seconds before released to zero. The corresponding intraocular pressure examined by Tonopen was 35 mm Hg, 45 mm Hg, 55 mm Hg and 75 mm Hg in these 4 groups, respectively. This circle was repeated for 10 times with 1 minute interval. The test was repeated every other day. The retina was examined by electron microscope after 2 weeks. There was no obvious difference in the retina ultrastructure between the control group and group I. The retina ultrastructure changed slightly in group II which showed more active metabolism. Some significant changes were found in group III and group IV with cell necrosis in group IV. Different elevations of intraocular pressure following periodical vacuum-suction have different effects on the retina of rabbit. Pressure less than 45 mm Hg has almost no effect, but some effects appear at 55 mm Hg pressure, and obviously damages are caused by 75 mm Hg pressure.

  12. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  13. Vacuum Decay via Lorentzian Wormholes

    Science.gov (United States)

    Rosales, J. L.

    We speculate about the space-time description due to the presence of Lorentzian worm-holes (handles in space-time joining two distant regions or other universes) in quantum gravity. The semiclassical rate of production of these Lorentzian wormholes in Reissner-Nordström space-times is calculated as a result of the spontaneous decay of vacuum due to a real tunneling configuration. In the magnetic case it only depends on the value of the field theoretical fine structure constant. We predict that the quantum probability corresponding to the nucleation of such geodesically complete space-times should be acutally negligible in our physical Universe.

  14. Lactic acid bacterial population dynamics during fermentation and storage of Thai fermented sausage according to restriction fragment length polymorphism analysis.

    Science.gov (United States)

    Wanangkarn, Amornrat; Liu, Deng-Cheng; Swetwiwathana, Adisorn; Jindaprasert, Aphacha; Phraephaisarn, Chirapiphat; Chumnqoen, Wanwisa; Tan, Fa-Jui

    2014-09-01

    This study applied restriction fragment length polymorphism (RFLP) analysis to identify the lactic acid bacteria (LAB) isolated from "mum" Thai fermented sausages during fermentation and storage. A total of 630 lactic acid bacteria were isolated from the sausages prepared using 2 methods. In Method 1, after stuffing, the sausages were stored at 30 °C for 14 days. In Method 2, after stuffing and storage at 30 °C for 3 days, the sausages were vacuum-packed and stored at 4 °C until Day 28. The sausages were sampled on Days 0, 3, 14, and 28 for analyses. The 16S rDNA was amplified and digested using restriction enzymes. Of the restriction enzymes evaluated, Dde I displayed the highest discrimination capacity. The LAB were classified and 7 species were identified For Methods 1 and 2, during fermentation, the Lactobacillus sakei and Lactobacillus plantarum species were dominant. For Method 2, the proportion of Leuconostoc mesenteroides markedly increased during storage, until L. sakei and Ln. mesenteroides represented the dominant species. The identification of LAB in the sausage samples could facilitate the selection of appropriate microorganisms for candidate starter cultures for future controlled mum production.

  15. Microbial Community Structure of Three Traditional Zambian Fermented Products: Mabisi, Chibwantu and Munkoyo

    NARCIS (Netherlands)

    Schoustra, S.E.; Kasase, C.; Toarta, C.; Kassen, R.; Poulain, A.J.

    2013-01-01

    Around the world, raw materials are converted into fermented food products through microbial and enzymatic activity. Products are typically produced using a process known as batch culture, where small volumes of an old culture are used to initiate a fresh culture. Repeated over many years, and provi

  16. Physiology of yeasts in alcoholic fermentation processes

    OpenAIRE

    Guimarães, Pedro M. R.

    2008-01-01

    Tese de Doutoramento em Engenharia Química e Biológica This thesis is focused on physiological aspects of the yeasts used in two alcoholic fermentation processes: primary brewing fermentation and fermentation of lactose (particularly lactose derived from cheese whey) to ethanol by recombinant Saccharomyces cerevisiae flocculent strains. The brewing fermentation is probably the most extensively studied alcoholic fermentation process. Nevertheless, developments in brewing tech...

  17. Process energy efficiency in pervaporation and vacuum membrane distillation separation of 2,3-butanediol

    Energy Technology Data Exchange (ETDEWEB)

    Shao, P.; Kumar, A. [National Research Council Canada (Canada)

    2011-10-15

    2,3- butanediol has not been produced lately as a fermentation product. Recovery of 2,3- butanediol by distillation is a very energy-intensive process, due to its low concentration in fermentation broth and strong hydrogen bonding interaction between water molecules. An initiative for recovery, an integrated process comprising solvent extraction and pervaporation (PV), has been proposed. This paper presents the energy efficiency of the pervaporative and vacuum membrane distillation separation processes of 2,3- butanediol. The mass and energy balance of the pervaporation process are simulated using a numerical model that is presented in this paper. From the study, it was observed that the distribution of the evaporation heat required over the membrane is asymmetric and within 60% of the membrane area, more than 85% of the heat was consumed. It was also discovered that recycling permeate improves the recovery process and enhances the energy efficiency of the process.

  18. Historical overview on Vacuum suitable Welding and fatigue resistance in Research Devices

    CERN Document Server

    Wolf, Martin

    2015-01-01

    New inventions change the approach of vacuum suitable welding for research purpose. With orbital welding, laser welding and robot welding the possibilities increase to fabricate larger vessels more accurately. Despite this development there is still no perfect understanding on how to avoid virtual leaks and how to make such joints suitable for dynamic stress. By recalling its historical development, it is apparent how welding mistakes began occurring systematically and how to avoid them. With ASDEX-Upgrade as an example, it is shown how the attempt to conduct vacuum suitable welding has decreased the fatigue strength. ITER could repeat the mistakes of ASDEX-Upgrade even for unwanted welding (accidental fusing of joints).

  19. The large-scale structure of vacuum

    CERN Document Server

    Albareti, F D; Maroto, A L

    2014-01-01

    The vacuum state in quantum field theory is known to exhibit an important number of fundamental physical features. In this work we explore the possibility that this state could also present a non-trivial space-time structure on large scales. In particular, we will show that by imposing the renormalized vacuum energy-momentum tensor to be conserved and compatible with cosmological observations, the vacuum energy of sufficiently heavy fields behaves at late times as non-relativistic matter rather than as a cosmological constant. In this limit, the vacuum state supports perturbations whose speed of sound is negligible and accordingly allows the growth of structures in the vacuum energy itself. This large-scale structure of vacuum could seed the formation of galaxies and clusters very much in the same way as cold dark matter does.

  20. Vacuum systems for the ILC helical undulator

    CERN Document Server

    Malyshev, O B; Clarke, J A; Bailey, I R; Dainton, J B; Malysheva, L I; Barber, D P; Cooke, P; Baynham, E; Bradshaw, T; Brummitt, A; Carr, S; Ivanyushenkov, Y; Rochford, J; Moortgat-Pick, G A

    2007-01-01

    The International Linear Collider (ILC) positron source uses a helical undulator to generate polarized photons of ∼10MeV∼10MeV at the first harmonic. Unlike many undulators used in synchrotron radiation sources, the ILC helical undulator vacuum chamber will be bombarded by photons, generated by the undulator, with energies mostly below that of the first harmonic. Achieving the vacuum specification of ∼100nTorr∼100nTorr in a narrow chamber of 4–6mm4–6mm inner diameter, with a long length of 100–200m100–200m, makes the design of the vacuum system challenging. This article describes the vacuum specifications and calculations of the flux and energy of photons irradiating the undulator vacuum chamber and considers possible vacuum system design solutions for two cases: cryogenic and room temperature.

  1. Impact of Gravity on Vacuum Stability

    CERN Document Server

    Branchina, Vincenzo; Zappala, Dario

    2016-01-01

    In a pioneering paper on the role of gravity on false vacuum decay, Coleman and De Luccia showed that a strong gravitational field can stabilize the false vacuum, suppressing the formation of true vacuum bubbles. This result is obtained for the case when the energy density difference between the two vacua is small, the so called thin wall regime, but is considered of more general validity. Here we show that when this condition does not hold, however, {\\it even a very strong gravitational field (Planckian physics) cannot suppress the formation of true vacuum bubbles}. Contrary to common expectations then, gravitational physics at the Planck scale {\\it does not stabilize the false vacuum}. These results are of crucial importance for the stability analysis of the electroweak vacuum and for searches of new physics beyond the Standard Model.

  2. Modelling ethanol production from cellulose: separate hydrolysis and fermentation versus simultaneous saccharification and fermentation

    NARCIS (Netherlands)

    Drissen, R.E.T.; Maas, R.H.W.; Tramper, J.; Beeftink, H.H.

    2009-01-01

    In ethanol production from cellulose, enzymatic hydrolysis, and fermentative conversion may be performed sequentially (separate hydrolysis and fermentation, SHF) or in a single reaction vessel (simultaneous saccharification and fermentation, SSF). Opting for either is essentially a trade-off between

  3. Molecular Dynamics in the Vacuum Ultraviolet

    Science.gov (United States)

    1989-01-30

    CLASSIFICATION OF THIS PAGE COMPLETED PROJECT SUMMARY TITLE: Molecular dynamics in the Vacuum Ultraviolet PRINCIPAL INVESTIGATOR: Paul L. Houston...DTIC TAB 0 Unannounced 0 By Distr ibution I Availability Codes Avail and I or Dist Special I Molecular Dynamics In the Vacuum Ultraviolet Final Technical...Further development of tunable vacuum ultraviolet sources has opened wide areas of molecular dynamics for study. Completed Research Photodissociation of

  4. THE VACUUM IN NONISENTROPIC GAS DYNAMICS

    Institute of Scientific and Technical Information of China (English)

    Geng Chen; Robin Young

    2012-01-01

    We investigate the vacuum in noniscntropic gas dynamics in one space variable,with the most general equation of states allowed by thermodynamics. Wc recall physical constraints on the equations of state and give explicit and easily checkable conditions under which vacuums occur in the solution of the Riemanu problem.We then present a class of models for which the Riemann problen admits unique global solutions without vacuums.

  5. Straw detector: 1 - Vacuum: 0

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    The NA62 straw tracker is using pioneering CERN technology to measure charged particles from very rare kaon decays. For the first time, a large straw tracker with a 4.4 m2 coverage will be placed directly into an experiment’s vacuum tank, allowing physicists to measure the direction and momentum of charged particles with extreme precision. NA62 measurements using this technique will help physicists take a clear look at the kaon decay rate, which might be influenced by particles and processes that are not included in the Standard Model.   Straw ends are glued to an aluminium frame, a crucial step in the assembly of a module. The ends are then visually inspected before a leak test is performed.  “Although straw detectors have been around since the 1980s, what makes the NA62 straw trackers different is that they can work under vacuum,” explains Hans Danielsson from the PH-DT group leading the NA62 straw project. Straw detectors are basically small drift cha...

  6. Sonoluminescence and the QED vacuum

    CERN Document Server

    Liberati, S; Belgiorno, F; Sciama, Dennis William; Visser, Matt

    1999-01-01

    In this talk I shall describe an extension of the quantum-vacuum approach to sonoluminescence proposed several years ago by J.Schwinger. We shall first consider a model calculation based on Bogolubov coefficients relating the QED vacuum in the presence of an expanded bubble to that in the presence of a collapsed bubble. In this way we shall derive an estimate for the spectrum and total energy emitted. This latter will be shown to be proportional to the volume of space over which the refractive index changes, as Schwinger predicted. After this preliminary check we shall deal with the physical constraints that any viable dynamical model for SL has to satisfy in order to fit the experimental data. We shall emphasize the importance of the timescale of the change in refractive index. This discussion will led us to propose a somewhat different version of dynamical Casimir effect in which the change in volume of the bubble is no longer the only source for the change in the refractive index.

  7. Vacuum technology in the chemical industry

    CERN Document Server

    Jorisch, Wolfgang

    2015-01-01

    Based on the very successful German edition and a seminar held by the German Engineers` Association (VDI) on a regular basis for years now, this English edition has been thoroughly updated and revised to reflect the latest developments. It supplies in particular the special aspects of vacuum technology, applied vacuum pump types and vacuum engineering in the chemical, pharmaceutical and process industry application-segments. The text includes chapters dedicated to latest European regulations for operating in hazardous zones with vacuum systems, methods for process pressure control and regulati

  8. The thermodynamics of a gravitating vacuum

    CERN Document Server

    Heyl, M; Siewert, M

    2014-01-01

    In the present days of modern cosmology it is assumed that the main ingredient to cosmic energy presently is vacuum energy with an energy density $\\epsilon_\\mathrm{vac}$ that is constant over the cosmic evolution. In this paper here we show, however, that this assumption of constant vacuum energy density is unphysical, since it conflicts with the requirements of cosmic thermodynamics. We start from the total vacuum energy including the negatively valued gravitational binding energy and show that cosmic thermodynamics then requires that the cosmic vacuum energy density can only vary with cosmic scale $R=R(t)$ according to $\\epsilon _\\mathrm{vac}\\sim R^{-\

  9. Cold vacuum drying facility design requirements

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1999-07-01

    This document provides the detailed design requirements for the Spent Nuclear Fuel Project Cold Vacuum Drying Facility. Process, safety, and quality assurance requirements and interfaces are specified.

  10. Vacuum Technology Considerations For Mass Metrology

    Science.gov (United States)

    Abbott, Patrick J.; Jabour, Zeina J.

    2011-01-01

    Vacuum weighing of mass artifacts eliminates the necessity of air buoyancy correction and its contribution to the measurement uncertainty. Vacuum weighing is also an important process in the experiments currently underway for the redefinition of the SI mass unit, the kilogram. Creating the optimum vacuum environment for mass metrology requires careful design and selection of construction materials, plumbing components, pumping, and pressure gauging technologies. We review the vacuum technology1 required for mass metrology and suggest procedures and hardware for successful and reproducible operation. PMID:26989593

  11. Vacuum-sealed silicon micromachined pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Esashi, Masayoshi [Tohoku Univ., Aobaku, Sendai (Japan); Sugiyama, Susumu [Ritsumeikan Univ., Kusatsu, Shiga (Japan); Ikeda, Kyoichi [Yokogawa Electric Corp., Nagano (Japan); Wang, Y. [Zhejian Univ., Hangzhou (China); Miyashita, Haruzo [Anelva Corp., Yamanashi (Japan)

    1998-08-01

    Considerable progress in silicon pressure sensors has been made in recent years. This paper discusses three types of vacuum-sealed silicon micromachined pressure sensors that represent the present state of the art in this important area. The devices are a capacitive vacuum sensor, a surface-micromachined microdiaphragm pressure sensor, and a resonant pressure sensor. Vacuum sealing for these devices is accomplished using anodic bonding, films deposited using low-pressure chemical vapor deposition, and thermal out-diffusion of hydrogen, respectively. These sensors emphasize high sensitivity; small size, and excellent stability, respectively. The silicon-diaphragm vacuum sensor uses electrostatic force balancing to achieve a wide pressure measurement range.

  12. Attractor Explosions and Catalyzed Vacuum Decay

    Energy Technology Data Exchange (ETDEWEB)

    Green, Daniel; Silverstein, Eva; Starr, David

    2006-05-05

    We present a mechanism for catalyzed vacuum bubble production obtained by combining moduli stabilization with a generalized attractor phenomenon in which moduli are sourced by compact objects. This leads straightforwardly to a class of examples in which the Hawking decay process for black holes unveils a bubble of a different vacuum from the ambient one, generalizing the new endpoint for Hawking evaporation discovered recently by Horowitz. Catalyzed vacuum bubble production can occur for both charged and uncharged bodies, including Schwarzschild black holes for which massive particles produced in the Hawking process can trigger vacuum decay. We briefly discuss applications of this process to the population and stability of metastable vacua.

  13. Vacuum Compatible Percussive Dynamic Cone Penetrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Honeybee Robotics proposes to develop a vacuum compatible percussive dynamic cone penetrometer (PDCP), for establishing soil bin characteristics, with the ultimate...

  14. APS Storage Ring vacuum chamber fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Goeppner, G.A.

    1990-01-01

    The 1104-m circumference Advanced Photon Source Storage Ring Vacuum System is composed of 240 individual sections, which are fabricated from a combination of aluminum extrusions and machined components. The vacuum chambers will have 3800 weld joints, each subject to strict vacuum requirements, as well as a variety of related design criteria. The vacuum criteria and chamber design are reviewed, including a discussion of the weld joint geometries. The critical fabrication process parameters for meeting the design requirements are discussed. The experiences of the prototype chamber fabrication program are presented. Finally, the required facilities preparation for construction activity is briefly described. 6 refs., 6 figs., 1 tab.

  15. Fermented liquid feed for pigs

    OpenAIRE

    Missotten, Joris; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël

    2010-01-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviat...

  16. 基于微生物固态发酵豆粕转化大豆异黄酮的研究%Biotransformation of Soybean Isoflavone by Microbial Solid-state Fermentation

    Institute of Scientific and Technical Information of China (English)

    杨守凤; 徐建雄

    2013-01-01

    Soybean insoflavones (SIF) are rich in nutrtional value and heathy benefit,which had been widely applied in various fields including food,feed,medicine and so on.To extend the application of SIF for industrialization production,the efficacy of biotransformafion of SIF by microbial solid-state fermentation was studied using EM strains,Bacillus subtilis ATCC 6633 and Lactobacillus planetarium ATCC 8014 for single and mixed fermentation.Effects of combined strains and incubation size were investigated for improve the biotransformation efficiency of SIF through vacuum sealed fermentation.The repeatability of the samples was also investigated under the op timized fermentation conditions.The results demonstrated that the single strain-mediated fermentation resulted in higher biotransformation efficacy than that with mixed strains,and the ratio of aglycone in total SIF content reached 64.56% after 7 d by solid-state fermentation with Bacillus subtilis ATCC 6633.The fermentation had high repeatability and stability.%大豆异黄酮具有较高的营养价值和生理保健功能,现已广泛应用到食品、饲料和医药等领域中.为了研究EM 菌、枯草芽孢杆菌ATCC 6633和植物乳酸杆菌ATCC8014单独和混合发酵对大豆异黄酮(Soybeaninsoflavones,SIF)转化效率的研究,本实验将接种量的接种水平全部考虑进去建立微生物固态发酵和菌种组合的方法,通过真空密封发酵和高效液相色谱(High performance liquid chromatography,HPLC)分析方法研究大豆异黄酮中糖苷转化为苷元的效率,此外,还研究了饲料发酵后的干物质含量和在优化条件下样品的重复性研究.结果表明,三种微生物的单独发酵都比混合发酵的效果好,在7d后枯草芽孢杆菌ATCC6633单独发酵的效果最好,其苷元含量占大豆异黄酮的比例达到64.56%,且样品重复性和稳定性较高,从而为工业化发酵转化SIF提供一定的理论基础和参考依据.

  17. Advanced light source vacuum policy and vacuum guidelines for beamlines and experiment endstations

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Z.

    1995-08-01

    The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third generation synchrotron radiation source whose beam lifetime depends on the quality of the vacuum in the storage ring and the connecting beamlines. The storage ring and most of the beamlines share a common vacuum and are operated under ultra-high-vacuum (UHV) conditions. All endstations and beamline equipment must be operated so as to avoid contamination of beamline components, and must include proper safeguards to protect the storage ring vacuum from an accidental break in the beamline or endstation vacuum systems. The primary gas load during operation is due to thermal desorption and electron/photon induced desorption of contaminants from the interior of the vacuum vessel and its components. The desorption rates are considerably higher for hydrocarbon contamination, thus considerable emphasis is placed on eliminating these sources of contaminants. All vacuum components in a beamline and endstation must meet the ALS vacuum specifications. The vacuum design of both beamlines and endstations must be approved by the ALS Beamline Review Committee (BRC) before vacuum connections to the storage ring are made. The vacuum design is first checked during the Beamline Design Review (BDR) held before construction of the beamline equipment begins. Any deviation from the ALS vacuum specifications must be approved by the BRC prior to installation of the equipment on the ALS floor. Any modification that is incorporated into a vacuum assembly without the written approval of the BRC is done at the user`s risk and may lead to rejection of the whole assembly.

  18. Advanced light source vacuum policy and vacuum guidelines for beamlines and experiment endstations

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Z.

    1995-08-01

    The purpose of this document is to: (1) Explain the ALS vacuum policy and specifications for beamlines and experiment endstations. (2) Provide guidelines related to ALS vacuum policy to assist in designing beamlines which are in accordance with ALS vacuum policy. This document supersedes LSBL-116. The Advanced Light Source is a third generation synchrotron radiation source whose beam lifetime depends on the quality of the vacuum in the storage ring and the connecting beamlines. The storage ring and most of the beamlines share a common vacuum and are operated under ultra-high-vacuum (UHV) conditions. All endstations and beamline equipment must be operated so as to avoid contamination of beamline components, and must include proper safeguards to protect the storage ring vacuum from an accidental break in the beamline or endstation vacuum systems. The primary gas load during operation is due to thermal desorption and electron/photon induced desorption of contaminants from the interior of the vacuum vessel and its components. The desorption rates are considerably higher for hydrocarbon contamination, thus considerable emphasis is placed on eliminating these sources of contaminants. All vacuum components in a beamline and endstation must meet the ALS vacuum specifications. The vacuum design of both beamlines and endstations must be approved by the ALS Beamline Review Committee (BRC) before vacuum connections to the storage ring are made. The vacuum design is first checked during the Beamline Design Review (BDR) held before construction of the beamline equipment begins. Any deviation from the ALS vacuum specifications must be approved by the BRC prior to installation of the equipment on the ALS floor. Any modification that is incorporated into a vacuum assembly without the written approval of the BRC is done at the user`s risk and may lead to rejection of the whole assembly.

  19. The quantum vacuum in electromagnetic fields: From the Heisenberg-Euler effective action to vacuum birefringence

    CERN Document Server

    Karbstein, Felix

    2016-01-01

    The focus of these lectures is on the quantum vacuum subjected to classical electromagnetic fields. To this end we explicitly derive the renowned Heisenberg-Euler effective action in constant electromagnetic fields in a rather pedagogical and easy to conceive way. As an application, we use it to study vacuum birefringence constituting one of the most promising optical signatures of quantum vacuum nonlinearity.

  20. Pseudo-redundant vacuum energy

    CERN Document Server

    Batra, Puneet; Hui, Lam; Kabat, Daniel

    2008-01-01

    We discuss models that can account for today's dark energy. The underlying cosmological constant may be Planck scale but starts as a redundant coupling which can be eliminated by a field redefinition. The observed vacuum energy arises when the redundancy is explicitly broken, say by a non-minimal coupling to curvature. We give a recipe for constructing models, including R + 1/R type models, that realize this mechanism and satisfy all solar system constraints on gravity. A similar model, based on Gauss-Bonnet gravity, provides a technically natural explanation for dark energy and exhibits an interesting see-saw behavior: a large underlying cosmological constant gives rise to both low and high curvature solutions. Such models could be statistically favored in the string landscape.

  1. Gravitational Correction to Vacuum Polarization

    CERN Document Server

    Jentschura, U D

    2015-01-01

    We consider the gravitational correction to (electronic) vacuum polarization in the presence of a gravitational background field. The Dirac propagators for the virtual fermions are modified to include the leading gravitational correction (potential term) which corresponds to a coordinate-dependent fermion mass. The mass term is assumed to be uniform over a length scale commensurate with the virtual electron-positron pair. The on-mass shell renormalization condition ensures that the gravitational correction vanishes on the mass shell of the photon, i.e., the speed of light is unaffected by the quantum field theoretical loop correction, in full agreement with the equivalence principle. Nontrivial corrections are obtained for off-shell, virtual photons. We compare our findings to other works on generalized Lorentz transformations and combined quantum-electrodynamic gravitational corrections to the speed of light which have recently appeared in the literature.

  2. False vacuum as an unstable state

    Science.gov (United States)

    Urbanowski, K.

    2016-11-01

    Calculations performed within the Standard Model suggest that the electroweak vacuum is unstable if MH Higgs particle). LHC discovery of the Higgs boson indicates that MH ≃ 125 GeV. So the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory. At asymptotically late times the survival probability as a function of time t has an inverse power-like form. We show that at this time region the energy of the false vacuum states tends to the energy of the true vacuum state as 1/t2 for t → ∞. This means that the energy density in the unstable vacuum state should have analogous properties and hence the cosmological constant Λ = Λ(t) too. So Λ in the Universe with the unstable vacuum should have a form of the sum of the "bare" cosmological constant and of the term of a type 1/t^2:Λ (t) ≡ Λbare + d/t^2, (where Λbare is the cosmological constant for the Universe with the true vacuum).

  3. Probing QED Vacuum with Heavy Ions

    CERN Document Server

    Rafelski, Johann; Müller, Berndt; Reinhardt, Joachim; Greiner, Walter

    2016-01-01

    We recall how nearly half a century ago the proposal was made to explore the structure of the quantum vacuum using slow heavy-ion collisions. Pursuing this topic we review the foundational concept of spontaneous vacuum decay accompanied by observable positron emission in heavy-ion collisions and describe the related theoretical developments in strong fields QED.

  4. Decoherence of quantum states in QCD vacuum

    Science.gov (United States)

    Kuvshinov, V.; Bagashov, E.

    2017-09-01

    The stochastic vacuum of quantum chromodynamics is used as an environment for quarks considered as color state vectors. It is shown that during interaction with the stochastic vacuum information of the quark color state is lost with time (decoherence of the quark state vector occurs), which effectively means that it is impossible to observe the quark as a free color particle (confinement).

  5. LEP vacuum chamber cross-section

    CERN Multimedia

    1987-01-01

    This diagram shows the layout of the vacuum chambers used at LEP, which was in operation at CERN between 1989 and 2000. Vacuum chambers are necessary in accelerators to prevent unwanted interactions that can destabilise the beam. The pump on the right sucks air out of the chamber allowing the beam to progress with minimal interactions.

  6. AA, vacuum tank for stochastic precooling

    CERN Multimedia

    1979-01-01

    The vaccum tank in which the fast stochastic precooling kicker was installed. It is clad with heating jackets for bake-out to 200 deg C, indispensable for reaching the operational vacuum of 7E-11 Torr. Alain Poncet, responsible for AA vacuum, is looking on. See also 7910268, 8002234.

  7. Silicates materials of high vacuum technology

    CERN Document Server

    Espe, Werner

    2013-01-01

    Materials of High Vacuum Technology, Volume 2: Silicates covers silicate insulators of special importance to vacuum technology. The book discusses the manufacture, composition, and physical and chemical properties of technical glasses, quartz glass, quartzware, vycor glass, ceramic materials, mica, and asbestos.

  8. Performance of a Rapid-Scan Vacuum Michelson Interferometer at the NSLS

    Energy Technology Data Exchange (ETDEWEB)

    P. Brierly; P. Dumas; M. Smith; G.P. Williams

    2001-09-01

    A commercial Nicolet Magna series rapid-scan Michelson Fourier Transform Infrared (FTIR) was installed in a vacuum housing and integrated into the U4IR beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. The frequency reference laser was mounted outside vacuum, but the moving mirror mechanism and the dynamic alignment system for the fixed mirror were in vacuum. The performance of the instrument was measured in the usual way by measuring the repeatability of data collected under specific conditions of aperture, resolution and mirror scanning velocity. We briefly discuss the beamline design, to put the interferometer in context, then present signal to noise data which we discuss in terms of both instrument performance and also storage ring stability. Under optimal conditions, the instrument has a reproducibility of 0.01% in 1 minute of measuring time at a resolution of 2 cmss,{sup -1}, over a range from 100-3000 cm{sup -1}.

  9. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  10. Characteristics of an immobilized yeast cell system using very high gravity for the fermentation of ethanol.

    Science.gov (United States)

    Ji, Hairui; Yu, Jianliang; Zhang, Xu; Tan, Tianwei

    2012-09-01

    The characteristics of ethanol production by immobilized yeast cells were investigated for both repeated batch fermentation and continuous fermentation. With an initial sugar concentration of 280 g/L during the repeated batch fermentation, more than 98% of total sugar was consumed in 65 h with an average ethanol concentration and ethanol yield of 130.12 g/L and 0.477 g ethanol/g consumed sugar, respectively. The immobilized yeast cell system was reliable for at least 10 batches and for a period of 28 days without accompanying the regeneration of Saccharomyces cerevisiae inside the carriers. The multistage continuous fermentation was carried out in a five-stage column bioreactor with a total working volume of 3.75 L. The bioreactor was operated for 26 days at a dilution rate of 0.015 h(-1). The ethanol concentration of the effluent reached 130.77 g/L ethanol while an average 8.18 g/L residual sugar remained. Due to the high osmotic pressure and toxic ethanol, considerable yeast cells died without regeneration, especially in the last two stages, which led to the breakdown of the whole system of multistage continuous fermentation.

  11. Vacuum Lightcone Fluctuations in a Dielectric

    CERN Document Server

    Bessa, C H G; Ford, L H; Svaiter, N F

    2014-01-01

    A model for observable effects of electromagnetic vacuum fluctuations is presented. The model involves a probe pulse which traverses a slab of nonlinear optical material with a nonzero second order polarizability. We argue that the pulse interacts with the ambient vacuum fluctuations of other modes of the quantized electric field, and these vacuum fluctuations cause variations in the flight time of the pulse through the material. The geometry of the slab of material defines a sampling function for the quantized electric field, which in turn determines that vacuum modes whose wavelengths are of the order of the thickness of the slab give the dominant contribution. Some numerical estimates are made, which indicate that fractional fluctuations in flight time of the order of $10^{-9}$ are possible in realistic situations. The model presented here is both an illustration of a physical effect of vacuum fluctuations, and an analog model for the lightcone fluctuations predicted by quantum gravity.

  12. Mechanics and Physics of Precise Vacuum Mechanisms

    CERN Document Server

    Deulin, E. A; Panfilov, Yu V; Nevshupa, R. A

    2010-01-01

    In this book the Russian expertise in the field of the design of precise vacuum mechanics is summarized. A wide range of physical applications of mechanism design in electronic, optical-electronic, chemical, and aerospace industries is presented in a comprehensible way. Topics treated include the method of microparticles flow regulation and its determination in vacuum equipment and mechanisms of electronics; precise mechanisms of nanoscale precision based on magnetic and electric rheology; precise harmonic rotary and not-coaxial nut-screw linear motion vacuum feedthroughs with technical parameters considered the best in the world; elastically deformed vacuum motion feedthroughs without friction couples usage; the computer system of vacuum mechanisms failure predicting. This English edition incorporates a number of features which should improve its usefulness as a textbook without changing the basic organization or the general philosophy of presentation of the subject matter of the original Russian work. Exper...

  13. DWI Repeaters and Non-Repeaters: A Comparison.

    Science.gov (United States)

    Weeber, Stan

    1981-01-01

    Discussed how driving-while-intoxicated (DWI) repeaters differed signigicantly from nonrepeaters on 4 of 23 variables tested. Repeaters were more likely to have zero or two dependent children, attend church frequently, drink occasionally and have one or more arrests for public intoxication. (Author)

  14. To Repeat or Not to Repeat a Course

    Science.gov (United States)

    Armstrong, Michael J.; Biktimirov, Ernest N.

    2013-01-01

    The difficult transition from high school to university means that many students need to repeat (retake) 1 or more of their university courses. The authors examine the performance of students repeating first-year core courses in an undergraduate business program. They used data from university records for 116 students who took a total of 232…

  15. Wireless Integrated Microelectronic Vacuum Sensor System

    Science.gov (United States)

    Krug, Eric; Philpot, Brian; Trott, Aaron; Lawrence, Shaun

    2013-01-01

    NASA Stennis Space Center's (SSC's) large rocket engine test facility requires the use of liquid propellants, including the use of cryogenic fluids like liquid hydrogen as fuel, and liquid oxygen as an oxidizer (gases which have been liquefied at very low temperatures). These fluids require special handling, storage, and transfer technology. The biggest problem associated with transferring cryogenic liquids is product loss due to heat transfer. Vacuum jacketed piping is specifically designed to maintain high thermal efficiency so that cryogenic liquids can be transferred with minimal heat transfer. A vacuum jacketed pipe is essentially two pipes in one. There is an inner carrier pipe, in which the cryogenic liquid is actually transferred, and an outer jacket pipe that supports and seals the vacuum insulation, forming the "vacuum jacket." The integrity of the vacuum jacketed transmission lines that transfer the cryogenic fluid from delivery barges to the test stand must be maintained prior to and during engine testing. To monitor the vacuum in these vacuum jacketed transmission lines, vacuum gauge readings are used. At SSC, vacuum gauge measurements are done on a manual rotation basis with two technicians, each using a handheld instrument. Manual collection of vacuum data is labor intensive and uses valuable personnel time. Additionally, there are times when personnel cannot collect the data in a timely fashion (i.e., when a leak is detected, measurements must be taken more often). Additionally, distribution of this data to all interested parties can be cumbersome. To simplify the vacuum-gauge data collection process, automate the data collection, and decrease the labor costs associated with acquiring these measurements, an automated system that monitors the existing gauges was developed by Invocon, Inc. For this project, Invocon developed a Wireless Integrated Microelectronic Vacuum Sensor System (WIMVSS) that provides the ability to gather vacuum

  16. Apparatus For Metal/Inert-Gas Welding In Vacuum

    Science.gov (United States)

    Stocks, C. O.

    1994-01-01

    Metal/inert-gas welding-torch assembly operates in vacuum. Plasma generated in interior chamber and focused onto workpiece in vacuum. Pinch rollers feed wire to weld puddle. Controlled flow of plasma reduces dispersal in vacuum, preventing extinction.

  17. Fermentation of irradiated sugarcane must

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Andre Ricardo; Horii, Jorge [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Agroindustria, Alimentos e Nutricao]. E-mail: aralcard@esalq.usp.br; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia

    2003-12-01

    Bacillus and Lactobacillus are bacteria that usually contaminate the ethanolic fermentation by yeasts and my influence yeast viability. As microorganisms can be killed by ionizing radiation, the efficacy of gamma radiation in reducing the population of certain contaminating bacteria from sugarcane must was examined and, as a consequence, the beneficial effect of lethal doses of radiation on some parameters of yeast-based ethanolic fermentation was verified. Must from sugarcane juice was inoculated with bacteria of the general Bacillus and Lactobacillus. The contaminated must was irradiated with 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. After ethanolic fermentation by the yeast (Saccharomyces cerevisiae) the total and volatile acidity produced during the process were evaluated: yeast viability and ethanol yield were also recorded. Treatments of gamma radiation reduced the population of the contaminating bacteria in the sugarcane must. The acidity produced during the fermentation decreased as the dose rate of radiation increased. Conversely, the yeast viability increased as the dose rate of radiation increased. Gamma irradiation was an efficient treatment to decontaminate the must and improved its parameters related to ethanolic fermentation, including ethanol yield, which increased 1.9%. (author)

  18. Kefir grains as a starter for whey fermentation at different temperatures: chemical and microbiological characterisation.

    Science.gov (United States)

    Londero, Alejandra; Hamet, María F; De Antoni, Graciela L; Garrote, Graciela L; Abraham, Analía G

    2012-08-01

    We report here a comparative analysis of the growth, acidification capacity, and chemical and microbiologic composition between kefir grains after 20 subcultures in whey at 20, 30, and 37°C and the original kefir grains coming from milk along with a determination of the microbiological composition of the fermented whey as compared with that of traditional fermented milk. When fermentation was carried out repeatedly at 30 or 37°C, kefir grains changed their kefir-like appearance, exhibited reduced growth rates, had a lower diversity of yeasts and water content, and a higher protein-to-polysaccharide ratio compared with the original kefir grains. In contrast, at 20°C kefir grains could remain in whey for prolonged periods without altering their acidification capacity, growth rate, macroscopic appearance or chemical and microbiologic composition-with the only difference being a reduction in certain yeast populations after 20 subcultures in whey. At this incubation temperature, the presence of Lactobacillus kefiranofaciens, Lb. kefir, Lb. parakefir, Lactococcus lactis, Kluyveromyces marxianus, Saccharomyces unisporus, and Sac. cerevisiae was detected in kefir grains and in fermented whey by denaturing-gradient-gel electrophoresis (DGGE). In whey fermented at 20°C the number of lactic-acid bacteria (LAB) was significantly lower (Pkefir grains as whey-fermentation starters.

  19. Experiments with Fungi Part 2: Fermentation.

    Science.gov (United States)

    Dale, Michele; Hetherington, Shane

    1996-01-01

    Gives details of three experiments with alcoholic fermentation by yeasts which yield carbon dioxide and ethanol. Lists procedures for making cider, vinegar, and fermentation gases. Provides some historical background and detailed equipment requirements. (DDR)

  20. Ethanolic fermentation of pentoses in lignocellulose hydrolysates

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B.; Linden, T.; Senac, T.; Skoog, K. [Lund Univ. Chemical Center (Sweden)

    1991-12-31

    In the fermentation of lignocellulose hydrolysates to ethanol, two major problems are encountered: the fermentation of the pentose sugar xylose, and the presence of microbial inhibitors. Xylose can be directly fermented with yeasts; such as Pachysolen tannophilus, Candida shehatae, and Pichia stipis, or by isomerization of xylose to xylulose with the enzyme glucose (xylose) isomerase, and subsequent fermentation with bakers yeast, Saccharomyces cerevisiae. The direct fermentation requires low, carefully controlled oxygenation, as well as the removal of inhibitors. Also, the xylose-fermenting yeasts have a limited ethanol tolerance. The combined isomerization and fermentation with XI and S. cerevisiae gives yields and productivities comparable to those obtained in hexose fermentations without oxygenation and removal of inhibitors. However, the enzyme is not very stable in a lignocellulose hydrolysate, and S. cerevisiae has a poorly developed pentose phosphate shunt. Different strategies involving strain adaptation, and protein and genetic engineering adopted to overcome these different obstacles, are discussed.

  1. Biotransformation of algal waste by biological fermentation

    African Journals Online (AJOL)

    GRACE

    2006-07-03

    Jul 3, 2006 ... Microbiological analyses confirmed that this garbage contains ... Key words: Gelidium sesquipedale, Agar, fermentation, ferment, ingredient, food. ... health. Morocco possesses several coasts with a marine biodiversity of fish ...

  2. Yeasts Diversity in Fermented Foods and Beverages

    Science.gov (United States)

    Tamang, Jyoti Prakash; Fleet, Graham H.

    People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

  3. Treatment of biomass to obtain fermentable sugars

    Science.gov (United States)

    Dunson, Jr., James B.; Tucker, Melvin; Elander, Richard; Hennessey, Susan M.

    2011-04-26

    Biomass is pretreated using a low concentration of aqueous ammonia at high biomass concentration. Pretreated biomass is further hydrolyzed with a saccharification enzyme consortium. Fermentable sugars released by saccharification may be utilized for the production of target chemicals by fermentation.

  4. an Ethiopian Traditional Fermented Cereal Beverage

    African Journals Online (AJOL)

    The Effects of Technological Modifications on the Fermentation of Borde, an Ethiopian ... information on the effects of various process ... earthenware pot with plastic jar; 2) maize fermented ..... Yeast and mould colonies were counted on YGC.

  5. Enzymatic conversion of lignocellulose into fermentable sugars

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Kristensen, Jan Bach; Felby, Claus

    2007-01-01

    The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose...

  6. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  7. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  8. Enhanced substrate conversion efficiency of fermentation processes

    OpenAIRE

    Sanders, J.P.M.; Weusthuis, R.A.; Mooibroek, H.

    2006-01-01

    The present invention relates to the field of fermentation technology. In particular the invention relates to fermentation processes for the production of a first and a second fermentation product by a single production organism wherein the first product is in a more reduced state than the substrate and the second fermentation product is in a more oxidised state than the substrate yet in less oxidised state than the final oxidation product CO2, such that the concurrent synthesis of the first ...

  9. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  10. Vacuum system for the SAMURAI spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Y., E-mail: yshimizu@ribf.riken.jp [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Otsu, H. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Kobayashi, T. [Department of Physics, Tohoku University, Aoba, Sendai 980-8578 (Japan); Kubo, T.; Motobayashi, T.; Sato, H.; Yoneda, K. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)

    2013-12-15

    Highlights: • The paper describes the vacuum system for the SAMURAI spectrometer including its beam line and the SAMURAI vacuum chamber. • The windows for detecting neutrons and charged particles are mounted on the SAMURAI vacuum chamber. • The deflection and induced stress of the windows were calculated by ANSYS program code. • The windows were constructed and examined with the test chamber before mounting on the SAMURAI vacuum chamber. • The SAMURAI was kept on a few Pa of the pressure during the experiment without any problems caused by these windows. -- Abstract: The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.

  11. Baking results of KSTAR vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. T.; Kim, Y. J.; Kim, K. M.; Im, D. S.; Joung, N. Y.; Yang, H. L.; Kim, Y. S.; Kwon, M. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    The Korea Superconducting Tokamak Advanced Research (KSTAR) is an advanced superconducting tokamak designed to establish a scientific and technological basis for an attractive fusion reactor. The fusion energy in the tokamak device is released through fusion reactions of light atoms such as deuterium or helium in hot plasma state, of which temperature reaches several hundreds of millions Celsius. The high temperature plasma is created in the vacuum vessel that provides ultra high vacuum status. Accordingly, it is most important for the vacuum condition to keep clean not only inner space but also surface of the vacuum vessel to make high quality plasma. There are two methods planned to clean the wall surface of the KSTAR vacuum vessel. One is surface baking and the other is glow discharge cleaning (GDC). To bake the vacuum vessel, De-Ionized (DI) water is heated to 130 .deg. C and circulated in the passage between double walls of the vacuum vessel (VV) in order to bake the surface. The GDC operation uses hydrogen and inert gas discharges. In this paper, general configuration and brief introduction of the baking result will be reported.

  12. Macroscopic modelling of solid-state fermentation

    NARCIS (Netherlands)

    Hoogschagen, M.J.

    2007-01-01

    Solid-state fermentation is different from the more well known process of liquid fermentation because no free flowing water is present. The technique is primarily used in Asia. Well-known products are the foods tempe, soy sauce and saké. In industrial solid-state fermentation, the substrate usually

  13. Antioxidant properties of fermented mango leaf extracts.

    Science.gov (United States)

    Park, Anna; Ku, Taekyu; Yoo, Ilsou

    2015-01-01

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

  14. Comments on the Vacuum Orientations in QCD

    CERN Document Server

    Huang, Z; Wu, D D; Huang, Zheng

    1992-01-01

    We study the QCD vacuum orientation angles in correlation with the strong CP phases. A vacuum alignment equation of the dynamical chiral symmetry breaking is derived based on the anomalous Ward identity. It is emphasized that a chiral rotation of the quark field causes a change of the vacuum orientation and a change in the definition of the light pseudoscalar generators. As an illustration of the idea, $\\h\\rightarrow 2\\p$ decays are carefully studied in different chiral frames. Contrary to the claim in Ref.[7], the $\\theta$-term does not directly contribute to the CP-violating processes.

  15. Some aspects of vacuum ultraviolet radiation physics

    CERN Document Server

    Damany, Nicole; Vodar, Boris

    2013-01-01

    Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

  16. Vacuum system for the SAMURAI spectrometer

    Science.gov (United States)

    Shimizu, Y.; Otsu, H.; Kobayashi, T.; Kubo, T.; Motobayashi, T.; Sato, H.; Yoneda, K.

    2013-12-01

    The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.

  17. Scalar and tensor perturbation in vacuum inflation

    CERN Document Server

    Huang, Zhiqiang

    2016-01-01

    It was recently proposed that a small true vacuum universe can inflate spontaneously, in principle. In this paper, this model is completed with experimental results. There should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the inflation simultaneously. We derive cosmological perturbations in this vacuum inflation model and express them with Hubble flow-functions. By comparing the perturbations with the experimental results, we can determine all the parameters in this model. Finally, we calculate the evolution of the matter density with the determined parameters and show that the matter produced in inflation roughly fits the observations at present.

  18. Extra Dimensions and Vacuum Dark Energy Models

    Institute of Scientific and Technical Information of China (English)

    CHEN Chi-Yi; SHEN You-Gen

    2004-01-01

    @@ The role of vacuum energy or cosmological constant in cosmology is discussed in a kind of nontrivial higherdimensional model. Under the framework of Einstein's gravity, we obtain the corresponding equations of motion and find that the cosmological constant and vacuum energy in the full regime does not drive its acceleration, but decelerates the expansion of the universe. The dimension of space is required to be n = 3 if we regard vacuum energy or cosmological constant as the candidate to drive the accelerated expansion of the universe.

  19. Vacuum engineering, calculations, formulas, and solved exercises

    CERN Document Server

    Berman, Armand

    1992-01-01

    This book was written with two main objectives in mind-to summarize and organize the vast material of vacuum technology in sets of useful formulas, and to provide a collection of worked out exercises showing how to use these formulas for solving technological problems. It is an ideal reference source for those with little time to devote to a full mathematical treatment of the many problems issued in vacuum practice, but who have a working knowledge of the essentials of vacuum technology, elementary physics, and mathematics. This time saving book employs a problem-solving approach throughout, p

  20. On Puthoff's Semiclassical Electron and Vacuum Energy

    Science.gov (United States)

    Pereira, N. R.

    2016-09-01

    A possible connection between a point electron and vacuum energy was recently claimed by Puthoff (Int. J. Theor. Phys. 46, 3005 (2007)). He envisions a point electron as an ideally conducting spherical shell with a distributed charge on the surface, in equilibrium with the radiation pressure from electromagnetic vacuum fluctuations on the outside, and claims that his analysis demonstrates the reality of high-energy-density vacuum fluctuation fields. The present paper finds, instead, that the analysis is meaningless without specific knowledge on the cutoff frequency that is a free parameter in the model.

  1. The fine art of preparing a vacuum

    CERN Multimedia

    2006-01-01

    The vacuum chambers, or beam pipes, of the LHC experiments are located right at the interface between the detectors and the accelerator, and are therefore crucial to the LHC project as a whole. In this domain, the ALICE and CMS experiments have just passed an important milestone, with the completion of the first of CMS's two end-cap vacuum chambers, together with the completion and bakeout of an 18-metre section of the ALICE vacuum chamber. These complex projects, for which CERN's AT/VAC Group is responsible, involved dozens of people over a number of years.

  2. Vacuum Furnace - Integrated "Sub zero" Treatment

    Institute of Scientific and Technical Information of China (English)

    B. Zieger; Hubert Schulte

    2004-01-01

    The vacuum heat treatment with overpressure gas quenching is more and more accepted due to considerable advantages compared to the traditional oil and salt bath processes. Continuous further developments and new concepts like multi-directional cooling systems, a separate quenching chamber and "sub zero" systems lead towards an oxidation free and low distortion vacuum heat treatment for a broad range of parts and materials. Short and energy saving processes guarantee a high economic efficiency and environmental compatibility.The "sub zero" system which is integrated into the standard vacuum furnace achieves a heat treatment result with a high conversion of retained austenite in fully automatic hardening and tempering processes.

  3. Quark Virtuality and QCD Vacuum Condensates

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-Juan; MA Wei-Xing

    2004-01-01

    @@ Based on the Dyson-Schwinger equations (DSEs) in the ‘rainbow' approximation, we investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, we calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are λ2u,d = 0.7 GeV2 for u, d quarks, and 2s 1.6 GeV2 for s quark.Our theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions.

  4. Inflaton Decay in an Alpha Vacuum

    CERN Document Server

    Naidu, S; Naidu, Siddartha; Holman, Richard

    2004-01-01

    We study the alpha vacua of de Sitter space by considering the decay rate of the inflaton field coupled to a scalar field placed in an alpha vacuum. We find an {\\em alpha dependent} Bose enhancement relative to the Bunch-Davies vacuum and, surprisingly, no non-renormalizable divergences. We also consider a modified alpha dependent time ordering prescription for the Feynman propagator and show that it leads to an alpha independent result. This result suggests that it may be possible to calculate in any alpha vacuum if we employ the appropriate causality preserving prescription.

  5. Sequestering effects on and of vacuum decay

    CERN Document Server

    Kaloper, Nemanja; Stefanyszyn, David

    2016-01-01

    We consider phase transitions and their contributions to vacuum energy in the manifestly local theory of vacuum energy sequestering. We demonstrate that the absence of instabilities imposes constraints on the couplings of gravitating and non-gravitating sectors, which can be satisfied in a large class of models. We further show by explicit construction that the vacuum energy contributions to the effective cosmological constant in the descendant vacua are generically strongly suppressed by the ratios of spacetime volumes of parent and descendant geometries. This means that the cosmological constant in de Sitter descendant vacua remains insensitive to phase transitions which may have occurred in the course of its cosmic history.

  6. Gravitational Baryogenesis in Running Vacuum models

    CERN Document Server

    Oikonomou, V K; Nunes, Rafael C

    2016-01-01

    We study the gravitational baryogenesis mechanism for generating baryon asymmetry in the context of running vacuum models. Regardless if these models can produce a viable cosmological evolution, we demonstrate that they produce a non-zero baryon-to-entropy ratio even if the Universe is filled with conformal matter. This is a sound difference between the running vacuum gravitational baryogenesis and the Einstein-Hilbert one, since in the latter case, the predicted baryon-to-entropy ratio is zero. We consider two running vacuum models and show that the resulting baryon-to-entropy ratio is compatible with the observational data.

  7. Report of the Synchrotron Radiation Vacuum Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Avery, R.T.

    1984-06-01

    The Synchrotron Radiation Vacuum Workshop was held to consider two vacuum-related problems that bear on the design of storage rings and beam lines for synchrotron radiation facilities. These problems are gas desorption from the vacuum chamber walls and carbon deposition on optical components. Participants surveyed existing knowledge on these topics and recommended studies that should be performed as soon as possible to provide more definitive experimental data on these topics. This data will permit optimization of the final design of the Advanced Light Source (ALS) and its associated beam lines. It also should prove useful for other synchrotron radiation facilities as well.

  8. Sequestering effects on and of vacuum decay

    Science.gov (United States)

    Kaloper, Nemanja; Padilla, Antonio; Stefanyszyn, David

    2016-07-01

    We consider phase transitions and their contributions to vacuum energy in the manifestly local theory of vacuum energy sequestering. We demonstrate that the absence of instabilities imposes constraints on the couplings of gravitating and nongravitating sectors, which can be satisfied in a large class of models. We further show by explicit construction that the vacuum energy contributions to the effective cosmological constant in the descendant vacua are generically strongly suppressed by the ratios of space-time volumes of parent and descendant geometries. This means that the cosmological constant in de Sitter descendant vacua remains insensitive to phase transitions which may have occurred in the course of its cosmic history.

  9. Vacuum-sealed casting process under pressure

    Institute of Scientific and Technical Information of China (English)

    LI Chen-xi; GUO Tai-ming; WU Chun-jing; WANG Hong

    2006-01-01

    A new casting method, the vacuum-sealed mold casting under pressure, has been developed, and thin wall iron castings with high precision and smooth surface have been produced successfully with this casting method. The experimental results show that the liquid iron has a very excellent filling ability because a high negative pressure is formed in the mold cavity during filling process. The vacuum-sealed mold under pressure has very high compressive strength greater than 650 kPa, which is 3-4 times as high as that of the molds produced by high-pressure molding process or vacuum-sealed molding process.

  10. Gases and vacua handbook of vacuum physics

    CERN Document Server

    Beck, A H

    2013-01-01

    Handbook of Vacuum Physics, Volume 1: Gases and Vacua presents three major topics, which are the fourth to sixth parts of this volume. These topics are the remarks on units of physical quantities; kinetic theory of gases and gaseous flow; and theory of vacuum diffusion pumps. The first topic aims to present concisely the significance of units of physical quantities, catering the need and interest of those who take measurements and make calculations in different fields of vacuum sciences. The technique and applications of this particular topic are also provided. The second main topic focuses sp

  11. Vacuum pyrolysis of waste print circuit board

    Institute of Scientific and Technical Information of China (English)

    GAN Ge; CHEN Lie-qiang; PENG Shao-hong; CAI Ming-zhao

    2005-01-01

    Waste print circuit board containing 11.38% Br was pyrolyzed in vacuum.Thermal stability of waste print circuit board was studied under vacuum condition by thermo-gravimetry(TG). Vacuum pyrolysis of WPCB was studied emphasizing on the kinetics of WPCB pyrolysis reactions. Based on the TG results, a kinetic model was proposed. Kinetic parameters were calculated for reaction with this model including all stages of decomposition. The average activation energy is 68 k J/mol with reaction order 3. These findings provide new insights into the WPCB thermal decomposition and useful data for rational design and operation of pyrolysis.

  12. A novel downstream process for 1,3-propanediol from glycerol-based fermentation.

    Science.gov (United States)

    Anand, Pinki; Saxena, Rajendra Kumar; Marwah, Ruchi G

    2011-05-01

    In this paper, a downstream process for purification of 1,3-propanediol from glycerol-based fermentation broth was investigated. The purification of 1,3-propanediol from fermentation broth was achieved by a process combining microfiltration, charcoal treatment, vacuum distillation, and silica gel chromatography. The broth was first filtered through hollow fiber cartridge, wherein 98.7% of biomass was removed. Soluble proteins and other color impurities in the broth were removed by the use of activated charcoal at optimal concentration of 30 g l(-1) where the soluble proteins in the broth decreased to 0.1 g l(-1) (96.0% protein loss). The obtained broth when concentrated by vacuum distillation resulted in the crystallization of inorganic salts. Subsequently, 1,3-propanediol was purified by gradient chromatography using silica gel as a stationary phase and mixture of chloroform and methanol as a mobile phase. Finally, with the optimal flow rate of 10 ml min(-1) and loading amount of 80 ml, the yield of 1,3-propanediol achieved was 89%. The overall yield of 1,3-propanediol using the proposed procedure was 75.47%. The developed method was found to be a simple, rapid, and efficient procedure for the purification of 1,3-propanediol from fermentation broth.

  13. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Bolic, Andrijana; Svanholm, Bent

    2012-01-01

    The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This manuscript therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: on-line sensors, mechanistic models and small-scale equipment for high-throughput experimentation. The manuscript ends with a short...

  14. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Bolic, Andrijana; Svanholm, Bent

    2012-01-01

    The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This manuscript therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: on-line sensors, mechanistic models and small-scale equipment for high-throughput experimentation. The manuscript ends with a short...

  15. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist

    The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This presentation therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: - On-line sensors, where for example spectroscopic measurements are increasingly applied - Mechanistic models, which can be used...

  16. Feasibility assessment of vacuum cooling followed by immersion vacuum cooling on water-cooked pork.

    Science.gov (United States)

    Dong, Xiaoguang; Chen, Hui; Liu, Yi; Dai, Ruitong; Li, Xingmin

    2012-01-01

    Vacuum cooling followed by immersion vacuum cooling was designed to cool water-cooked pork (1.5±0.05 kg) compared with air blast cooling (4±0.5°C, 2 m/s), vacuum cooling (10 mbar) and immersion vacuum cooling. This combined cooling method was: vacuum cooling to an intermediate temperature of 25°C and then immersion vacuum cooling with water of 10°C to the final temperature of 10°C. It was found that the cooling loss of this combined cooling method was significantly lower (Pvacuum cooling. This combined cooling was faster (Pvacuum cooling in terms of cooling rate. Moreover, the pork cooled by combined cooling method had significant differences (P<0.05) in water content, color and shear force. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Is there vacuum when there is mass? Vacuum and non-vacuum solutions for massive gravity

    Science.gov (United States)

    Martín-Moruno, Prado; Visser, Matt

    2013-08-01

    Massive gravity is a theory which has a tremendous amount of freedom to describe different cosmologies, but at the same time, the various solutions one encounters must fulfil some rather nontrivial constraints. Most of the freedom comes not from the Lagrangian, which contains only a small number of free parameters (typically three depending on counting conventions), but from the fact that one is in principle free to choose the reference metric almost arbitrarily—which effectively introduces a non-denumerable infinity of free parameters. In the current paper, we stress that although changing the reference metric would lead to a different cosmological model, this does not mean that the dynamics of the universe can be entirely divorced from its matter content. That is, while the choice of reference metric certainly influences the evolution of the physically observable foreground metric, the effect of matter cannot be neglected. Indeed the interplay between matter and geometry can be significantly changed in some specific models; effectively since the graviton would be able to curve the spacetime by itself, without the need of matter. Thus, even the set of vacuum solutions for massive gravity can have significant structure. In some cases, the effect of the reference metric could be so strong that no conceivable material content would be able to drastically affect the cosmological evolution. Dedicated to the memory of Professor Pedro F González-Díaz

  18. SHINE Vacuum Pump Test Verification

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Gregg A; Peters, Brent

    2013-09-30

    Normetex pumps used world-wide for tritium service are no longer available. DOE and other researchers worldwide have spent significant funds characterizing this pump. Identification of alternate pumps is required for performance and compatibility with tritium gas. Many of the pumps that could be used to meet the functional performance requirements (e.g. pressure and flow conditions) of the Normetex pump have features that include the use of polymers or oils and greases that are not directly compatible with tritium service. This study assembles a test system to determine the flow characteristics for candidate alternate pumps. These tests are critical to the movement of tritium through the SHINE Tritium Purification System (TPS). The purpose of the pump testing is two-fold: (1) obtain baseline vacuum pump characteristics for an alternate (i.e. ''Normetex replacement'') pump intended for use in tritium service; and (2) verify that low pressure hydrogen gas can be transported over distances up to 300 feet by the candidate pumps. Flow rates and nominal system pressures have been identified for the SHINE Mo-99 production process Tritium Purification System (TPS). To minimize the line sizes for the transfer of low pressure tritium from the Neutron Driver Accelerator System (NDAS) to the primary processing systems in the TPS, a ''booster'' pump has been located near the accelerator in the design. A series of pump tests were performed at various configurations using hydrogen gas (no tritium) to ensure that this concept is practical and maintains adequate flow rates and required pressures. This report summarizes the results of the tests that have been performed using various pump configurations. The current design of the Tritium Purification System requires the ''booster'' pump to discharge to or to be backed by another vacuum pump. Since Normetex pumps are no longer manufactured, a commercially available Edwards

  19. Vacuum condensates and `ether-drift' experiments

    OpenAIRE

    Consoli, M.; Pagano, A.; Pappalardo, L.

    2003-01-01

    The idea of a `condensed' vacuum state is generally accepted in modern elementary particle physics. We argue that this should motivate a new generation of precise `ether-drift' experiments with present-day technology.

  20. Stability of relativistic plasma-vacuum interfaces

    CERN Document Server

    Trakhinin, Yuri

    2010-01-01

    We study the plasma-vacuum interface problem in relativistic magnetohydrodynamics for the case when the plasma density does not go to zero continuously, but jumps. Unlike the nonrelativistic version of this problem, we have to assume that the plasma expands into the vacuum (otherwise, the problem is underdetermined). We show that even if this necessary condition is satisfied the planar interface can be still violently unstable. By using a suitable secondary symmetrization of the Maxwell equations in vacuum, we find a sufficient condition that precludes violent instabilities. Under this condition we derive a basic a priori estimate in the anisotropic weighted Sobolev space $H^1_*$ for the variable coefficients linearized problem for nonplanar plasma-vacuum interfaces and prove the well-posedness of this problem.

  1. Source replenishment device for vacuum deposition

    Science.gov (United States)

    Hill, Ronald A.

    1988-01-01

    A material source replenishment device for use with a vacuum deposition apparatus. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  2. Cold vacuum drying facility design requirements

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, J.J.

    1997-09-24

    This release of the Design Requirements Document is a complete restructuring and rewrite to the document previously prepared and released for project W-441 to record the design basis for the design of the Cold Vacuum Drying Facility.

  3. Observation of subluminal twisted light in vacuum

    CERN Document Server

    Bouchard, Frédéric; Mand, Harjaspreet; Boyd, Robert W; Karimi, Ebrahim

    2015-01-01

    Einstein's theory of relativity establishes the speed of light in vacuum, c, as a fundamental constant. However, the speed of light pulses can be altered significantly in dispersive materials. While significant control can be exerted over the speed of light in such media, no experimental demonstration of altered light speeds has hitherto been achieved in vacuum for ``twisted'' optical beams. We show that ``twisted'' light pulses exhibit subluminal velocities in vacuum, being slowed by 0.1\\% relative to c. This work does not challenge relativity theory, but experimentally supports a body of theoretical work on the counterintuitive vacuum group velocities of twisted pulses. These results are particularly important given recent interest in applications of twisted light to quantum information, communication and quantum key distribution.

  4. FRIB driver linac vacuum model and benchmarks

    CERN Document Server

    Durickovic, Bojan; Kersevan, Roberto; Machicoane, Guillaume

    2014-01-01

    The Facility for Rare Isotope Beams (FRIB) is a superconducting heavy-ion linear accelerator that is to produce rare isotopes far from stability for low energy nuclear science. In order to achieve this, its driver linac needs to achieve a very high beam current (up to 400 kW beam power), and this requirement makes vacuum levels of critical importance. Vacuum calculations have been carried out to verify that the vacuum system design meets the requirements. The modeling procedure was benchmarked by comparing models of an existing facility against measurements. In this paper, we present an overview of the methods used for FRIB vacuum calculations and simulation results for some interesting sections of the accelerator. (C) 2013 Elsevier Ltd. All rights reserved.

  5. Fate of Electroweak Vacuum during Preheating

    CERN Document Server

    Ema, Yohei; Nakayama, Kazunori

    2016-01-01

    Our electroweak vacuum may be metastable in light of the current experimental data of the Higgs/top quark mass. If this is really the case, high-scale inflation models require a stabilization mechanism of our vacuum during inflation. A possible candidate is the Higgs-inflaton/-curvature coupling because it induces an additional mass term to the Higgs during the slow roll regime. However, after the inflation, the additional mass term oscillates, and it can potentially destabilize our electroweak vacuum via production of large Higgs fluctuations during the inflaton oscillation era. In this paper, we study whether or not the Higgs-inflaton/-curvature coupling can save our vacuum by properly taking account of Higgs production during the preheating stage. We put upper bounds on the Higgs-inflaton/-curvature coupling, and discuss possible dynamics that might relax them.

  6. Vapor-barrier Vacuum Isolation System

    Science.gov (United States)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  7. LCLS XTOD Tunnel Vacuum System (XVTS)

    Energy Technology Data Exchange (ETDEWEB)

    Beale, R; Duffy, P; Kishiyama, K; Mckernan, M; McMahon, D; Lewis, S; Trent, J; Tung, L; Shen, S

    2005-11-04

    The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.

  8. Physical Vacuum Properties and Internal Space Dimension

    CERN Document Server

    Gorbatenko, M V

    2004-01-01

    The paper addresses matrix spaces, whose properties and dynamics are determined by Dirac matrices in Riemannian spaces of different dimension and signature. Among all Dirac matrix systems there are such ones, which nontrivial scalar, vector or other tensors cannot be made up from. These Dirac matrix systems are associated with the vacuum state of the matrix space. The simplest vacuum system realization can be ensured using the orthonormal basis in the internal matrix space. This vacuum system realization is not however unique. The case of 7-dimensional Riemannian space of signature 7(-) is considered in detail. In this case two basically different vacuum system realizations are possible: (1) with using the orthonormal basis; (2) with using the oblique-angled basis, whose base vectors coincide with the simple roots of algebra E_{8}. Considerations are presented, from which it follows that the least-dimension space bearing on physics is the Riemannian 11-dimensional space of signature 1(-)& 10(+). The consi...

  9. Analytical and numerical tools for vacuum systems

    CERN Document Server

    Kersevan, R

    2007-01-01

    Modern particle accelerators have reached a level of sophistication which require a thorough analysis of all their sub-systems. Among the latter, the vacuum system is often a major contributor to the operating performance of a particle accelerator. The vacuum engineer has nowadays a large choice of computational schemes and tools for the correct analysis, design, and engineering of the vacuum system. This paper is a review of the different type of algorithms and methodologies which have been developed and employed in the field since the birth of vacuum technology. The different level of detail between simple back-of-the-envelope calculations and more complex numerical analysis is discussed by means of comparisons. The domain of applicability of each method is discussed, together with its pros and cons.

  10. Re-circulating linac vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-05-09

    The vacuum system for a proposed 2.5 GeV, 10{Mu}A recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10{Mu}A average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing.

  11. True random numbers from amplified quantum vacuum

    CERN Document Server

    Jofre, M; Steinlechner, F; Anzolin, G; Torres, J P; Mitchell, M W; Pruneri, V; 10.1364/OE.19.020665

    2011-01-01

    Random numbers are essential for applications ranging from secure communications to numerical simulation and quantitative finance. Algorithms can rapidly produce pseudo-random outcomes, series of numbers that mimic most properties of true random numbers while quantum random number generators (QRNGs) exploit intrinsic quantum randomness to produce true random numbers. Single-photon QRNGs are conceptually simple but produce few random bits per detection. In contrast, vacuum fluctuations are a vast resource for QRNGs: they are broad-band and thus can encode many random bits per second. Direct recording of vacuum fluctuations is possible, but requires shot-noise-limited detectors, at the cost of bandwidth. We demonstrate efficient conversion of vacuum fluctuations to true random bits using optical amplification of vacuum and interferometry. Using commercially-available optical components we demonstrate a QRNG at a bit rate of 1.11 Gbps. The proposed scheme has the potential to be extended to 10 Gbps and even up t...

  12. Effect of harvest time on fermentation profiles of maize ensiled in laboratory silos and determination of drying losses at 60°C

    DEFF Research Database (Denmark)

    Nielsen, Tina Skau; Kristensen, Niels Bastian; Weisbjerg, Martin Riis

    2007-01-01

    The objectives were to investigate the effect of premature ensiling of maize on alcohol fermentation in laboratory silos and the loss of fermentation products and glucose in silage following drying at 60°C for 48 h. During four consecutive weeks maize was harvested and ensiled for 60 days in vacuum......-sealed laboratory silos. The content of DM in silage increased (p...-glucose content was reduced by approximately 45% after drying. Alcohols and esters were completely lost in drying. We conclude that ensiling of pre-mature maize does not lead to extensive alcohol fermentation in laboratory silos following 60 days of ensiling, and that dry matter correction based on fermentation...

  13. Anaerobic xylose fermentation by Spathaspora passalidarum

    DEFF Research Database (Denmark)

    Hou, Xiaoru

    2012-01-01

    A cost-effective conversion of lignocellulosic biomass into bioethanol requires that the xylose released from the hemicellulose fraction (20–40% of biomass) can be fermented. Baker’s yeast, Saccharomyces cerevisiae, efficiently ferments glucose but it lacks the ability to ferment xylose. Xylose-fermenting...... yeast such as Pichia stipitis requires accurately controlled microaerophilic conditions during the xylose fermentation, rendering the process technically difficult and expensive. In this study, it is demonstrated that under anaerobic conditions Spathaspora passalidarum showed high ethanol production...

  14. Electrostatic particle collection in vacuum

    Science.gov (United States)

    Afshar-Mohajer, Nima; Damit, Brian; Wu, Chang-Yu; Sorloaica-Hickman, Nicoleta

    2011-09-01

    Lunar grains accumulate charges due to solar-based ionizing radiations, and the repelling action of like-charged particles causes the levitation of lunar dust. The lunar dust deposit on sensitive and costly surfaces of investigative equipment is a serious concern in lunar explorations. Inspired by electrostatic precipitators (ESPs), the Electrostatic Lunar Dust Collector (ELDC) was proposed for collecting already charged lunar dust particles to prevent the lunar dust threat. As the conditions for terrestrial counterparts are not valid in the lunar environment, equations developed for terrestrial devices yield incorrect predictions in lunar application. Hence, a mathematical model was developed for the ELDC operating in vacuum to determine its collection efficiency. The ratios of electrical energy over potential energy, kinetic energy over potential energy and the ratio of ELDC dimensions were identified to be the key dimensionless parameters. Sensitivity analyses of the relevant parameters showed that depending on ELDC orientation, smaller particles would be collected more easily at vertical orientation, whereas larger particles were easier to collect in a horizontal ELDC configuration. In the worst case scenario, the electrostatic field needed to be 10 times stronger in the vertical mode in order to adequately collect larger particles. The collection efficiency was very sensitive to surface potential of lunar dust and it reached the maximum when surface potential was between 30 and 120 V. Except for regions of the lunar day side with surface potential close to zero, providing 1 kV ( E = 20 kV m -1) with the ELDC was more than enough for collecting all the particles in the most critical orientation. The needed field strength was about 4000 times less than that for repelling 1-μm size particles already settled on the surfaces. The analysis shows that the ELDC offers a viable solution for lunar dust control due to its effectiveness, ease of cleaning and low voltage

  15. Fermentation efficiency of cells immobilized on delignified brewers' spent grains after low- and high-temperature thin layer thermal drying.

    Science.gov (United States)

    Tsaousi, Konstantina; Koutinas, Athanasios A; Bekatorou, Argyro; Loukatos, Paul

    2010-09-01

    Low-cost dried yeasts immobilized on delignified brewers' spent grains for use in wine making and brewing were produced by simple thermal drying techniques. To optimize the thermal drying process, vacuum and air stream conditions were examined. Drying of thin layers of the biocatalysts was performed at low (30-38 degrees C) and high temperatures (40-70 degrees C). The fermentation efficiency of the thermally dried biocatalysts was acceptable, with immobilized cells showing a significantly higher thermotolerance compared with free cells. Immobilized cells dried at high temperatures presented slightly improved glucose fermentation efficiency compared with the low-temperature dried biocatalysts. Gas chromatography-mass spectrometry analysis of aroma volatiles of the fermented products revealed an increase of esters, lower higher alcohol formation, and significantly lower concentration of carbonylic compounds.

  16. Cosmic String Created from Vacuum Fluctuaions

    OpenAIRE

    Popov, Arkadii

    1998-01-01

    The possibility of the cosmic string creation by the vacuum fluctuations of quantum fields in the self-consistent semiclassical theory of gravity is discussed. We use the approximate method for obtaining vacuum expectation value of the renormalized stress-energy tensor of conformally invariant quantum fields in static cylindrically symmetric spacetimes. We have obtained the particular solutions of Einstein equations for the different boundary conditions at the cylinder symmetry axis.

  17. Vacuum decay in an interacting multiverse

    CERN Document Server

    Robles-Pérez, S; Bastos, C; Bertolami, O

    2015-01-01

    We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behaviour that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  18. Vacuum decay in an interacting multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Robles-Pérez, S. [Centro de Física “Miguel Catalán”, Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 121, 28006 Madrid (Spain); Estación Ecológica de Biocosmología, Pedro de Alvarado, 14, 06411 Medellín (Spain); Alonso-Serrano, A. [Centro de Física “Miguel Catalán”, Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 121, 28006 Madrid (Spain); Estación Ecológica de Biocosmología, Pedro de Alvarado, 14, 06411 Medellín (Spain); School of Mathematics and Statistics, Victoria University of Wellington, PO Box 600, Wellington 6140 (New Zealand); Bastos, C., E-mail: catarina.bastos@tecnico.ulisboa.pt [GoLP, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Bertolami, O. [Departamento de Física e Astronomia and Centro de Física do Porto, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2016-08-10

    We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of “true” vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  19. Vacuum decay in an interacting multiverse

    Science.gov (United States)

    Robles-Pérez, S.; Alonso-Serrano, A.; Bastos, C.; Bertolami, O.

    2016-08-01

    We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  20. Vacuum decay in an interacting multiverse

    Directory of Open Access Journals (Sweden)

    S. Robles-Pérez

    2016-08-01

    Full Text Available We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of “true” vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behavior that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  1. Stabilization flyuorytopodibnoyi structure in oxide vacuum condensate

    Directory of Open Access Journals (Sweden)

    О.М. Заславський

    2006-01-01

    Full Text Available  The influence of the oxide-stabilizer content, M'-cation radius and film deposition temperature on the stabilization of the fluorite-like solid solutions in the zirconium and hafnium oxides-based vacuum condensates, obtained by Laser-evaporating method, was investigated. The optimum parameters of the coatication of the isotropic thermostable coverings was determined. This results were explained by using of the high-speed condensation in vacuum theory.

  2. Progress of HIRFL-CSR Vacuum System

    Institute of Scientific and Technical Information of China (English)

    YangXiaotian; ZhangJunhui; MengJun; ZhangXijun; ZhangXiping; HouShengjun; HuZhenjun; NiuZhiwei; HaoBingan; WuHuimin

    2003-01-01

    The HIRFL-CSR vacuum system progressed steadily during the past year. The 2/3rd of CSR, injection beam line (SSC-CSR, m)'s vacuum chambers were installed in site in Jan. 2003 (Fig.l). The beam diagnostic devices were inserted in the chambers as well. The pressures in unbaked section were kept in 1~5×10-7 Pa range and in baked section were 2~5×10-9 Pa.

  3. Structure of Nonlocal Vacuum Condensate of Quarks

    Institute of Scientific and Technical Information of China (English)

    周丽娟; 马维兴

    2003-01-01

    The Dyson-Schwinger formalism is used to derive a fully dressed quark propagator. By use of the derived form of the quark propagator, the structure of non-local quark vacuum condensate is studied, and the values of local quark vacuum condensate as well as quark gluon mixed condensate are calculated. The theoretical predictions are in good agreement with the empirical one used commonly in the literature.

  4. Vacuum decay in an interacting multiverse

    OpenAIRE

    Robles-Pérez, S.; Alonso-Serrano, A.; Bastos, C.; Bertolami, O.

    2016-01-01

    We examine a new multiverse scenario in which the component universes interact. We focus our attention to the process of "true" vacuum nucleation in the false vacuum within one single element of the multiverse. It is shown that the interactions lead to a collective behaviour that might lead, under specific conditions, to a pre-inflationary phase and ensued distinguishable imprints in the comic microwave background radiation.

  5. An Improved Vacuum System for COLLAPS

    CERN Document Server

    Bruchim, Daniel

    2015-01-01

    The COLLAPS beamline in general, and the current ROC setup specifically, has very many valves and pumps. We require a safety system in order to prevent action that would cause damage to vacuum components, i.e. opening a valve between atmosphere and vacuum. The system needs to be adaptable (programmable) to the various possible setups of COLLAPS and needs to be as robust as possible in order to prevent damage of equipment.

  6. Vacuum gas carburizing – fate of hydrocarbons

    OpenAIRE

    Khan, Rafi Ullah

    2008-01-01

    This work focuses on gaseous reactive flows in ideal and non-ideal reactors. The objective of this research is the development of models for the numerical simulation of homogeneous reactive flows under vacuum carburizing conditions of steel with propane and acetylene. These models can be used for further investigations of heterogeneous reactions during vacuum carburizing of steel to predict the carbon flux on the complex shaped steel parts to understand and, eventually, optimize the behavior ...

  7. Fumaric acid production by fermentation

    NARCIS (Netherlands)

    Roa Engel, C.A.; Straathof, A.J.J.; Zijlmans, T.W.; Van Gulik, W.M.; Van der Wielen, L.A.M.

    2008-01-01

    Abstract The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid fr

  8. Balancing phosphine in manure fermentation.

    Science.gov (United States)

    Eismann, F; Glindemann, D; Bergmann, A; Kuschk, P

    1997-11-01

    The evolution of phosphine gas during the anaerobic batch fermentation of fresh swine manure was detected and correlated to the production of methane and hydrogen sulphide. A close temporal relationship between phosphine liberation and methane formation was found. However, the gaseous phosphine released from manure during fermentation only represents a tiny fraction of the overall phosphine balance. The majority of phosphine is captured in solid manure constituents. This matrix-bound phosphine is eliminated by more than 50% during anaerobic batch-fermentation. Seasonally determined phosphine concentrations in biogas and manure from two large-scale manure treatment plants also revealed net losses of phosphine in fermentation. Consequently, manure has to be considered more as a sink of phosphine rather than a phosphine-generating medium. Furthermore, a close relationship between phosphine in the feed of swine and manure of these swine was observed, implying that phosphine residues in the feed (possibly as a result of grain fumigation) represent an important source of phosphine in manure technologies that is relevant before the faecals of swine enter manure treatment plants.

  9. Cleaning Validation of Fermentation Tanks

    DEFF Research Database (Denmark)

    Salo, Satu; Friis, Alan; Wirtanen, Gun

    2008-01-01

    Reliable test methods for checking cleanliness are needed to evaluate and validate the cleaning process of fermentation tanks. Pilot scale tanks were used to test the applicability of various methods for this purpose. The methods found to be suitable for validation of the clenlinees were visula...

  10. Fermentative processes for environmental remediation

    OpenAIRE

    Grilli, Selene

    2013-01-01

    The growing interest in environmental protection has led to the development of emerging biotechnologies for environmental remediation also introducing the biorefinery concept. This work mainly aimed to evaluate the applicability of innovative biotechnologies for environmental remediation and bioenergy production, throught fermentative processes. The investigated biotechnologies for waste and wastewater treatment and for the valorisation of specific feedstocks and energy recovery, were m...

  11. Biogenic amines in fermented foods

    NARCIS (Netherlands)

    Spano, G.; Russo, P.; Lonvaud-Funel, A.; Lucas, P.; Alexandre, H.; Grandvalet, C.; Coton, E.; Coton, M.; Barnavon, L.; Bach, B.; Rattray, F.; Bunte, A.; Magni, C.; Ladero, V.; Alvarez, M.; Fernández, M.; Lopez, P.; Palencia, P.F. de; Corbi, A.; Trip, H.; Lolkema, J.S.

    2010-01-01

    Food-fermenting lactic acid bacteria (LAB) are generally considered to be non-toxic and non-pathogenic. Some species of LAB, however, can produce biogenic amines (BAs). BAs are organic, basic, nitrogenous compounds, mainly formed through decarboxylation of amino acids. BAs are present in a wide rang

  12. ENDOSPORES OF THERMOPHILIC FERMENTATIVE BACTERIA

    DEFF Research Database (Denmark)

    Volpi, Marta

    2016-01-01

    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  13. African fermented foods and probiotics.

    Science.gov (United States)

    Franz, Charles M A P; Huch, Melanie; Mathara, Julius Maina; Abriouel, Hikmate; Benomar, Nabil; Reid, Gregor; Galvez, Antonio; Holzapfel, Wilhelm H

    2014-11-03

    Africa has an age old history of production of traditional fermented foods and is perhaps the continent with the richest variety of lactic acid fermented foods. These foods have a large impact on the nutrition, health and socio-economy of the people of the continent, often plagued by war, drought, famine and disease. Sub-Saharan Africa is the world's region with the highest percentage of chronically malnourished people and high child mortality. Further developing of traditional fermented foods with added probiotic health features would be an important contribution towards reaching the UN Millennium Development Goals of eradication of poverty and hunger, reduction in child mortality rates and improvement of maternal health. Specific probiotic strains with documented health benefits are sparsely available in Africa and not affordable to the majority of the population. Furthermore, they are not used in food fermentations. If such probiotic products could be developed especially for household food preparation, such as cereal or milk foods, it could make a profound impact on the health and well-being of adults and children. Suitable strains need to be chosen and efforts are needed to produce strains to make products which will be available for clinical studies. This can gauge the impact of probiotics on consumers' nutrition and health, and increase the number of people who can benefit.

  14. Cleaning Validation of Fermentation Tanks

    DEFF Research Database (Denmark)

    Salo, Satu; Friis, Alan; Wirtanen, Gun

    2008-01-01

    Reliable test methods for checking cleanliness are needed to evaluate and validate the cleaning process of fermentation tanks. Pilot scale tanks were used to test the applicability of various methods for this purpose. The methods found to be suitable for validation of the clenlinees were visula o...

  15. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics.

  16. Physical vacuum properties and internal space dimension

    Science.gov (United States)

    Gorbatenko, M. V.; Pushkin, A. V.

    2005-10-01

    The paper addresses matrix spaces, whose properties and dynamics are determined by Dirac matrices in Riemannian spaces of different dimension and signature. Among all Dirac matrix systems there are such ones, which nontrivial scalar, vector or other tensors cannot be made up from. These Dirac matrix systems are associated with the vacuum state of the matrix space. The simplest vacuum system realization can be ensured using the orthonormal basis in the internal matrix space. This vacuum system realization, however, is not unique. The case of 7-dimensional Riemannian space of signature 7(-) is considered in detail. In this case two basically different vacuum system realizations are possible: (1) with using the orthonormal basis; (2) with using the oblique-angled basis, whose base vectors coincide with the simple roots of the Lie algebra E 8. Considerations are presented, from which it follows that the least-dimen-si-on space bearing on physics is the Riemannian 11-dimensional space of signature 1(-)& 10(+). The considerations consist in the condition of maximum vacuum energy density and vacuum fluctuation energy density.

  17. Analysis of repeated measures data

    CERN Document Server

    Islam, M Ataharul

    2017-01-01

    This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

  18. The Brewing Process: Optimizing the Fermentation

    Directory of Open Access Journals (Sweden)

    Teodora Coldea

    2014-11-01

    Full Text Available Beer is a carbonated alcoholic beverage obtained by alcoholic fermentation of malt wort boiled with hops. Brown beer obtained at Beer Pilot Station of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca was the result of a recipe based on blond, caramel and black malt in different proportions, water, hops and yeast. This study aimed to monitorize the evolution of wort in primary and secondary alcoholic fermentation in order to optimize the process. Two wort batches were assambled in order to increase the brewing yeast fermentation performance. The primary fermentation was 14 days, followed by another 14 days of secondary fermentation (maturation. The must fermentation monitoring was done by the automatic FermentoStar analyzer. The whole fermentation process was monitorized (temperature, pH, alcohol concentration, apparent and total wort extract.

  19. [Chemistry of life: ferments and fermentation in 17th-century iatrochemistry].

    Science.gov (United States)

    Clericuzio, Antonio

    2003-01-01

    The concepts of ferment and fermentation played an important, though heretofore neglected, role in 17th-century physiology. Though these notions can be found in ancient philosophy and medicine, as well as in medieval medicine, they became integral part of the chemical medicine that was advocated by Paracelsus and his school. Paracelsians made fermentation a central concept in their successful effort to give chemical foundation to medicine. Jean Baptiste van Helmont and Sylvius used the concepts of ferment and fermentation to explain a variety of physiological processes in human body. Corpuscular philosophers like Robert Boyle and Thomas Willis reinterpreted these notions in corpuscular terms and separated the concept of ferment from that of fermentation. In the second half of the seventeenth century, physiologist tried to explain fermentation by means of chemical reactions, as for instance acid -alkali, and ruled out the notion of ferment as superfluous to their investigations. At the end of hte seventeenth century fermentation attracted the interest of physicists like Johannes Bernoulli and Isaac Newton, who tried to explain fermentative processes in terms of matter and motion (Bernoulli) and short-range forces (Newton). George Ernst Stahl devoted a work to fermentation: the Zymotechnia. He explained fermentation as the outcome of the reactions of molecules formed of saline, oily and earthy corpuscles with particles of water. He saw fermentation as a mechanical process, i.e. as collision of different kinds of corpuscles.

  20. Health Benefits of Fiber Fermentation.

    Science.gov (United States)

    Dahl, Wendy J; Agro, Nicole C; Eliasson, Åsa M; Mialki, Kaley L; Olivera, Joseph D; Rusch, Carley T; Young, Carly N

    2017-02-01

    Although fiber is well recognized for its effect on laxation, increasing evidence supports the role of fiber in the prevention and treatment of chronic disease. The aim of this review is to provide an overview of the health benefits of fiber and its fermentation, and describe how the products of fermentation may influence disease risk and treatment. Higher fiber intakes are associated with decreased risk of cardiovascular disease, type 2 diabetes, and some forms of cancer. Fiber may also have a role in lowering blood pressure and in preventing obesity by limiting weight gain. Fiber is effective in managing blood glucose in type 2 diabetes, useful for weight loss, and may provide therapeutic adjunctive roles in kidney and liver disease. In addition, higher fiber diets are not contraindicated in inflammatory bowel disease or irritable bowel syndrome and may provide some benefit. Common to the associations with disease reduction is fermentation of fiber and its potential to modulate microbiota and its activities and inflammation, specifically the production of anti-inflammatory short chain fatty acids, primarily from saccharolytic fermentation, versus the deleterious products of proteolytic activity. Because fiber intake is inversely associated with all-cause mortality, mechanisms by which fiber may reduce chronic disease risk and provide therapeutic benefit to those with chronic disease need further elucidation and large, randomized controlled trials are needed to confirm causality.Teaching Points• Strong evidence supports the association between higher fiber diets and reduced risk of cardiovascular disease, type 2 diabetes, and some forms of cancer.• Higher fiber intakes are associated with lower body weight and body mass index, and some types of fiber may facilitate weight loss.• Fiber is recommended as an adjunctive medical nutritional therapy for type 2 diabetes, chronic kidney disease, and certain liver diseases.• Fermentation and the resulting shifts in

  1. Fermentation of hexoses to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Lena [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology]|[Chalmers Univ. of Technology, Goeteborg (Sweden). Dept of Chemical Reaction Engineering

    2000-06-01

    The Goals of the project has been: to increase the ethanol yield by reducing the by-product formation, primarily biomass and glycerol, and to prevent stuck fermentations, i.e. to maintain a high ethanol production rate simultaneously with a high ethanol yield. The studies have been performed both in defined laboratory media and in a mixture of wood- and wheat hydrolysates. The yeast strains used have been both industrial strains of bakers yeast, Saccharomyces cerevisiae, and haploid laboratory strains. The Relevance of these studies with respect to production of ethanol to be used as fuel is explained by: With the traditional process design used today, it is very difficult to reach a yield of more than 90 % of the theoretical maximal value of ethanol based on fermented hexose. During 'normal' growth and fermentation conditions in either anaerobic batch or chemostat cultures, substrate is lost as biomass and glycerol in the range of 8 to 11 % and 6 to 11 % of the substrate consumed (kg/kg). It is essential to reduce these by-products. Traditional processes are mostly batch processes, in which there is a risk that the biocatalyst, i.e. the yeast, may become inactivated. If for example yeast biomass production is avoided by use of non-growing systems, the ethanol production rate is instantaneously reduced by at least 50%. Unfortunately, even if yeast biomass production is not avoided on purpose, it is well known that stuck fermentations caused by cell death is a problem in large scale yeast processes. The main reason for stuck fermentations is nutrient imbalances. For a good process economy, it is necessary to ensure process accessibility, i.e. to maintain a high and reproducible production rate. This will both considerably reduce the necessary total volume of the fermentors (and thereby the investment costs), and moreover minimize undesirable product fall-out.

  2. Commercialization of a novel fermentation concept.

    Science.gov (United States)

    Mazumdar-Shaw, Kiran; Suryanarayan, Shrikumar

    2003-01-01

    Fermentation is the core of biotechnology where current methodologies span across technologies based on the use of either solid or liquid substrates. Traditionally, solid substrate fermentation technologies have been the widely practiced in the Far East to manufacture fermented foods such as soya sauce, sake etc. The Western World briefly used solid substrate fermentation for the manufacture of antibiotics and enzymes but rapidly replaced this technology with submerged fermentation which proved to be a superior technology in terms of automation, containment and large volume fermentation. Biocon India developed its enzyme technology based on solid substrate fermentation as a low-cost, low-energy option for the production of specialty enzymes. However, the limitations of applying solid substrate fermentation to more sophisticated biotechnology products as well as large volume fermentations were recognized by Biocon India as early as 1990 and the company embarked on a 8 year research and development program to develop a novel bioreactor capable of conducting solid substrate fermentation with comparable levels of automation and containment as those practiced by submerged fermentation. In addition, the novel technology enabled fed-batch fermentation, in situ extraction and other enabling features that will be discussed in this article. The novel bioreactor was christened the "PlaFractor" (pronounced play-fractor). The next level of research on this novel technology is now focused on addressing large volume fermentation. This article traces the evolution of Biocon India's original solid substrate fermentation to the PlaFractor technology and provides details of the scale-up and commercialization processes that were involved therein. What is also apparent in the article is Biocon India's commercially focused research programs and the perceived need to be globally competitive through low costs of innovation that address, at all times, processes and technologies that

  3. Recovery of succinic acid produced by fermentation of a metabolically engineered Mannheimia succiniciproducens strain.

    Science.gov (United States)

    Song, Hyohak; Huh, Yun Suk; Lee, Sang Yup; Hong, Won Hi; Hong, Yeon Ki

    2007-12-01

    There have recently been much advances in the production of succinic acid, an important four-carbon dicarboxylic acid for many industrial applications, by fermentation of several natural and engineered bacterial strains. Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce succinic acid with high efficiency, but also produces acetic, formic and lactic acids just like other anaerobic succinic acid producers. We recently reported the development of an engineered M. succiniciproducens LPK7 strain which produces succinic acid as a major fermentation product while producing much reduced by-products. Having an improved succinic acid producer developed, it is equally important to develop a cost-effective downstream process for the recovery of succinic acid. In this paper, we report the development of a simpler and more efficient method for the recovery of succinic acid. For the recovery of succinic acid from the fermentation broth of LPK7 strain, a simple process composed of a single reactive extraction, vacuum distillation, and crystallization yielded highly purified succinic acid (greater than 99.5% purity, wt%) with a high yield of 67.05wt%. When the same recovery process or even multiple reactive extraction steps were applied to the fermentation broth of MBEL55E, lower purity and yield of succinic acid were obtained. These results suggest that succinic acid can be purified in a cost-effective manner by using the fermentation broth of engineered LPK7 strain, showing the importance of integrating the strain development, fermentation and downstream process for optimizing the whole processes for succinic acid production.

  4. Ranking of in vitro fermentability of 20 feedstuffs with an automated gas production technique. Resuls of a ring test

    NARCIS (Netherlands)

    Gelder, van A.H.; Hetta, M.; Rodrigues, M.A.M.; Boever, de J.L.; Hartigh, Den H.; Rymer, C.; Oostrum, van M.; Kaathoven, van R.; Cone, J.W.

    2005-01-01

    A ring test was completed to determine within laboratory repeatability, and reproducibility among laboratories, of a gas production technique for measuring fermentation kinetics of feeds in rumen fluid. Eight laboratories in different European countries received 20 feed samples. All used the same ga

  5. Vacuum Energy and Inflation: 4. An Inflationary Universe

    Science.gov (United States)

    Huggins, Elisha

    2013-01-01

    This is the fourth paper in a series of four. The first paper in the series, "Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy" [EJ1024183] discusses an example of vacuum energy. Vacuum energy is explained as an energy with a negative pressure whose energy density remains constant in an expanding space. Paper 2, "Vacuum…

  6. Vacuum Energy and Inflation: 4. An Inflationary Universe

    Science.gov (United States)

    Huggins, Elisha

    2013-01-01

    This is the fourth paper in a series of four. The first paper in the series, "Vacuum Energy and Inflation: 1. A Liter of Vacuum Energy" [EJ1024183] discusses an example of vacuum energy. Vacuum energy is explained as an energy with a negative pressure whose energy density remains constant in an expanding space. Paper 2, "Vacuum…

  7. Vacuum system of SST-1 Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Ziauddin, E-mail: ziauddin@ipr.res.in [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382 428 (India); Pathan, Firozkhan; George, Siju; Semwal, Pratibha; Dhanani, Kalpesh; Paravastu, Yuvakiran; Thankey, Prashant; Ramesh, Gattu; Himabindu, Manthena; Pradhan, Subrata [Institute for Plasma Research, Near Indira Bridge, Bhat, Gandhinagar 382 428 (India)

    2013-10-15

    Highlights: ► Air leaks developed during ongoing SST-1 cooldown campaign were detected online using RGA. ► The presence of N{sub 2} and O{sub 2} gases with the ratio of their partial pressures with ∼3.81:1 confirmed the air leaks. ► Baking of SST-1 was done efficiently by flowing hot N{sub 2} gas in C-channels welded on inner surfaces without any problem. ► In-house fabricated demountable bull nose couplers were demonstrated for high temperature and pressure applications. ► Cryopumping effect was observed when liquid helium cooled superconducting magnets reached below 63 K. -- Abstract: Vacuum chambers of Steady State Superconducting (SST-1) Tokamak comprises of the vacuum vessel and the cryostat. The plasma will be confined inside the vacuum vessel while the cryostat houses the superconducting magnet systems (TF and PF coils), LN{sub 2} cooled thermal shields and hydraulics for these circuits. The vacuum vessel is an ultra-high (UHV) vacuum chamber while the cryostat is a high-vacuum (HV) chamber. In order to achieve UHV inside the vacuum vessel, it would be baked at 150 °C for longer duration. For this purpose, U-shaped baking channels are welded inside the vacuum vessel. The baking will be carried out by flowing hot nitrogen gas through these channels at 250 °C at 4.5 bar gauge pressure. During plasma operation, the pressure inside the vacuum vessel will be raised between 1.0 × 10{sup −4} mbar and 1.0 × 10{sup −5} mbar using piezoelectric valves and control system. An ultimate pressure of 4.78 × 10{sup −6} mbar is achieved inside the vacuum vessel after 100 h of pumping. The limitation is due to the development of few leaks of the order of 10{sup −5} mbar l/s at the critical locations of the vacuum vessel during baking which was confirmed with the presence of nitrogen gas and oxygen gas with the ratio of ∼3.81:1 indicating air leak. Similarly an ultimate vacuum of 2.24 × 10{sup −5} mbar is achieved inside the cryostat. Baking of the

  8. Fermentation characteristics of corn forage ensiled in mini-silos.

    Science.gov (United States)

    Cherney, D J R; Cherney, J H; Cox, W J

    2004-12-01

    To evaluate numerous experimental variables and their interactions involving different corn (Zea mays, L.) silage hybrids, scaled down mini-silos are necessary. Objectives of this study were to evaluate the influence of sample size on pH, NH3, and volatile fatty acid profile of 8 corn silage hybrids, selected to vary in fiber digestibility and ensiled in vacuum-sealed polyethylene bags for 90 d, and to assess the suitability of these mini-silos for detecting differences among corn silage samples. Hybrids were grown at the Cornell Teaching and Research Center located near Harford, NY, and harvested at a dry matter content of about 32% in the fall of 2002. Samples from 3 field replications of each hybrid were chipper-shredder chopped and vacuum-ensiled in bags with sample sizes of 50, 100, 200, 400, and 600 g. Increasing sample size resulted in decreased lactic acid, acetic acid, total acids, and NH3. Most of the difference among sample sizes occurred between the 50- and 100-g sample sizes. Lactic acid:acetic acid ratio (3.1 +/- 0.13) and pH (3.9 +/-0.08) did not vary among sample sizes. There was no detectable butyric acid in the samples. Fermentation characteristics suggested that all samples were well ensiled but that the fermentation profile of the 50-g samples differed the most from other sample sizes. Hybrids did vary in lactic acid, acetic acid, lactic acid:acetic acid, and pH. Differences among hybrids were also noted for dry matter and crude protein. Field-chopped corn hybrids that were ensiled using mini-silos had higher acids than corresponding field-chopped corn hybrids ensiled in Ag-bags, in part due to no effluent escaping from the mini-silos. It is possible to use vacuum-sealed plastic bags to ensile corn, with samples as small as 200 g, and to use these mini-silos to assess differences among corn silage samples. Caution should be used when extrapolating mini-silo data to field-scale ensiling.

  9. RELATION BETWEEN FUNCTION AND FORM IN VACUUM CLEANERS DESIGN

    Directory of Open Access Journals (Sweden)

    RADU Ștefan

    2015-11-01

    Full Text Available The paper analyses how robotic vacuum cleaner works, describing their cleaning capabilities and additional features. The paper illustrates advantages of using robotic vacuum cleaners that have intelligent programming and a vacuum cleaning system, the components of a robotic vacuum cleaner. The paper develops aspects concerning to create 2D scale models for the evaluation of specific features of the new components for a prototype robotic vacuum cleaner.

  10. RELATION BETWEEN FUNCTION AND FORM IN VACUUM CLEANERS DESIGN

    OpenAIRE

    RADU Ștefan

    2015-01-01

    The paper analyses how robotic vacuum cleaner works, describing their cleaning capabilities and additional features. The paper illustrates advantages of using robotic vacuum cleaners that have intelligent programming and a vacuum cleaning system, the components of a robotic vacuum cleaner. The paper develops aspects concerning to create 2D scale models for the evaluation of specific features of the new components for a prototype robotic vacuum cleaner.

  11. 27 CFR 24.197 - Production by fermentation.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Production by fermentation... fermentation. In producing special natural wine by fermentation, flavoring materials may be added before or during fermentation. Special natural wine produced by fermentation may be ameliorated in the same...

  12. Insertion Test of the Inner Vacuum Tank inside the Outer Vacuum Tank

    CERN Multimedia

    B. LEVESY

    2002-01-01

    Photos of the insertion test held on 13th of june 2002. The CMS Magnet inner Vacuum Tank is inserted inside the outer vacuum tank. False thermal shield have been placed on the inner vaccum tank to simulated the coil outer thermal shield. This test is a training for the 2 final insertions.

  13. Cold Vacuum Drying (CVD) Set Point Determination

    Energy Technology Data Exchange (ETDEWEB)

    PHILIPP, B.L.

    2000-09-04

    The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO annulus on high Tempered Water (TW) inlet temperature. For the MCO isolation and purge, the SCIC receives MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switch status, seismic trip status, and time-under-vacuum trips signals. The SCIC system will isolate the MCO and start an SCHe system purge if any of the following occur. (1) Isolation and purge from one of the SCHe ''isolation'' and ''purge'' buttons is manually initiated (administratively controlled). (2) The first vacuum cycle exceeds 8 hours at vacuum, or any subsequent vacuum cycle exceeds 4 hours at vacuum without re-pressurizing the MCO for a minimum of 4 hours. (This is referred to as the 8/4/4 requirement and provides thermal equilibrium within the MCO.) (3) MCO is below atmospheric pressure and the helium flow is below the minimum required to keep hydrogen less than 4% by volume. (When MCO pressure is below 12 torr there is insufficient hydrogen to exceed the 4% level and therefore no purge is required. A five minute time delay on low flow allows flow to be stopped in order to reach < 12 torr.) (4) The duration for the transition from above atmospheric pressure to vacuum (time to reach pressure below -11.7 psig [{approx}155 torr]) exceeds 5 minutes. (5) The duration for the transition from vacuum (below -11.1 psig [{approx}185 torr]) back to pressure [greater than 0.5 psig] exceeds 5 minutes. (6) MCO reaches a vacuum state (<0.5 psig) without an adequate, verified purge volume. (The MCO must be maintained above atmospheric pressure

  14. Vacuum Bellows, Vacuum Piping, Cryogenic Break, and Copper Joint Failure Rate Estimates for ITER Design Use

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader

    2010-06-01

    The ITER international project design teams are working to produce an engineering design in preparation for construction of the International Thermonuclear Experimental Reactor (ITER) tokamak. During the course of this work, questions have arisen in regard to safety barriers and equipment reliability as important facets of system design. The vacuum system designers have asked several questions about the reliability of vacuum bellows and vacuum piping. The vessel design team has asked about the reliability of electrical breaks and copper-copper joints used in cryogenic piping. Research into operating experiences of similar equipment has been performed to determine representative failure rates for these components. The following chapters give the research results and the findings for vacuum system bellows, power plant stainless steel piping (amended to represent vacuum system piping), cryogenic system electrical insulating breaks, and copper joints.

  15. CERN Vacuum-System Activities during the Long Shutdown 1: The LHC Beam Vacuum

    CERN Document Server

    Baglin, V; Chiggiato, P; Jimenez, JM; Lanza, G

    2014-01-01

    After the Long Shutdown 1 (LS1) and the consolidation of the magnet bus bars, the CERN Large Hadron Collider (LHC) will operate with nominal beam parameters. Larger beam energy, beam intensities and luminosity are expected. Despite the very good performance of the beam vacuum system during the 2010-12 physics run (Run 1), some particular areas require attention for repair, consolidation and upgrade. Among the main activities, a large campaign aiming at the repair of the RF bridges of some vacuum modules is conducted. Moreover, consolidation of the cryogenic beam vacuum systems with burst disk for safety reasons is implemented. In addition, NEG cartridges, NEG coated inserts and new instruments for the vacuum system upgrade are installed. Besides these activities, repair, consolidation and upgrades of other beam equipment such as collimators, kickers and beam instrumentations are carried out. In this paper, the motivation and the description for such activities, together with the expected beam vacuum performa...

  16. Engineering Matter Interactions Using Squeezed Vacuum

    Directory of Open Access Journals (Sweden)

    Sina Zeytinoğlu

    2017-06-01

    Full Text Available Virtually all interactions that are relevant for atomic and condensed matter physics are mediated by quantum fluctuations of the electromagnetic field vacuum. Consequently, controlling the vacuum fluctuations can be used to engineer the strength and the range of interactions. Recent experiments have used this premise to demonstrate novel quantum phases or entangling gates by embedding electric dipoles in photonic cavities or wave guides, which modify the electromagnetic fluctuations. Here, we show theoretically that the enhanced fluctuations in the antisqueezed quadrature of a squeezed vacuum state allow for engineering interactions between electric dipoles without the need for a photonic structure. Thus, the strength and range of the interactions can be engineered in a time-dependent way by changing the spatial profile of the squeezed vacuum in a traveling-wave geometry, which also allows the implementation of chiral dissipative interactions. Using experimentally realized squeezing parameters and including realistic losses, we predict single-atom cooperativities C of up to 10 for the squeezed-vacuum-enhanced interactions.

  17. CSRm Ultra-High Vacuum System

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The new accelerator project ( HIRFL-CSR ) constructed at the Heavy Ion Research Facility in Lanzhou (HIRFL) is approaching completion. It is a multipurpose cooler-storage-ring system [1], consisting of a maim ring (CSRm), an experimental ring (CSRe) and two transfer beam lines. The UHV system of CSRm is the most representative subsystem in the project. To minimize the beam loss due to charge exchange of the heavy ions with the residual gas molecules,the pressure of the CSRm vacuum system should reach 3.5 × 10-9 Pa (N2 equivalent) and the pressure of 8 × 10-10 Pa is expected for very heavy ion such as uranium to make its lifetime longer than 50 s in the ring. Now, the vacuum system of CSRm has been completed and a pressure less than 5 × 10-10 Pa has been obtained. In this paper the layout of the CSRm vacuum system, the vacuum equipment in CSRm, the treatment method for the CSRm vacuum chambers, and the installation and operation of the system will be reported.

  18. Compressed Air/Vacuum Transportation Techniques

    Science.gov (United States)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  19. Decay of the Cosmic Vacuum Energy

    CERN Document Server

    Clifton, Timothy

    2014-01-01

    Energy-momentum conservation suggests that a vacuum in thermal equilibrium with a bath of radiation during inflation should gradually diminish the vacuum energy. We find that coupling to a bath of black-body radiation at temperature $T=H/2 \\pi$ requires the Hubble rate, $H$, to evolve as in the "intermediate inflation" scenario, with $H \\propto t^{-1/3}$, rather than as a constant. Such behaviour does not conflict with observations when the vacuum energy is described by a slowly-rolling scalar field, but will change the asymptotic states of the universe. We find that this scenario introduces a curvature singularity at early times. The scale factor takes a finite non-zero value at this singularity, while the energy densities in radiation and the vacuum diverge to positive and negative infinity, respectively. This shows that inflation is possible even when the energy density of the vacuum is large and negative. Furthermore, the introduction of an additional non-interacting perfect fluid into the space-time reve...

  20. Recent advances in vacuum sciences and applications

    Science.gov (United States)

    Mozetič, M.; Ostrikov, K.; Ruzic, D. N.; Curreli, D.; Cvelbar, U.; Vesel, A.; Primc, G.; Leisch, M.; Jousten, K.; Malyshev, O. B.; Hendricks, J. H.; Kövér, L.; Tagliaferro, A.; Conde, O.; Silvestre, A. J.; Giapintzakis, J.; Buljan, M.; Radić, N.; Dražić, G.; Bernstorff, S.; Biederman, H.; Kylián, O.; Hanuš, J.; Miloševič, S.; Galtayries, A.; Dietrich, P.; Unger, W.; Lehocky, M.; Sedlarik, V.; Stana-Kleinschek, K.; Drmota-Petrič, A.; Pireaux, J. J.; Rogers, J. W.; Anderle, M.

    2014-04-01

    Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure measurements with temporal resolution of 2 ms. Vacuum issues in the construction of huge ultra-high vacuum devices worldwide are reviewed. Recent advances in surface science and thin films include new phenomena observed in electron transport near solid surfaces as well as novel results on the properties of carbon nanomaterials. Precise techniques for surface and thin-film characterization have been applied in the conservation technology of cultural heritage objects and recent advances in the characterization of biointerfaces are presented. The combination of various vacuum and atmospheric-pressure techniques enables an insight into the complex phenomena of protein and other biomolecule conformations on solid surfaces. Studying these phenomena at solid-liquid interfaces is regarded as the main issue in the development of alternative techniques for drug delivery, tissue engineering and thus the development of innovative techniques for curing cancer and cardiovascular diseases. A review on recent advances in plasma medicine is presented as well as novel hypotheses on cell apoptosis upon treatment with gaseous plasma. Finally, recent advances in plasma nanoscience are illustrated with several examples and a roadmap for future activities is presented.

  1. Butyric acid fermentation in a fibrous bed bioreactor with immobilized Clostridium tyrobutyricum from cane molasses.

    Science.gov (United States)

    Jiang, Ling; Wang, Jufang; Liang, Shizhong; Wang, Xiaoning; Cen, Peilin; Xu, Zhinan

    2009-07-01

    Butyrate fermentation by immobilized Clostridium tyrobutyricum was successfully carried out in a fibrous bed bioreactor using cane molasses. Batch fermentations were conducted to investigate the influence of pH on the metabolism of the strain, and the results showed that the fermentation gave a highest butyrate production of 26.2 g l(-1) with yield of 0.47 g g(-1) and reactor productivity up to 4.13 g l(-1)h(-1) at pH 6.0. When repeated-batch fermentation was carried out, long-term operation with high butyrate yield, volumetric productivity was achieved. Several cane molasses pretreatment techniques were investigated, and it was found that sulfuric acid treatment gave better results regarding butyrate concentration (34.6+/-0.8 g l(-1)), yield (0.58+/-0.01 g g(-1)), and sugar utilization (90.8+/-0.9%). Also, fed-batch fermentation from cane molasses pretreated with sulfuric acid was performed to further increase the concentration of butyrate up to 55.2 g l(-1).

  2. A bilberry drink with fermented oatmeal decreases postprandial insulin demand in young healthy adults

    Directory of Open Access Journals (Sweden)

    Björck Inger ME

    2011-05-01

    Full Text Available Abstract Background in traditional medicine, blueberries have been used to facilitate blood glucose regulation in type 2 diabetes. Recent studies in diabetic mice have indicated facilitated glycaemic regulation following dietary supplementation with extracts from European blueberries, also called bilberries, (Vaccinium myrtillus. The purpose of the present study was to investigate the impact of fermented oat meal drinks containing bilberries or rosehip (Rosa canina on glycaemic and insulinaemic responses. Methods glycaemic and insulinaemic responses in young healthy adults were measured in two series. In series 1, two drinks based on oat meal (5%, fermented using Lactobacillus plantarum 299v, and added with fruit (10%; bilberries (BFOMD or rose hip (RFOMD respectively, were studied. In series 2, BFOMD was repeated, additionally, a drink enriched with bilberries (47% was tested (BBFOMD. As control a fermented oat meal drink (FOMD was served. Results in series 1 the bilberry- and rosehip drinks, gave high glucose responses similar to that after the reference bread. However, the insulin index (II after the BFOMD was significantly lower (II = 65 (P Conclusion a fermented oat meal drink added with bilberries induced a lower insulin response than expected from the glycaemic response. The mechanism for the lowered acute insulin demand is still unclear, but may be related to some bio-active component present in the bilberries, or to the fermented oat meal base.

  3. Limitations on quantum key repeaters.

    Science.gov (United States)

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  4. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Virgil [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Della Torre, Edward; Bennett, Lawrence H. [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States); ElBidweihy, Hatem, E-mail: Hatem@gwmail.gwu.edu [Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052 (United States)

    2014-02-15

    The Gd{sub 5}Ge{sub 2}Si{sub 2} alloy and the off-stoichiometric Ni{sub 50}Mn{sub 35}In{sub 15} Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd{sub 5}Ge{sub 2}Si{sub 2} and Ni{sub 50}Mn{sub 35}In{sub 15} alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  5. Controlled fermentation and preservation of UGBA –an indigenous Nigerian fermented food

    National Research Council Canada - National Science Library

    Okorie, Chimezie Princewill; Olasupo, Nurudeen Ayoade

    2013-01-01

    Studies were carried out to screen various microbial isolates of UGBA obtained from both traditionally fermented and laboratory samples for some technical properties required for the fermentation of the product...

  6. Characterization of Microbial Community during the Fermentation of Chinese Homemade paocai, a Traditional Fermented Vegetable Food

    National Research Council Canada - National Science Library

    Liang, Huipeng; Zhang, An; Wu, Zhengyun; Liu, Chaolan; Zhang, Wenxue

    2016-01-01

    The microbial community in the fermentation process of Chinese homemade paocai (CHP), which was a traditional fermented vegetable food in China, was analyzed firstly by PCR-denaturing gradient gel electrophoresis...

  7. Pilot-scale semisolid fermentation of straw.

    Science.gov (United States)

    Grant, G A; Han, Y W; Anderson, A W

    1978-03-01

    Semisolid fermentation of ryegrass straw to increase its animal feed value was successfully performed on a pilot scale. The pilot plant, which could handle 100 kg of straw per batch, was designed so that all major operations could take place in one vessel. The straw was hydrolyzed at 121 degrees C for 30 min with 0.5 N H2SO4 (7:3 liquid:solid), treated with ammonia to raise the pH to 5.0, inoculated with Candida utilis, and fermented in a semisolid state (70% moisture). During fermentation the straw was held stationary with air blown up through it. Batch fermentation times were 12 to 29 h. Semisolid fermentation did not require agitation and supported abundant growth at 20 to 40 degrees C even at near zero oxygen tensions. Fermentation increased the protein content, crude fat content, and in vitro rumen digestibility of the straw.

  8. Acetone-butanol fermentation of marine macroalgae.

    Science.gov (United States)

    Huesemann, Michael H; Kuo, Li-Jung; Urquhart, Lindsay; Gill, Gary A; Roesijadi, Guri

    2012-03-01

    The objective of this study was to subject mannitol, either as a sole carbon source or in combination with glucose, and aqueous extracts of the kelp Saccharina spp., containing mannitol and laminarin, to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Ultrafiltration of hemicellulose hydrolysate fermentation broth

    Science.gov (United States)

    Kresnowati, M. T. A. P.; Desiriani, Ria; Wenten, I. G.

    2017-03-01

    Hemicelulosic material is often used as the main substrate to obtain high-value products such as xylose. The five carbon sugar, xylose, could be further processed by fermentation to produce xylitol. However, not only the hemicellulose hydrolysate fermentation broth contains xylitol, but also metabolite products, residual substances, biomass and mineral salts. Therefore, in order to obtain the end products, various separation processes are required to separate and purify the desired product from the fermentation broth. One of the most promising downstream processing methods of fermentation broth clarification is ultrafiltration due to its potential for energy saving and higher purity. In addition, ultrafiltration membrane has a high performance in separating inhibitory components in the fermentation broth. This paper assesses the influence of operating conditions; including trans-membrane pressure, velocity, pH of the fermentation broth solutions, and also to the xylitol concentration in the product. The challenges of the ultrafiltration process will be pointed out.

  10. Continuous ethanol fermentation by beer yeast

    Energy Technology Data Exchange (ETDEWEB)

    Kida, Kenji; Morimura, Shigeru; Shima, Noriyuki; Asano, Shinichi; Yamadaki, Motozumi; Miyazawa, Toshiki

    1987-01-25

    Cooked and uncooked continuous fermentation tests and a bench-scale continuous fermentation test were carried out using a flocculating yeast, beer yeast IFO-2018, and using molasses of various origin. Heat of fermentation was measured at the same time. High productivity was found in a non-cooking continuous fermentation, but lowering of a flocculating ability was a problem. A theoretical equation for calculating the heat of fermentation was introduced and its adaptability was examined. The continuous fermentation unit was a single tank type using a tower type fermentor. The fermentor had a capacity of 0.7 l actual volume, made of glass, and consisted of the two parts, a flowing part and a precipitation/separation part. The yeast used was Saccharomyces crevisiae IFO-2018 in comparison with such yeast as S. cerevisiae IFO-0224 and S. cervisiae EP-1. (7 figs,3 tabs,21 refs)

  11. Quality Management of CERN Vacuum Controls

    CERN Document Server

    Antoniotti, F; Fortescue-Beck, E; Gama, J; Gomes, P; Le Roux, P; Pereira, H; Pigny, G

    2014-01-01

    The vacuum controls Section (TE-VSC-ICM) is in charge of the monitoring, maintenance and consolidation of the control systems of all accelerators and detectors in CERN; this represents 6 000 instruments distributed along 128 km of vacuum chambers, often of heterogeneous architectures and of diverse technical generations. In order to improve the efficiency of the services provided by ICM, to vacuum experts and to accelerator operators, a Quality Management Plan is being put into place. The first step was the standardization of the naming convention across different accelerators. The traceability of problems, requests, repairs, and other actions, has also been put into place (VTL). This was combined with the effort to identify each individual device by a coded label, and register it in a central database (MTF). Occurring in parallel, was the gathering of old documents and the centralization of information concerning architectures, procedures, equipment and settings (EDMS). To describe the topology of control c...

  12. Vacuum packaging design and analysis for UFPA

    Science.gov (United States)

    Liu, Dafu; Xu, Qinfei

    2010-10-01

    Uncooled focal plane array (UFPA) has broad application prospects in civilian and space because it's cheaper, more compact and high reliability. Many research institutes and companies have carried out the research of uncooled focal plane array. This paper shows a vacuum package design of UFPA, and its architecture will be given. The assembly is an all-metal vacuum package, which has been proven rugged and reliable. Out-gassing, permeation, evaporator, and air leak are factors to reduce the component vacuum lifetime. Theoretical analysis shows that material out-gassing is the main factor of pressure rise inside package. Theoretical analysis and calculation show that designed metallic structure can meet the need of 10-years life.

  13. Vacuum System for HL-2A Tokamak

    Institute of Scientific and Technical Information of China (English)

    曹曾; 崔成和; 刘德权; 蔡萧; 高霄燕

    2005-01-01

    The vacuum system for HL-2A was built in 2003. The test results indicated that this system is feasible. It consists of three main parts: a pumping system, a pumping divertor and a glow discharge cleaning (GDC) system. For the pumping system, there are three main functions:(1) evacuating the vacuum vessel thus to produce an ultra high vacuum, (2) removal of impurities released during baking and (3) pumping during GDC. The pumping divertor controls the particles at the plasma edge and the GDC system provides a clean wall conditioning. During the first campaign of physical trial experiment on HL-2A, the ultimate pressure reached 4.6×10-6 Pa, and of ASDEX.

  14. A Foundation for Vacuuming Temporal Databases

    DEFF Research Database (Denmark)

    Skyt, Janne; Jensen, Christian Søndergaard; Mark, L.

    2003-01-01

    A wide range of real-world database applications, including financial and medical applications, are faced with accountability and traceability requirements. These requirements lead to the replacement of the usual update-in-place policy by an append-only policy that retain all previous states...... in the database. This policy result in so-called transaction-time databases which are ever-growing. A variety of physical storage structures and indexing techniques as well as query languages have been proposed for transaction-time databases, but the support for physical removal of data, termed vacuuming, has...... only received little attention. Such vacuuming is called for by, e.g., the laws of many countries and the policies of many businesses. Although necessary, with vacuuming, the database’s perfect recollection of the past may be compromised via, e.g., selective removal of records pertaining to past states...

  15. Vacuum birefringence in strong inhomogeneous electromagnetic fields

    CERN Document Server

    Karbstein, Felix; Reuter, Maria; Zepf, Matt

    2015-01-01

    Birefringence is one of the fascinating properties of the vacuum of quantum electrodynamics (QED) in strong electromagnetic fields. The scattering of linearly polarized incident probe photons into a perpendicularly polarized mode provides a distinct signature of the optical activity of the quantum vacuum and thus offers an excellent opportunity for a precision test of non-linear QED. Precision tests require accurate predictions and thus a theoretical framework that is capable of taking the detailed experimental geometry into account. We derive analytical solutions for vacuum birefringence which include the spatio-temporal field structure of a strong optical pump laser field and an x-ray probe. We show that the angular distribution of the scattered photons depends strongly on the interaction geometry and find that scattering of the perpendicularly polarized scattered photons out of the cone of the incident probe x-ray beam is the key to making the phenomenon experimentally accessible with the current generatio...

  16. Metastable electroweak vacuum. Implications for inflation

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg; Westphal, Alexander [DESY Theory Group, Hamburg (Germany)

    2012-10-15

    Within the Standard Model, the current Higgs and top quark data favor metastability of the electroweak vacuum, although the uncertainties are still significant. The true vacuum is many orders of magnitude deeper than ours and the barrier separating the two is tiny compared to the depth of the well. This raises a cosmological question: how did the Higgs field get trapped in the shallow minimum and why did it stay there during inflation? The Higgs initial conditions before inflation must be fine-tuned to about one part in 10{sup 8} in order for the Higgs field to end up in the right vacuum. In this note, we show that these problems can be resolved if there is a small positive coupling between the Higgs and the inflaton.

  17. Quantum vacuum radiation in optical glass

    CERN Document Server

    Liberati, Stefano; Visser, Matt

    2011-01-01

    A recent experimental claim of the detection of analogue Hawking radiation in an optical system [PRL 105 (2010) 203901] has led to some controversy [PRL 107 (2011) 149401, 149402]. While this experiment strongly suggests some form of particle creation from the quantum vacuum (and hence it is per se very interesting), it is also true that it seems difficult to completely explain all features of the observations by adopting the perspective of a Hawking-like mechanism for the radiation. For instance, the observed photons are emitted parallel to the optical horizon, and the relevant optical horizon is itself defined in an unusual manner by combining group and phase velocities. This raises the question: Is this really Hawking radiation, or some other form of quantum vacuum radiation? Naive estimates of the amount of quantum vacuum radiation generated due to the rapidly changing refractive index --- sometimes called the dynamical Casimir effect --- are not encouraging. However we feel that naive estimates could be ...

  18. Vacuum interrupters and thyratrons as opening switches

    Science.gov (United States)

    Honig, E. M.

    High power opening switches for inductive storage for large scale energy storage applications are described. The triggered vacuum interrupter and the magnetically quenched thyratrons are discussed. By electrically retriggering the discharge in the vacuum interrupter between pulses, the dependence on mechanical motion is eliminated. This should enable repetition rate operation at 10 to 15 kHz while still maintaining the vacuum interrupter's proven interrupting performance of tens of kiloamps at tens of kilovolts. The magnetically quenched thyratron uses a cross magnetic field to raise the switch impedance by decreasing the electron mobility and driving the discharge into an arc chute wall where it is quenched. Attempts to understand the basic mechanisms involved and to increase the switch, ratings, and particularly the conduction time, are discussed.

  19. Mathematical Model for the Continuous Vacuum Drying

    Institute of Scientific and Technical Information of China (English)

    DAI Hui-liang

    2002-01-01

    An improved mathematical model for the continuous vacuum drying of highly viscous and heatsensitive foodstuffs was proposed, The process of continuous vacuum drying was presented as a moving boundary problem of moisture evaporation in cylindrical coordinates. Boundary condition of the first kind for the known functional dependence of the drying body surface temperature on time was considered. Finally, the appropriate system of differential equations was solved numerically and the values of drying rate, integral moisture content of the material, moving boundary position as well as temperature in any point of the material and at any moment time were obtained. This procedure was applied to continuous vacuum drying of foods such as natural cheese and fresh meat paste.

  20. Friedmann cosmology with decaying vacuum density

    CERN Document Server

    Borges, H A

    2005-01-01

    Among the several proposals to solve the incompatibility between the observed small value of the cosmological constant and the huge value obtained by quantum field theories, we can find the idea of a decaying vacuum energy density, leading from high values at early times of universe evolution to the small value observed nowadays. In this paper we consider a variation law for the vacuum density recently proposed by Schutzhold on the basis of quantum field estimations in the curved, expanding background, characterized by a vacuum density proportional to the Hubble parameter. We show that, in the context of an isotropic and homogeneous, spatially flat model, the corresponding solutions retain the well established features of the standard cosmology, and, in addition, are in accordance with the observed cosmological parameters. Our scenario presents an initial phase dominated by radiation, followed by a dust era long enough to permit structure formation, and by an epoch dominated by the cosmological term, which te...

  1. A Foundation for Vacuuming Temporal Databases

    DEFF Research Database (Denmark)

    Skyt, Janne; Jensen, Christian Søndergaard; Mark, L.

    2003-01-01

    A wide range of real-world database applications, including financial and medical applications, are faced with accountability and traceability requirements. These requirements lead to the replacement of the usual update-in-place policy by an append-only policy that retain all previous states...... in the database. This policy result in so-called transaction-time databases which are ever-growing. A variety of physical storage structures and indexing techniques as well as query languages have been proposed for transaction-time databases, but the support for physical removal of data, termed vacuuming, has...... only received little attention. Such vacuuming is called for by, e.g., the laws of many countries and the policies of many businesses. Although necessary, with vacuuming, the database’s perfect recollection of the past may be compromised via, e.g., selective removal of records pertaining to past states...

  2. Materials for high vacuum technology, an overview

    CERN Document Server

    Sgobba, Stefano

    2007-01-01

    In modern accelerators stringent requirements are placed on materials of vacuum systems. Their physical and mechanical properties, machinability, weldability or brazeability are key parameters. Adequate strength, ductility, magnetic properties at room as well as low temperatures are important factors for vacuum systems of accelerators working at cryogenic temperatures, such as the Large Hadron Collider (LHC) under construction at CERN. In addition, baking or activation of Non-Evaporable Getters (NEG) at high temperatures impose specific choices of material grades of suitable tensile and creep properties in a large temperature range. Today, stainless steels are the dominant materials of vacuum constructions. Their metallurgy is extensively treated. The reasons for specific requirements in terms of metallurgical processes are detailed, in view of obtaining adequate purity, inclusion cleanliness, and fineness of the microstructure. In many cases these requirements are crucial to guarantee the final leak tightnes...

  3. Effective Theory of Higgs Sector Vacuum States

    CERN Document Server

    Egana-Ugrinovic, Daniel

    2015-01-01

    The effective field theory description for modifications of Standard Model-like Higgs boson interactions arising from tree-level mixing with heavy Higgs sector vacuum states without conserved quantum numbers is presented. An expansion in terms of effective operator dimension based on powers of the heavy mass scale rather than operator dimension is utilized to systematically organize interactions within the effective theory. Vacuum states arising from electroweak singlet extensions of the Higgs sector yield at leading order only two effective dimension-six operators. One of these uniformly dilutes all the interactions of a single physical Higgs boson as compared with Standard Model expectations, while the combination of the two operators give more general modifications of all remaining interactions with two or more physical Higgs bosons. Vacuum states arising from an additional electroweak doublet yield three types of effective dimension-six operators that modify physical Higgs boson couplings to fermion pairs...

  4. Development of vacuum die-casting process

    Institute of Scientific and Technical Information of China (English)

    Masashi Uchida

    2009-01-01

    The vacuum die-casting process, started 25 years ago in Japan, has been widely applied. This technology contributes very much to improvement of castings quality. The main factor causing the defects of die castings is the trapped air in the mold cavity, while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting. At the same time, due to the shot speed and the casting pressure reduced in half, the service life of the die is prolonged and the productivity is enhanced, as well. Vacuum die-casting process is of great significance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting.

  5. Pesticides' influence on wine fermentation.

    Science.gov (United States)

    Caboni, Pierluigi; Cabras, Paolo

    2010-01-01

    Wine quality strongly depends on the grape quality. To obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. The most common fungal diseases affecting grape quality are downy and powdery mildew (Plasmopara viticola and Uncinula necator), and gray mold (Botrytis cinerea). On the other hand, the most dangerous insects are the grape moth (Lobesia botrana), vine mealybug (Planococcus ficus), and the citrus mealybug (Planococcus citri). Farmers fight grape diseases and insects applying pesticides that can be found at harvest time on grapes. The persistence of pesticides depends on the chemical characteristic of the active ingredients as well as on photodegradation, thermodegradation, codistillation, and enzymatic degradation. The pesticide residues on grapes can be transferred to the must and this can influence the selection and development of yeast strains. Moreover, yeasts can also influence the levels of the pesticides in the wine by reducing or adsorbing them on lees. During the fermentative process, yeasts can cause the disappearance of pesticide residues by degradation or absorption at the end of the fermentation when yeasts are deposited as lees. In this chapter, we reviewed the effect of commonly used herbicides, insecticides, and fungicides on yeasts. We also studied the effect of alcoholic and malolactic fermentation on pesticide residues.

  6. Carbon dioxide absorption and release properties of pyrolysis products of dolomite calcined in vacuum atmosphere.

    Science.gov (United States)

    Wang, Fei; Kuzuya, Toshihiro; Hirai, Shinji; Li, Jihua; Li, Te

    2014-01-01

    The decomposition of dolomite into CaO and MgO was performed at 1073 K in vacuum and at 1273 K in an Ar atmosphere. The dolomite calcined in vacuum was found to have a higher specific surface area and a higher micropore volume when compared to the dolomite calcined in the Ar atmosphere. These pyrolysis products of dolomite were reacted with CO2 at 673 K for 21.6 ks. On the absorption of CO2, the formation of CaCO3 was observed. The degree of absorption of the dolomite calcined in vacuum was determined to be above 50%, which was higher than the degree of absorption of the dolomite calcined in the Ar atmosphere. The CO2 absorption and release procedures were repeated three times for the dolomite calcined in vacuum. The specific surface area and micropore volume of calcined dolomite decreased with successive repetitions of the CO2 absorption and release cycles leading to a decrease in the degree of absorption of CO2.

  7. Thermodynamical aspects of running vacuum models

    Energy Technology Data Exchange (ETDEWEB)

    Lima, J.A.S. [Universidade de Sao Paulo, Departamento de Astronomia, Sao Paulo (Brazil); Basilakos, Spyros [Academy of Athens, Research Center for Astronomy and Applied Mathematics, Athens (Greece); Sola, Joan [Univ. de Barcelona, High Energy Physics Group, Dept. d' Estructura i Constituents de la Materia, Institut de Ciencies del Cosmos (ICC), Barcelona, Catalonia (Spain)

    2016-04-15

    The thermal history of a large class of running vacuum models in which the effective cosmological term is described by a truncated power series of the Hubble rate, whose dominant term is Λ(H) ∝ H{sup n+2}, is discussed in detail. Specifically, by assuming that the ultrarelativistic particles produced by the vacuum decay emerge into space-time in such a way that its energy density ρ{sub r} ∝ T{sup 4}, the temperature evolution law and the increasing entropy function are analytically calculated. For the whole class of vacuum models explored here we find that the primeval value of the comoving radiation entropy density (associated to effectively massless particles) starts from zero and evolves extremely fast until reaching a maximum near the end of the vacuum decay phase, where it saturates. The late-time conservation of the radiation entropy during the adiabatic FRW phase also guarantees that the whole class of running vacuum models predicts the same correct value of the present day entropy, S{sub 0} ∝ 10{sup 87}-10{sup 88} (in natural units), independently of the initial conditions. In addition, by assuming Gibbons¨CHawking temperature as an initial condition, we find that the ratio between the late-time and primordial vacuum energy densities is in agreement with naive estimates from quantum field theory, namely, ρ{sub Λ0}/ρ{sub ΛI} 10{sup -123}. Such results are independent on the power n and suggests that the observed Universe may evolve smoothly between two extreme, unstable, non-singular de Sitter phases. (orig.)

  8. Challenges in industrial fermentation technology research

    DEFF Research Database (Denmark)

    Formenti, Luca Riccardo; Nørregaard, Anders; Bolic, Andrijana;

    2014-01-01

    Industrial fermentation processes are increasingly popular, and are considered an important technological asset for reducing our dependence on chemicals and products produced from fossil fuels. However, despite their increasing popularity, fermentation processes have not yet reached the same...... engineering challenges: scaling up and scaling down fermentation processes, the influence of morphology on broth rheology and mass transfer, and establishing novel sensors to measure and control insightful process parameters. The greatest emphasis is on the challenges posed by filamentous fungi, because...

  9. Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation and dilution crystallization

    Institute of Scientific and Technical Information of China (English)

    GAO Sujun; ZHANG Daijia; SUN Yaqin; XIU Zhilong

    2007-01-01

    The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol.In this paper,the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investigated.The broth was first filtered by ultrafiltration,and 99%of cells,89.4% of proteins and 69% of nucleic acids were removed.The obtained broth was further condensed by vacuum distillation,and then alcohol was added.The macromolecular impurities,such as nucleic acids,polysaccharides and proteins,were precipitated,and inorganic and organic salts were crystallized.The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to tivity decreased by 97.4%,89.7% and 95.8%,respectively,compared with the fermentative broth.The influences of pH and water content in condensed broth on alcohol precipitation and dilution crystallization were also investigated.The experimental results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth.

  10. Virtualities of quark and gluon in QCD vacuum

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The non-local vacuum condensates of quantum chromodynamics (QCD) describe the distributions of quarks and gluons in the non-perturbative QCD vacuum state. Physically, this means that vacuum quarks and gluons have a nonzero mean-squared momentum in the vacuum, called virtuality. The quark virtuality is given by the ratio of the local quark-gluon mixed vacuum condensate to the quark local vacuum condensate. The gluon virtuality is expressed by gluon vacuum condensates and four-quark vacuum condensates. We study the two virtualities by solving Dyson-Schwinger Equations and calculating quark and gluon vacuum condensates. Our theoretical results for quark virtuality are in good agreement with many other theoretical model predictions such as QCD sum rules and lattice QCD calculations. Our calculation on gluon virtuality is initial and the results are quite interesting.

  11. Fermented Meat Products%发酵肉制品

    Institute of Scientific and Technical Information of China (English)

    凌静

    2008-01-01

    This article introduced the types,characteristics of the fermented meat product and the research situation of the domestic and foreign fermented meat product.It also indicated the developing prospect of the fermented meat products.

  12. Microbial fermented tea - a potential source of natural food preservatives

    NARCIS (Netherlands)

    Mo, H.Z.; Yang Zhu, Yang; Chen, Z.M.

    2008-01-01

    Antimicrobial activities of microbial fermented tea are much less known than its health beneficial properties. These antimicrobial activities are generated in natural microbial fermentation process with tea leaves as substrates. The antimicrobial components produced during the fermentation process h

  13. Microbial fermented tea - a potential source of natural food preservatives

    NARCIS (Netherlands)

    Mo, H.Z.; Yang Zhu, Yang; Chen, Z.M.

    2008-01-01

    Antimicrobial activities of microbial fermented tea are much less known than its health beneficial properties. These antimicrobial activities are generated in natural microbial fermentation process with tea leaves as substrates. The antimicrobial components produced during the fermentation process

  14. Fermentation characteristics of yeasts isolated from traditionally fermented masau (Ziziphus mauritiana) fruits

    NARCIS (Netherlands)

    Nyanga, L.K.; Nout, M.J.R.; Smid, E.J.; Boekhout, T.; Zwietering, M.H.

    2013-01-01

    Yeast strains were characterized to select potential starter cultures for the production of masau fermented beverages. The yeast species originally isolated from Ziziphus mauritiana (masau) fruits and their traditionally fermented fruit pulp in Zimbabwe were examined for their ability to ferment

  15. NaCl-Added Soybean Fermentation and Post-Fermentation Moisture Modulation

    NARCIS (Netherlands)

    Rakshit, M.; Nout, M.J.R.; Sarkar, P.K.

    2015-01-01

    The present study aimed to evaluate the effect of adding NaCl prior to fermentation and moisture reduction after the fermentation on the safety and shelf life of kinema, a Bacillus-fermented soybean food. The physicochemical parameters of kinema decreased with an increase in the concentration of NaC

  16. The QCD vacuum probed by overlap fermions

    CERN Document Server

    Weinberg, V; Koller, K; Koma, Y; Schierholz, G; Streuer, T

    2006-01-01

    We summarize different uses of the eigenmodes of the Neuberger overlap operator for the analysis of the QCD vacuum, here applied to quenched configurations simulated by means of the Luescher-Weisz action. We describe the localization and chiral properties of the lowest modes. The overlap-based topological charge density (with and without UV-filtering) is compared with the results of UV-filtering for the field strength tensor. The latter allows to identify domains of good (anti-)selfduality. All these techniques together lead to a dual picture of the vacuum, unifying the infrared instanton picture with the presence of singular defects co-existent at different scales.

  17. Tachyon Vacuum in Cubic Superstring Field Theory

    CERN Document Server

    Erler, Theodore

    2008-01-01

    In this paper we give an exact analytic solution for tachyon condensation in the modified (picture 0) cubic superstring field theory. We prove the absence of cohomology and, crucially, reproduce the correct value for the D-brane tension. The solution is surprising for two reasons: First, the existence of a tachyon vacuum in this theory has not been definitively established in the level expansion. Second, the solution {\\it vanishes} in the GSO$(-)$ sector, implying a ``tachyon vacuum'' solution exists even for a {\\it BPS} D-brane.

  18. Catalysis of Schwinger Vacuum Pair Production

    CERN Document Server

    Dunne, Gerald V; Schützhold, Ralf

    2009-01-01

    We propose a new catalysis mechanism for non-perturbative vacuum electron-positron pair production, by superimposing a plane-wave X-ray probe beam with a strongly focused optical laser pulse, such as is planned at the Extreme Light Infrastructure (ELI) facility. We compute the absorption coefficient arising from vacuum polarization effects for photons below threshold in a strong electric field. This set-up should facilitate the (first) observation of this non-perturbative QED effect with planned light sources such as ELI yielding an envisioned intensity of order 10^{26}W/cm^2.

  19. Higgs Vacuum Stability and Modified Chaotic Inflation

    CERN Document Server

    Saha, Abhijit Kumar

    2016-01-01

    The issue of electroweak vacuum stability is studied in presence of a scalar field which participates in modifying the minimal chaotic inflation model. It is shown that the threshold effect on the Higgs quartic coupling originating from the Higgs-inflaton sector interaction can essentially make the electroweak vacuum stable upto the Planck scale. On the other hand we observe that the new physics parameters in this combined framework are enough to provide deviation from the minimal chaotic inflation predictions so as to keep it consistent with recent observation by Planck 2015.

  20. The fate of the Higgs vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Burda, Philipp [Racah Institute of Physics, Hebrew University,Jerusalem 91904 (Israel); Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Gregory, Ruth [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Perimeter Institute,31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada); Moss, Ian G. [School of Mathematics and Statistics, Newcastle University,Newcastle Upon Tyne, NE1 7RU (United Kingdom)

    2016-06-06

    We have recently suggested that tiny black holes can act as nucleation seeds for the decay of the metastable Higgs vacuum. Previous results applied only to the nucleation of thin-wall bubbles, and covered a very small region of parameter space. This paper considers bubbles of arbitrary profile and reaches the same conclusion: black holes seed rapid vacuum decay. Seeded and unseeded nucleation rates are compared, and the gravitational back reaction of the bubbles is taken into account. The evolution of the bubble interior is described for the unseeded nucleation. Results are presented for the renormalisation group improved Standard Model Higgs potential, and a simple effective model representing new physics.

  1. MEMS ion-sorption high vacuum pump

    Science.gov (United States)

    Grzebyk, T.; Knapkiewicz, P.; Szyszka, P.; Gorecka-Drzazga, A.; Dziuban, J. A.

    2016-11-01

    In the article a miniature MEMS-type ion-sorption vacuum pump has been presented. The influence of electric and magnetic field, as well as horizontal and vertical dimensions of the micropump and type of material used for electrodes on the pump properties has been investigated. It has been found that the micropump works efficiently as long as the magnetic field is higher than 0.3 T, and pumping cell is larger than 1x1x1 mm3. The pump allows generating vacuum at the level of 10-7-10-9 hPa in 100 mm3 volume.

  2. Vacuum stability in neutrinophilic Higgs doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Horita, Tomohiro, E-mail: tomohiro@het.phys.sci.osaka-u.ac.jp [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2011-11-03

    A neutrinophilic Higgs model has tiny vacuum expectation value (VEV), which can naturally explain tiny masses of neutrinos. There is a large energy scale hierarchy between a VEV of the neutrinophilic Higgs doublet and that of usual standard model-like Higgs doublet. In this Letter we at first analyze vacuum structures of Higgs potential in both supersymmetry (SUSY) and non-SUSY neutrinophilic Higgs models, and next investigate a stability of this VEV hierarchy against radiative corrections. We will show that the VEV hierarchy is stable against radiative corrections in both Dirac neutrino and Majorana neutrino scenarios in both SUSY and non-SUSY neutrinophilic Higgs doublet models.

  3. Cold Vacuum Drying (CVD) Set Point Determination

    Energy Technology Data Exchange (ETDEWEB)

    PHILIPP, B.L.

    2000-03-21

    The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated, would result in a safety event. Specifically, actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO on high tempered water MCO inlet temperature. For the MCO isolation and purge, the SCIC receives signals from MCO pressure (both positive pressure and vacuum), helium flow rate, bay high temperature switches, seismic trips and time under vacuum trips.

  4. EAMJ Dec. Repeatability.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... Results:Kappa values for four-week repeatability for the wheeze and asthma questions were 0.61 ... for logistic, cultural and ethical reasons, to use ... individual with baseline forced expiratory volume in .... period is likely to also include the effects of true ... data, the writing of the manuscript or the decision.

  5. Polymalic acid fermentation by Aureobasidium pullulans for malic acid production from soybean hull and soy molasses: Fermentation kinetics and economic analysis.

    Science.gov (United States)

    Cheng, Chi; Zhou, Yipin; Lin, Meng; Wei, Peilian; Yang, Shang-Tian

    2017-01-01

    Polymalic acid (PMA) production by Aureobasidium pullulans ZX-10 from soybean hull hydrolysate supplemented with corn steep liquor (CSL) gave a malic acid yield of ∼0.4g/g at a productivity of ∼0.5g/L·h. ZX-10 can also ferment soy molasses, converting all carbohydrates including the raffinose family oligosaccharides to PMA, giving a high titer (71.9g/L) and yield (0.69g/g) at a productivity of 0.29g/L·h in fed-batch fermentation under nitrogen limitation. A higher productivity of 0.64g/L·h was obtained in repeated batch fermentation with cell recycle and CSL supplementation. Cost analysis for a 5000 MT plant shows that malic acid can be produced at $1.10/kg from soy molasses, $1.37/kg from corn, and $1.74/kg from soybean hull. At the market price of $1.75/kg, malic acid production from soy molasses via PMA fermentation offers an economically competitive process for industrial production of bio-based malic acid.

  6. Simulations and Vacuum Tests of a CLIC Accelerating Structure

    CERN Document Server

    Garion, C

    2011-01-01

    The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

  7. Preliminary studies for the LHCb vertex detector vacuum system

    CERN Document Server

    Doets, M; Van Bakel, N; Van den Brand, J F J; van den Brand, Jo

    2000-01-01

    We lay down some general considerations which will serve as a starting point for design studies of a realistic LHCb vertex detector vacuum system. Based on these considerations, we propose a design strategy and identify issues to be further studied. In particular we try to outline some boundary conditions imposed by LHC and LHCb on the vacuum system. We discuss two possibilities for the LHCb vertex detector vacuum system. The preferred strategy uses a differentially pumped vacuum system with the silicon detectors separated from the beam line vacuum. Some estimations on static vacuum pressures and gas flows are presented.

  8. Procurement specification high vacuum test chamber and pumping system

    Energy Technology Data Exchange (ETDEWEB)

    Cormick, J. E.

    1976-05-31

    The specification establishes requirements for a high-vacuum test chamber, associated vacuum pumps, valves, controls, and instrumentation that shall be designed and fabricated for use as a test chamber for testing a closed loop Brayton Isotope Power System (BIPS) Ground Demonstration System (GDS). The vacuum system shall include all instrumentation required for pressure measurement and control of the vacuum pumping system. A general outline of the BIPS-GDS in the vacuum chamber and the preliminary piping and instrumentation interface to the vacuum chamber are shown.

  9. Flow manipulation and control methodologies for vacuum infusion processes

    Science.gov (United States)

    Alms, Justin B.

    Vacuum Infusion Processes (VIPs) are very attractive composite manufacturing processes since large structures such as fuselages and wind blades can be fabricated in a cost effective manner. In VIPs, the fabric layers are placed on a one sided mold which is closed by enveloping the entire mold with a thin plastic film and evacuating the air out. The vacuum compresses the fabric and when a resin inlet is opened, resin flows into the mold. The resin is allowed to cure before demolding the structure. However, VIPs causes non-repeatable and problematic resin filling patterns due to the heterogeneous nature of the material, nesting between various layers, and the hand labor utilized for laying up the fabric. The design of the manufacturing process routinely involves a trial and error model which make manufacturing costs and development time difficult to estimate. The clear solution to improving the reliability and robustness of VIPs is to implement a system capable of on-line flow control. While on-line flow control has been studied and developed for other composite manufacturing processes, the VIPs have been largely ignored as there are few process parameters that lend themselves to effective flow control. In this work, two new processes were discovered with the goal of on-line control of VIPs in mind. These two processes referred to as Flow Flooding Chamber (FFC) and Vacuum Induced Preform Relaxation (VIPR) will be discussed. They both employ an external vacuum chamber to influence the permeability of the fabric temporarily which allows one to redirect the resin flow to resin starved regions of the mold. The VIPR process in addition uses a low and regulated vacuum pressure in the external chamber to increase the permeability of the fabric in a controllable manner. The objective is to understand how the VIPR process affects the resin flow in order to implement it into a complete flow control and automated environment which will reduce or eliminate the variability

  10. Large volume injection in gas chromatography using the through oven transfer adsorption desorption interface operating under vacuum.

    Science.gov (United States)

    Aragón, Álvaro; Toledano, Rosa M; Gea, Sara; Cortés, José M; Vázquez, Ana M; Villén, Jesús

    2014-06-01

    The present work describes a modification of the Through Oven Transfer Adsorption Desorption (TOTAD) interface, consisting of coupling a vacuum system to reduce the consumption of the helium needed to totally remove the eluent for large volume injection (LVI) in gas chromatography (GC). Two different retention materials in the liner of the TOTAD interface were evaluated: Tenax TA, which was seen to be unsuitable for working under vacuum conditions, and polydimethylsiloxane (PDMS), which provided satisfactory repeatability as well as a good sensitivity. No variability was observed in the retention times in either case. Solutions containing organophosphorous pesticides in two different solvents, a polar (methanol/water) and a non-polar (hexane) solvent, were used to evaluate the modification. The vacuum system coupled to the TOTAD interface allowed up to 90% helium to be saved without affecting the performance.

  11. Kinetics model development of cocoa bean fermentation

    Science.gov (United States)

    Kresnowati, M. T. A. P.; Gunawan, Agus Yodi; Muliyadini, Winny

    2015-12-01

    Although Indonesia is one of the biggest cocoa beans producers in the world, Indonesian cocoa beans are oftenly of low quality and thereby frequently priced low in the world market. In order to improve the quality, adequate post-harvest cocoa processing techniques are required. Fermentation is the vital stage in series of cocoa beans post harvest processing which could improve the quality of cocoa beans, in particular taste, aroma, and colours. During the fermentation process, combination of microbes grow producing metabolites that serve as the precursors for cocoa beans flavour. Microbial composition and thereby their activities will affect the fermentation performance and influence the properties of cocoa beans. The correlation could be reviewed using a kinetic model that includes unstructured microbial growth, substrate utilization and metabolic product formation. The developed kinetic model could be further used to design cocoa bean fermentation process to meet the expected quality. Further the development of kinetic model of cocoa bean fermentation also serve as a good case study of mixed culture solid state fermentation, that has rarely been studied. This paper presents the development of a kinetic model for solid-state cocoa beans fermentation using an empirical approach. Series of lab scale cocoa bean fermentations, either natural fermentations without starter addition or fermentations with mixed yeast and lactic acid bacteria starter addition, were used for model parameters estimation. The results showed that cocoa beans fermentation can be modelled mathematically and the best model included substrate utilization, microbial growth, metabolites production and its transport. Although the developed model still can not explain the dynamics in microbial population, this model can sufficiently explained the observed changes in sugar concentration as well as metabolic products in the cocoa bean pulp.

  12. Wormholes in vacuum Brans-Dicke theory

    CERN Document Server

    Bhadra, A; Bhadra, Arunava; Sarkar, Kabita

    2005-01-01

    It is shown that among the different classes of claimed static wormhole solutions of the vacuum Brans-Dicke theory only Brans Class I solution with coupling constant $\\omega$ less than -1.5 (excluding the point $\\omega =2$) gives rise to physically viable traversable wormhole geometry. Usability of this wormhole geometry for interstellar travel has been examined.

  13. The HIE-ISOLDE Vacuum System

    CERN Document Server

    Vandoni, G; Radwan, K; Chiggiato, P

    2014-01-01

    The High Intensity and Energy Isolde (HIE-Isolde) project aims at increasing the energy and intensity of the radioactive ion beams (RIB) delivered by the present Rex-Isolde facility. Energy up to 10MeV/amu will be reached by a new post-accelerating, superconducting (SC) linac. Beam will be delivered via a HEBT to three experimental stations for nuclear physics. To keep the SC linac compact and avoid cold-warm transitions, the cryomodules feature a common beam and insulation vacuum. Radioactive ion beams require a hermetically sealed vacuum, with transfer of the effluents to the nuclear ventilation chimney. Hermetically sealed, dry, gas transfer vacuum pumps are preferred to gas binding pumps, for an optimized management of radioactive contamination risk during maintenance and intervention. The vacuum system of the SC-linac is isolated by two fast valves, triggered by fast reacting cold cathode gauges installed on the warm linac, the HEBT and the experimental stations. Rough pumping is distributed, while the H...

  14. ALICE's first vacuum bakeout a success

    CERN Multimedia

    2007-01-01

    At the beginning of April, the ALICE central beryllium beam pipe and absorber beam pipes were successfully conditioned. The installation and bakeout shell surround the beam pipe (lower left), running through the middle of the ITS and TPC. Notice the high-tech cooling system, an additional precaution to avoid overheating the ALICE detection equipment.One end of the vacuum sector during the bakeout and pure gas refill. It is unusual for a vacuum sector to end as it does in the middle of a non-accessible detector and made the installation and cabling of the bakeout equipment a more difficult procedure. Just before Easter, the first bakeout and NEG activation of experimental chambers in the LHC was carried out, followed by ultra pure gas refill. The bakeout consisted of externally heating the chambers under vacuum in order to lower their outgassing. This same heating process also activates the NEG, a coating on the inside surface of the beam vacuum chambers, which pumps the residual gas. ALICE's bakeout was pa...

  15. Exact Vacuum Solutions to the Einstein Equation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the author presents a framework for getting a series of exact vacuum solutions to the Einstein equation. This procedure of resolution is based on a canonical form of the metric. According to this procedure, the Einstein equation can be reduced to some 2-dimensional Laplace-like equations or rotation and divergence equations,which are much convenient for the resolution.

  16. Prototype Vacuum Chamber for ISR Intersection Region

    CERN Multimedia

    1974-01-01

    The vacuum chambers at the ISR interaction region had to be as transparent as possible to the secondary particles emerging from the collision points. Made from stainless steel or titanium, only a fraction of a millimeter thick, they were most delicate to handle.

  17. Graviton Corrections to Vacuum Polarization during Inflation

    CERN Document Server

    Leonard, Katie E

    2014-01-01

    We use dimensional regularization to compute the one loop quantum gravitational contribution to the vacuum polarization on de Sitter background. Adding the appropriate BPHZ counterterms gives a fully renormalized result which can be used to quantum correct Maxwell's equations. We use the Hartree approximation to argue that the electric field strengths of photons experience a secular suppression during inflation.

  18. SNS Vacuum Instrumentation and Control System

    Energy Technology Data Exchange (ETDEWEB)

    J. Y. Tang; L. A. Smart; H. C. Hseuh; P. S. Marroquin; L. R. Dalesio; S. A. Lewis; C. A. Lionberger; K. Kishiyama; D. P. Gurd; M. Hechler; W. Schneider

    2001-11-01

    The Spallation Neutron Source (SNS) vacuum instrumentation and control systems are being designed at Lawrence Berkeley National Laboratory (LBNL), Brookhaven National Laboratory (BNL), Thomas Jefferson National Accelerator facility (TJNAF) and Los Alamos National Laboratory (LANL). Each participating lab is responsible for a different section of the machine: LBNL for the Front-End section, LANL for the warm LINAC section, TJNAF for the cold LINAC section and BNL for the Ring and transfer line sections. The vacuum instrumentation and control systems are scheduled to be installed and be in operation at Oak Ridge National Laboratory in 2004 or 2005. Although the requirements vary for different sections of the machine, a collaborative effort has been made to standardize vacuum instrumentation components and the global control system interfaces. This paper summarizes the design of each sub-section of vacuum instrumentation and control system and discusses SNS standards for Ion Pump and Gauge controllers, Programmable Logic Controller (PLC) interfaces, Ladder Logic programming and the SNS global control system interfaces.

  19. Design of the EBIS vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Mapes, M.; Smart, L.; Weiss, D.

    2011-03-28

    At Brookhaven National Laboratory the Electron Beam Ion Source (EBIS) is presently being commissioned. The EBIS will be a new heavy ion pre-injector for the Relativistic Heavy Ion Collider (RHIC). The new preinjector has the potential for significant future intensity increases and can produce heavy ion beams of all species including uranium. The background pressure in the ionization region of the EBIS required to be low enough that it does not produce a significant number of ions from background gas. The pressure in the regions of the electron gun and electron collector can be higher than in the ionization region provided there is efficient vacuum separation between the sections. For injection the ions must be accelerated to 100KV by pulsing the EBIS platform. All associated equipment including the vacuum equipment on the platform is at a 100KV potential. The vacuum system design and the vacuum controls for the EBIS platform and transport system will be presented as well as the interface with the Booster Ring which has a pressure 10-11 Torr.

  20. Vacuum alignment and radiatively induced Fermi scale

    CERN Document Server

    Alanne, Tommi

    2016-01-01

    We extend the discussion about vacuum misalignment by quantum corrections in models with composite pseudo-Goldstone Higgs boson to renormalisable models with elementary scalars. As a concrete example, we propose a framework, where the hierarchy between the unification and the Fermi scale emerges radiatively. This scenario provides an interesting link between the unification and Fermi scale physics.

  1. Vacuum chamber at intersection I-6

    CERN Multimedia

    1971-01-01

    The vacuum chamber at intersection region I-6, one of these where experiments in colliding-beam physics will be taking place. The "wheels" prevent the thin wall (1.5 mm) of the chamber from collapsing. The chamber is equipped with heating tapes and its wrapped in thermal insulation. Residual gas pressure at this and other similar regions is around 10_11.

  2. True random numbers from amplified quantum vacuum.

    Science.gov (United States)

    Jofre, M; Curty, M; Steinlechner, F; Anzolin, G; Torres, J P; Mitchell, M W; Pruneri, V

    2011-10-10

    Random numbers are essential for applications ranging from secure communications to numerical simulation and quantitative finance. Algorithms can rapidly produce pseudo-random outcomes, series of numbers that mimic most properties of true random numbers while quantum random number generators (QRNGs) exploit intrinsic quantum randomness to produce true random numbers. Single-photon QRNGs are conceptually simple but produce few random bits per detection. In contrast, vacuum fluctuations are a vast resource for QRNGs: they are broad-band and thus can encode many random bits per second. Direct recording of vacuum fluctuations is possible, but requires shot-noise-limited detectors, at the cost of bandwidth. We demonstrate efficient conversion of vacuum fluctuations to true random bits using optical amplification of vacuum and interferometry. Using commercially-available optical components we demonstrate a QRNG at a bit rate of 1.11 Gbps. The proposed scheme has the potential to be extended to 10 Gbps and even up to 100 Gbps by taking advantage of high speed modulation sources and detectors for optical fiber telecommunication devices.

  3. Nonstatic vacuum strings: Exterior and interior solutions

    Energy Technology Data Exchange (ETDEWEB)

    Stein-Schabes, J.A.

    1986-06-15

    New nonstatic cylindrically symmetric solutions of Einstein's equations are presented. Some of these solutions represent stringlike objects. An exterior vacuum solution is matched to a nonvacuum interior solution for different forms of the energy-momentum tensor. They generalize the standard static string.

  4. Miniature piezo electric vacuum inlet valve

    Science.gov (United States)

    Keville, Robert F.; Dietrich, Daniel D.

    1998-03-24

    A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

  5. Quantum teleportation of entangled squeezed vacuum states

    Institute of Scientific and Technical Information of China (English)

    蔡新华

    2003-01-01

    An optical scheme for probabilistic teleporting entangled squeezed vacuum states (SVS) is proposed. In this scheme,the teleported state is a bipartite entangled SVS,and the quantum channel is a tripartite entangled SVS.The process of the teleportation is achieved by using a 50/50 symmetric beamsplitter and photon detectors with the help of classical information.

  6. Directionality switchable gain stabilized linear repeater

    Science.gov (United States)

    Ota, Takayuki; Ohmachi, Tadashi; Aida, Kazuo

    2004-10-01

    We propose a new approach to realize a bidirectional linear repeater suitable for future optical internet networks and fault location in repeater chain with OTDR. The proposed approach is the linear repeater of simple configuration whose directionality is rearranged dynamically by electrical control signal. The repeater is composed of a magneto-optical switch, a circulator, a dynamically gain stabilized unidirectional EDFA, and control circuits. The repeater directionality is rearranged as fast as 0.1ms by an electrical control pulse. It is experimentally confirmed that OTDR with the directionality switchable repeater is feasible for repeater chain. The detailed design and performance of the repeater are also discussed, including the multi-pass interference (MPI) which may arise in the proposed repeater, the effect of the MPI on SNR degradation of the repeater chain and the feed-forward EDFA gain control circuit.

  7. Selective Pressure of Temperature on Competition and Cross-Feeding within Denitrifying and Fermentative Microbial Communities.

    Science.gov (United States)

    Hanke, Anna; Berg, Jasmine; Hargesheimer, Theresa; Tegetmeyer, Halina E; Sharp, Christine E; Strous, Marc

    2015-01-01

    In coastal marine sediments, denitrification and fermentation are important processes in the anaerobic decomposition of organic matter. Microbial communities performing these two processes were enriched from tidal marine sediments in replicated, long term chemostat incubations at 10 and 25°C. Whereas denitrification rates at 25°C were more or less stable over time, at 10°C denitrification activity was unstable and could only be sustained either by repeatedly increasing the amount of carbon substrates provided or by repeatedly decreasing the dilution rate. Metagenomic and transcriptomic sequencing was performed at different time points and provisional whole genome sequences (WGS) and gene activities of abundant populations were compared across incubations. These analyses suggested that a temperature of 10°C selected for populations related to Vibrionales/Photobacterium that contributed to both fermentation (via pyruvate/formate lyase) and nitrous oxide reduction. At 25°C, denitrifying populations affiliated with Rhodobacteraceae were more abundant. The latter performed complete denitrification, and may have used carbon substrates produced by fermentative populations (cross-feeding). Overall, our results suggest that a mixture of competition-for substrates between fermentative and denitrifying populations, and for electrons between both pathways active within a single population -, and cross feeding-between fermentative and denitrifying populations-controlled the overall rate of denitrification. Temperature was shown to have a strong selective effect, not only on the populations performing either process, but also on the nature of their ecological interactions. Future research will show whether these results can be extrapolated to the natural environment.

  8. Selective pressure of temperature on competition and cross-feeding within denitrifying and fermentative microbial communities

    Directory of Open Access Journals (Sweden)

    Anna eHanke

    2016-01-01

    Full Text Available In coastal marine sediments, denitrification and fermentation are important processes in the anaerobic decomposition of organic matter. Microbial communities performing these two processes were enriched from tidal marine sediments in replicated, long term chemostat incubations at 10ºC and 25ºC. Whereas denitrification rates at 25ºC were more or less stable over time, at 10ºC denitrification activity was unstable and could only be sustained either by repeatedly increasing the amount of carbon substrates provided or by repeatedly decreasing the dilution rate. Metagenomic and transcriptomic sequencing was performed at different time points and provisional whole genome sequences and gene activities of abundant populations were compared across incubations. These analyses suggested that a temperature of 10ºC selected for populations related to Vibrionales/Photobacterium that contributed to both fermentation (via pyruvate/formate lyase and nitrous oxide reduction. At 25ºC, denitrifying populations affiliated with Rhodobacteracaea were more abundant. The latter performed complete denitrification, and may have used carbon substrates produced by fermentative populations (cross-feeding. Overall, our results suggest that a mixture of competition – for substrates between fermentative and denitrifying populations, and for electrons between both pathways active within a single population –, and cross feeding – between fermentative and denitrifying populations – controlled the overall rate of denitrification. Temperature was shown to have a strong selective effect, not only on the populations performing either process, but also on the nature of their ecological interactions. Future research will show whether these results can be extrapolated to the natural environment.

  9. Volatile fatty acids productions by mesophilic and thermophilic sludge fermentation: Biological responses to fermentation temperature.

    Science.gov (United States)

    Hao, Jiuxiao; Wang, Hui

    2015-01-01

    The volatile fatty acids (VFAs) productions, as well as hydrolases activities, microbial communities, and homoacetogens, of mesophilic and thermophilic sludge anaerobic fermentation were investigated to reveal the microbial responses to different fermentation temperatures. Thermophilic fermentation led to 10-fold more accumulation of VFAs compared to mesophilic fermentation. α-glucosidase and protease had much higher activities in thermophilic reactor, especially protease. Illumina sequencing manifested that raising fermentation temperature increased the abundances of Clostridiaceae, Microthrixaceae and Thermotogaceae, which could facilitate either hydrolysis or acidification. Real-time PCR analysis demonstrated that under thermophilic condition the relative abundance of homoacetogens increased in batch tests and reached higher level at stable fermentation, whereas under mesophilic condition it only increased slightly in batch tests. Therefore, higher fermentation temperature increased the activities of key hydrolases, raised the proportions of bacteria involved in hydrolysis and acidification, and promoted the relative abundance of homoacetogens, which all resulted in higher VFAs production.

  10. Vacuum Acceptance Tests for the UHV Room Temperature Vacuum System of the LHC during LS1

    CERN Document Server

    Cattenoz, G; Bregliozzi, G; Calegari, D; Gallagher, J; Marraffa, A; Chiggiato, P

    2014-01-01

    During the CERN Large Hadron Collider (LHC) first long shut down (LS1), a large number of vacuum tests are carried out on consolidated or newly fabricated devices. In such a way, the vacuum compatibility is assessed before installation in the UHV system of the LHC. According to the equipment’s nature, the vacuum acceptance tests consist in functional checks, leak test, outgassing rate measurements, evaluation of contaminants by Residual Gas Analysis (RGA), pumping speed measurements and qualification of the H2 sticking probability of Non-Evaporable-Getter (NEG) coating. In this paper, the methods used for the tests and the acceptance criteria are described. A summary of the measured vacuum characteristics for the tested components is also given.

  11. Spent nuclear fuel project cold vacuum drying facility vacuum and purge system design description

    Energy Technology Data Exchange (ETDEWEB)

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Vacuum and Purge System (VPS) . The SDD was developed in conjunction with HNF-SD-SNF-SAR-O02, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-002, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the VPS equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SDD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  12. Measurement-based quantum repeaters

    CERN Document Server

    Zwerger, M; Briegel, H J

    2012-01-01

    We introduce measurement-based quantum repeaters, where small-scale measurement-based quantum processors are used to perform entanglement purification and entanglement swapping in a long-range quantum communication protocol. In the scheme, pre-prepared entangled states stored at intermediate repeater stations are coupled with incoming photons by simple Bell-measurements, without the need of performing additional quantum gates or measurements. We show how to construct the required resource states, and how to minimize their size. We analyze the performance of the scheme under noise and imperfections, with focus on small-scale implementations involving entangled states of few qubits. We find measurement-based purification protocols with significantly improved noise thresholds. Furthermore we show that already resource states of small size suffice to significantly increase the maximal communication distance. We also discuss possible advantages of our scheme for different set-ups.

  13. A Repeating Fast Radio Burst

    CERN Document Server

    Spitler, L G; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-01-01

    Fast Radio Bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measures (i.e. integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of the fast radio bursts has led several authors to hypothesise that they originate in cataclysmic astrophysical events. Here we report the detection of ten additional bursts from the direction of FRB121102, using the 305-m Arecibo telescope. These new bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and wh...

  14. Extractive fermentation of acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Busche, R.M. [Bio En-Gene-Er Associates, Inc., Wilmington, DE (United States)

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  15. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  16. Scleroglucan: Fermentative Production, Downstream Processing and Applications

    Directory of Open Access Journals (Sweden)

    Shrikant A. Survase

    2007-01-01

    Full Text Available Exopolysaccharides produced by a variety of microorganisms find multifarious industrial applications in foods, pharmaceutical and other industries as emulsifiers, stabilizers, binders, gelling agents, lubricants, and thickening agents. One such exopolysaccharide is scleroglucan, produced by pure culture fermentation from filamentous fungi of genus Sclerotium. The review discusses the properties, fermentative production, downstream processing and applications of scleroglucan.

  17. Solid state fermentation for foods and beverages

    NARCIS (Netherlands)

    Chen, J.; Zhu, Y.; Nout, M.J.R.; Sarkar, P.K.

    2013-01-01

    The book systematically describes the production of solid-state fermented food and beverage in terms of the history and development of SSF technology and SSF foods, bio-reactor design, fermentation process, various substrate origins and sustainable development. It emphasizes Oriental traditional foo

  18. Solid state fermentation for foods and beverages

    NARCIS (Netherlands)

    Chen, J.; Zhu, Y.; Nout, M.J.R.; Sarkar, P.K.

    2013-01-01

    The book systematically describes the production of solid-state fermented food and beverage in terms of the history and development of SSF technology and SSF foods, bio-reactor design, fermentation process, various substrate origins and sustainable development. It emphasizes Oriental traditional

  19. Characterization of antimicrobial activity in Kombucha fermentation

    NARCIS (Netherlands)

    Sreeramulu, G.; Zhu, Y.; Knol, W.

    2001-01-01

    Fermented tea drink, Kombucha, can inhibit the growth of Shigella sonnei, Escherichia coli, Salmonella enteritidis and Salmonella typhimurium. Several metabolites were analyzed every two days during a 14-day Kombucha fermentation. Levels of acetic acid and gluconic acid were found to increase with

  20. Butanol production by fermentation: efficient bioreactors

    Science.gov (United States)

    Energy security, environmental concerns, and business opportunities in the emerging bio-economy have generated strong interest in the production of n-butanol by fermentation. Acetone butanol ethanol (ABE or solvent) batch fermentation process is product limiting because butanol even at low concentra...

  1. Method for anaerobic fermentation and biogas production

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a method for biomass processing, anaerobic fermentation of the processed biomass, and the production biogas. In particular, the invention relates to a system and method for generating biogas from anaerobic fermentation of processed organic material that comprises...

  2. CO-FERMENTATION OF KOCHO WITH BARLEY

    African Journals Online (AJOL)

    improved protein content in which kocho and barley flour were fermented for 96 hrs with barley flour. ... involving co-fermentation of kocho and barley flour for the production of nutritionally improved ..... chickpeas. J. Food Sci. 44:234-236.

  3. Handbook of Indigenous Foods Involving Alkaline Fermentation

    NARCIS (Netherlands)

    Sarkar, P.K.; Nout, M.J.R.

    2014-01-01

    This book details the basic approaches of alkaline fermentation, provides a brief history, and offers an overview of the subject. The book discusses the diversity of indigenous fermented foods involving an alkaline reaction, as well as the taxonomy, ecology, physiology, and genetics of predominant m

  4. Heretics of the False Vacuum Gravitational Effects On and Of Vacuum Decay 2

    CERN Document Server

    Banks, T

    2002-01-01

    This paper reexamines the question of vacuum decay in theories of quantum gravity. In particular it suggests that decay into stable flat or AdS vacua, never occurs. Instead, vacuum decay occurs, if at all, into a cosmological spacetime. If the latter has negative cosmological constant, it undergoes a Big Crunch, which suggests that the whole picture is inconsistent. The question of decay of de Sitter space must be very carefully defined.

  5. Study on local vacuum electron beam welding of flange rim

    CERN Document Server

    He Cheng Dan; Ying Lei; Xu Qi Jin

    2002-01-01

    Local vacuum electron beam welding and its application prospect in military and civil industry are introduced. A home made local vacuum electron beam welding is completed. Its main technical parameters and key techniques are also presented

  6. Fermented Cyprinus carpio L . Sausage

    OpenAIRE

    Ali ARSLAN; DİNÇOĞLU, Ahmet H.

    2001-01-01

    This study was carried out to investigate the appropriateness of carp (Cyprinus carpio L.) meat in the making of fermented sausage. Carp were obtained from Keban Dam Lake. Four groups of sausages were produced. The first group was made from carp meat alone, the second from mixtures of 67% carp meat and 33% red meat, the third from mixture of 50% carp meat and 50% red meat and the fourth from mixtures of 33% carp meat and 67% red meat. Samples of sausage were analysed for sensory properties...

  7. Electromagnetic vacuum of complex media II: the Lamb, the bulk and the total vacuum energy

    CERN Document Server

    Donaire, M

    2011-01-01

    We study the physical content of the electromagnetic vacuum energy of a random medium made of atomic electric dipoles. We show that the Lamb energy is only a part of it and, consequently, that the Lamb-shift derives from a partial variation of the total vacuum energy. While at leading order in the molecular density the total vacuum energy is that of the optical bulk modes and equals the free-space Lamb energy, the Lamb, the bulk and the total vacuum energies differ at second order. In contrast to the bulk energy, local field factors (LFFs) are present both in the total vacuum energy and in the Lamb energy. They yield natural cutoffs for both spectra at a wavelength of the order of the typical correlation length. Functionally, the difference between the total vacuum and the Lamb energies is due to the presence of higher order LFFs in the former. Physically, the difference is attributed to a shift in the binding energies which structure the spatial configuration of the dipoles. For a Maxwell-Garnett dielectric,...

  8. Recent advances in fermentative biohydrogen production

    Institute of Scientific and Technical Information of China (English)

    Xuemei Liu; Nanqi Ren; Funan Song; Chuanping Yang; Aijie Wang

    2008-01-01

    Hydrogen energy, as a kind of clean energy with great potential, has been a hotspot for study worldwide. Based on the recent research on biohydrogen production, this paper gives a brief review on the following aspects: fermentative hydrogen production process and the engineering control statagy, key factors affecting the efficiency of hydrogen production, such as substrates, cysteine, metal ions, anaerobic fermentation terminal products, and formic acid and ammonia. Moreover, anaerobic fermentative hydrogen-producing strain and regulation and control of enzyme gene in fermentative hydrogen production are also discussed. Finally, the prospect of anaerobic fermentative biohydrogen production is proposed in three study areas, namely developing new techniques for breeding hydrogen-producing bacteria, exploitations of more strains and gene resources, and intensifying the application of microbial molecular breeding in hydrogen production.

  9. FERMENTED MILK AS A FUNCTIONAL FOOD

    Directory of Open Access Journals (Sweden)

    Irena Rogelj

    2000-06-01

    Full Text Available Certain foods have been associated with health benefits for many years; fermented milks and yoghurt are typical examples. The health properties of these dairy products were a part of folklore until the concept of probiotics emerged, and the study of fermented milks and yoghurt containing probiotic bacteria has become more systematic. Functional foods have thus developed as a food, or food ingredient, with positive effects on host health and/or well-being beyond their nutritional value, and fermented milk with probiotic bacteria has again become the prominent representative of this new category of food. Milk alone is much more than the sum of its nutrients. It contains an array of bioactivities: modulating digestive and gastrointestinal functions, haemodynamics, controlling probiotic microbial growth, and immunoregulation. When fermented milk is enriched with probiotic bacteria and prebiotics it meets all the requirements of functional food. The possible positive effects of enriched fermented milk on host health will be reviewed.

  10. Functional genomics for food fermentation processes.

    Science.gov (United States)

    Smid, E J; Hugenholtz, J

    2010-01-01

    This review describes recent scientific and technological drivers of food fermentation research. In addition, a number of practical implications of the results of this development will be highlighted. The first part of the manuscript elaborates on the message that genome sequence information gives us an unprecedented view on the biodiversity of microbes in food fermentation. This information can be made applicable for tailoring relevant characteristics of food products through fermentation. The second part deals with the integration of genome sequence data into metabolic models and the use of these models for a number of topics that are relevant for food fermentation processes. The final part will be about metagenomics approaches to reveal the complexity and understand the functionality of undefined complex microbial consortia used in a diverse range of food fermentation processes.

  11. Lactic acid fermentation of crude sorghum extract

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, W.A.; Lee, Y.Y.; Anthony, W.B.

    1980-04-01

    Crude extract from sweet sorghum supplemented with vetch juice was utilized as the carbohydrate source for fermentative production of lactic acid. Fermentation of media containing 7% (w/v) total sugar was completed in 60-80 hours by Lactobacillus plantarum, product yield averaging 85%. Maximum acid production rates were dependent on pH, initial substrate distribution, and concentration, the rates varying from 2 to 5 g/liter per hour. Under limited medium supplementation the lactic acid yield was lowered to 67%. The fermented ammoniated product contained over eight times as much equivalent crude protein (N x 6.25) as the original medium. Unstructured kinetic models were developed for cell growth, lactic acid formation, and substrate consumption in batch fermentation. With the provision of experimentally determined kinetic parameters, the proposed models accurately described the fermentation process. 15 references.

  12. Improved anchoring of SSS with vacuum barrier to avoid displacement

    CERN Document Server

    Capatina, O; Foreste, A; Parma, V; Renaglia, T; Quesnel, J

    2009-01-01

    As presented in the previous speech, the incident in sector 3-4 of the LHC caused a high pressure build-up inside the cryostat insulation vacuum resulting in high longitudinal forces acting on the insulation vacuum barriers. This resulted in braking floor and floor fixations of the SSS with vacuum barrier. The strategy of improving anchoring of SSS with vacuum barrier to avoid displacement is presented and discussed.

  13. Influence of Photon Mass on Vacuum Birefringence Experiment

    Institute of Scientific and Technical Information of China (English)

    CHEN Min; SHAO Cheng-Gang

    2007-01-01

    Influence of photon mass on vacuum birefringence experiment is analysed according to the nonlinearities of vacuum quantum electrodynamics for the light propagation through an intense electromagnetic field.It is shown that although the photon mass will cause a change of the refractive indices n⊥ and n(‖) of vacuum birefringence,the difference n(‖)-n⊥is unchanged,which means that the effect of photon mass cannot be observed in vacuum birefringence experiment.

  14. Improvement in the bioreactor specific productivity by coupling continuous reactor with repeated fed-batch reactor for acetone-butanol-ethanol production.

    Science.gov (United States)

    Setlhaku, Mpho; Brunberg, Sina; Villa, Eva Del Amor; Wichmann, Rolf

    2012-10-15

    In comparison to the different fermentation modes for the production of acetone, butanol and ethanol (ABE) researched to date, the continuous fermentation is the most economically favored. Continuous fermentation with two or more reactor cascade is reported to be the most efficient as it results in a more stable solvent production process. In this work, it is shown that a continuous (first-stage) reactor coupled to a repeated fed-batch (second stage) is superior to batch and fed-batch fermentations, including two-stage continuous fermentation. This is due to the efficient catalyst use, reported through the specific product rate and rapid glucose consumption rate. High solvents are produced at 19.4 g(ABE) l⁻¹, with volumetric productivities of 0.92 g(butanol) l⁻¹ h⁻¹ and 1.47 g(ABE) l ⁻¹ h⁻¹. The bioreactor specific productivities of 0.62 and 0.39 g g⁻¹(cdw) h⁻¹ obtained show a high catalyst activity. This new process mode has not been reported before in the development of ABE fermentation and it shows great potential and superiority to the existing fermentation methods. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Appropriate starter culture technologies for small-scale fermentation in developing countries.

    Science.gov (United States)

    Holzapfel, W H

    2002-05-25

    Modern food biotechnology has moved a long way since ancient times of empirical food fermentations. Preservation and safeguarding of food are, however, still major objectives of fermentation. In addition, other aspects, such as wholesomeness, acceptability and overall quality, have become increasingly important and valued features to consumers even in developing countries where old traditions and cultural particularities in food fermentations are generally well maintained. Due to limitations in infrastructure and existing low technologies, rural areas in most developing countries have not been able to keep abreast of global developments toward industrialisation. At the same time, fermented foods play a major role in the diet of numerous regions in Africa and Asia. In many traditional approaches, the advantages of some form of inoculation of a new batch, e.g. by back-slopping or the repeated use of the same container (e.g. a calabash) is appreciated and generally practised. Still, the benefits of small-scale starter culture application as a means of improved hygiene, safety and quality control, in support of HACCP approaches, are not yet realised in small-scale fermentation operations. Approaches and considerations for the selection of pure cultures for small-scale, low-tech applications may differ in some respects from the large-scale industrial approaches practised since 100 years. Selection criteria should take account of the substrate, technical properties of the strain, food safety requirements and quality expectations. Lack of experience in the application of starter cultures in small-scale operations and under rural conditions presents a major obstacle but also an exciting challenge to food microbiologist and technologist. Culture preservation, maintenance and distribution demand special logistic and economic considerations. Quality, safety and acceptability of traditional fermented foods may be significantly improved through the use of starter cultures

  16. 46 CFR 153.368 - Pressure-vacuum valves.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Pressure-vacuum valves. 153.368 Section 153.368 Shipping... Systems § 153.368 Pressure-vacuum valves. (a) The pressure side of a required pressure-vacuum relief valve... relief valve must meet the requirements of Subpart 162.017 of this chapter....

  17. 7 CFR 58.913 - Evaporators and vacuum pans.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Evaporators and vacuum pans. 58.913 Section 58.913....913 Evaporators and vacuum pans. All equipment used in the removal of moisture from milk or milk... Sanitary Standards for Milk and Milk Products Evaporators and Vacuum Pans. ...

  18. Test of an undulated vacuum chamber for the ISR

    CERN Multimedia

    1975-01-01

    This picture shows mechanical tests of an undulated vacuum chamber for downstream arms of ISR intersections. This chamber, made of 0.3 mm thick inconel, had inner dimensions of 150 mm by 50 mm. The deflection under vacuum is measured by dial gauges. On the left one sees the large vessel where vacuum chambers were tested at pressures above atmospheric pressure.

  19. 21 CFR 884.5070 - Vacuum abortion system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vacuum abortion system. 884.5070 Section 884.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... § 884.5070 Vacuum abortion system. (a) Identification. A vacuum abortion system is a device designed...

  20. Structure and decay in the QED vacuum

    Science.gov (United States)

    Labun, Lance Andrew

    This thesis is a guide to a selection of the author's published work that connect and contribute to understanding the vacuum of quantum electrodynamics in strong, prescribed electromagnetic fields. This theme is elaborated over the course of two chapters: The first chapter sets the context, defining the relevant objects and conditions of the study and reviewing established knowledge upon which this study builds. The second chapter organizes and explains important results appearing in the published work. The papers 1. (Labun and Rafelski, 2009) "Vacuum Decay Time in Strong External Fields" 2. (Labun and Rafelski, 2010a) "Dark Energy Simulacrum in Nonlinear Electrodynamics" 3. (Labun and Rafelski, 2010b) "QED Energy-Momentum Trace as a Force in Astrophysics" 4. (Labun and Rafelski, 2010c) "Strong Field Physics: Probing Critical Acceleration and Inertia with Laser Pulses and Quark-Gluon Plasma" 5. (Labun and Rafelski, 2010d) "Vacuum Structure and Dark Energy" 6. (Labun and Rafelski, 2011) "Spectra of Particles from Laser-Induced Vacuum Decay" are presented in their published format as appendices. Related literature is cited throughout the body where it directly supports the content of this overview; more extensive references are found within the attached papers. This study begins with the first non-perturbative result in quantum electrodynamics, a result obtained by Heisenberg and Euler (1936) for the energy of a zero-particle state in a prescribed, long-wavelength electromagnetic field. The resulting Euler-Heisenberg effective potential generates a nonlinear theory of electromagnetism and exhibits the ability of the electrical fields to decay into electron-positron pairs. Context for phenomena arising from the Euler-Heisenberg effective potential is established by considering the energy-momentum tensor of a general nonlinear electromagnetic theory. The mass of a field configuration is defined, and I discuss two of its consequences pertinent to efforts to observe

  1. Origin and fate of repeats in bacteria.

    Science.gov (United States)

    Achaz, G; Rocha, E P C; Netter, P; Coissac, E

    2002-07-01

    We investigated 53 complete bacterial chromosomes for intrachromosomal repeats. In previous studies on eukaryote chromosomes, we proposed a model for the dynamics of repeats based on the continuous genesis of tandem repeats, followed by an active process of high deletion rate, counteracted by rearrangement events that may prevent the repeats from being deleted. The present study of long repeats in the genomes of Bacteria and Archaea suggests that our model of interspersed repeats dynamics may apply to them. Thus the duplication process might be a consequence of very ancient mechanisms shared by all three domains. Moreover, we show that there is a strong negative correlation between nucleotide composition bias and the repeat density of genomes. We hypothesise that in highly biased genomes, non-duplicated small repeats arise more frequently by random effects and are used as primers for duplication mechanisms, leading to a higher density of large repeats.

  2. Fermented liquid feed for pigs.

    Science.gov (United States)

    Missotten, Joris A M; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël A

    2010-12-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviation of the transition from the sow milk to solid feed and may also reduce the time spent to find both sources of nutrients, and secondly, that offering FLF with a low pH may strengthen the potential of the stomach as a first line of defence against possible pathogenic infections. Because of these two advantages, FLF is often stated as an ideal feed for weaned piglets. The results obtained so far are rather variable, but in general they show a better body weight gain and worse feed/gain ratio for the piglets. However, for growing-finishing pigs on average a better feed/gain ratio is found compared to pigs fed dry feed. This better performance is mostly associated with less harmful microbiota and better gut morphology. This review provides an overview of the current knowledge of FLF for pigs,dealing with the FLF itself as well as its effect on the gastrointestinal tract and animal performance.

  3. Yersinia enterocolitica in fermented sausages

    Science.gov (United States)

    Mitrović, R.; Janković, V.; Baltić, B.; Ivanović, J.

    2017-09-01

    Different types of food, among them meat, can be the cause of food-borne diseases, and infections are commonly caused by Campylobacter, Salmonella, Yersinia enterocolitica, verotoxic Escherichia coli and Listeria monocytogenes. All these bacteria, depending on a number of factors, including animal species, geographical origin, climatic factors, methods of animal breeding and meat production, could cause disease. Here, we summarise results on production of different groups of sausages produced with or without added starter culture, and contaminated with Y.enterocolitica (control sausages were not contaminated). During the ripening, changes in the microbiological status of the fermented sausages and their physical and chemical properties were monitored. For all tests, standard methods were used. In these fermented sausages, the number of Y. enterocolitica decreased during ripening. The number of Y. enterocolitica was statistically significantly lower in sausages with added starter culture on all days of the study Zoonotic pathogens in meat should be controlled through the complete production chain, from the farms to consumers, in order to reduce the probability of disease in humans. However, the necessary controls in the production chain are not the same for all bacteria.

  4. Bio-ethanol Production from Green Onion by Yeast in Repeated Batch.

    Science.gov (United States)

    Robati, Reza

    2013-09-01

    Considered to be the cleanest liquid fuel, bio-ethanol can be a reliable alternative to fossil fuels. It is produced by fermentation of sugar components of plant materials. The common onions are considered to be a favorable source of fermentation products as they have high sugar contents as well as contain various nutrients. This study focused on the effective production of ethanol from Green onion (Allium fistulosum L.) by the yeast "Saccharomyces cerevisiae" in repeated batch. The results showed that the total sugar concentration of onion juice was 68.4 g/l. The maximum rate of productivity, ethanol yield and final bio-ethanol percentage was 7 g/l/h (g ethanol per liter of onion juice per hour), 35 g/l (g ethanol per liter of onion juice) and 90 %, respectively.

  5. Recent advances to improve fermentative butanol production: genetic engineering and fermentation technology.

    Science.gov (United States)

    Zheng, Jin; Tashiro, Yukihiro; Wang, Qunhui; Sonomoto, Kenji

    2015-01-01

    Butanol has recently attracted attention as an alternative biofuel because of its various advantages over other biofuels. Many researchers have focused on butanol fermentation with renewable and sustainable resources, especially lignocellulosic materials, which has provided significant progress in butanol fermentation. However, there are still some drawbacks in butanol fermentation in terms of low butanol concentration and productivity, high cost of feedstock and product inhibition, which makes butanol fermentation less competitive than the production of other biofuels. These hurdles are being resolved in several ways. Genetic engineering is now available for improving butanol yield and butanol ratio through overexpression, knock out/down, and insertion of genes encoding key enzymes in the metabolic pathway of butanol fermentation. In addition, there are also many strategies to improve fermentation technology, such as multi-stage continuous fermentation, continuous fermentation integrated with immobilization and cell recycling, and the inclusion of additional organic acids or electron carriers to change metabolic flux. This review focuses on the most recent advances in butanol fermentation especially from the perspectives of genetic engineering and fermentation technology.

  6. Mathematical modeling of thin-layer drying of fermented and non-fermented sugarcane bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Mazutti, Marcio A.; Zabot, Giovani; Boni, Gabriela; Skovronski, Aline; de Oliveira, Debora; Di Luccio, Marco; Oliveira, J. Vladimir; Treichel, Helen [Department of Food Engineering, URI - Campus de Erechim, P.O. Box 743, CEP 99700-000, Erechim - RS (Brazil); Rodrigues, Maria Isabel; Maugeri, Francisco [Department of Food Engineering, Faculty of Food Engineering, University of Campinas - UNICAMP, P.O. Box 6121, CEP 13083-862, Campinas - SP (Brazil)

    2010-05-15

    This work reports hot-air convective drying of thin-layer fermented and non-fermented sugarcane bagasse. For this purpose, experiments were carried out in a laboratory-scale dryer assessing the effects of solid-state fermentation (SSF) on the drying kinetics of the processing material. The fermented sugarcane bagasse in SSF was obtained with the use of Kluyveromyces marxianus NRRL Y-7571. Drying experiments were carried out at 30, 35, 40 and 45 C, at volumetric air flow rates of 2 and 3 m{sup 3} h{sup -1}. The ability of ten different thin-layer mathematical models was evaluated towards representing the experimental drying profiles obtained. Results showed that the fermented sugarcane bagasse presents a distinct, faster drying, behavior from that verified for the non-fermented material at the same conditions of temperature and volumetric air flow rate. It is shown that the fermented sugarcane bagasse presented effective diffusion coefficient values of about 1.3 times higher than the non-fermented material. A satisfactory agreement between experimental data and model results of the thin-layer drying of fermented and non-fermented sugarcane bagasse was achieved at the evaluated experimental conditions. (author)

  7. [Diversity and genetic stability of yeast flocculation caused by variation of tandem repeats in yeast flocculin genes].

    Science.gov (United States)

    Yue, Feng; Guo, Xuena; He, Xiuping; Zhang, Borun

    2013-07-01

    Yeast flocculation is described as a reversible, asexual and calcium dependent process, in which cells adhere to form flocs by interaction of specific cell surface proteins named flocculins on yeast cells with mannose residues present on the cell wall of adjacent yeast cells. Yeast flocculation provides a very economical and convenient pathway for separation of yeast cells from the fermentation broth or removal of heavy metal ions from effluent. A large number of tandem repeats have been found in genes encoding flocculins, which not only have great regulatory effect on the structure and function of flocculins, generating the diversity of flocculation characteristics, but lead to genetic instability in flocculation as well for driving slippage and recombination reactions within and between FLO genes. Here, the research progress in effect of variation of tandem repeats in FLO genes on flocculation characteristics and genetic stability were reviewed to direct and promote the controllable application of flocculation in industrial fermentation process and environmental remediation.

  8. Representing the vacuum polarization on de Sitter

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Katie E.; Woodard, Richard P. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Prokopec, Tomislav [Institute of Theoretical Physics (ITP) and Spinoza Institute, Utrecht University, Postbus 80195, 3508 TD Utrecht (Netherlands)

    2013-03-15

    Previous studies of the vacuum polarization on de Sitter have demonstrated that there is a simple, noncovariant representation of it in which the physics is transparent. There is also a cumbersome, covariant representation in which the physics is obscure. Despite being unwieldy, the latter form has a powerful appeal for those who are concerned about de Sitter invariance. We show that nothing is lost by employing the simple, noncovariant representation because there is a closed form procedure for converting its structure functions to those of the covariant representation. We also present a vastly improved technique for reading off the noncovariant structure functions from the primitive diagrams. And we discuss the issue of representing the vacuum polarization for a general metric background.

  9. LHC Vacuum Upgrade during LS1

    CERN Document Server

    Jimenez, J M; Chiggiato, P; Cruikshank, P; Gallilee, M; Garion, C; Gomes, P

    2012-01-01

    The last two years of LHC operation have highlighted concerns on the levels of the dynamic vacuum in the long straight sections in presence of high intensity beams. The analysis of the existing data has shown relationship between pressures spikes and beam screen temperature oscillations or micro-sparking in the RF fingers of the bellows on one side and coincidence of pressure bumps with stimulated desorption by electron cloud, beam losses and/or thermal out gassing stimulated by higher order modes (HOM) losses. The electron cloud mitigation solutions will be adapted to the different configurations: cold/warm transitions, non-coated surfaces in direct view of beams, photoelectrons, etc. All scenarios will be presented together with their efficiencies. Additional pumping and reengineering of components will reduce the sensitivity of the vacuum system to beam losses or HOM inducing out gassing. The expected margin at nominal intensity and energy resulting from these consolidations will be summarized. Finally, th...

  10. Interacting vacuum energy in the dark sector

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, L. P. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Cuidad Universitaria, Buenos Aires 1428 (Argentina); Carneiro, S. [Instituto de Física, Uníversídade Federal da Bahia, 40210-340, Salvador, BA (Brazil)

    2015-03-26

    We analyse three cosmological scenarios with interaction in the dark sector, which are particular cases of a general expression for the energy flux from vacuum to matter. In the first case the interaction leads to a transition from an unstable de Sitter phase to a radiation dominated universe, avoiding in this way the initial singularity. In the second case the interaction gives rise to a slow-roll power-law inflation. Finally, the third scenario is a concordance model for the late-time universe, with the vacuum term decaying into cold dark matter. We identify the physics behind these forms of interaction and show that they can be described as particular types of the modified Chaplygin gas.

  11. Classical enhancement of quantum vacuum fluctuations

    CERN Document Server

    De Lorenci, V A

    2016-01-01

    We propose a mechanism for the enhancement of vacuum fluctuations by means of a classical field. The basic idea is that if an observable quantity depends quadratically upon a quantum field, such as the electric field, then the application of a classical field produces a cross term between the classical and quantum fields. This cross term may be significantly larger than the purely quantum part, but also undergoes fluctuations driven by the quantum field. We illustrate this effect in a model for lightcone fluctuations involving pulses in a nonlinear dielectric. Vacuum electric field fluctuations produce fluctuations in the speed of a probe pulse, and form an analog model for quantum gravity effects. If the material has a nonzero third-order susceptibility, then the fractional light speed fluctuations are proportional to the square of the fluctuating electric field. Hence the application of a classical electric field can enhance the speed fluctuations. We give an example where this enhancement can be an increas...

  12. Vacuum Interpretation for Supergravity M-Branes

    CERN Document Server

    Chen, C M; Sharakin, S A; Chen, Chiang-Mei; Gal'tsov, Dmitri V.; Sharakin, Sergei A.

    2000-01-01

    A non-local classical duality between the three-block truncated 11D supergravity and the 8D vacuum gravity with two commuting Killing symmetries is established. The supergravity four-form field is generated via an inverse dualisation of the corresponding Killing two-forms in six dimensions. 11D supersymmetry condition is shown to be equivalent to existence of covariantly constant spinors in eight dimensions. Thus any solution to the vacuum Einstein equations in eight dimensions depending on six coordinates and admitting Killing spinors have supersymmetric 11D-supergravity counterparts. Using this duality we derive some new brane solutions to 11D-supergravity including 1/4 supersymmetric intersecting M-branes with a NUT parameter and a dyon solution joining the M2 and M5-branes intersecting at a point.

  13. Synchronization in arrays of vacuum microdiodes

    CERN Document Server

    Ilkov, Marjan; Manolescu, Andrei; Valfells, Ágúst

    2014-01-01

    Simulations have shown that space-charge effects can lead to regular modulation of photoemitted beams in vacuum diodes with gap sizes on the order of 1 micron and accelerating voltage on the order of 1V. These modulations are in the THz regime and can be tuned by simply changing the emitter area or accelerating vacuum field. The average current in the diode corresponds to the Child-Langmuir current, but the amplitude of the oscillations is affected by various factors. Given the small size and voltage of the system, the maximum radiated AC power is expected to be small. In this work we show that an array of small emitters produces higher frequency signals than a single large emitter of same area, and how these emitters may be synchronized to produce higher power signals.

  14. Posing the first LEAR vacuum chamber

    CERN Multimedia

    1982-01-01

    The photo shows one of the four bending magnets of LEAR. They were of C-type with the opening ('mouth') to the outside of the ring (yoke to the inside). Last preparations are made before the vacuum chamber is slid through the mouth into the magnet. Stochastic cooling pickups/kickers were installed inside the chamber. One can distinguish a large number of feed-throughs on the chamber (leading to the pickup/kicker gaps). The free space in the middle of the block was left to offer room for an internal target in the magnet. This possibility was never exploited. Instead it is used here, to accommodate a pumping port for the high vacuum system. Michel Chanel (left) and Pierre Lefevre admire the mechanics at work.

  15. Electron Backscatter Diffraction in Low Vacuum Conditions

    Energy Technology Data Exchange (ETDEWEB)

    El-Dasher, B S; Torres, S G

    2008-07-17

    Most current scanning electron microscopes (SEMs) have the ability to analyze samples in a low vacuum mode, whereby a partial pressure of water vapor is introduced into the SEM chamber, allowing the characterization of nonconductive samples without any special preparation. Although the presence of water vapor in the chamber degrades electron backscatter diffraction (EBSD) patterns, the potential of this setup for EBSD characterization of nonconductive samples is immense. In this chapter we discuss the requirements, advantages and limitations of low vacuum EBSD (LV-EBSD), and present how this technique can be applied to a two-phase ceramic composite as well as hydrated biominerals as specific examples of when LV-EBSD can be invaluable.

  16. Towards measuring the Archimedes force of vacuum

    CERN Document Server

    Calloni, Enrico; De Rosa, Rosario; Di Fiore, Luciano; Esposito, Giampiero; Garufi, Fabio; Rosa, Luigi; Rovelli, Carlo; Ruggi, Paolo; Tafuri, Francesco

    2014-01-01

    We discuss the force exerted by the gravitational field on a Casimir cavity in terms of Archimedes' force of vacuum, we identify the force that can be tested against observation and we show that the present technology makes it possible to perform the first experimental tests. We motivate the use of suitable high-Tc superconductors as modulators of Archimedes' force. We analyze the possibility of using gravitational wave interferometers as detectors of the force, transported through an optical spring from the Archimedes vacuum force apparatus to the gravitational interferometers test masses to maintain the two systems well separated. We also analyze the use of balances to actuate and detect the force, we compare different solutions and discuss the most important experimental issues.

  17. Vacuum polarization and chiral lattice fermions

    Science.gov (United States)

    Randjbar-Daemi, S.; Strathdee, J.

    1996-02-01

    The vacuum polarization due to chiral fermions on a 4-dimensional Euclidean lattice is calculated according to the overlap prescription. The fermions are coupled to weak and slowly varying background gauge and Higgs fields, and the polarization tensor is given by second order perturbation theory. In this order the overlap constitutes a gauge-invariant regularization of the fermion vacuum amplitude. Its low-energy-long-wavelength behaviour can be computed explicitly and we verify that it coincides with the Feynman graph result obtainable, for example, by dimensional regularization of continuum gauge theory. In particular, the Standard Model Callan-Symanzik RG functions are recovered. Moreover, there are no residual lattice artefacts such as a dependence on Wilson-type mass parameters.

  18. Vacuum polarization and chiral lattice fermions

    CERN Document Server

    Strathdee, J A

    1995-01-01

    The vacuum polarization due to chiral fermions on a 4--dimensional Euclidean lattice is calculated according to the overlap prescription. The fermions are coupled to weak and slowly varying background gauge and Higgs fields, and the polarization tensor is given by second order perturbation theory. In this order the overlap constitutes a gauge invariant regularization of the fermion vacuum amplitude. Its low energy -- long wavelength behaviour can be computed explicitly and we verify that it coincides with the Feynman graph result obtainable, for example, by dimensional regularization of continuum gauge theory. In particular, the Standard Model Callan--Symanzik RG functions are recovered. Moreover, there are no residual lattice artefacts such as a dependence on Wilson--type mass parameters.

  19. Are there Boltzmann brains in the vacuum

    CERN Document Server

    Davenport, Matthew

    2010-01-01

    "Boltzmann brains" are human brains that arise as thermal or quantum fluctuations and last at least long enough to think a few thoughts. In many scenarios involving universes of infinite size or duration, Boltzmann brains are infinitely more common than human beings who arise in the ordinary way. Thus we should expect to be Boltzmann brains, in contradiction to observation. We discuss here the question of whether Boltzmann brains can arise as quantum fluctuations in the vacuum. Such Boltzmann brains pose an even worse problem than those arising as fluctuations in the thermal state of an exponentially expanding universe. We give several arguments for and against inclusion of vacuum Boltzmann brains in the anthropic reference class, but find neither choice entirely satisfactory.

  20. Thermal vacuum chamber repressurization with instrument purging

    Science.gov (United States)

    Woronowicz, Michael S.

    2016-09-01

    At the conclusion of cryogenic vacuum testing of the James Webb Space Telescope Optical Telescope Element Integrated Science Instrument Module (JWST-OTIS) in NASA Johnson Space Center's (JSCs) thermal vacuum (TV) Chamber A, contamination control (CC) engineers are postulating that chamber particulate material stirred up by the repressurization process may be kept from falling into the Integrated Science Instrument Module (ISIM) interior to some degree by activating instrument purge flows over some initial period before opening the chamber valves. This manuscript describes development of a series of models designed to describe this process. The models are strung together in tandem with a fictitious set of conditions to estimate overpressure evolution from which net outflow velocity behavior may be obtained. Creeping flow assumptions are then used to determine the maximum particle size that may be kept suspended above the ISIM aperture, keeping smaller particles from settling within the instrument module.