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1

Vacuum stripping of ethanol during high solids fermentation of corn.  

PubMed

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). PMID:24659046

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

2014-05-01

2

Fermentation  

NSDL National Science Digital Library

The North Carolina Community College System BioNetwork's interactive eLearning tools (IETs) are reusable chunks of training that can be deployed in a variety of courses or training programs. IETs are designed to enhance, not replace hands-on training. Learners are able to enter a hands-on lab experience better prepared and more confident. This particular IET delves into fermentation as they grow and harvest e. coli through a fermentation process on a laboratory scale. Students keep a lab notebook and receive a certificate of completion once the module is complete.

2012-03-06

3

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

PubMed

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. PMID:24387851

Neumayerová, Helena; Juránková, Jana; Saláková, Alena; Gallas, Leo; Kova??ík, Kamil; Koudela, B?etislav

2014-05-01

4

Fermentative alcohol production  

SciTech Connect

An improved fermentation process is disclosed for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases. One is a fermentor proper operated at atmospheric pressure and the other is a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using ''water load balancing'' (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

Blanch, H.W.; Cysewski, G.R.; Maiorella, B.L.; Wilke, C.R.

1982-11-16

5

Improved fermentative alcohol production  

SciTech Connect

An improved fermentation process is described for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using water load balancing (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

Wilke, C.R.; Maiorella, B.L.; Blanch, M.W.; Cysewski, G.R.

1980-11-26

6

Fermentative alcohol production  

DOEpatents

An improved fermentation process for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using "water load balancing" (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

Wilke, Charles R. (El Cerrito, CA); Maiorella, Brian L. (Berkeley, CA); Blanch, Harvey W. (Berkeley, CA); Cysewski, Gerald R. (Kennewick, WA)

1982-01-01

7

Fermentation efficiency of thermally dried kefir  

Microsoft Academic Search

Three thermal drying methods (conventional, vacuum and convective) were used for drying of kefir biomass and their effect on cell viability, fermentation rate and other kinetic parameters of lactose and whey fermentation were studied. Convective drying rate was higher than conventional and even higher than vacuum at each studied temperature (28, 33 and 38°C). After that, fermentations were performed by

Harris Papapostolou; Loulouda A. Bosnea; Athanasios A. Koutinas; Maria Kanellaki

2008-01-01

8

Fermentation process  

SciTech Connect

Fermentation process consists essentially of fermenting a 10-45% w/w aqueous slurry of granular starch for the production of ethanol with an ethanol-producing microorganism in the presence of alpha-amylase and glucoamylase, the conduct of said fermentation being characterized by low levels of dextrin and fermentable sugars in solution in the fermentation broth throughout the fermentation, and thereafter recovering enzymes from the fermentation broth for use anew in fermentation of granular starch.

Lutzen, N.W.

1982-02-23

9

Manufacturing Ethyl Acetate From Fermentation Ethanol  

NASA Technical Reports Server (NTRS)

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.

Rohatgi, Naresh K.; Ingham, John D.

1991-01-01

10

By-product inhibition effects on ethanolic fermentation by Saccharomyces cerevisiae  

Microsoft Academic Search

Inhibition by secondary fermentation products may limit the ultimate productivity of new glucose to ethanol fermentation processes. New processes are under development whereby ethanol is selectively removed from the fermenting broth to eliminate ethanol inhibition effects. These processes can concentrate minor secondary products to the point where they become toxic to the yeast. Vacuum fermentation selectively concentrates nonvolatile products in

B. Mairoella; Harvey W. Blanch; Charles R. Wilke

1983-01-01

11

Fermentation industry  

Microsoft Academic Search

This article reviews current literature on the fermentation industry. The reuse, recycling and recovery of by-products previously discarded as waste are mentioned, including a Swedish brewery that hopes to reduce discharge of pollutants and the production of single cell protein from a variety of fermentation wastes. The treatment of wastes to produce food substitutes and fertilizers is mentioned together with

1980-01-01

12

Fermentation industry  

SciTech Connect

This article reviews current literature on the fermentation industry. The reuse, recycling and recovery of by-products previously discarded as waste are mentioned, including a Swedish brewery that hopes to reduce discharge of pollutants and the production of single cell protein from a variety of fermentation wastes. The treatment of wastes to produce food substitutes and fertilizers is mentioned together with treatment methods used in distilleries, wineries and in the pharmaceutical industry. (87 References)

Irvine, R.L.

1980-06-01

13

Fermenting Beer Vs. Fermenting Vaccines  

NSDL National Science Digital Library

Listener Luci Levesque from Augusta, Maine, heard that vaccines are made in fermenters, devices normally associated with beer. She asks, whats the connection? We turned to microbiologist Agnes Day of Howard University College of Medicine.

Science Update (AAAS;)

2006-05-30

14

Fermentation Industry.  

ERIC Educational Resources Information Center

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)

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

1978-01-01

15

Ethanol production by bacterial fermentation  

SciTech Connect

The goal of this study is to develop and optimize the process technology for the production of ethanol using the bacteria Zymomonas mobilis. Specifically, the process and operating conditions will be studied to maximize the yield of ethanol. The experimental design is described using both batch and continuous cultures with glucose as the substrate. Separation methods, therefore, will be developed to remove the alcohol from the fermentation media to prevent the inhibitory effects of ethanol on Z. mobilis. Vacuum fermentation and solvent extraction can be used to separate the alcohol from the media. Kinetic data will be obtained from both the batch and continuous fermentors. The kinetic data can be correlated using mathematical models. Mathematical models for Z. mobilis will be developed for the effect of pH, temperature and nutrient composition on the specific growth rate. A model will also be developed to account for the possible product inhibition by ethanol. Dynamic tests will also be conducted on the continuous system to determine how fast the fermentation will respond to environmental changes. The simultaneous hydrolysis of cellulose to glucose and fermentation of glucose to ethanol is one of the most exciting possibilities. A literature survey will be made to determine the compatibility of conducting the hydrolysis reaction along with the bacterial fermentation. The final objective will be to make an economic assessment of the process of producing ethanol using Z. mobilis.

King, F.G.

1985-01-01

16

Vacuum Technology  

SciTech Connect

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.

Biltoft, P J

2004-10-15

17

Vacuum mechatronics  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

18

Vacuum Virtues  

ERIC Educational Resources Information Center

Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

Rathey, Allen

2007-01-01

19

By-product inhibition effects on ethanolic fermentation by Saccharomyces cerevisiae  

SciTech Connect

Inhibition by secondary fermentation products may limit the ultimate productivity of new glucose to ethanol fermentation processes. New processes are under development whereby ethanol is selectively removed from the fermenting broth to eliminate ethanol inhibition effects. These processes can concentrate minor secondary products to the point where they become toxic to the yeast. Vacuum fermentation selectively concentrates nonvolatile products in the fermentation broth. Membrane fermentation systems may concentrate large molecules which are sterically blocked from membrane transport. Extractive fermentation systems, employing nonpolar solvents, may concentrate small organic acids. By-product production rates and inhibition levels in continuous fermentation with Saccharomyces cerevisiae have been determined for acetaldehyde, glycerol, formic, lactic, and acetic acids, 1-propanol, 2-methyl-1-butanol, and 2,3-butanediol to assess the potential effects of these by-products on new fermentation processes. Mechanisms are proposed for the various inhibition effects observed.

Mairoella, B.; Blanch, H.W.; Wilke, C.R.

1983-01-01

20

Thermalized Vacuum and Vacuum Effects  

E-print Network

Some of the well-known effects regarding the vacuum are revisited under the formalism of the imaginary-time field theory. From these effects, they could imply the existence of one thermal vacuum in different circumstances. The imaginary-time hamiltonian of the vacuum is found to provide not only exact distribution functions in the calculations of the Casimir effect and the Van der Waals force but also cutoff functions. The thermal bath for the Unruh effect is constructed from the imaginary-time Green function. From the field theory in the curved space-time, field quantizations are defined according to different vacuum states and lead to the Hawking radiation; the introduced conformal invariance agree with the formalism of the imaginary-time field theory. The induced Green functions in the curved space-time are in accordance with those from the picture given from the thermal vacuum.

Yi-Cheng Huang

2013-11-14

21

Vacuum Gauges  

NSDL National Science Digital Library

This is a description for a learning module from Maricopa Advanced Technology Education Center. This PDF describes the module; access may be purchased by visiting the MATEC website. Semiconductor manufacturing equipment requires the use of many different types of vacuum gauges. Selection is based on range of process operations and production requirements. This MATEC module explores the theory and functionality of vacuum gauges and provides many examples of different types of gauges. The focus is on understanding the operating ranges and application constraints of each type of gauge. Mathematical equations are used to explain calibration, sensitivity, and overall operations of each type of gauge.

2012-11-28

22

Vacuum Technology: Vacuum Technology III  

NSDL National Science Digital Library

This is a link to a PDF version of lecture slides that discuss gas sources in a vacuum. The presentation explains concepts such as vapor pressure curves, thermal desorption and first and second order desorption. Keywords: Vaporization, desorption, diffusion, permeation, backstreaming

Rack, Philip D.

2012-12-12

23

Vacuum waves  

NASA Astrophysics Data System (ADS)

An exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space. They should not be confused with standard gravitational waves, since their phase velocity can exceed that of light. They resemble de Broglie waves, and may give insight to wave-particle duality.

Wesson, Paul S.

2013-05-01

24

Shelf life of packaged sliced dry fermented sausage under different temperature.  

PubMed

The aim of this study was to investigate the shelf-life of commercial sliced dry fermented sausage during storage at different temperatures. Different laminate composition was used for vacuum and nitrogen (100% N(2)) packaging. The microbiological, physico-chemical and sensory parameters were analysed during 120 days storage at 4, 22 and 37°C. Packaging materials were analysed for their barrier characteristic (oxygen permeability). Sensory quality limited the shelf-life of sliced dry fermented sausages before the limiting effects of microbial proliferation occurred. Nitrogen atmosphere packaging allowed longer storage (>120 days) than vacuum (95 days) packaged dry fermented sausages at 4°C. PMID:23305830

S?etar, Mario; Kova?i?, Edita; Kurek, Mia; Gali?, Kata

2013-04-01

25

Ferment in Technology  

ERIC Educational Resources Information Center

A pollution-reducing and energy-saving alternative to petroleum use could be the fermentation industry and other technologies based on the use of renewable resources. Expansion of the fermentation industry could reduce our dependence on petroleum, reduce growing waste disposal problems, and help solve world food shortages. (BT)

Crossland, Janice

1974-01-01

26

Modeling Wine Fermentation  

NSDL National Science Digital Library

Humans have been producing wines for thousands of years. How did wine making get started? How has it changed? The Wine Mini-Model simulation enables us to explore the basic fermentation process as well as model enhancements such as the higher alcohol tolerance of cultivated yeasts used in modern wine making. * model the fermentation process in early and modern wines

Ethel D. Stanley (Beloit College;Biology); Howard T. Odum (Beloit College;Biology); Elisabeth C. Odum (Beloit College;Biology); Virginia G. Vaughan (Beloit College;Biology)

2006-05-20

27

Factorial design and simulation for the optimization and determination of control structures for an extractive alcoholic fermentation  

Microsoft Academic Search

The design, optimization and control of an extractive alcoholic fermentation were studied. The fermentation process was coupled to a vacuum flash vessel that extracted part of the ethanol. Response surface analysis was used in combination with modelling and simulation to determine the operational conditions that maximize yield and productivity. The concepts of factorial design were used in the study of

Aline C Costa; Daniel I. P Atala; Francisco Maugeri; Rubens Maciel

2001-01-01

28

Fermentation industry. [Industrial wastes  

Microsoft Academic Search

A literature review of wastes generated from the fermentation industry, and their reuse in biomass production, animal feeds, fertilizers and building materials is presented. Several waste treatment alternatives are discussed for breweries, yeast manufacturing, distilleries, wineries, and pharmaceutical companies.

S. C. Chiesa; R. L. Irvine; J. F. Jr. Manning

1982-01-01

29

Vacuum self-magnetization?  

Microsoft Academic Search

We study vacuum properties in a strong magnetic field as the zero temperature and zero density limit of quantum statistics. For charged vector bosons (W bosons) the vacuum energy density diverges for B > Bc = mw2\\/e, leading to vacuum instability. A logarithmic divergence of vacuum magnetization is found for B = Bc, which suggests that if the magnetic field

H. Pe´rez Rojas; E. Rodri´guez Querts

2006-01-01

30

Natural vacuum electronics  

NASA Technical Reports Server (NTRS)

The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

Leggett, Nickolaus

1990-01-01

31

The Feasibility of Producing Vacuum-Packed Fermented Vegetable Products  

Microsoft Academic Search

The average intake of vegetables in Ireland falls below the recommendations of Bord Glas and FSAI. Carrots are the third most consumed vegetable in Ireland and they are an excellent source of vitamins A and B as well as phytochemicals. Lactic acid bacteria (LAB) are well-known in food for their benefits such as improvement of the nutritional value of food

Antoni Llovera

2008-01-01

32

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

Microsoft Academic Search

In this paper, a downstream process for purification of 1,3-propanediol from glycerol-based fermentation broth was investigated.\\u000a The purification of 1,3-propanediol from fermentation broth was achieved by a process combining microfiltration, charcoal\\u000a treatment, vacuum distillation, and silica gel chromatography. The broth was first filtered through hollow fiber cartridge,\\u000a wherein 98.7% of biomass was removed. Soluble proteins and other color impurities in

Pinki Anand; Rajendra Kumar Saxena; Ruchi G. Marwah

2011-01-01

33

Indian Vacuum Society: The Indian Vacuum Society  

NASA Astrophysics Data System (ADS)

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 expert members on the subject to deliver lectures and take part in devising courses in the universities. IVS publishes a quarterly called the `Bulletin of Indian Vacuum Society' since its inception, in which articles on vacuum and related topics are published. NIRVAT, news, announcements, and reports are the other features of the Bulletin. The articles in the Bulletin are internationally abstracted. The Bulletin is distributed free to all the members of the society. The society also publishes proceedings of national/international symposia and seminars, manuals, lecture notes etc. It has published a `Vacuum Directory' containing very useful information on vacuum technology. IVS has also set up its own website http://www.ivsnet.org in January 2002. The website contains information about IVS, list of members, list of EC members, events and news, abstracts of articles published in the `Bulletin of Indian Vacuum Society', utilities, announcements, reports, membership and other forms which can be completed online and also gives links to other vacuum societies. Our Society has been a member of the executive council of the International Union of Vacuum Science, Techniques and Applications (IUVSTA) and its various committees since 1970. In 1983 IVS conducted an International Symposium on Vacuum Technology and Nuclear Applications in BARC, Mumbai, under the sponsorship of IUVSTA. In 1987 IVS arranged the Triennial International Conference on Thin Films in New Delhi, where more than 200 foreign delegates participated. IVS also hosted the IUVSTA Executive Council Meeting along with the conference. The society organized yet again an International Conference on Vacuum Science and Technology and SRS Vacuum Systems at CAT, Indore in1995. IVS arranges the prestigious Professor Balakrishnan Memorial Lecture in memory of its founder vice-president. Leading scientists from India and abroad in the field are invited to deliver the talks. So far 23 lectures have been held in this series. IVS has instituted the `IVS- Professor D Y Phadke Memorial Prize' in memory of our founder presid

Saha, T. K.

2008-03-01

34

Xylose fermentation to ethanol  

SciTech Connect

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.

McMillan, J.D.

1993-01-01

35

Solid state fermentation system for production of ethanol from apple pomace  

SciTech Connect

A solid state fermentation system for the production of ethanol from apple pomace with a Montrachet strain of Saccharomyces cerevisiae is described. The yields of ethanol varied from about 29 g to more than 40 g/kg of apple pomace, depending on the samples fermented. Separation of up to 99% of the ethanol from spent qpple pomace was achieved with a rotary vacuum evaporator. Alcohol fermentation of apple pomace might be an efficient method of alleviating waste disposal problems with the concomitant production of ethanol.

Hang, Y.D.; Lee, C.Y.; Woodams, E.E.

1982-01-01

36

Educational Vacuum Trainers  

NSDL National Science Digital Library

Have you inherited a bell jar vacuum system and are scratching your head over how to set it up or are unsure of its operations or capabilities? Or do you want to do more with your bell jar vacuum? The forum on Bell Jar Vacuums - with the topic Vacuum Trainers can help you. The intent of this forum is for this to be a place where technical issues, classroom exercises, activities, etc. can be discussed. There's no endorsement by manufacturers and commercial issues are off limits. Steve Hansen (bell jar expert) gives some brief descriptions of the vacuum trainers that are or have been available over the past decade or so - Varian, MKS, Science Source, American Vacuum Society. Links are provided to various data sheets, articles and online exercises. Steve, the forum moderator has experience in all of these.Keywords: vacuum, "vacuum trainer","bell jar" and/or belljar, MKSVarian, VPAL, VTS, sputtering, plasma

Hansen, Steve

2012-07-31

37

Stainless Steel Vacuum Chambers  

Microsoft Academic Search

The vacuum properties of stainless steel are excellent. The fabrication and welding process can be handled easily by a large number of vacuum manufacturers. In particular, the use for intermediate energy light sources gives a lot of advantages, which leads to a cost effective and industrial vacuum system design. Several design solutions are compared in this paper. The common fabrication

Lothar Schulz

38

Zymomonas ethanol fermentations  

SciTech Connect

Studies on various industrial raw materials indicate that a Zymomonas process has its greatest commercial potential in fermenting starch-based substrates. High yields, productivities and ethanol concentrations can be achieved. Genetic manipulation is now being used to extend the substrate range to lactose and other carbohydrates. 31 references.

Rogers, P.L.; Goodman, A.E.; Heyes, R.E.

1984-09-01

39

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

PubMed

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). At 72 hr of fermentation, total acidity increased 11%, 17%, and 23% for tarhana samples vacumn-dried, sun-dried, and dried in the shade, respectively. Preservation methods also affected the moisture, ash, crude protein, total acidity, pH, salt, fat, reducing sugar levels, and the sensory assestment of tarhana soup (p < .01). Sensory characteristics were not significantly affected by baker's yeast in any of the preservation methods used (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. PMID:21108130

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

2010-01-01

40

Fermentation method producing ethanol  

DOEpatents

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.

Wang, Daniel I. C. (Belmont, MA); Dalal, Rajen (Chicago, IL)

1986-01-01

41

Space vacuum processing  

NASA Technical Reports Server (NTRS)

The unique ultra-vacuum environment of low-earth orbit space is to be utilized for vacuum processing of advanced semiconductor and superconductor materials through epitaxial thin-film growth. The quality of semiconductor single crystal (epitaxial) thin-films can be significantly enhanced in the space ultra-vacuum through the reduction of impurities. This will be accomplished by the development of the free-flying Wake Shield Facility presently being built by the Space Vacuum Epitaxy Center in conjunction with industry and NASA under a low-cost, short time commercial approach to space hardware development.

Ignatiev, A.; Shih, H. D.; Daniels, M.; Sega, R.; Bonner, T.

1991-01-01

42

NSLS II Vacuum System  

SciTech Connect

National Synchrotron Light Source II, being constructed at Brookhaven, is a 3-GeV, 500 mA, 3rd generation synchrotron radiation facility with ultra low emittance electron beams. The storage ring vacuum system has a circumference of 792 m and consists of over 250 vacuum chambers with a simulated average operating pressure of less than 1 x 10{sup -9} mbar. A summary of the update design of the vacuum system including girder supports of the chambers, gauges, vacuum pumps, bellows, beam position monitors and simulation of the average pressure will be shown. A brief description of the techniques and procedures for cleaning and mounting the chambers are given.

Ferreira, M.; Doom, L.; Hseuh, H.; Longo, C.; Settepani, P.; Wilson, K.; Hu, J.

2009-09-13

43

Short communication Effective purification of succinic acid from fermentation broth produced by Mannheimia succiniciproducens  

Microsoft Academic Search

The present studydeals with thedevelopmentof purificationand separation processes required toproduce thehighlypurified succinicacid from the fermentation broth produced by recombinant microorganism, Mannheimia succiniciproducens. The newly developed process consists of the pretreatment process such as reactive extraction and vacuum distillation step and the crystallization process for the highly purified succinic acid production. By-produced acids were effectively removed by the reactive extraction as

Yun Suk Huh; Young-Si Jun; Yeon Ki Hong; Hyohak Song; Sang Yup Lee; Won Hi Hong

44

Effective purification of succinic acid from fermentation broth produced by Mannheimia succiniciproducens  

Microsoft Academic Search

The present study deals with the development of purification and separation processes required to produce the highly purified succinic acid from the fermentation broth produced by recombinant microorganism, Mannheimia succiniciproducens. The newly developed process consists of the pretreatment process such as reactive extraction and vacuum distillation step and the crystallization process for the highly purified succinic acid production. By-produced acids

Yun Suk Huh; Young-Si Jun; Yeon Ki Hong; Hyohak Song; Sang Yup Lee; Won Hi Hong

2006-01-01

45

Vacuum control valve  

Microsoft Academic Search

A vacuum modulating chamber of a vacuum control valve is communicated with a diaphragm chamber of a EGR valve for controlling an amount of exhaust gas to be recirculated into combustion chambers of an engine, so that a modulated negative pressure is applied thereto. The chamber is provided with a diaphragm deflected responding to the negative pressure in the chamber.

M. Naito; K. Itou; K. Tsuzuki; K. Yano

1984-01-01

46

Working in a Vacuum  

ERIC Educational Resources Information Center

In this article, the author discusses several myths about vacuum cleaners and offers tips on evaluating and purchasing this essential maintenance tool. These myths are: (1) Amps mean performance; (2) Everyone needs high-efficiency particulate air (HEPA): (3) Picking up a "bowling ball" shows cleaning power; (4) All vacuum bags are the same; (5)…

Rathey, Allen

2005-01-01

47

Vacuum pump aids ejectors  

Microsoft Academic Search

The steam ejector\\/vacuum pump hybrid system has been operating satisfactorily since the summer of 1981. This system has essentially been as troublefree as the all-ejector system and, of course, has provided a substantial cost savings. Construction is currently under way to convert the vacuum system of another crude still which is equipped with steam ejectors and barometric condensers to the

1982-01-01

48

Vacuum Energy Decay  

E-print Network

The problem of the vacuum energy decay is studied through the analysis of the vacuum survival amplitude ${\\mathcal A}(z, z')$. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior is discussed up to first order in the coupling constant, $\\l$.

Enrique Álvarez; Roberto Vidal

2011-11-09

49

Stellarator helical vacuum vessel  

Microsoft Academic Search

A design study of a stainless steel, heavy wall, helically shaped vacuum torus has been made for use in a proposed Stellarator configuration. The study concerns itself with the shape of the vacuum vessel and the division of the vessel into components that can be machined and welded together into a helical configuration. A complication in the design requires that

Yavornik

1983-01-01

50

Yeast ecology of Kombucha fermentation  

Microsoft Academic Search

Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and

Ai Leng Teoh; Gillian Heard; Julian Cox

2004-01-01

51

Lactic acid fermented vegetable juices  

Microsoft Academic Search

Fermented foods are food substrates that are invaded or overgrown by edible microorganisms whose en- zymes, particularly amylases, proteases and lipases, hy- drolyse polysaccharides, proteins and lipids to non-toxic products with flavours, aromas and textures pleasant and attractive to the human consumer (STEINKRAUS 1997). The lactic acid fermentation of vegetable products, applied as a preservation method for the production of

J. KAROVI?OVÁ; Z. KOHAJDOVÁ

52

Fumaric acid production by fermentation.  

PubMed

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 from maleic anhydride and the fermentation process yields only 85% w/w from glucose, the latter raw material is three times cheaper. Besides, the fermentation fixes CO2. Production of fumaric acid by Rhizopus species and the involved metabolic pathways are reviewed. Submerged fermentation systems coupled with product recovery techniques seem to have achieved economically attractive yields and productivities. Future prospects for improvement of fumaric acid production include metabolic engineering approaches to achieve low pH fermentations. PMID:18214471

Roa Engel, Carol A; Straathof, Adrie J J; Zijlmans, Tiemen W; van Gulik, Walter M; van der Wielen, Luuk A M

2008-03-01

53

Fumaric acid production by fermentation  

PubMed Central

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 from maleic anhydride and the fermentation process yields only 85% w/w from glucose, the latter raw material is three times cheaper. Besides, the fermentation fixes CO2. Production of fumaric acid by Rhizopus species and the involved metabolic pathways are reviewed. Submerged fermentation systems coupled with product recovery techniques seem to have achieved economically attractive yields and productivities. Future prospects for improvement of fumaric acid production include metabolic engineering approaches to achieve low pH fermentations. PMID:18214471

Roa Engel, Carol A.; Zijlmans, Tiemen W.; van Gulik, Walter M.; van der Wielen, Luuk A. M.

2008-01-01

54

Comparative Detoxification of Vacuum Evaporation\\/Steam Stripping Combined with Overliming on Corn Stover Prehydrolyzate  

Microsoft Academic Search

Two kinds of physical methods, vacuum evaporation and steam stripping, combined with overliming (calcium hydroxide) were applied to remove inhibitors which were produced simultaneously during the pretreatment of lignocellulosic biomass. Corn stover was steam exploded; the filtrate was hydrolyzed with dilute sulfuric acid. The acid hydrolyzate was then detoxified and fermented by yeast. Physical methods could remove volatile compounds from

Jun-jun Zhu; Qiang Yong; Yong Xu; Shi-yuan Yu

2009-01-01

55

Vacuum-driven Metamorphosis  

E-print Network

We show that nonperturbative vacuum effects can produce a vacuum-driven transition from a matter-dominated universe to one in which the effective equation of state is that of radiation plus cosmological constant. The actual material content of the universe after the transition remains that of non-relativistic matter. This metamorphosis of the equation of state can be traced to nonperturbative vacuum effects that cause the scalar curvature to remain nearly constant at a well-defined value after the transition, and is responsible for the observed acceleration of the recent expansion of the universe.

Parker, L; Parker, Leonard; Raval, Alpan

1999-01-01

56

Vacuum-driven Metamorphosis  

E-print Network

We show that nonperturbative vacuum effects can produce a vacuum-driven transition from a matter-dominated universe to one in which the effective equation of state is that of radiation plus cosmological constant. The actual material content of the universe after the transition remains that of non-relativistic matter. This metamorphosis of the equation of state can be traced to nonperturbative vacuum effects that cause the scalar curvature to remain nearly constant at a well-defined value after the transition, and is responsible for the observed acceleration of the recent expansion of the universe.

Leonard Parker; Alpan Raval

1999-08-26

57

Collapse of Vacuum Bubbles in a Vacuum  

E-print Network

Motivated by the discovery of a plenitude of metastable vacua in a string landscape and the possibility of rapid tunneling between these vacua, we revisit the dynamics of a false vacuum bubble in a background de Sitter spacetime. We find that there exists a large parameter space that allows the bubble to collapse into a black hole or to form a wormhole. This may have interesting implications to inflationary physics.

Kin-Wang Ng; Shang-Yung Wang

2010-06-17

58

Welding space vacuum technology  

NASA Technical Reports Server (NTRS)

The objective was to assist the EH 42 Division in putting together a vacuum system that could attain the desired pressure and be large enough to accommodate the gas-metal arc (GMA) welding fixture apparatus. A major accomplishment was the design and fabrication of the controller/annunciator for the 4' by 8' system. It contains many safety features such as thermocouple set point relays that will only allow inlet and exit gas and vacuum valves to be operated at pre-selected system pressures, and a fail safe mode for power interruptions and operator mistakes. It is felt that significant progress was made in this research effort to weld in a vacuum environment. With continued efforts to increase the pump speeds for vacuum chambers and further studies on weld fixtures and gas inlet pressures, the NASA program will be successful.

Johnson, R. Barry

1991-01-01

59

Welding space vacuum technology  

NASA Astrophysics Data System (ADS)

The objective was to assist the EH 42 Division in putting together a vacuum system that could attain the desired pressure and be large enough to accommodate the gas-metal arc (GMA) welding fixture apparatus. A major accomplishment was the design and fabrication of the controller/annunciator for the 4' by 8' system. It contains many safety features such as thermocouple set point relays that will only allow inlet and exit gas and vacuum valves to be operated at pre-selected system pressures, and a fail safe mode for power interruptions and operator mistakes. It is felt that significant progress was made in this research effort to weld in a vacuum environment. With continued efforts to increase the pump speeds for vacuum chambers and further studies on weld fixtures and gas inlet pressures, the NASA program will be successful.

Johnson, R. Barry

1991-12-01

60

Vacuum Camera Cooler  

NASA Technical Reports Server (NTRS)

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.

Laugen, Geoffrey A.

2011-01-01

61

Vacuum control valve  

SciTech Connect

A vacuum modulating chamber of a vacuum control valve is communicated with a diaphragm chamber of a EGR valve for controlling an amount of exhaust gas to be recirculated into combustion chambers of an engine, so that a modulated negative pressure is applied thereto. The chamber is provided with a diaphragm deflected responding to the negative pressure in the chamber. The vacuum control valve is further provided with a cam member and a spring which urges the diaphragm in one direction so as to change a value at which the pressure in the vacuum modulating chamber is controlled. A push rod is movably held by a cam follower and another spring is provided for urging the push rod in the above direction. The spring force of the other spring is applied to the diaphragm, when a rotational angle of the cam member exceeds a predetermined angle, so that the negative pressure is changed rapidly.

Naito, M.; Itou, K.; Tsuzuki, K.; Yano, K.

1984-04-03

62

Bacteriophage Ecology in Commercial Sauerkraut Fermentations  

Microsoft Academic Search

Knowledge of bacteriophage ecology in vegetable fermentations is essential for developing phage control strategies for consistent and high quality of fermented vegetable products. The ecology of phages infecting lactic acid bacteria (LAB) in commercial sauerkraut fermentations was investigated. Brine samples were taken from four commercial sauerkraut fermentation tanks over a 60- or 100-day period in 2000 and 2001. A total

Z. Lu; F. Breidt; V. Plengvidhya; H. P. Fleming

2003-01-01

63

Vacuum Boundary Effects  

E-print Network

The effect of boundary conditions on the vacuum structure of quantum field theories is analysed from a quantum information viewpoint. In particular, we analyse the role of boundary conditions on boundary entropy and entanglement entropy. The analysis of boundary effects on massless free field theories points out the relevance of boundary conditions as a new rich source of information about the vacuum structure. In all cases the entropy does not increase along the flow from the ultraviolet to the infrared.

M. Asorey; J. M. Munoz-Castaneda

2008-03-18

64

Vacuum self-magnetization?  

SciTech Connect

We study vacuum properties in a strong magnetic field as the zero temperature and zero density limit of quantum statistics. For charged vector bosons (W bosons) the vacuum energy density diverges for B > B{sub c} = m{sub w}{sup 2}/e, leading to vacuum instability. A logarithmic divergence of vacuum magnetization is found for B = Bc, which suggests that if the magnetic field is large enough, it is self-consistently maintained, and this mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the instability of the ground state for B > B{sub c}{sup '} = m{sub n}{sup 2}/q also leads to the vacuum energy density divergence for fields B > B{sub c}{sup '} and to the magnetization divergence for B B{sub c}{sup '}. The possibility of virtual electron-positron pairs bosonization in strong magnetic field and the applicability of the neutral bosons model to describe the virtual positronium behavior in a magnetic field are discussed. We conjecture that this could lead to vacuum self-magnetization in QED.

Perez Rojas, H.; Rodriguez Querts, E. [Instituto de Cibernetica, Matematica y Fisica, Calle E No. 309, esq. a 15 Vedado, C. Havana (Cuba)

2006-06-19

65

Fermentation of Cellodextrins by Different Yeast Strains  

PubMed Central

The fermentation of cellodextrins by eight yeast species capable of fermenting cellobiose was monitored. Only two of these species, Torulopsis molischiana and T. wickerhamii, were able to ferment ?-glucosides with a degree of polymerization between one and six. These two species showed exocellular ?-glucosidase activity. Four other species were able to ferment cellotriose, and the last two species only fermented cellobiose. These latter six species produced a ?-glucosidase capable of attacking cellodextrins, but this enzyme was endocellular. PMID:16346606

Gonde, Pierre; Blondin, Bruno; Leclerc, Marc; Ratomahenina, Robert; Arnaud, Alain; Galzy, Pierre

1984-01-01

66

Stellarator helical vacuum vessel  

SciTech Connect

A design study of a stainless steel, heavy wall, helically shaped vacuum torus has been made for use in a proposed Stellarator configuration. The study concerns itself with the shape of the vacuum vessel and the division of the vessel into components that can be machined and welded together into a helical configuration. A complication in the design requires that a circular magnet coil be located at the minor toroidal axis and that this coil be embedded within the periphery of the vacuum vessel. The vacuum vessel has a minor toroidal axis diameter of 4 meters, a 68.6-cm shell diameter, and a 1.9-cm wall thickness. It twists about the minor toroidal axis twice in 360/sup 0/C. (An n value of 2). It is proposed that the unit be made of cylindrical segments with the ends of the cylinders cut at appropriate lengths and angles to form the helix. A mathematical derivation of the dimensions necessary to produce the required shapes of the segments has been made. Also, drawings of the vacuum vessel components have been produced on LANL's CTR CAD/CAM system. The procedure developed can be used for any value of n as dictated by physics requirements.

Yavornik, E.J.

1983-01-01

67

(Reverse) Engineering Vacuum Alignment  

E-print Network

In the presence of spontaneous symmetry breaking, the alignment of the vacuum with respect to the gauge group is often controlled by quadratically divergent operators in the low energy non-linear sigma model. In principle the magnitudes and signs of these operators can be changed by making different assumptions about the ultraviolet physics, but in practice all known ways of regulating these theories preserve the naive vacuum alignment. We show that by "integrating in" different sets of heavy spin-one fields, it is possible to UV extend certain non-linear sigma models into two distinct UV insensitive theories. These UV extensions have identical low energy degrees of freedom but different radiative potentials, making it possible to engineer two different vacuum alignments for the original non-linear sigma model. Our construction employs "non-square" theory spaces which generically violate the common lore that the preferred vacuum alignment preserves the maximal gauge symmetry. By UV extending the SO(9)/(SO(4) X SO(5)) little Higgs model, we find a radiative potential that deviates from the naive expectation but does not stabilize the correct vacuum for proper electroweak symmetry breaking.

Clifford Cheung; Jesse Thaler

2006-04-28

68

Acceleration and vacuum temperature  

NASA Astrophysics Data System (ADS)

The quantum fluctuations of an “accelerated” vacuum state, that is, vacuum fluctuations in the presence of a constant electromagnetic field, can be described by the temperature TM. Considering TM for the gyromagnetic factor g=1 we show that TM(g=1)=TU, where TU is the Unruh temperature experienced by an accelerated observer. We conjecture that both particle production and nonlinear field effects inherent in the Unruh accelerated observer case are described by the case g=1 QED of strong fields. We present rates of particle production for g=0, 1, 2 and show that the case g=1 is experimentally distinguishable from g=0, 2. Therefore, either accelerated observers are distinguishable from accelerated vacuum or there is unexpected modification of the theoretical framework.

Labun, Lance; Rafelski, Johann

2012-08-01

69

Vacuum Arc Ion Sources  

E-print Network

The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

Brown, I

2014-01-01

70

Fermentations with new recombinant organisms  

SciTech Connect

US fuel ethanol production in 1998 exceeded the record production of 1.4 billion gallons set in 1995. Most of this ethanol was produced from over 550 million bushels of corn. Expanding fuel ethanol production will require developing lower-cost feedstocks, and only lignocellulosic feedstocks are available in sufficient quantities to substitute for corn starch. Major technical hurdles to converting lignocellulose to ethanol include the lack of low-cost efficient enzymes for saccharification of biomass to fermentable sugars and the development of microorganisms for the fermentation of these mixed sugars. To date, the most successful research approaches to develop novel biocatalysts that will efficiently ferment mixed sugar syrups include isolation of novel yeasts that ferment xylose, genetic engineering of Escherichia coli and other gram negative bacteria for ethanol production, and genetic engineering of Saccharomyces cerevisiae and Zymomonas mobilis for pentose utilization. The authors have evaluated the fermentation of corn fiber hydrolyzates by the various strains developed. E. coli K011, E. coli SL40, E. coli FBR3, Zymomonas CP4 (pZB5), and Saccharomyces 1400 (pLNH32) fermented corn fiber hydrolyzates to ethanol in the range of 21--34 g/L with yields ranging from 0.41 to 0.50 g of ethanol per gram of sugar consumed. Progress with new recombinant microorganisms has been rapid and will continue with the eventual development of organisms suitable for commercial ethanol production. Each research approach holds considerable promise, with the possibility existing that different industrially hardened strains may find separate applications in the fermentation of specific feedstocks.

Bothast, R.J.; Nichols, N.N.; Dien, B.S.

1999-10-01

71

Vacuum arc deposition devices  

SciTech Connect

The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

Boxman, R.L.; Zhitomirsky, V.N. [Electrical Discharge and Plasma Laboratory, Faculty of Engineering, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978 (Israel)

2006-02-15

72

Experiments with Vacuum Tubes  

Microsoft Academic Search

IN my letter published in the last number of NATURE I omitted to say that we have compared vacuum tubes without electrodes with a tube containing water. A tube was filled about nine-tenths full of water and then sealed hermetically. It was then applied to the prime conductor of the electric machine and electrified in the same way as the

J. T. Bottomley

1881-01-01

73

Cryogenic vacuum techniques  

Microsoft Academic Search

A survey is made of the state-of-the-art in cryopumping technologies. Among the aspects of the technology reviewed are: molecular flow in nonisothermal vacuum chambers, diverse methods of cryopumping such as condensation, cryosorption at solid gas condensates, and at porous solids such as molecular sieves and activated charcoal, cryotrapping and cryogettering at metal films. Also covered are calculation of cryopump systems

R. A. Haefer

1981-01-01

74

Vacuum ultraviolet holography  

NASA Technical Reports Server (NTRS)

The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded.

Bjorklund, G. C.; Harris, S. E.; Young, J. F.

1974-01-01

75

Sorption vacuum trap  

NASA Technical Reports Server (NTRS)

Modified sorption trap for use in high vacuum systems contains provisions for online regeneration of sorbent material. Trap is so constructed that it has a number of encapsulated resistance heaters and a valving and pumping device for removing gases from heated sorbing material. Excessive downtime is eliminated with this trap.

Barrington, A. E.; Caruso, A. J.

1970-01-01

76

Vacuum thermal insulation panel  

Microsoft Academic Search

A vacuum thermal insulation panel comprises a pair of laminated plastic and aluminum sheets together with a plastic edge strip sealed to the edges of the sheets so as to define an evacuable volume in which a glass fiber mat is disposed. The insulation panel of the present invention takes advantage of the light-weight, low cost and low thermal conductivity

J. R. Young; R. M. Schreck

1984-01-01

77

Topics in vacuum decay  

NASA Astrophysics Data System (ADS)

If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of the new vacuum. The outward pressure of the truer vacuum makes the bubble expand and consequently eat away more of the old phase. In the presence of gravity this phenomenon gets more complicated and meanwhile more interesting. It can potentially have important cosmological consequences. Some aspects of this decay are studied in this thesis. Solutions with different symmetry than the generically used O(4) symmetry are studied and their actions calculated. Vacuum decay in a spatial vector field is studied and novel features like kinky domain walls are presented. The question of stability of vacua in a landscape of potentials is studied and the possible instability in large dimension of fields is shown. Finally a compactification of the Einstein-Maxwell theory is studied which can be a good lab to understand the decay rates in compactification models of arbitrary dimensions.

Masoumi, Ali

78

Langmuir vacuum and superconductivity  

SciTech Connect

It is shown that, in the 'jelly' model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

Veklenko, B. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2012-06-15

79

Welding space vacuum technology  

Microsoft Academic Search

The objective was to assist the EH 42 Division in putting together a vacuum system that could attain the desired pressure and be large enough to accommodate the gas-metal arc (GMA) welding fixture apparatus. A major accomplishment was the design and fabrication of the controller\\/annunciator for the 4' by 8' system. It contains many safety features such as thermocouple set

R. Barry Johnson

1991-01-01

80

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

PubMed

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. PMID:25005265

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

2014-09-01

81

Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.  

ERIC Educational Resources Information Center

Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

Greenslade, Thomas B., Jr.

1989-01-01

82

Yeast ecology of Kombucha fermentation.  

PubMed

Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species. PMID:15282124

Teoh, Ai Leng; Heard, Gillian; Cox, Julian

2004-09-01

83

FERMENTATION REACTIONS OF ERYSIPELOTHRIX RHUSIOPATHIAE  

PubMed Central

White, Thomas G. (U. S. Department of Agriculture, Ames, Iowa), and Richard D. Shuman. Fermentation reactions of Erysipelothrix rhusiopathiae. J. Bacteriol. 82:595–599. 1961.—A study was made to determine the effect of four different basal media, to which fermentable carbon compounds had been added, upon 22 selected strains of Erysipelothrix rhusiopathiae (insidiosa). Acid production was measured by (i) chemical indicator, (ii) change in pH, and (iii) production of titrable acidity. At least two determinations, usually four, were made for each test on each strain. The fermentation pattern varied according to the medium, the indicator, and the method of measuring acid production. Andrade's base plus serum was the most dependable medium because it permitted the least variation in the total number of different patterns. Of the three methods used to measure acid production, the chemical indicator gave the most valid and reproducible results. The within-strain variation was not extreme and most strains persisted in a given fermentation pattern under like conditions of growth and acid production. Results of the study indicated that, regardless of the medium and indicator routinely used, one should be familiar with the fermentation pattern of known strains of the erysipelas organism. PMID:14006576

White, Thomas G.; Shuman, Richard D.

1961-01-01

84

Tritium handling in vacuum systems  

SciTech Connect

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.

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

85

Vacuum Energy in Quantum Graphs  

E-print Network

We calculate the vacuum energy in quantum graphs. Vacuum energy arose in quantum physics but has an independent mathematical interest as a functional carrying information about the eigenvalue spectrum of a system. A quantum graph is a metric graph...

Wilson, Justin

2007-07-14

86

Treatment of biomass to obtain fermentable sugars  

DOEpatents

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.

Dunson, Jr., James B. (Newark, DE); Tucker, Melvin (Lakewood, CO); Elander, Richard (Evergreen, CO); Hennessey, Susan M. (Avondale, PA)

2011-04-26

87

Vacuum Frying of Carrot Chips  

Microsoft Academic Search

Vacuum frying is an alternative method to produce high quality vegetable or fruit chips. The effect of frying temperature and vacuum degree on moisture content, oil content, color, and texture of fried carrot chips were investigated. During the early stage of vacuum frying, the rate of moisture removal and oil absorption increased with increasing frying oil temperature and degree of

Liu-ping Fan; Min Zhang; Arun S. Mujumdar

2005-01-01

88

Portable vacuum object handling device  

DOEpatents

The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object.

Anderson, Gordon H. (Los Alamos, NM)

1983-08-09

89

Vacuum Energy: Myths and Reality  

E-print Network

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; zero-point energy of the vacuum between the plates in Casimir effect must gravitate, that is why the zero-point energy in the vacuum outside the plates must also gravitate; etc. All these and some other conjectures appear to be wrong when one considers the thermodynamics of the ground state of the quantum many-body system, which mimics macroscopic thermodynamics of quantum vacuum. In particular, in spite of the ultraviolet divergence of the zero-point energy, the natural value of the vacuum energy is comparable with the observed dark energy. That is why the vacuum energy is the plausible candidate for the dark energy.

G. E. Volovik

2006-04-14

90

Ethanol fermentation using novel techniques  

SciTech Connect

Potato starch, sweet potato, and Jerusalem artichoke were hydrolyzed using high pressure extrusion and/or acid and the hydrolysates were utilized as substrates for ethanol fermentation. The first extrusion at 13,000 to 40,000 psi did not completely hydrolyze the starch solution to fermentable sugar. At elevated temperatures (79-97/sup 0/C) and in the presence of HCl, the high pressure extrusion (13,000 psi) effectively hydrolyzed starch into fermentable sugars to yield 12.1, 22.4, and 30.5 dextrose equivalent (DE) in 1, 2, and 3 N HCl, respectively. Maximal reducing sugar value of 84.2 DE and 0.056% hydroxymethylfurfural (HMF) was achieved after heating 8% sweet potato slurry (SPS) in 1 N HCl at 110/sup 0/C for 15 min. The degraded SPS was then fermented at 37/sup 0/C using an alcohol-tolerant strain of Saccharomyces cerevisiae to give 41.6 g of 200 proof ethanol from 400 g fresh Georgia Red Sweet potato tuber. A maximal reducing sugar value of 83.5 fructose equivalent and 0.004% HMF was formed from Jerusalem artichoke slurry (JAS) containing 8% total solid following heating in 0.1 N HCl at 97/sup 0/C for 10 min. The degraded JAS was then fermented at 37 C and 29.1 g 200 proof ethanol was produced from 320 g fresh tuber of Jerusalem artichoke. Continuous ethanol fermentation was successfully achieved using a bioreactor where cells were immobilized onto inorganic, channeled porous alumina beads. A maximum productivity (27.0/g ethanol/l.h) was achieved with the bioreactor at 35 C using malt yeast extract broth containing 10% glucose as the feedstock. The immobilized cell system showed good operational and storage stability, and could be stored for more than five months without loss of productivities.

Kim, K.

1984-01-01

91

Methyl Glyoxal as an Intermediary in Fermentation  

Microsoft Academic Search

WHILST the earlier work on fermentation, especially Prof. Neuberg's investigation of the second form of fermentation, rendered the participation of methyl glyoxal as an intermediary stage probable, proof that methyl glyoxal is formed by systems capable of fermenting or glycolysing sugar has been obtained by the recent work of Toeniessen and Fischer (Zeits. physiol. Chem., 161, 254), Ariyama (Jour. Biol.

J. O. Girsavicius

1930-01-01

92

Compact vacuum insulation  

DOEpatents

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1993-01-01

93

Compact vacuum insulation embodiments  

DOEpatents

An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1992-01-01

94

Vacuum Structure and Potential  

E-print Network

Based on overall experimental observations, especially the pair processes, I developed a model structure of the vacuum along with a basic-particle formation scheme begun in 2000 (with collaborator P-I Johansson). The model consists in that the vacuum is, briefly, filled of neutral but polarizable vacuuons, consisting each of a p-vaculeon and n- vaculeon of charges $+e$ and $-e$ of zero rest masses but with spin motions, assumed interacting each other with a Coulomb force. The model has been introduced in full in a book (Nova Sci, 2005) and referred to in a number of journal/E-print papers. I outline in this easier accessible paper the detailed derivation of the model and a corresponding quantitative determination of the vacuuon size.

J. X. Zheng-Johansson

2007-04-02

95

An automated vacuum system  

SciTech Connect

Software tools available with the Ground Test Accelerator (GTA) control system provide the capability to express a control problem as a finite state machine. System states and transitions are expressed in terms of accelerator parameters and actions are taken based on state transitions. This is particularly useful for sequencing operations which are modal in nature or are unwieldy when implemented with conventional programming. State diagrams are automatically translated into code which is executed by the control system. These tools have been applied to the vacuum system for the GTA accelerator to implement automatic sequencing of operations. With a single request, the operator may initiate a complete pump-down sequence. He can monitor the progress and is notified if an anomaly occurs requiring intervention. The operator is not required to have detailed knowledge of the vacuum system and is protected from taking inappropriate actions. 1 ref., 6 figs.

Atkins, W.H. (Oak Ridge National Lab., TN (USA)); Vaughn, G.D. (Los Alamos National Lab., NM (USA)); Bridgman, C. (Grumman Corp., Bethpage, NY (USA))

1991-01-01

96

Vacuum tool manipulator  

DOEpatents

Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

Zollinger, William T. (3927 Almon Dr., Martinez, GA 30907)

1993-01-01

97

Integrated structure vacuum tube  

NASA Technical Reports Server (NTRS)

High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

Dimeff, J.; Kerwin, W. J. (inventors)

1976-01-01

98

Is vacuum dispersive?  

E-print Network

The question we ask is: does the speed of light {\\it{in vacuo}} depend on its frequency? While the answer is NO in the frame of classical physics, we point out that the opposite could be true if one takes into account the polarization of Dirac sea. We estimate the dependence of the index of refraction of vacuum + Dirac sea versus the wavelength of an incoming beam, and suggest a way to test this effect.

Yves Pomeau

2014-09-02

99

The vacuum energy crisis  

E-print Network

The smallness of the vacuum energy density and its near coincidence with the average matter density of the universe are naturally explained by anthropic selection. An alternative explanation, based on the cyclic model of Steinhardt and Turok, does not address the coincidence problem and is therefore less convincing. This article appeared in ``Science'' (4 May 2006) as a ``perspective'' for Steinhardt and Turok's paper in the same issue (astro-ph/0605173).

Alexander Vilenkin

2006-05-09

100

Vacuum Energy: Myths and Reality  

E-print Network

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; zero-point energy of the vacuum between the plates in Casimir effect must gravitate, that is why the zero-point energy in the vacuum outside the plates must also gravitate; etc. All these and some other conjectures appear to be wrong when one considers the thermodynamics of the ground state of the quantum many-body system, which mimics macroscopic thermodynamics of quantum vacuum. In particular, in spite of the ultraviolet divergence of the zero-point energy, the natural value of the vacuum energy is comparable with the...

Volovik, G E

2006-01-01

101

African fermented foods and probiotics.  

PubMed

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. PMID:25203619

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

2014-11-01

102

Indonesian Tap? Ketan Fermentation 1  

PubMed Central

Indonesian tapé ketan is a fermentation in which a mold, Amylomyces rouxii Calmette (Chlamydomucor oryzae Went and Prinsen Geerligs), in combination with one or more yeasts such as Endomycopsis burtonii converts steamed rice to a sweet-sour, slightly alcoholic paste. A study was made to determine the biochemical changes that occur in the substrate during fermentation. It was found that the product was ready for consumption after fermentation at 30°C for 36 to 48 h. A. rouxii used about 30% of the total rice solids, resulting in a crude protein of 12% in 96 h, whereas the combination of the mold with E. burtonii reduced total solids by 50% in 192 h, causing crude protein to increase to 16.5%. Soluble solids increased from 5 to about 67% in 36 h and decreased to 12% at 192 h with A. rouxii alone, whereas soluble solids fell to about 8% at 192 h in the fermentation with both the mold and the yeast. The mold, by itself, reduced the starch content of the rice from 78 to 10% in 48 h and to less than 2% in 144 h. The mold plus yeast reduced the starch content to about 18% in 48 h; however the “starch” content did not fall below 6% even at 192 h, presumably because the yeast was producing glycogen, which was determined along with the residual starch. With both the mold and the mold plus yeast fermentations, reducing sugars increased from less than 1% to approximately 5% in 24 h and reached maximum concentration, 16 to 17%, between 36 and 48 h. A. rouxii by itself produced a maximum of about 5.6% (vol/vol) ethanol at 96 h. The highest concentration of ethanol (8%, vol/vol) was produced by the mold plus E. burtonii at 144 h. The mold by itself reduced the starting pH from 6.3 to about 4.0 in 48 h. The combination of the mold and yeast reduced the pH to 4.1 in 144 h. The mold increased total acidity to approximately 6.2 meq of H+ per 100 ml, and the combination of the mold and yeast increased the total acidity to 7.8 meq of H+ per 100 ml in 192 h. At 48 h there was practically no difference in the volatile acidity (0.20) for the combined fermentation compared with 0.26 meq of H+ per 100 ml for the mold fermentation. The mold and at least one species of yeast were required to develop the rich aroma and flavor of typical Indonesian tapé. PMID:16345243

Cronk, T. C.; Steinkraus, K. H.; Hackler, L. R.; Mattick, L. R.

1977-01-01

103

Charged vacuum bubble stability  

NASA Astrophysics Data System (ADS)

A type of scenario is considered where electrically charged vacuum bubbles, formed from degenerate or nearly degenerate vacua separated by a thin domain wall, are cosmologically produced due to the breaking of a discrete symmetry, with the bubble charge arising from fermions residing within the domain wall. Stability issues associated with wall tension, fermion gas, and Coulombic effects for such configurations are examined. The stability of a bubble depends upon parameters such as the symmetry breaking scale and the fermion coupling. A dominance of either the Fermi gas or the Coulomb contribution may be realized under certain conditions, depending upon parameter values.

Morris, J. R.

1999-01-01

104

R&D ERL: Vacuum  

SciTech Connect

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 cryostat vacuum thermally insulating the SRF cavities need only reduce the convective heat load such that heat loss is primarily radiation through several layers of multi-layer insulation and conductive end-losses which are contained by 5{sup o}K thermal transitions. Prior to cool down rough vacuum {approx}10{sup -5} torr range is established and maintained by a dedicated turbomolecular pump station. Cryopumping by the cold mass and heat shields reduces the insulating vacuum to 10{sup -7} torr range after cool down.

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

2010-01-01

105

Vacuum vapor deposition  

NASA Technical Reports Server (NTRS)

A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate.

Poorman, Richard M. (inventor); Weeks, Jack L. (inventor)

1995-01-01

106

Accelerator Vacuum Protection System  

NASA Astrophysics Data System (ADS)

A new and elaborate automatic vacuum protection system using fast acting valve has been installed to avoid accidental venting of accelerator from experimental chamber side. To cover all the beam lines and to reduce the system cost, it has been installed at a common point from where all the seven beam lines originate. The signals are obtained by placing fast response pressure sensing gauges (HV SENSOR) near all the experimental stations. The closing time of the fast valve is 10 milli-second. The fast closing system protects only one vacuum line at a time. At IUAC, we have seven beam lines so one sensor was placed in each of the beam lines near experimental chamber and a multiplexer was incorporated into the fast closing system. At the time of experiment, the sensor of the active beam line is selected through the multiplexer and the Fast closing valve is interlocked with the selected sensor. As soon as the pressure sensor senses the pressure rise beyond a selected pressure, the signal is transferred and the fast valve closes within 10 to 12 millisecond.

Barua, Pradip; Kothari, Ashok; Archunan, M.; Joshi, Rajan

2012-11-01

107

Microbiological and fermentation characteristics of togwa, a Tanzanian fermented food.  

PubMed

Selected microbiological and metabolic characteristics of sorghum, maize, millet and maize-sorghum togwa were investigated during natural fermentation for 24 h. The process was predominated by lactic acid bacteria (LAB) and yeasts. The mesophiles, lactic acid bacteria, and yeasts increased and the Enterobacteriaceae decreased to undetectable levels within 24 h. The isolated microorganisms were tentatively identified as Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus cellobiosus, Pediococcus pentosaceus, Weissella confusa, Issatchenkia orientalis, Saccharomyces cerevisiae, Candida pelliculosa and Candida tropicalis. The pH decreased from 5.24-5.52 to 3.10-3.34. Maltose increased initially and then decreased, fructose decreased and glucose levels increased during the first 12 h of fermentation. The organic acids detected during fermentation included DL-lactic, succinic, formic, pyruvic, citric, pyroglutamic and uric acid. Lactate was the predominant acid and increased significantly with time. The volatile organic compounds (VOC) detected included acetaldehyde, 2-methyl-propanal, 2-methyl-butanal, 3-methyl-butanal, ethanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, diacetyl and acetoin. Ethanol was the predominant VOC and it increased significantly with time. PMID:12423921

Mugula, J K; Nnko, S A M; Narvhus, J A; Sørhaug, T

2003-02-15

108

Portable vacuum object handling device  

DOEpatents

The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object. 1 fig.

Anderson, G.H.

1983-08-09

109

Vacuum leak detector and method  

DOEpatents

Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

Edwards, Jr., David (7 Brown's La., Bellport, NY 11713)

1983-01-01

110

Manipulator For A Vacuum Chamber  

NASA Technical Reports Server (NTRS)

Rotary seal provides for external actuators. Positioner in vacuum employs four actuators; up/down, horizontal rotary, horizontal, and vertical rotary. External up/down and azimuthal actuators drives shaft entering vacuum chamber through sliding and rotating seal. Placement of actuator motors outside vacuum chamber reduces heat-removal load on system. Atop 2.5-cm-diameter shaft is stage supporting masses as great as 15 kg. Small motors on stage provide horizontal translation and rotation in vertical plane. Manipulator developed for calibrating plasma detectors by subjecting them to particle beams in vacuum. Standard, commercially available parts used.

Hunsaker, F.; Ogilvie, K.

1988-01-01

111

Microbiology of Anaerobic Sludge Fermentation  

PubMed Central

An anaerobic medium containing sludge supernatant fluid and glucose was used for enumeration of bacteria from the sludge fermentation. Comparison of viable counts from several separate samples consistently showed 10 to 100 times more anaerobic than aerobic bacteria. However, viable counts of the various samples differed by as much as 10 times; this variation probably reflects a change in the natural environment or sampling errors, or a combination of the two. Direct microscopic counts yielded values of about 1010/ml. The discrepancy between viable (108 to 109/ml) and direct counts may be due to large numbers of dead cells. Random isolates of representative colonies from high dilutions exhibited the ability to ferment sugars and are not likely to be methane bacteria. PMID:5645419

Mah, Robert A.; Sussman, Carol

1968-01-01

112

Biogenic amines in fermented foods  

Microsoft Academic Search

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 range of foods, including dairy products, and can occasionally accumulate in high concentrations. The consumption of food containing

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

2010-01-01

113

In situ fermentation dynamics during production of gundruk and khalpi , ethnic fermented vegetable products of the Himalayas  

Microsoft Academic Search

Gundruk is a fermented leafy vegetable and khalpi is a fermented cucumber product, prepared and consumed in the Himalayas. In situ fermentation dynamics during production of gundruk and khalpi was studied. Significant increase in population of lactic acid bacteria (LAB) was found during first few days of gundruk and khlapi fermentation, respectively. Gundruk fermentation was initiated by Lactobacillus brevis, Pediococcus

Buddhiman Tamang; Jyoti Prakash Tamang

2010-01-01

114

Bacterial synthesis gas (syngas) fermentation.  

PubMed

Acetogenic bacteria employing the Wood-Ljungdahl pathway can be used as biocatalysts in syngas fermentation for the production ofbiofuels such as ethanol or butanol as well as biocommodities such as acetate, lactate, butyrate, 2,3 butanediol, and acetone. The potential of such processes can be projected by the global syngas output, which was 70,817 megawatts thermal in 2010 and is expected to increase up to 72% in 2016. To date, different acetogens are used as commercial production strains for industrial syngas fermentations in pilot or demonstration plants (Coskata, INEOS Bio, LanzaTech) and first commercial units are expected to launch operation in the near future (INEOS Bio, LanzaTech). Considerations on potential yields are quite promising for fermentative production. New methods for metabolic engineering were established to construct novel recombinant acetogenic biocatalysts. Synthetic biology will certainly play a major role in constructing strains for commercial operations. This way, a cheap and abundant carbon source most probably replace, processes based on crude oil or sugar in the near future. PMID:24350425

Bengelsdorf, Frank R; Straub, Melanie; Dürre, Peter

2013-01-01

115

Promising ethanologens for xylose fermentation  

SciTech Connect

An economical biomass-to-ethanol process depends on the efficient conversion of both its cellulose and hemicellulose components. On a dry weight basis, the typical feedstock contains approx 25-50% (w/w) glucose, 10-30% (w/w) xylose, 15-30% (w/w) lignin, and 1-5% (w/w) of other minor pentose and hexose sugars. Although many microorganisms can ferment the glucose component in cellulose to ethanol, conversion of pentose sugars in the hemicellulose fraction, particularly xylose, has been hindered by the lack of a suitable biocatalyst. Despite the development of recombinant strains with improved fermentation performance, increased ethanol yields and concentrations and shorter fermentation times are key targets that have yet to be achieved from lignocellulosic hydrolyzates. Our objective is to develop biocatalysts for the rapid and efficient conversion of xylose by engineering key metabolic pathways in selected organisms. To identify promising biocatalysts for these efforts, we have surveyed several industrial microorganisms according to several primary traits considered to be essential, as well as a number of secondary traits considered to be desirable, in a commercial biomass-to-ethanol process.

Zhang, M.; Franden, M.A.; Newman, M. [National Renewable Energy Lab., Golden, CO (United States)] [and others

1995-12-31

116

Cosmic Vacuum Prevents Radiopanspermia  

NASA Astrophysics Data System (ADS)

The paper describes the new physical mechanism for the explanation of the irreversible damage of vegetative cells and spores of microorganisms (m/o) under space thermovacuum conditions (tvc) (vacuum+high temperatures), developed by the authors based on the published experimental data of various authors. The suggestion was made that this mechanism could inactivate most vegetative cells and spores of the m/o at the initial stage of their spontaneous migration into the cosmos from the platforms where life has originated and evolved. The authors believe the Earth and Earth-like planets to be such platforms. Such a mechanism could restrict the application of the radiopanspermia hypothesis to the explanation of the origin of life on the Earth.

Nussinov, M. D.; Lysenko, S. V.

1983-12-01

117

Vacuum thermal insulation panel  

SciTech Connect

A vacuum thermal insulation panel comprises a pair of laminated plastic and aluminum sheets together with a plastic edge strip sealed to the edges of the sheets so as to define an evacuable volume in which a glass fiber mat is disposed. The insulation panel of the present invention takes advantage of the light-weight, low cost and low thermal conductivity of plastic materials to form an evacuable volume into which a glass fiber insulating mat is disposed for support of the panel which is evacuated to provide improved thermal insulation. Additionally, a gas permeation barrier is employed on the edge strip of the panel to minimize gas permeation at its edges. A metal foil layer provides gas permeation protection through the large surface areas of the sheets themselves.

Young, J.R.; Schreck, R.M.

1984-04-24

118

Future complete vacuum spacetimes  

E-print Network

In this paper we prove a global existence theorem, in the direction of cosmological expansion, for sufficiently small perturbations of a family of spatially compact variants of the $k=-1$ Friedmann--Robertson--Walker vacuum spacetime. We use a special gauge defined by constant mean curvature slicing and a spatial harmonic coordinate condition, and develop energy estimates through the use of the Bel-Robinson energy and its higher order generalizations. In addition to the smallness condition on the data, we need a topological constraint on the spatial manifold to exclude the possibility of a non--trivial moduli space of flat spacetime perturbations, since the latter could not be controlled by curvature--based energies such as those of Bel--Robinson type. Our results also demonstrate causal geodesic completeness of the perturbed spacetimes (in the expanding direction) and establish precise rates of decay towards the background solution which serves as an attractor asymptotically.

Lars Andersson; Vincent Moncrief

2003-03-11

119

Abdominal intrauterine vacuum aspiration.  

PubMed

Evaluating and "cleaning" of the uterine cavity is probably the most performed operation in women. It is done for several reasons: abortion, evaluation of irregular bleeding in premenopausal period, and postmenopausal bleeding. Abortion is undoubtedly the number one procedure with more than 44 million pregnancies terminated every year. This procedure should not be underestimated and a careful preoperative evaluation is needed. Ideally a sensitive pregnancy test should be done together with an ultrasound in order to confirm a uterine pregnancy, excluding extra-uterine pregnancy, and to detect genital and/or uterine malformations. Three out of four abortions are performed by surgical methods. Surgical methods include a sharp, blunt, and suction curettage. Suction curettage or vacuum aspiration is the preferred method. Despite the fact that it is a relative safe procedure with major complications in less than one percent of cases, it is still responsible for 13% of all maternal deaths. All the figures have not declined in the last decade. Trauma, perforation, and bleeding are a danger triage. When there is a perforation, a laparoscopy should be performed immediately, in order to detect intra-abdominal lacerations and bleeding. The bleeding should be stopped as soon as possible in order to not destabilize the patient. When there is a perforation in the uterus, this "entrance" can be used to perform the curettage. This is particularly useful if there is trauma of the isthmus and uterine wall, and it is difficult to identify the uterine canal. A curettage is a frequent performed procedure, which should not be underestimated. If there is a perforation in the uterus, then this opening can safely be used for vacuum aspiration. PMID:25134300

Tjalma, W A A

2014-01-01

120

Water Relations in Solid-state Fermentation  

Microsoft Academic Search

For the majority of filamentous fungal species, solid-state media are the natural life media. Growth can occur on the surface,\\u000a or within the whole substrate, depending on the porosity. Industrial solid-state fermentations have been developed largely\\u000a in traditional food industries such as cheese, Oriental fermentations, fermented vegetables, meat, and other products, and\\u000a in biotechnological industries such as antibiotics and enzymes.

Patrick Gervais

121

Vacuum enhanced cutaneous biopsy instrument  

DOEpatents

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.

Collins, Joseph (St. Petersburg, FL)

2000-01-01

122

Vacuum pyrolysis of sugarcane bagasse  

Microsoft Academic Search

The objective of this study was to provide background data on sugarcane bagasse vacuum pyrolysis. Product yields and properties were investigated. Vacuum pyrolysis tests were performed at bench and pilot plant scales. The bagasse finest particles with a diameter smaller than 450 ?m were removed in order to overcome difficulties caused by their low density and high ash content. In

Abdelkader Chaala; Christian Roy

2002-01-01

123

Vacuum flash evaporated polymer composites  

DOEpatents

A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

Affinito, J.D.; Gross, M.E.

1997-10-28

124

Statistical mechanics of the vacuum  

E-print Network

The vacuum is full of virtual particles which exist for short moments of time. In this paper we construct a chaotic model of vacuum fluctuations associated with a fundamental entropic field that generates an arrow of time. The dynamics can be physically interpreted in terms of fluctuating virtual momenta. This model leads to a generalized statistical mechanics that distinguishes fundamental constants of nature.

Christian Beck

2011-12-07

125

Vacuum flash evaporated polymer composites  

DOEpatents

A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

Affinito, John D. (Kennewick, WA); Gross, Mark E. (Pasco, WA)

1997-01-01

126

Vacuum Technology for Ion Sources  

E-print Network

The basic notions of vacuum technology for ion sources are presented, with emphasis on pressure profile calculation and choice of pumping technique. A Monte Carlo code (Molflow+) for the evaluation of conductances and the vacuum-electrical analogy for the calculation of time-dependent pressure variations are introduced. The specific case of the Linac4 H- source is reviewed.

Chiggiato, P

2013-01-01

127

Vacuum Gas Tungsten Arc Welding  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

128

Fermentation Challenge: Making Ethanol from Cellulose  

NSDL National Science Digital Library

This high school or beginning undergraduate level lab demonstration and inquiry activity will introduce students to the process of fermenting cellulosic biomass into cellulosic ethanol, along with the challenges researchers face in this area. The demonstration uses a Vernier probe or balloons to measure fermentation rates of different feedstocks to begin the discussion of why some carbohydrates are easily fermented by yeast while others are not. Students can design and carry out their own labs to try to improve fermentation rates of various feedstocks. The downloadable package of materials includes 1) Teacher Instructions and Answer Key 2) Student Activities and Worksheets 3) Supplementary Materials

2012-03-09

129

PERVAPORATION MEMBRANE SYSTEMS FOR VOLATILE FERMENTATION PRODUCT RECOVERY AND DEHYDRATION  

EPA Science Inventory

The economics of fermentative production of fuels and commodity chemicals can be a strong function of the efficiency with which the fermentation products are removed from the biological media. Due to growth inhibition by some fermentation products, including ethanol, concentrati...

130

Fermentation Kinetics and Process Economics for the Production of Ethanol.  

National Technical Information Service (NTIS)

The aim of this study was to develop and optimize fermentation technology for the production of ethanol. Using glucose as the fermentable substrate, optimal fermentation parameters of pH, temperature, oxygen tension, and sugar concentration were determine...

C. R. Wilke, G. R. Cysewski

1976-01-01

131

Cosmology with decaying vacuum energy  

SciTech Connect

Motivated by recent attempts to solve the cosmological constant problem, we examine the observational consequences of a vacuum energy density which decays in time. For all times later than t approx. 1 sec, the ratio of the vacuum to the total energy density of the universe must be small. Although the vacuum cannot provide the ''missing mass'' required to close the universe today, its presence earlier in the history of the universe could have important consequences. We discuss restrictions on the vacuum energy arising from primordial nucleosynthesis, the microwave and gamma ray background spectra, and galaxy formation. A small vacuum component at the era of nucleosynthesis, 0.01 < rho/sub vac//rho/sup rad/ < 0.1, increase the number of allowed neutino species to N/sup nu/ > 5, but in some cases would severely distort the microwave spectrum. 9 refs., 3 figs.

Freese, K.; Adams, F.; Frieman, J.; Mottola, E.

1987-09-01

132

Bubbling the False Vacuum Away  

E-print Network

We investigate the role of nonperturbative, bubble-like inhomogeneities on the decay rate of false-vacuum states in two and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubble-like inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay -- known as resonant nucleation -- is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and cross-over. Possible applications are briefly discussed.

Marcelo Gleiser; Barrett Rogers; Joel Thorarinson

2007-08-28

133

Safety and quality of ready-to-eat dry fermented sausages subjected to E-beam radiation.  

PubMed

The inactivation kinetics in the death of Listeriainnocua NTC 11288 (more radioresistant than five different strains of Listeriamonocytogenes) and Salmonella Enterica serovar Enteritidis and S. enterica serovar Typhimurium by E-beam irradiation has been studied in two types of vacuum-packed RTE dry fermented sausages ("salchichon" and "chorizo") in order to optimize the sanitation treatment of these products. A treatment of 1.29kGy was calculated to reach the food safety objective (FSO) according to the "zero tolerance" criterion for the three strains. No irradiation treatment was necessary to meet the 10(2)c.f.u./g microbiological criterion for L. monocytogenes. Dry fermented sausages treated with ?2kGy had negligible sensory (appearance, odour and taste) modifications. Therefore, this treatment produces safe dry fermented sausages with similar sensory properties to the non-irradiated product. PMID:20416723

Cabeza, M C; de la Hoz, L; Velasco, R; Cambero, M I; Ordóñez, J A

2009-10-01

134

Vacuum energy, antigravity, and modern cosmology  

E-print Network

Vacuum energy, antigravity, and modern cosmology John Peacock, University of Edinburgh Loretto and zero- point energy (inevitable from uncertainty principle) ­ not the only contribution to vacuum energy;Vacuum energy: Einstein's missed chance Now: `Dark Energy' can cause the

Peacock, John

135

NCSX Vacuum Vessel Fabrication  

SciTech Connect

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 1.02?, and its contours must be within 0.188" (4.76 mm). It is scheduled for completion in January 2006.

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

136

Vacuum plasma spray coating  

NASA Technical Reports Server (NTRS)

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.

Holmes, Richard R.; Mckechnie, Timothy N.

1989-01-01

137

Vacuum energy and cosmological evolution  

E-print Network

An expanding universe is not expected to have a static vacuum energy density. The so-called cosmological constant $\\Lambda$ should be an approximation, certainly a good one for a fraction of a Hubble time, but it is most likely a temporary description of a true dynamical vacuum energy variable that is evolving from the inflationary epoch to the present day. We can compare the evolving vacuum energy with a Casimir device where the parallel plates slowly move apart ("expand"). The total vacuum energy density cannot be measured, only the effect associated to the presence of the plates, and then also their increasing separation with time. In the universe there is a nonvanishing spacetime curvature $R$ as compared to Minkowskian spacetime that is changing with the expansion. The vacuum energy density must change accordingly, and we naturally expect $\\delta\\Lambda\\sim R\\sim H^2$. A class of dynamical vacuum models that trace such rate of change can be constructed. They are compatible with the current cosmological data, and conveniently extended can account for the complete cosmic evolution from the inflationary epoch till the present days. These models are very close to the $\\Lambda$CDM model for the late universe, but very different from it at the early times. Traces of the inherent vacuum dynamics could be detectable in our recent past.

Joan Sola

2014-02-27

138

Vacuum Brazing of Accelerator Components  

NASA Astrophysics Data System (ADS)

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.

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

2012-11-01

139

Vacuum energy and cosmological evolution  

NASA Astrophysics Data System (ADS)

An expanding universe is not expected to have a static vacuum energy density. The so-called cosmological constant ? should be an approximation, certainly a good one for a fraction of a Hubble time, but it is most likely a temporary description of a true dynamical vacuum energy variable that is evolving from the inflationary epoch to the present day. We can compare the evolving vacuum energy with a Casimir device where the parallel plates slowly move apart ("expand"). The total vacuum energy density cannot be measured, only the effect associated to the presence of the plates, and then also their increasing separation with time. In the universe there is a nonvanishing spacetime curvature R as compared to Minkowskian spacetime that is changing with the expansion. The vacuum energy density must change accordingly, and we naturally expect ??˜R˜H2. A class of dynamical vacuum models that trace such rate of change can be constructed. They are compatible with the current cosmological data, and conveniently extended can account for the complete cosmic evolution from the inflationary epoch till the present days. These models are very close to the ?CDM model for the late universe, but very different from it at the early times. Traces of the inherent vacuum dynamics could be detectable in our recent past.

Solà, Joan

2014-07-01

140

Xylitol recovery from fermented sugarcane bagasse hydrolyzate  

Microsoft Academic Search

Sugarcane bagasse hemicellulosic hydrolyzate, obtained by acid hydrolysis, was fermented by Candida guilliermondii FTI 20037 to produce xylitol. Assays were made in order to determine the best conditions to clarify the fermented broth using activated carbon. The clarified medium was treated with ion-exchange resins after which xylitol crystallization was attempted. The best clarifying treatment was found by adding 25 g

P. V. Gurgel; I. M. Mancilha; R. P. Peçanha; J. F. M. Siqueira

1995-01-01

141

glycerol fermentation and a reversal of the  

E-print Network

glycerol fermentation and a reversal of the -oxidation cycle as efficient biological platforms's discovery that Escherichia coli can anaerobically ferment glycerol, laid the foundation for the development of technologies to convert glycerol to higher-value products. Dr. Gonzalez received the prestigious National

Subramanian, Venkat

142

Kinetics of ethanol inhibition in alcohol fermentation  

Microsoft Academic Search

The inhibitory effect of ethanol on yeast growth and fermentation has been studied for the strain Saccharo-myces cerevisiae ATCC No. 4126 under anaerobic batch conditions. The results obtained reveal that there is no striking difference between the response of growth and ethanol fermentation. Two kinetic models are also proposed to describe the kinetic pattern of ethanol inhibition on the specific

J. H. T. Luong; J. H. T

1985-01-01

143

Fermentation Studies on Extracts of Beet.  

National Technical Information Service (NTIS)

Fodder beet juice and sugar beet juice were found to be good substrates for the production of ethanol. Two strains of flocculent yeast were selected to ferment fodder beet juice and sugar beet juice. Strain CFCC 8 fermented 10% w/v sucrose-equivalent fodd...

J. M. Smith

1983-01-01

144

Scleroglucan: Fermentative Production, Downstream Processing and Applications  

Microsoft Academic Search

Summary Exopolysaccharides produced by a variety of microorganisms find multifarious indus- trial 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 Scle- rotium. The review discusses the properties, fermentative production, downstream process- ing and applications of scleroglucan.

Shrikant A. Survase; Parag S. Saudagar; Ishwar B. Bajaj; Rekha S. Singhal

145

Modeling the Dynamics of Fermentation and Respiratory  

E-print Network

products are consumed by reaction with terminal electron acceptors (TEAs). The fermentation is overall rate the rates and parameter values for fermentation processes and individual respiratory terminal electron limiting, and is thus described with kinetic rate expressions. The respiration, or terminal electron

Sheffield, University of

146

Exploring Microbial Fermentation with Korean Kimchee  

NSDL National Science Digital Library

To get a closer look at metabolism and succession, consider the fermentation process for making traditional Kimchee. This non-pathogenic system provides opportunities for real time data acquisition and analysis. Experimental data is provided for variables such as pH and O2 levels. * measure key metabolic indicators and observe succession in a fermentation culture for making Kimchee

John M. Greenler (Beloit College;Biology); Robin McC. Greenler (Beloit College;Biology)

2006-05-20

147

The localized quantum vacuum field  

NASA Astrophysics Data System (ADS)

A model for the localized quantum vacuum is proposed in which the zero-point energy (ZPE) of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated with the ZPE of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift. It also offers a new insight into the Zitterbewegung of material particles.

Dragoman, D.

2008-03-01

148

Vacuum Function Operation and Systems  

NSDL National Science Digital Library

The understanding of vacuum function and systems is essential for students and employees working within the micro- and nanofabrication industry. This presentation/webinar highlights the use, construction, and examples of current vacuum technology systems today. Prepared by WHO, of the Nanotechnology Applications and Career Knowledge (NACK), a National ATE Center, this presentation provides material presented from the instructor/engineer viewpoint. Discussions include vacuum pump function, gauge use and ranges, applicable design considerations, as well as insight on cost and equipment training methodologies that have been utilized by the NACK Center. This site requires a free log-in to access.

2009-10-06

149

Vacuum energy and cosmological evolution  

E-print Network

An expanding universe is not expected to have a static vacuum energy density. The so-called cosmological constant $\\Lambda$ should be an approximation, certainly a good one for a fraction of a Hubble time, but it is most likely a temporary description of a true dynamical vacuum energy variable that is evolving from the inflationary epoch to the present day. We can compare the evolving vacuum energy with a Casimir device where the parallel plates slowly move apart ("expand"). The total vacuum energy density cannot be measured, only the effect associated to the presence of the plates, and then also their increasing separation with time. In the universe there is a nonvanishing spacetime curvature $R$ as compared to Minkowskian spacetime that is changing with the expansion. The vacuum energy density must change accordingly, and we naturally expect $\\delta\\Lambda\\sim R\\sim H^2$. A class of dynamical vacuum models that trace such rate of change can be constructed. They are compatible with the current cosmological d...

Sola, Joan

2014-01-01

150

Cold cathode vacuum gauging system  

DOEpatents

A vacuum gauging system of the cold cathode type is provided for measuring the pressure of a plurality of separate vacuum systems, such as in a gas centrifuge cascade. Each casing is fitted with a gauge tube assembly which communicates with the vacuum system in the centrifuge casing. Each gauge tube contains an anode which may be in the form of a slender rod or wire hoop and a cathode which may be formed by the wall of the gauge tube. The tube is provided with an insulated high voltage connector to the anode which has a terminal for external connection outside the vacuum casing. The tube extends from the casing so that a portable magnet assembly may be inserted about the tube to provide a magnetic field in the area between the anode and cathode necessary for pressure measurements in a cold cathode-type vacuum gauge arrangement. The portable magnetic assembly is provided with a connector which engages the external high voltage terminal for providing power to the anode within in the gauge tube. Measurement is made in the same manner as the prior cold cathode gauges in that the current through the anode to the cathode is measured as an indication of the pressure. By providing the portable magnetic assembly, a considerable savings in cost, installation, and maintenance of vacuum gauges for pressure measurement in a gas centrifuge cascade is realizable.

Denny, Edward C. (Knoxville, TN)

2004-03-09

151

Technical specification for vacuum systems  

SciTech Connect

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)

Khaw, J. (ed.)

1987-01-01

152

Traditionally fermented biomedicines, arishtas and asavas from Ayurveda  

Microsoft Academic Search

Ayurveda comprises of various types of medicines including the fermented forms namely arishtas (fermented decoctions) and asavas (fermented infusions). These are regarded as valuable therapeutics due to their efficacy and desirable features. The bulk of knowledge on these fermented medicines remains undocumented, unrecognized and invalidated. In the paper, the fundamental concepts in the designing of arishtas and asavas with representative

S Sekar; S Mariappan

153

Food fermentations: role of microorganisms in food production and preservation  

Microsoft Academic Search

Preservation of foods by fermentation is a widely practiced and ancient technology. Fermentation ensures not only increased shelf life and microbiological safety of a food but also may also make some foods more digestible and in the case of cassava fermentation reduces toxicity of the substrate. Lactic acid bacteria because of their unique metabolic characteristics are involved in many fermentation

Elizabeth Caplice; Gerald F Fitzgerald

1999-01-01

154

Concentration control in alcoholic fermentation processes from ultrasonic velocity measurements  

Microsoft Academic Search

A study of the alcoholic fermentation of several carbohydrate aqueous solutions, using an ultrasonic velocity measurement technique, is presented in this paper. It is shown that the changes occurring during the course of an alcoholic fermentation can be monitored on-line by measuring the velocity of an elastic wave propagating through the fermenting medium. During the alcoholic fermentation, carbohydrates are transformed

Pablo Resa; Luis Elvira; Francisco Montero de Espinosa

2004-01-01

155

Lactic acid bacteria from fermented table olives.  

PubMed

Table olives are one of the main fermented vegetables in the world. Olives can be processed as treated or natural. Both have to be fermented but treated green olives have to undergo an alkaline treatment before they are placed in brine to start their fermentation. It has been generally established that lactic acid bacteria (LAB) are responsible for the fermentation of treated olives. However, LAB and yeasts compete for the fermentation of natural olives. Yeasts play a minor role in some cases, contributing to the flavour and aroma of table olives and in LAB development. The main microbial genus isolated in table olives is Lactobacillus. Other genera of LAB have also been isolated but to a lesser extent. Lactobacillus plantarum and Lactobacillus pentosus are the predominant species in most fermentations. Factors influencing the correct development of fermentation and LAB, such as pH, temperature, the amount of NaCl, the polyphenol content or the availability of nutrients are also reviewed. Finally, current research topics on LAB from table olives are reviewed, such as using starters, methods of detection and identification of LAB, their production of bacteriocins, and the possibility of using table olives as probiotics. PMID:22475936

Hurtado, Albert; Reguant, Cristina; Bordons, Albert; Rozès, Nicolas

2012-08-01

156

Process for enhanced fermentation of xylose to ethanol  

SciTech Connect

A process is described for producing an enhanced ethanol yield by aerobically fermenting D-xylose in a fermentation medium with Pachysolen tannophilus having deposit accession numbers. The improvement comprises adding glucose to the fermentation medium after the fermentation has commenced and during the carrying forth of the fermentation with the adding being continuously or at intervals during each 24 hours of the carrying forth of the fermentation and being of an amount of the glucose providing a glucose concentration not exceeding one percent by weight of the fermentation medium until substantially all D-xylose is consumed.

Jeffries, T.W.

1987-05-05

157

Bacteriophage Ecology in a Commercial Cucumber Fermentation  

PubMed Central

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent phage isolates were obtained, indicating that 10% of the bacterial isolates were sensitive to phage attack. Phage hosts include Lactobacillus brevis (67% of all hosts), Lactobacillus plantarum (21%), Weissella paramesenteroides, Weissella cibaria, and Pediococcus ethanolidurans. Nearly 50% of phages were isolated on day 14, and the majority of them attacked L. brevis. Some phages had a broad host range and were capable of infecting multiple hosts in two genera. Other phages were species specific or strain specific. About 30% of phage isolates produced turbid pinpoint plaques or only caused reduced cell growth on the bacterial lawns. Six phages with distinct host ranges were characterized. The data from this study showed that abundant and diverse phages were present in the commercial cucumber fermentation, which could cause significant mortality to the lactic acid bacteria population. Therefore, a phage control strategy may be needed in low-salt cucumber fermentations. PMID:23023756

Perez-Diaz, I. M.; Hayes, J. S.; Breidt, F.

2012-01-01

158

Isolation of enteric pathogens in the fermentation process of Kimchi (Korean fermented vegetables) and its radicidation by gamma irradiation  

Microsoft Academic Search

The isolation of enteric bacteria in the fermentation process of Kimchi and its radicidation by gamma irradiation were investigated. Viable cell numbers of enteric bacteria were 104 CFU g?1 at the initiation of the Kimchi fermentation process, gradually reducing during the fermentation period, and not detected after 10 days. The enteric bacteria in the early fermentation period of Kimchi were

Dong-Ho Kim; Hyun-Pa Song; Hong-Sun Yook; Yung-Gi Ryu; Myung-Woo Byun

2004-01-01

159

Alcoholic fermentation of sorghum without cooking  

SciTech Connect

Sorgum was used as raw material for alcoholic fermentation without cooking. Two varieties of sorghum grown in Thailand, KU 439 and KU 257, contained 80.0 and 75.8% of total sugar. Optimum amount of sorghum for alcoholic fermentation should be between 30 and 35% (w/v) in the fermentation broth. In these conditions 13.0 and 12.6% (v/v) of alcohol could be obtained in 84 and 91.9% yield based on the theoretical value of the starch content from KU 439 and KU 257, respectively.

Thammarutwasik, P.; Koba, Y.; Ueda, S.

1986-07-01

160

Biotechnology of Flavor Generation in Fermented Meats  

NASA Astrophysics Data System (ADS)

Traditionally, meat fermentation was based on the use of natural flora, including the “back-slopping”, or addition of a previous successful fermented sausage. However, these practices gave a great variability in the developed flora and affected the safety and quality of the sausages (Toldrá, 2002; Toldrá & Flores, 2007). The natural flora of fermented meat has been studied for many years (Leistner, 1992; Toldrá, 2006a), and more recently, these micro-organisms have been isolated and biochemically identified through molecular methods applied to extracted DNA and RNA (Cocolin, Manzano, Aggio, Cantoni, & Comi, 2001; Cocolin, Manzano, Cantoni, & Comi, 2001; Comi, Urso, Lacumin, Rantsiou, Cattaneo & Cantoni, 2005).

Toldrá, Fidel

161

Dry fermentation of agricultural residues  

NASA Astrophysics Data System (ADS)

A dry fermentation process is discussed which converts agricultural residues to methane, using the residues in their as produced state. The process appears to simplify and enhance the possibilities for using crop residues as an energy source. The major process variables investigated include temperature, the amount and type of inoculum, buffer requirements, compaction, and pretreatment to control the initial available organic components that create pH problems. A pilot-scale reactor operation on corn stover at a temperature of 550 C, with 25 percent initial total solids, a seed-to-feed ratio of 2.5 percent, and a buffer-to-feed ratio of 8 percent achieved 33 percent total volatile solids destruction in 60 days. Volumetric biogas yields from this unit were greater than 1 vol/vol day for 12 days, and greater than 0.5 vol/vol day for 32 days, at a substrate density of 169 kg/m (3).

Jewell, W. J.; Chandler, J. A.; Dellorto, S.; Fanfoni, K. J.; Fast, S.; Jackson, D.; Kabrick, R. M.

1981-09-01

162

Inhibition of malolactic fermentation by a peptide produced by Saccharomyces cerevisiae during alcoholic fermentation  

Microsoft Academic Search

The ability of Saccharomyces to inhibit Oenococcus oeni during the alcoholic fermentation by mechanisms other than SO2 production was investigated. During fermentation in synthetic grape juice, S. cerevisiae strain RUBY.ferm inhibited the malolactic fermentation by O. oeni while strain EC1118 did not despite both strains producing similar amounts of SO2. The bacterial inhibition exerted by RUBY.ferm was diminished when the

James P. Osborne; Charles G. Edwards

2007-01-01

163

PCR-DGGE analysis of bacterial communities in funazushi , fermented crucian carp with rice, during fermentation  

Microsoft Academic Search

Funazushi (fermented Crucian Carp with rice) is a fermented fish product found only around Lake Biwa in Shiga Prefecture, Japan. It\\u000a is characterized by a unique cheese-like flavor and characteristic sour taste. We analyzed the changes in the microbial community\\u000a during funazushi fermentation by denaturing gradient gel electrophoresis of PCR-amplified 16S rDNA fragments (PCR-DGGE) and by plate counts.\\u000a The plate

Tateo Fujii; Shoko Watanabe; Masako Horikoshi; Hajime Takahashi; Bon Kimura

2011-01-01

164

Probability distribution of the vacuum energy density  

SciTech Connect

As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.

Duplancic, Goran; Stefancic, Hrvoje [Theoretical Physics Division, Rudjer Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia); Glavan, Drazen [Department of Physics, Faculty of Science, University of Zagreb, P.O. Box 331, HR-10002 Zagreb (Croatia)

2010-12-15

165

Finite Time Vacuum Survival Amplitude and Vacuum Energy Decay  

E-print Network

The problem of the vacuum energy decay is studied for both signs of the cosmological constant, through the analysis of the vacuum survival amplitude, defined in terms of the {\\em conformal time}, $z$, by ${\\mathcal A}(z,z^\\prime)\\equiv $. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior (directly related to the putative decay width of the state) as well as the transients are discussed up to first order in the coupling constant, $\\lambda$.

Enrique Álvarez; Roberto Vidal

2011-07-15

166

Vacuum as a hyperbolic metamaterial  

E-print Network

As demonstrated by Chernodub, vacuum in a strong magnetic field behaves as a periodic Abrikosov vortex lattice in a type-II superconductor. We investigate electromagnetic behavior of vacuum in this state. Since superconductivity is realized along the axis of magnetic field only, strong anisotropy of the vacuum dielectric tensor is observed. The diagonal components of the tensor are positive in the x and y directions perpendicular to the magnetic field, and negative in the z direction along the field. As a result, vacuum behaves as a hyperbolic metamaterial medium. If the magnetic field is constant, low frequency extraordinary photons experience this medium as a (3+1) Minkowski spacetime in which the role of time is played by the spatial z coordinate. Spatial variations of the magnetic field curve this effective spacetime, and may lead to formation of "event horizons", which are analogous to electromagnetic black holes in hyperbolic metamaterials. We also note that hyperbolic metamaterials behave as diffractionless "perfect lenses". Since large enough magnetic fields probably had arisen in the course of evolution of early Universe, the demonstrated hyperbolic behavior of early vacuum may have imprints in the large scale structure of the present-day Universe.

Igor I. Smolyaninov

2011-08-10

167

Fermentation products and their industrial use  

SciTech Connect

A review on the tonnage of production of various industrial chemicals, their methods of synthesis, and the possibilities of the fermentative method being competitive with the synthetic method is given.

Lefebvre, G.; Arlie, J.P.

1982-01-01

168

Coupled quintessence and vacuum decay  

NASA Astrophysics Data System (ADS)

We discuss observational consequences of a class of cosmological models characterized by the dilution of pressureless matter attenuated with respect to the usual a-3 scaling due to the decay of vacuum energy. We carry out a joint statistical analysis of observational data from the new gold sample of 182 SNe Ia, recent estimates of the cosmic microwave background shift parameter, and baryon acoustic oscillations measurements from the SDSS to show that such models favor the decay of vacuum only into the dark matter sector, and that the separately conserved baryons cannot be neglected. In order to explore ways to more fundamentally motivate these models, we also derive a coupled scalar field version for this general class of vacuum decay scenarios.

Costa, F. E. M.; Alcaniz, J. S.; Maia, J. M. F.

2008-04-01

169

Method for vacuum fusion bonding  

DOEpatents

An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

Ackler, Harold D. (Sunnyvale, CA); Swierkowski, Stefan P. (Livermore, CA); Tarte, Lisa A. (Livermore, CA); Hicks, Randall K. (Stockton, CA)

2001-01-01

170

Vacuum Plasma Spraying Replaces Electrodeposition  

NASA Technical Reports Server (NTRS)

Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

1992-01-01

171

Mass Dependence of Vacuum Energy  

E-print Network

The regularized vacuum energy (or energy density) of a quantum field subjected to static external conditions is shown to satisfy a certain partial differential equation with respect to two variables, the mass and the "time" (ultraviolet cutoff parameter). The equation is solved to provide integral expressions for the regularized energy (more precisely, the cylinder kernel) at positive mass in terms of that for zero mass. Alternatively, for fixed positive mass all coefficients in the short-time asymptotics of the regularized energy can be obtained recursively from the first nontrivial coefficient, which is the renormalized vacuum energy.

S. A. Fulling

2005-07-05

172

Comparison of recombinant xylose-fermenting saccharomyces and natural xylose-fermenting yeasts in fermenting mixed sugars containing both glucose and xylose  

SciTech Connect

Cellulosic biomass is an ideal renewable feedstock for the production of ethanol fuels. A Saccharomyces yeast has been genetically engineered to ferment xylose, a constituent of biomass. Results are described and compared with other natural xylose-fermenting yeasts.

Ho, N.W.Y.; Chen, Zhengdao; Brainard, A. [Purdue Univ., West Lafayette, IN (United States)

1995-12-01

173

Particle description of zero energy vacuum. II. Basic vacuum systems  

E-print Network

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).

J. Y. Grandpeix; F. Lurcat

2001-06-25

174

Effect of the packaging method and the storage time on lipid oxidation and colour stability on dry fermented sausage salchichón manufactured with raw material with a high level of mono and polyunsaturated fatty acids  

Microsoft Academic Search

The effects of fatty acid composition, two packaging methods (vacuum and 20% CO2\\/80% N2) and storage under refrigeration for 210 days were evaluated on a dry fermented sausage (salchichón), manufactured with raw material enriched in monounsaturated or polyunsaturated fatty acids. Fatty acid composition was determined on sausage mixtures and on ripened sausages and lipid oxidation and colour stability was determined

Begoña Rubio; Beatriz Martínez; M García-Cachán; Jordi Rovira; Isabel Jaime

2008-01-01

175

Viricidal Effects of Lactobacillus and Yeast Fermentation  

PubMed Central

The survival of selected viruses in Lactobacillus- and yeast-fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Five viruses, including Newcastle disease virus, infectious canine hepatitis virus, a porcine picornavirus, frog virus 3, and bovine virus diarrhea, were inoculated into a mixture of ground food waste (collected from a school lunch program) containing Lactobacillus acidophilus. Mixtures were incubated at 20, 30, and 40°C for 216 h. In a second trial, four viruses, including Newcastle disease virus, infectious canine hepatitis virus, frog virus 3, and a porcine picornavirus, were inoculated into similar edible waste material containing Saccharomyces cerevisiae. Mixtures were incubated at 20 and 30°C for 216 h. Samples were obtained daily for quantitative (trial 1) and qualitative (trial 2) virus isolation. Temperature, pH, and redox potential were monitored. Controlled pH and temperature studies were also done and compared with the inactivation rates in the fermentation processes. In trial 1 (Lactobacillus fermentation), infectious canine hepatitis virus survived the entire test period in the fermentation process but was inactivated below pH 4.5 in the controlled studies. Newcastle disease virus was inactivated by day 8 in the fermentation process and appeared to be primarily heat sensitive and secondarily pH sensitive in the controlled studies. The porcine picornavirus survived the fermentation process for 8 days at 20°C but was inactivated more rapidly at 30 and 40°C. The controlled studies verified these findings. Frog virus 3 was inactivated by day 3 in the fermentation process and appeared to be sensitive to low pH in the controlled studies. Bovine virus diarrhea was rapidly inactivated in the fermentation process (less than 2 h) and was pH and temperature sensitive. In trial 2 (yeast fermentation), infectious hepatitis virus survived the entire test period in the fermentation process. Newcastle disease virus was inactivated by day 7 at 20°C and day 6 at 30°C. The porcine picornavirus was inactivated by day 7 at 30°C but survived the entire test period at 20°C. Frog virus 3 was inactivated by day 3 at 20°C and day 2 at 30°C. PMID:6414372

Gilbert, Jeannine P.; Wooley, Richard E.; Shotts, Emmett B.; Dickens, J. Andra

1983-01-01

176

Hadrons in Vacuum and Matter  

Microsoft Academic Search

In the first part of this thesis, we investigate the correlators and form factors of hadrons in vacuum viewed as a dilute gas of instantons and antiinstantons. Relying heavily on approximate bosonization techniques in four dimensions, we construct an effective action for constituent quarks in interaction with mesons and glueballs. The effective action is then used to study various meson,

Mourad Kacir

1995-01-01

177

Vacuum-jacketed line spacer  

NASA Technical Reports Server (NTRS)

Device has three integral, equally spaced leaf springs. Springs separate outer vacuum jacket from fluid carrying line, yet minimize conductive heat leaks and liquid boiloff. One-piece heat spring has sufficient flexibility to accommodate differential thermal expansion of inner and outer line.

Houte, F. A.; Mckee, H. B.; Patten, T. C.

1976-01-01

178

Switching in High Vacuum Enviroment  

Microsoft Academic Search

An analysis is made of the properties and problems of Maximum current interrupting ability and photos of contacts contacts, switching, and holding off high and low voltages, high which are interrupting up to 18,000 a are shown. and low currents ac, dc, and RF in a high vacuum environment with some relation to outer space problems. Characteristics of contacts from

H. Ross

1963-01-01

179

Plates for vacuum thermal fusion  

DOEpatents

A process for effectively bonding arbitrary size or shape substrates. The process incorporates vacuum pull down techniques to ensure uniform surface contact during the bonding process. The essence of the process for bonding substrates, such as glass, plastic, or alloys, etc., which have a moderate melting point with a gradual softening point curve, involves the application of an active vacuum source to evacuate interstices between the substrates while at the same time providing a positive force to hold the parts to be bonded in contact. This enables increasing the temperature of the bonding process to ensure that the softening point has been reached and small void areas are filled and come in contact with the opposing substrate. The process is most effective where at least one of the two plates or substrates contain channels or grooves that can be used to apply vacuum between the plates or substrates during the thermal bonding cycle. Also, it is beneficial to provide a vacuum groove or channel near the perimeter of the plates or substrates to ensure bonding of the perimeter of the plates or substrates and reduce the unbonded regions inside the interior region of the plates or substrates.

Davidson, James C. (Livermore, CA); Balch, Joseph W. (Livermore, CA)

2002-01-01

180

A vacuum ultraviolet spectrophotometric system  

NASA Technical Reports Server (NTRS)

The development of a vacuum ultraviolet spectrophotometric system for measuring transmittance and reflectance at variable angles is presented. Using various detectors and sources, the spectrophotometric system has been used for wavelengths from 80 nm to 300 nm with optical components up to 80 mm in diameter. The capability exists to make measurements through the visible range.

Spann, James F.; Keffer, Charles E.; Zukic, Muamer

1993-01-01

181

Chapter 13. The Vacuum System  

E-print Network

The vacuum chamber sectors are a welded fabrication of aluminum alloy 6061 plate. The standard chambers have the quadrupole feedthroughs, and for positioning of the internal support frame. There are 30 fixed NMR probes per primarily to provide rails for the NMR trolley cable car. The support frame is shown in Fig. 13

Brookhaven National Laboratory - Experiment 821

182

Quantum Vacuum Structure and Cosmology  

SciTech Connect

Contemporary physics faces three great riddles that lie at the intersection of quantum theory, particle physics and cosmology. They are: (1) The expansion of the universe is accelerating - an extra factor of two appears in the size; (2) Zero-point fluctuations do not gravitate - a matter of 120 orders of magnitude; and (3) The 'True' quantum vacuum state does not gravitate. The latter two are explicitly problems related to the interpretation and the physical role and relation of the quantum vacuum with and in general relativity. Their resolution may require a major advance in our formulation and understanding of a common unified approach to quantum physics and gravity. To achieve this goal we must develop an experimental basis and much of the discussion we present is devoted to this task. In the following, we examine the observations and the theory contributing to the current framework comprising these riddles. We consider an interpretation of the first riddle within the context of the universe's quantum vacuum state, and propose an experimental concept to probe the vacuum state of the universe.

Rafelski, Johann; Labun, Lance; Hadad, Yaron; /Arizona U. /Munich U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC

2011-12-05

183

Vacuum-insulated catalytic converter  

DOEpatents

A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

Benson, David K. (Golden, CO)

2001-01-01

184

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

The objective of this project is to improve the productivity and lower the expense of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCBs, and lead-based paint and provides worker protection by continuously recycling the material and dust for the decontamination tasks. The proposed work would increase the cleaning rate and provide safe and cost-effective decontamination of the DOE sites. This work focuses on redesigning and improving existing vacuum blasting technology including blast head nozzles, ergonomic handling of the blast head by reducing its weight; brush-ring design, vacuum level regulator, efficiency of the dust separator, and operational control sensors. The redesign is expected to enhance the productivity and economy of the vacuum blasting system by at least 50% over current vacuum blasting systems. There are three phases in the project. Phase I consists of developing and testing mathematical models. Phase II consists of pre-prototype design and fabrication and pre-prototype unit testing. Phase III consists of prototype design and field verification testing. In phase I, mathematical models are developed and analyzed for the nozzle, blast head, wind curtain, and dust separator, first as individual devices and then combined as an integrated model. This allows study of respective airflow and design parameters. The Contractor shall, based on the results of the mathematical modeling studies, design experimental models of the components and test these models. In addition, the Contractor shall develop sensors to detect the relationship of the blast head to the blast surfaces and controls to minimize the dependency on an operator's skill and judgment to obtain optimum positioning, as well as real-time characterization sensors to determine as the blast head is moving the depth to which coatings must be removed, thereby improving production and minimizing waste. In phase II, the Contractor shall design and construct a pre-prototype of the nozzle, blast head with wind curtain, sensors, and dust separator and test this system to assess the performance of the new design under controlled conditions at the contractor's facility. In phase III, the Contractor shall design and construct a prototype of the High Productivity Vacuum Blasting System, based on the results of the pre-prototype design and testing performed. This unit will be a full-scale prototype and will be tested at a designated Department of Energy (DOE) facility. Based on the results, the system performance, the productivity, and the economy of the improved vacuum blasting system will be evaluated.

William S. McPhee

1999-05-31

185

Importance of lactic acid bacteria in Asian fermented foods  

PubMed Central

Lactic acid bacteria play important roles in various fermented foods in Asia. Besides being the main component in kimchi and other fermented foods, they are used to preserve edible food materials through fermentation of other raw-materials such as rice wine/beer, rice cakes, and fish by producing organic acids to control putrefactive microorganisms and pathogens. These bacteria also provide a selective environment favoring fermentative microorganisms and produce desirable flavors in various fermented foods. This paper discusses the role of lactic acid bacteria in various non-dairy fermented food products in Asia and their nutritional and physiological functions in the Asian diet. PMID:21995342

2011-01-01

186

Vacuum polarization and Hawking radiation  

NASA Astrophysics Data System (ADS)

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.

Rahmati, Shohreh

187

Materials for ultra-high vacuum  

SciTech Connect

This report discusses materials for use in ultrahigh vacuum systems of 1 {times} 10{sup {minus}9} Torr or lower. The author briefly discusses alloys, solders, insulators and joining methods for vacuum systems. (JDL)

Lee, G.

1989-08-15

188

Fermentation studies using Saccharomyces diastaticus yeast strains  

SciTech Connect

The yeast species, Saccharomyces diastaticus, has the ability to ferment starch and dextrin, because of the extracellular enzyme, glucoamylase, which hydrolyzes the starch/dextrin to glucose. A number of nonallelic genes--DEX 1, DEX 2, and dextrinase B which is allelic to STA 3--have been isolated, which impart to the yeast the ability to ferment dextrin. Various diploid yeast strains were constructed, each being either heterozygous or homozygous for the individual dextrinase genes. Using 12 (sup 0) plato hopped wort (30% corn adjunct) under agitated conditions, the fermentation rates of the various diploid yeast strains were monitored. A gene-dosage effect was exhibited by yeast strains containing DEX 1 or DEX 2, however, not with yeast strains containing dextrinase B (STA 3). The fermentation and growth rates and extents were determined under static conditions at 14.4 C and 21 C. With all yeast strains containing the dextrinase genes, both fermentation and growth were increased at the higher incubation temperature. Using 30-liter fermentors, beer was produced with the various yeast strains containing the dextrinase genes and the physical and organoleptic characteristics of the products were determined. The concentration of glucose in the beer was found to increase during a 3-mo storage period at 21 C, indicating that the glucoamylase from Saccharomyces diastaticus is not inactivated by pasteurization. (Refs. 36).

Erratt, J.A.; Stewart, G.G.

1981-01-01

189

Xylose fermentation to ethanol. A review  

SciTech Connect

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.

McMillan, J.D.

1993-01-01

190

Inhibition of cellulase by fermentation products  

SciTech Connect

Cellulosic materials are important resources for the production of fuels and chemicals. One of the processes designed to utilize cellulosic materials is enzymatic hydrolysis followed by fermentation to final products. It was shown that simultaneous saccharification and fermentation (SSF) is effective in the production of ethanol from cellulose. The acceleration of the rate of cellulose degradation in SSF was caused by less inhibition of cellulase by ethanol than by glucose and/or cellobiose. In order to apply the SSF method effectively to the production of substances derived from glucose by fermentation, several conditions should be satisfied. One of them is the coincidence of conditions of enzymatic hydrolysis and fermentation of hydrolyzate, such as pH and temperature. The second condition is that the inhibition of cellulase by the final product is less than that by glucose and/or cellobiose. There has been a comprehensive review and some reports on inhibition of cellulase by saccharides such as glucose, cellobiose, xylose, lactose, maltose, metals, and some chemicals such as dyes, detergents, halogenated compounds, and phenolic compounds. In this communication, the inhibition of cellulase by several substances derived by fermentation of glucose is reported. 7 references.

Takagi, M.

1984-12-01

191

Utilize Vacuum Forming to Make Interdisciplinary Connections  

ERIC Educational Resources Information Center

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…

Love, Tyler S.; Valenza, Frank

2011-01-01

192

Ion pump provides increased vacuum pumping speed  

NASA Technical Reports Server (NTRS)

Multiple-cell ion pumps with increased vacuum pumping speed are used for producing ultrahigh vacuums in vacuum tubes and mass spectrometers. The pump has eight cathode-anode magnetron cells arranged in a cylinder which increase the surface area of the cathode.

1965-01-01

193

REVIEW ARTICLE Vacuum Rabi splitting in semiconductors  

E-print Network

of a nanocavity. This review describes the history of realizing vacuum Rabi splitting (VRS) in the single-QD (SQDREVIEW ARTICLE Vacuum Rabi splitting in semiconductors The recent development of techniques. We discuss the recent results on vacuum Rabi splitting with a single quantum dot, emphasizing

Loss, Daniel

194

Vacuum energy of CP(1) solitons  

E-print Network

The vacuum energy of two CP(1) solitons on a torus is computed numerically. A numerical technique for zeta-function regularisation is proposed to remove the divergences of the vacuum energy. After performing the numerical regularisation, we observe the effect of the vacuum energy on the two soliton interactions.

Ian G Moss; Noriko Shiiki; Takashi Torii

2001-03-22

195

27 CFR 24.197 - Production by fermentation.  

Code of Federal Regulations, 2012 CFR

27 Alcohol, Tobacco Products and...false Production by fermentation. 24.197 Section 24.197 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...197 Production by fermentation. In producing...

2012-04-01

196

27 CFR 24.197 - Production by fermentation.  

Code of Federal Regulations, 2011 CFR

27 Alcohol, Tobacco Products and...false Production by fermentation. 24.197 Section 24.197 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...197 Production by fermentation. In producing...

2011-04-01

197

27 CFR 24.197 - Production by fermentation.  

Code of Federal Regulations, 2010 CFR

27 Alcohol, Tobacco Products and...false Production by fermentation. 24.197 Section 24.197 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...197 Production by fermentation. In producing...

2010-04-01

198

Fermentation and recovery process for lactic acid production  

DOEpatents

A method is described for converting starch to glucose and fermenting glucose to lactic acid, including simultaneous saccharification and fermentation through use of a novel consortium of bacterial strains. 2 figs.

Tsai, S.P.; Moon, S.H.; Coleman, R.

1995-11-07

199

Quantum vacuum and dark matter  

E-print Network

Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the non-existence of dark disks in spiral galaxies and distribution of dark matter after collision of clusters of galaxies (the Bullet cluster is a famous example). Only some of these phenomena (but not all of them) can (in principle) be explained by the dark matter and the theories of modified gravity. However, we argue that the framework of the gravitational polarization of the quantum vacuum allows the understanding of the totality of these phenomena.

Dragan Slavkov Hajdukovic

2011-11-21

200

Radiation Reaction in Quantum Vacuum  

E-print Network

From the development of the electron theory by H. A. Lorentz in 1906, many authors have tried to reformulate this model named "radiation reaction". P. A. M. Dirac derived the relativistic-classical electron model in 1938, which is now called the Lorentz-Abraham-Dirac model. But this model has the big difficulty of the run-away solution. Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. Therefore, it is desirable to stabilize this model of the radiation reaction for estimations. Via my recent research, I found a stabilized model of radiation reaction in quantum vacuum. This leads us to an updated Fletcher-Millikan's charge to mass ratio including radiation, de/dm, derived as the 4th order tensor measure. In this paper, I will discuss the latest update of the model and the ability of the equation of motion with radiation reaction in quantum vacuum via photon-photon scatterings.

Seto, Keita

2014-01-01

201

Radiation Reaction in Quantum Vacuum  

E-print Network

From the development of the electron theory by H. A. Lorentz in 1906, many authors have tried to reformulate this model named "radiation reaction". P. A. M. Dirac derived the relativistic-classical electron model in 1938, which is now called the Lorentz-Abraham-Dirac model. But this model has the big difficulty of the run-away solution. Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. Therefore, it is desirable to stabilize this model of the radiation reaction for estimations. Via my recent research, I found a stabilized model of radiation reaction in quantum vacuum. This leads us to an updated Fletcher-Millikan's charge to mass ratio including radiation, de/dm, derived as the 4th order tensor measure. In this paper, I will discuss the latest update of the model and the ability of the equation of motion with radiation reaction in quantum vacuum via photon-photon scatterings.

Keita Seto

2014-05-26

202

Dark Energy From Vacuum Fluctuations  

E-print Network

We describe briefly a novel interpretation of the physical nature of dark energy (DE), based on the vacuum fluctuations model by Gurzadyan & Xue, and describe an internally consistent solution for the behavor of DE as a function of redshift. A key choice is the nature of the upper bound used for the computation of energy density contributions by vacuum modes. We show that use of the comoving horizon radius produces a viable model, whereas use of the proper horizon radius is inconsistent with the observations. After introduction of a single phenomenological parameter, the model is consistent with all of the curently available data, and fits them as well as the standard cosmological constant model, while making testable predictions. While some substantial interpretative uncertainties remain, future developments of this model may lead to significant new insights into the physical nature of DE.

S. G. Djorgovski; V. G. Gurzadyan

2006-10-06

203

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

PubMed

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 glucose and fructose using standard broth under aerated and non-aerated conditions. Most Saccharomyces cerevisiae strains were superior to other species in ethanol production. The best ethanol producing S. cerevisiae strains, and strains of the species Pichia kudriavzevii, Pichia fabianii and Saccharomycopsis fibuligera were tested for production of flavor compounds during fermentation of masau fruit juice. Significant differences in the production of ethanol and other volatile compounds during fermentation of masau juice were observed among and within the four tested species. Alcohols and esters were the major volatiles detected in the fermented juice. Trace amounts of organic acids and carbonyl compounds were detected. Ethyl hexanoate and ethyl octanoate were produced in highest amounts as compared to the other volatile compounds. S. cerevisiae strains produced higher amounts of ethanol and flavor compounds as compared to the other species, especially fatty acid ethyl esters that provide the major aroma impact of freshly fermented wines. The developed library of characteristics can help in the design of mixtures of strains to obtain a specific melange of product functionalities. PMID:24029027

Nyanga, Loveness K; Nout, Martinus J R; Smid, Eddy J; Boekhout, Teun; Zwietering, Marcel H

2013-09-16

204

A review on traditional Turkish fermented non-alcoholic beverages: microbiota, fermentation process and quality characteristics.  

PubMed

Shalgam juice, hardaliye, boza, ayran (yoghurt drink) and kefir are the most known traditional Turkish fermented non-alcoholic beverages. The first three are obtained from vegetables, fruits and cereals, and the last two ones are made of milk. Shalgam juice, hardaliye and ayran are produced by lactic acid fermentation. Their microbiota is mainly composed of lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus paracasei subsp. paracasei in shalgam fermentation and L. paracasei subsp. paracasei and Lactobacillus casei subsp. pseudoplantarum in hardaliye fermentation are predominant. Ayran is traditionally prepared by mixing yoghurt with water and salt. Yoghurt starter cultures are used in industrial ayran production. On the other hand, both alcohol and lactic acid fermentation occur in boza and kefir. Boza is prepared by using a mixture of maize, wheat and rice or their flours and water. Generally previously produced boza or sourdough/yoghurt are used as starter culture which is rich in Lactobacillus spp. and yeasts. Kefir is prepared by inoculation of raw milk with kefir grains which consists of different species of yeasts, LAB, acetic acid bacteria in a protein and polysaccharide matrix. The microbiota of boza and kefir is affected from raw materials, the origin and the production methods. In this review, physicochemical properties, manufacturing technologies, microbiota and shelf life and spoilage of traditional fermented beverages were summarized along with how fermentation conditions could affect rheological properties of end product which are important during processing and storage. PMID:23859403

Altay, Filiz; Karbanc?oglu-Güler, Funda; Daskaya-Dikmen, Ceren; Heperkan, Dilek

2013-10-01

205

Enamel microhardness and fluoride uptake underneath fermenting and non-fermenting artificial plaque.  

PubMed

Washed cells of Streptococcus sanguis were used to form artificial plaque on the surface of bovine enamel and incubated underneath buffer solutions, initial pH 6, for 36 h at 37 degrees C. The decrease in the microhardness of the enamel surface under fermenting "plaque" could be prevented with fluoride. Enamel under a fermenting "plaque" took up significantly more (P less than 0.0u) fluoride than enamel under a non-fermenting "plaque" (initial F- in buffer: 10 parts/10(6)). The artificial plaque did not accumulate fluoride. Within fermenting "plaques/, the pH decreased significantly more without flouride (P less than 0.01) than with fluoride. Fluoride combined with sucrose more than negated the softening of the enamel caused by sucrose fermentation, i.e. it increased the hardness above the original values. The diffusion of fluoride through the fermenting artificial plaque was more rapid than through a non-fermenting plaque. These findings suggest that caries-conducive circumstances may promote fluoride uptake by enamel compared with non-caries-conducive circumstances. PMID:22924

Turtola, L O

1977-09-01

206

Bubbles created from vacuum fluctuation  

E-print Network

We show that the bubbles $S^2\\times S^2$can be created from vacuum fluctuation in certain De Sitter universe, so the space-time foam-like structure might really be constructed from bubbles of $S^2\\times S^2$ in the very early inflating phase of our universe. But whether such foam-like structure persisted during the later evolution of the universe is a problem unsolved now.

Liao Liu; Feng He

2001-01-05

207

Vacuum Energy as Spectral Geometry  

E-print Network

Quantum vacuum energy (Casimir energy) is reviewed for a mathematical audience as a topic in spectral theory. Then some one-dimensional systems are solved exactly, in terms of closed classical paths and periodic orbits. The relations among local spectral densities, energy densities, global eigenvalue densities, and total energies are demonstrated. This material provides background and motivation for the treatment of higher-dimensional systems (self-adjoint second-order partial differential operators) by semiclassical approximation and other methods.

Stephen A. Fulling

2007-06-19

208

New Aspects of Fungal Starter Cultures for Fermented Foods  

Microsoft Academic Search

The production of a variety of foods include a fermentation step by filamentous fungi. Nowadays these fermented foods are\\u000a produced by selected fungal starter cultures instead of relying on the indigenous flora, which may contain spoilage or mycotoxinogenic\\u000a strains. The most important fungal species for food fermentation are Penicillium nalgiovense for the production of mould fermented meat products, P. camemberti

Rolf Geisen; Paul Färber

209

Holographic description of vacuum bubbles  

E-print Network

We discuss a holographic description of vacuum bubbles, with possible implications for a consistent description of the multiverse. In particular, we elaborate on the recent observation by Maldacena, that the interior of AdS bubbles can be described in terms of CFT degrees of freedom living on the worldsheet of the bubble wall. We consider the scattering of bulk gravitons in the ambient parent vacuum, off the bubble wall. In the dual description, the transmission coefficient is interpreted as the probability that a graviton is absorbed by the worldsheet CFT degrees of freedom. The result is in agreement with intuitive expectations. Conformal invariance is not exact in this setup, and the leading corrections due to the IR and UV cut-offs are displayed. Aside from bulk scattering states, we find that when a bubble nucleates within a parent dS vacuum, there is a zero mode of the graviton which describes lower dimensional gravity with a finite Newton's constant. This massless graviton lives within one Hubble radius away from the bubble wall. Possible implications for a fully holographic description of the inflating multiverse are briefly discussed.

Jaume Garriga

2010-12-29

210

Cosmic vacuum and galaxy formation  

NASA Astrophysics Data System (ADS)

It is demonstrated that the protogalactic perturbations must enter the nonlinear regime before the red shift z? 1; otherwise they would be destroyed by the antigravity of the vacuum dark energy at the subsequent epoch of the vacuum domination. At the zrrV={M/[(8?/3)?V]}1/3, where M is the mass of a given over-density and ?V is the vacuum density. The criterion provides a new relation between the largest mass condensations and their spatial scales. All the real large-scale systems follow this relation definitely. It is also shown that a simple formula is possible for the key quantity in the theory of galaxy formation, namely the initial amplitude of the perturbation of the gravitational potential in the protogalactic structures. The amplitude is time independent and given in terms of the Friedmann integrals, which are genuine physical characteristics of the cosmic energies. The results suggest that there is a strong correspondence between the global design of the Universe as a whole and the cosmic structures of various masses and spatial scales.

Chernin, A. D.

2006-04-01

211

Antioxidant activity of lactic-fermented Chinese cabbage  

Microsoft Academic Search

Lactic-fermented cabbage, similar to Kimchi in Korea, is a very popular fermented vegetable product in Taiwan and China. In this study, fermented cabbage prepared by a dry-salt method was first extracted with water and methanol. Antioxidant activity such as DPPH radical scavenging effects, reducing power and Fe2+-chelating ability of the solvent extracts of fermented cabbage was determined and the effect

Yu-Ping Sun; Cheng-Chun Chou; Roch-Chui Yu

2009-01-01

212

Holographic description of vacuum bubbles  

E-print Network

We discuss a holographic description of vacuum bubbles, with possible implications for a consistent description of the multiverse. In particular, we elaborate on the recent observation by Maldacena, that the interior of AdS bubbles can be described in terms of CFT degrees of freedom living on the worldsheet of the bubble wall. We consider the scattering of bulk gravitons in the ambient parent vacuum, off the bubble wall. In the dual description, the transmission coefficient is interpreted as the probability that a graviton is absorbed by the worldsheet CFT degrees of freedom. The result is in agreement with intuitive expectations. Conformal invariance is not exact in this setup, and the leading corrections due to the IR and UV cut-offs are displayed. Aside from bulk scattering states, we find that when a bubble nucleates within a parent dS vacuum, there is a zero mode of the graviton which describes lower dimensional gravity with a finite Newton's constant. This massless graviton lives within one Hubble radiu...

Garriga, Jaume

2010-01-01

213

Ultrasonic Monitoring of the Progress of Lactic Acid Fermentation  

NASA Astrophysics Data System (ADS)

Promotion of lactic acid fermentation by ultrasonic irradiation has been attempted. It is possible to determine the progress of fermentation and production of a curd, i.e., yoghurt and or kefir, by measuring acidity using a pH meter. However, this method is inconvenient and indirect for the evaluation of the progress of lactic acid fermentation under anaerobic condition. In this study, an ultrasonic monitoring method for evaluating the progress of lactic acid fermentation was examined.

Masuzawa, Nobuyoshi; Kimura, Akihiro; Ohdaira, Etsuzo

2003-05-01

214

Reconciling competing models: a case study of wine fermentation kinetics  

E-print Network

the biology of wine yeast fermentation through functional genomics, and contribute to our understanding worldwide losses from stuck or sluggish fermentations are estimated at 7 billion AC annually. Yeast starterReconciling competing models: a case study of wine fermentation kinetics Rodrigo Assar1, Felipe A

Paris-Sud XI, Université de

215

CBR Fermentation Suite Service Fee Schedule Updated Oct 2011  

E-print Network

CBR Fermentation Suite Service Fee Schedule Updated Oct 2011 Please note that fees can be changed-Mill For yeast cells (volume > 1-L) 30 min 37.50$ BeadBeater For yeast cells (volume : Fermenter user must harvest but CBR can provide bottles for the use of CBR centrifuge 7-L Fermenters

Strynadka, Natalie

216

Sophorolipids production by Candida bombicola using self-cycling fermentation  

Microsoft Academic Search

The self-cycling fermentation (SCF) technique was applied to cultures of Candida bombicola. Sophorolipids, secondary metabolites, were observed only when the SCF was operated with an extended phase of fermentation at the end of each cycle. A new control strategy was developed to allow the production of sophorolipids by coupling the fermentation control to the secondary metabolism of the culture. Cycling

William C. McCaffrey; David G. Cooper

1995-01-01

217

Corynebacterium nuruki sp. nov., isolated from an alcohol fermentation starter  

E-print Network

Corynebacterium nuruki sp. nov., isolated from an alcohol fermentation starter Na-Ri Shin, Mi , was isolated from a Korean alcohol fermentation starter. Optimal growth occurred at 37 6C, at pH 8 and in 1 was isolated from nuruk, which is an alcohol fermentation starter used as an amylolytic substance

Bae, Jin-Woo

218

Optimization of conditions and cell feeding procedures for alcohol fermentation  

Microsoft Academic Search

Alcohol fermentation was studied with an emphasis on the separation of cell growth and alcohol production stages. Experiments were conducted to establish the optimal conditions for alcohol production in batch fermentations and to simulate continuous fermentations with cell feeding at various stages. It was found that the glucose concentration should be kept under 10% (w\\/v), and the temperature should be

T. Ciftci; A. Constantinides; S. S. Wang

1983-01-01

219

Anaerobic fermentation of beef cattle manure. Final report  

SciTech Connect

The research to convert livestock manure and crop residues into methane and a high protein feed ingredient by thermophilic anaerobic fermentation are summarized. The major biological and operational factors involved in methanogenesis were discussed, and a kinetic model that describes the fermentation process was presented. Substrate biodegradability, fermentation temperature, and influent substrate concentration were shown to have significant effects on CH/sub 4/ production rate. The kinetic model predicted methane production rates of existing pilot and full-scale fermentation systems to within 15%. The highest methane production rate achieved by the fermenter was 4.7 L CH/sub 4//L fermenter day. This is the highest rate reported in the literature and about 4 times higher than other pilot or full-scale systems fermenting livestock manures. Assessment of the energy requirements for anaerobic fermentation systems showed that the major energy requirement for a thermophilic system was for maintaining the fermenter temperature. The next major energy consumption was due to the mixing of the influent slurry and fermenter liquor. An approach to optimizing anaerobic fermenter designs by selecting design criteria that maximize the net energy production per unit cost was presented. Based on the results, we believe that the economics of anaerobic fermentation is sufficiently favorable for farm-scale demonstration of this technology.

Hashimoto, A.G.; Chen, Y.R.; Varel, V.H.

1981-01-01

220

Fermentation to ethanol of pentose-containing spent sulfite liquor  

Microsoft Academic Search

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

Shiyuan Yu; Morris Wayman; Sarad K. Parekh

1987-01-01

221

Changes in biochemical and nutritional qualities of aerobic and vacuum-packaged Thua Nao during shelf-life storage.  

PubMed

Thai traditionally fermented soybean (Thua Nao) has been suggested as a good source of available amino acids and aglycone isoflavones. The objective of this research was to investigate the changes of biochemical and nutritional qualities in aerobic- and vacuum-packed thua Nao during the storage at 4 and 40 degrees C for 60 days. Three Thua Nao samples including Bacillus subtilis TN51-fermented Thua Nao (TNB51), spontaneously fermented Thua Nao (TNMX) and commercial product (MH) were used in this study. It was found that the storage of packed Thua Nao at 4 degrees C could prolong the product shelf-life up to 40 days. The moisture contents, pH values and colour L a* b* of these products were not different in both aerobic and vacuum-packaged products and remained stable throughout the experiment. The Thiobarbituric Acid (TBA) values of all storage Thua Nao were increased during storage; this is in particular for the aerobic packages of the TNMX and TNB51 products, indicating high oxidation of lipids. There was a slight decrease in DPPH radical scavenging effect (18%) and phenolic compounds (6%) of the vacuum-packaged product when stored at 4 degrees C. In contrast, the great losses in total phenolic content (44%), inhibitory activity of DPPH radicals (83%) and total antioxidant (41%) were observed when the products were stored aerobically at 40 degrees C. A reduction in total free amino acids was also found with the highest decrease of Arg in both aerobic- (69%) and vacuum-packages (68%). PMID:24498818

Dajantaa, Katekan; Apishartsarangku, Arune; Chukeatirote, Ekachai

2013-06-01

222

Compactified Vacuum in Ten Dimensions.  

NASA Astrophysics Data System (ADS)

Since the 1920's, theories which unify gravity with the other fundamental forces have called for more than the four observed dimensions of space-time. According to such a theory, the vacuum consists of flat four-dimensional space-time described by the Minkowski metric M ^4 and a "compactified" space B. The dimensions of B are small, and the space can only be observed at distance scales smaller than the present experimental limit. These theories have had serious difficulties. The equations of gravity severely restrict the possible choices for the space B. The allowed spaces are complicated and difficult to study. The vacuum is furthermore unstable in the sense that a small perturbation causes the compactified dimensions to expand indefinitely. There is an addition a semi-classical argument which implies that the compactified vacuum be annihilated by virtual black holes. It follows that a universe with compactified extra dimensions could not have survived to the present. These results were derived by applying the equations of general relativity to spaces of more than four dimensions. The form of these equations was assumed to be unchanged by an increase in the number of dimensions. Recently, it has been proposed that gravity in more than four dimensions may involve terms of higher order in the curvature as well as the linear terms present in ordinary general relativity. I illustrate the effect of such terms by considering the example B = S^6 where S ^6 is the six-dimensional sphere. Only when the extra terms are included is this choice of the compactified space allowed. I explore the effect of a small perturbation on such a vacuum. The ten-dimensional spherically symmetric potential is examined, and I determine conditions under which the formation of virtual black holes is forbidden. The example M^4 times S^6 is still plagued by the semi -classical instability, but this result does not hold in general. The requirement that virtual black holes be forbidden provides a test for any theory which predicts a compactified vacuum.

Wurmser, Daniel

1987-09-01

223

Third Generation Biofuels via Direct Cellulose Fermentation  

PubMed Central

Consolidated bioprocessing (CBP) is a system in which cellulase production, substrate hydrolysis, and fermentation are accomplished in a single process step by cellulolytic microorganisms. CBP offers the potential for lower biofuel production costs due to simpler feedstock processing, lower energy inputs, and higher conversion efficiencies than separate hydrolysis and fermentation processes, and is an economically attractive near-term goal for “third generation” biofuel production. In this review article, production of third generation biofuels from cellulosic feedstocks will be addressed in respect to the metabolism of cellulolytic bacteria and the development of strategies to increase biofuel yields through metabolic engineering. PMID:19325807

Carere, Carlo R.; Sparling, Richard; Cicek, Nazim; Levin, David B.

2008-01-01

224

Fermentative metabolism of Chlamydomonas reinhardtii  

SciTech Connect

The anaerobic starch breakdown into end-products in the green alga Chlamydomonas reinhardtii F-60 has been investigated in the dark and in the light. The effects of 3-(3,4-dicholorophenyl)-1,1-dimethylurea (DCMU) and carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone (FCCP) on the fermentation in the light have also been investigated. Anaerobic starch breakdown rate (13.1 +/- 3.5 micromoles C per milligram chlorophyll per hour) is increased 2-fold by FCCP in the dark. Light (100 watts per square meter) decreases up to 4-fold the dark rate, an inhibition reversed by FCCP. In the dark, formate, acetate, and ethanol are formed in the ratios of 2.07:1.07:0.91, and account for roughly 100% of the C from the starch. H/sub 2/ production is 0.43 mole per mole glucose in the starch. Glycerol, D-lactate, and CO/sub 2/ have been detected in minor amounts. In the light, with DCMU and FCCP present, acetate is produced in a 1:1 ratio to formate, and H/sub 2/ evolution is 2.13 moles per mole glucose. When FCCP only is present, acetate production is lower, and CO/sub 2/ and H/sub 2/ evolutions is 1.60 and 4.73 moles per mole glucose, respectively. When DCMU alone is present, CO/sub 2/ and H/sub 2/ photoevolution is higher than in the dark. Without DCMU, CO/sub 2/ and H/sub 2/ evolution is about 100% higher than in its presence. In both conditions, acetate is not formed. In all conditions in the light, ethanol is a minor product. Formate production is least affected by light. The stoichiometry in the dark indicates that starch is degraded via the glycolytic pathway, and pyruvate is broken down into acetyl-CoA and formate. Acetyl-CoA is further dissimilated into acetate and ethanol. In the light, acetate is produced only in the presence of FCCP and, when photophosphorylation is possible, it is used in unidentified reactions. Ethanol formation is inhibited by the light in all conditions. 30 references, 5 figures, 2 tables.

Gfeller, R.P.; Gibbs, M.

1984-05-01

225

Vacuum Energy and Inflation: 2. A Vacuum Energy Universe  

NASA Astrophysics Data System (ADS)

In most of our undergraduate physics courses, we study what can happen in space, but space itself plays a passive role. In basic cosmology, the opposite is true. It is the behavior of space that plays the major role. In this, paper #2, we first discuss the nature of a simple expanding space, and then look at the consequence of applying Newton's law of gravity in this space. The calculations are particularly simple if most of the energy behaves like the vacuum energy discussed earlier in paper #1. The calculation is easy but the results are spectacular.

Huggins, Elisha

2013-10-01

226

The Comparative Evaluation of Fermented and Non-fermented Soybean Extract on Antioxidation and Whitening  

PubMed Central

The present study was performed to compare the antioxidative and whitening activities of fermented soybean extract (FSB) and non-fermented soybean extract (SB). Antioxidative and whitening activities of FSB and SB were evaluated by the determination of DPPH, superoxide radical and hydroxyl radical scavenging activities, linoleic acid inhibition activity, and tyrosinase inhibition activity. FSB showed the higher effect than SB in the antioxidative activities. Also FSB showed the better effect than SB in whitening activity. These results demonstrated that the fermentation played a more excellent role than the non-fermentation in antioxidation and whitening. Therefore, this study suggested that FSB could be a useful cosmetic ingredient for antioxidation and skin whitening. PMID:24278573

Chae, Ga Yeon

2011-01-01

227

Analysis of problems with dry fermentation process for biogas production  

NASA Astrophysics Data System (ADS)

The technology of dry anaerobic fermentation is still meeting with some scepticism, and therefore in most biogas plants are used wet fermentation technology. Fermentation process would be not complete without an optimal controlled condition: dry matter content, density, pH, and in particular the reaction temperature. If is distrust of dry fermentation eligible it was on the workplace of the Department of Power Engineering at University of Zilina built an experimental small-scale biogas station that allows analysis of optimal parameters of the dry anaerobic fermentation, in particular, however, affect the reaction temperature on yield and quality of biogas.

Pilát, Peter; Patsch, Marek; Janda?ka, Jozef

2012-04-01

228

Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii  

DOEpatents

A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol.

Spindler, Diane D. (Indian Hills, CO); Grohmann, Karel (Littleton, CO); Wyman, Charles E. (Lakewood, CO)

1992-01-01

229

Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii  

DOEpatents

A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol. 2 figs.

Spindler, D.D.; Grohmann, K.; Wyman, C.E.

1992-03-31

230

Pilot-Scale Fermentation and Laboratory Nutrient Studies on Mixed-Acid Fermentation  

E-print Network

conversion (effect of air into the model reduced the absolute error of all predictions by >50%. To analyze fermentation data with semi-continuous streams, the Slope method calculates the average flowrate of material from...%, respectively. To estimate nitrogen concentration profiles, a segregated-nitrogen model uses separate mass balances for solid- and liquid-phase nitrogen; the nitrogen reaction flux between phases is assumed to be zero. Using five fermentation trains, each...

Smith, Aaron Douglas

2011-08-08

231

Fermentation Dynamics During Production of Bhaati Jaanr, a Traditional Fermented Rice Beverage of the Eastern Himalayas  

Microsoft Academic Search

Bhaati jaanr is an inexpensive high calorie mild-alcoholic beverage prepared from steamed glutinous rice, consumed as a staple food beverage in the Eastern Himalayan regions of Nepal, India and Bhutan. In this paper, fermentation dynamics including growth kinetics and physico-chemical changes during fermentation of bhaati jaanr were studied. The population of filamentous moulds declined significantly (P < 0.05) each day and finally

Jyoti Prakash Tamang; Saroj Thapa

2006-01-01

232

ULTRASONIC INTENSIFICATION OF METHANE FERMENTATION PROCESS  

Microsoft Academic Search

The investigation studies presented in the paper involve the search for favourable conditions for the disintegration process which prepares the excess sludge for fermentation. The disintegration of sludge involves the application of ultrasounds of narrow frequency (15-50 kHz) and high intensity. The cavitation excited by the acoustic wave passing through the sludge brings about number mechanical and sonochemical effects. The

Ewa ZIELEWICZ-MADEJ

233

Enzymatic and bacterial conversions during sourdough fermentation.  

PubMed

Enzymatic and microbial conversion of flour components during bread making determines bread quality. Metabolism of sourdough microbiota and the activity of cereal enzymes are interdependent. Acidification, oxygen consumption, and thiols accumulation by microbial metabolism modulate the activity of cereal enzymes. In turn, cereal enzymes provide substrates for bacterial growth. This review highlights the role of cereal enzymes and the metabolism of lactic acid bacteria in conversion of carbohydrates, proteins, phenolic compounds and lipids. Heterofermentative lactic acid bacteria prevailing in wheat and rye sourdoughs preferentially metabolise sucrose and maltose; the latter is released by cereal enzymes during fermentation. Sucrose supports formation of acetate by heterofermentative lactobacilli, and the formation of exopolysaccharides. The release of maltose and glucose by cereal enzymes during fermentation determines the exopolysaccharide yield in sourdough fermentations. Proteolysis is dependent on cereal proteases. Peptidase activities of sourdough lactic acid bacteria determine the accumulation of (bioactive) peptides, amino acids, and amino acid metabolites in dough and bread. Enzymatic conversion and microbial metabolism of phenolic compounds is relevant in sorghum and millet containing high levels of phenolic compounds. The presence of phenolic compounds with antimicrobial activity in sorghum selects for fermentation microbiota that are resistant to the phenolic compounds. PMID:24230468

Gänzle, Michael G

2014-02-01

234

Monitoring alcoholic fermentation: an untargeted approach.  

PubMed

This work describes the utility and efficiency of a metabolic profiling pipeline that relies on an unsupervised and untargeted approach applied to a HS-SPME/GC-MS data. This noninvasive and high throughput methodology enables "real time" monitoring of the metabolic changes inherent to the biochemical dynamics of a perturbed complex biological system and the extraction of molecular candidates that are latter validated on its biochemical context. To evaluate the efficiency of the pipeline five different fermentations, carried on a synthetic media and whose perturbation was the nitrogen source, were performed in 5 and 500 mL. The smaller volume fermentations were monitored online by HS-SPME/GC-MS, allowing to obtain metabolic profiles and molecular candidates time expression. Nontarget analysis was applied using MS data in two ways: (i) one dimension (1D), where the total ion chromatogram per sample was used, (ii) two dimensions (2D), where the integrity time vs m/z per sample was used. Results indicate that the 2D procedure captured the relevant information more efficiently than the 1D. It was also seen that although there were differences in the fermentation performance in different scales, the metabolic pathways responsible for production of metabolites that impact the quality of the volatile fraction was unaffected, so the proposed pipeline is suitable for the study of different fermentation systems that can undergo subsequent sensory validation on a larger scale. PMID:24976138

Ferreira, António César Silva; Monforte, Ana Rita; Teixeira, Carla Silva; Martins, Rosa; Fairbairn, Samantha; Bauer, Florian F

2014-07-16

235

Regulation of alcohol fermentation by Escherichia coli  

SciTech Connect

The purpose of this project is to elucidate the way in which the synthesis of ethanol and related fermentation products are regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its coding sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase and have recently cloned the ldh gene. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

Clark, D.P.

1990-01-01

236

Recovery of carboxylic acids produced by fermentation.  

PubMed

Carboxylic acids such as citric, lactic, succinic and itaconic acids are useful products and are obtained on large scale by fermentation. This review describes the options for recovering these and other fermentative carboxylic acids. After cell removal, often a primary recovery step is performed, using liquid-liquid extraction, adsorption, precipitation or conventional electrodialysis. If the carboxylate is formed rather than the carboxylic acid, the recovery process involves a step for removing the cation of the formed carboxylate. Then, bipolar electrodialysis and thermal methods for salt splitting can prevent that waste inorganic salts are co-produced. Final carboxylic acid purification requires either distillation or crystallization, usually involving evaporation of water. Process steps can often be combined synergistically. In-situ removal of carboxylic acid by extraction during fermentation is the most popular approach. Recovery of the extractant can easily lead to waste inorganic salt formation, which counteracts the advantage of the in-situ removal. For industrial production, various recovery principles and configurations are used, because the fermentation conditions and physical properties of specific carboxylic acids differ. PMID:24751382

López-Garzón, Camilo S; Straathof, Adrie J J

2014-01-01

237

Forecasting for fermentation operational decision making.  

PubMed

An awareness of the likely future behavior of a batch or a fed-batch fermentation process is valuable information that can be exploited to improve product consistency and maximize profitability. For example, by making operational policy changes in a feedforward control sense, improved consistency can be facilitated, while prior knowledge of batch productivity, or the end time, can help determine the downstream processing configuration and upstream process scheduling. In this article, forecasting methods based on multivariate batch statistical data analysis procedures are contrasted with case-based reasoning (CBR). Additionally, the importance of appropriate statistical data prescreening and the choice of a suitable metric for case selection are investigated. Two industrial case studies are considered, a fed-batch pharmaceutical fermentation and a batch beer fermentation process. It is demonstrated that, following appropriate statistical prescreening of the data, in terms of forecasting performance, CBR is comparable to linear projection to latent structures (PLS), for the more straightforward problem, i.e., the batch beer fermentation, while for the more complex case-the pharmaceutical process-CBR exhibits enhanced performance over PLS. PMID:19194911

Montague, Gary A; Martin, Elaine B; O'Malley, Christopher J

2008-01-01

238

Removing Biostatic Agents From Fermentation Solutions  

NASA Technical Reports Server (NTRS)

Liquid carbon dioxide inexpensive solvent. Inexpensive process proposed for removing such poisons as furfural and related compounds from fermentation baths of biomass hydrolysates. New process based on use of liquid carbon dioxide as extraction solvent. Liquid CO2 preferable to such other liquid solvents as ether or methylene chloride.

Du Fresne, E. R.

1984-01-01

239

Fermentable sugars by chemical hydrolysis of biomass  

E-print Network

Fermentable sugars by chemical hydrolysis of biomass Joseph B. Binder and Ronald T. Raines1 19, 2009) Abundant plant biomass has the potential to become a sustainable source of fuels of biomass into monosaccharides. Add- ing water gradually to a chloride ionic liquid-containing catalytic

Raines, Ronald T.

240

Can yeast transcriptomics help improve wine fermentation?  

Microsoft Academic Search

Wine fermentation is a dynamic and complex process in which the yeast cell is subjected to multiple stress conditions. A successful adaptation involves changes in gene expression profiles where a large number of genes are up- or down-regulated. Functional genomic approaches are com- monly used to obtain global gene expression profiles, providing a comprehensive view of yeast physiology. We used

C. Varela; J. Cárdenas; E. Agosin

241

A review of antifoam mechanisms in fermentation.  

PubMed

Antifoam (defoamer) chemicals are a crucial part of many commercial fermentation processes. Reviewed are the types of defoamers and their mode of operation. Also presented is a simple model, which simulates foam growth as functions of defoamer concentration, air hold-up, reactor volume and air flow rate. PMID:12355311

Pelton, R

2002-10-01

242

Biotechnology, fermentation, foods and the future  

SciTech Connect

This article reviews the future of biotechnology in the food industry - the continuing development of methods for controlled fermentation and enzyme reaction, combined with the projected culturing of new and useful organisms through gene-splicing. At present, the largest enzyme market in the food industry is for glucose isomerase to convert glucose to high-fructose corn syrup.

Wesley, P.

1981-02-01

243

Traditional fermented protein condiments in Nigeria  

Microsoft Academic Search

Traditional fermented condiments (dawadawa, iru, ogiri) based on vegetable proteins, and consumed by different ethnic groups in Nigeria have been the pride of culinary traditions for centuries. It is evident that these products have played a major role in the food habits of communities in the rural regions serving not only as a nutritious non-meat proteins substitute but also as

O. K. Achi

244

Olive fermentation brine: biotechnological potentialities and valorization  

Microsoft Academic Search

Olive fermentation brine causes an important local environmental problem in Mediterranean countries. Valorization is a relatively new concept in the field of industrial residue management, promoting the principle of sustainable development. One of the valorization objectives regarding food processing by-products is the recovery of fine chemicals and the production of value metabolites via chemical and biotechnological processes. In this article,

Imen Fendri; Mohamed Chamkha; Mohamed Bouaziz; Marc Labat; Sami Sayadi; Slim Abdelkafi

2012-01-01

245

Probiotics Bacteria in Fermented Dairy Products  

Microsoft Academic Search

The nutritional value of diary based product that contains probiotic bacteria on the gastrointestinal health and functions have been investigated in this study. Both probiotic Lactobacillus bulgaricus and Streptococcus thermophilus species, contribute to the formation of yogurt as a result of anaerobi c fermentation of lactic acid in the milk. The benefits of yogurt consumption on the gastrointestinal function mediated

Omer Turki Mamdoh Ershidat; Ayman Suliman Mazahreh

2009-01-01

246

Effects of fermentation substrate conditions on corn-soy co-fermentation for fuel ethanol production.  

PubMed

Soy skim, a protein-rich liquid co-product from the aqueous extraction of soybeans, was co-fermented with corn to produce ethanol. Effects of soy skim addition level, type of skim, corn particle size, water-to-solids ratio, and urea on co-fermentation were determined. The addition of 20-100% skim increased the fermentation rate by 18-27% and shortened the fermentation time by 5-7h without affecting ethanol yield. Finely ground corn or high water-to-solids ratio (? 3.0) in the mash gave higher fermentation rates, but did not increase the ethanol yield. When the water was completely replaced with soy skim, the addition of urea became unnecessary. Soy skim retentate that was concentrated by nanofiltration increased fermentation rate by 25%. The highest level of skim addition resulted in a finished beer with 16% solids, 47% protein (dwb) containing 3.6% lysine, and an ethanol yield of 39 g/100g dry corn. PMID:22784965

Yao, Linxing; Lee, Show-Ling; Wang, Tong; de Moura, Juliana M L N; Johnson, Lawrence A

2012-09-01

247

Inhibition of malolactic fermentation by a peptide produced by Saccharomyces cerevisiae during alcoholic fermentation.  

PubMed

The ability of Saccharomyces to inhibit Oenococcus oeni during the alcoholic fermentation by mechanisms other than SO(2) production was investigated. During fermentation in synthetic grape juice, S. cerevisiae strain RUBY.ferm inhibited the malolactic fermentation by O. oeni while strain EC1118 did not despite both strains producing similar amounts of SO(2). The bacterial inhibition exerted by RUBY.ferm was diminished when the wine was treated with proteases but not through the addition of nutrients. Wine fermented by RUBY.ferm was fractionated based on molecular weight and each fraction tested for the ability to inhibit the growth of O. oeni. The fraction containing compounds larger than 3 kDa was the sole inhibitory fraction. The inhibitory fraction was analyzed by SDS PAGE and showed a 5.9 kDa protein band present in wine fermented by RUBY.ferm that was not present in wine fermented by a non-antagonistic yeast, S. cerevisiae strain Saint Georges S101. The ability of the peptide to inhibit O. oeni seemed to be dependent on the presence of SO(2). PMID:17610976

Osborne, James P; Edwards, Charles G

2007-08-15

248

Vacuum friction in rotating particles  

E-print Network

We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

A. Manjavacas; F. J. García de Abajo

2010-09-21

249

Leak Detection in Vacuum Technology  

NSDL National Science Digital Library

This is a description for a learning module from Maricopa Advanced Technology Education Center. This PDF describes the module; access may be purchased by visiting the MATEC website. This module explains the importance of determining vacuum system integrity through leak qualification tests. Learners are introduced to a systematic set of methods for determining the existence of a leak, as well as its size, type and location. Emphasis is placed on the use of a helium mass spectrometer leak detector (MSLD). The centerpiece of this module is a computer program that simulates leak detection with an MSLD.

2012-12-26

250

Vacuum energy and relativistic invariance  

E-print Network

It is argued that the zero-point energies of free quantum fields diverge at most quadratically and not quartically, as is generally believed. This is a consequence of the relativistic invariance which requires that the energy density of the vacuum $\\rho$ and its pressure $p$ satisfy $\\rho=-p$. The usually obtained quartic divergence is an artifact of the use of a noninvariant regularization which violates this relation. One consequence of our results is that the zero-point energies of free massless fields vanish. Implications for the cosmological constant problem are briefly discussed.

E. Kh. Akhmedov

2002-04-04

251

Shielding vacuum fluctuations with graphene  

E-print Network

The Casimir-Polder interaction of ground-state and excited atoms with graphene is investigated with the aim to establish whether graphene systems can be used as a shield for vacuum fluctuations of an underlying substrate. We calculate the zero-temperature Casimir-Polder potential from the reflection coefficients of graphene within the framework of the Dirac model. For both doped and undoped graphene we show limits at which graphene could be used effectively as a shield. Additional results are given for AB-stacked bilayer graphene.

Sofia Ribeiro; Stefan Scheel

2013-10-22

252

Laser-triggered vacuum switch  

DOEpatents

A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable.

Brannon, Paul J. (Albuquerque, NM); Cowgill, Donald F. (Danville, CA)

1990-01-01

253

Vacuum Friction in Rotating Particles  

SciTech Connect

We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

Manjavacas, A.; Garcia de Abajo, F. J. [Instituto de Optica--CSIC, Serrano 121, 28006 Madrid (Spain)

2010-09-10

254

Acoustical experiment of yogurt fermentation process.  

PubMed

One of the important factors through food manufacturing is hygienic management. Thus, food manufactures prove their hygienic activities by taking certifications like a Hazard Analysis and Critical Control Point (HACCP). This concept also applies to food monitoring. Acoustical measurements have advantage for other measurement in food monitoring because they make it possible to measure with noncontact and nondestructive. We tried to monitor lactic fermentation of yogurt by a probing sensor using a pair of acoustic transducers. Temperature of the solution changes by the reaction heat of fermentation. Consequently the sound velocity propagated through the solution also changes depending on the temperature. At the same time, the solution change its phase from liquid to gel. The transducers usage in the solution indicates the change of the temperature as the change of the phase difference between two transducers. The acoustic method has advantages of nondestructive measurement that reduces contamination of food product by measuring instrument. The sensor was inserted into milk with lactic acid bacterial stain of 19 degrees C and monitored phase retardation of propagated acoustic wave and its temperature with thermocouples in the mild. The monitoring result of fermentation from milk to Caspian Sea yogurt by the acoustic transducers with the frequency of 3.7 MHz started to show gradient change in temperature caused by reaction heat of fermentation but stop the gradient change at the end although the temperature still change. The gradient change stopped its change because of phase change from liquid to gel. The present method will be able to measure indirectly by setting transducers outside of the measuring object. This noncontact sensing method will have great advantage of reduces risk of food contamination from measuring instrument because the measurement probes are set out of fermentation reactor or food containers. Our proposed method will contribute to the hygienization for the food manufacture industry. PMID:16793107

Ogasawara, H; Mizutani, K; Ohbuchi, T; Nakamura, T

2006-12-22

255

2-KETOGLUCONATE FERMENTATION BY STREPTOCOCCUS FAECALIS  

PubMed Central

Goddard, J. L. (University of Oklahoma School of Medicine, Oklahoma City), and J. R. Sokatch. 2-Ketogluconate fermentation by Streptococcus faecalis. J. Bacteriol. 87:844–851. 1964.—Streptococcus faecalis 10Cl did not grow with 2-ketogluconate alone as an energy source, but did grow when gluconate was added. More growth was obtained than could be accounted for by the gluconate alone. The requirement for gluconate in the stimulation of growth on 2-ketogluconate was found to be stoichiometric, not catalytic. Glucose did not replace gluconate in this phenomenon, apparently owing to the repression of the 2-ketogluconate pathway by glucose. Resting cells grown on a combination of gluconate and 2-ketogluconate did ferment 2-ketogluconate without added gluconate. Fermentation balance studies with resting cells detected the following products in moles (per mole of 2-ketogluconate): carbon dioxide, 0.98; lactic acid, 0.19; formic acid, 1.42; acetic acid, 0.70; and ethanol, 0.42. 2-Ketogluconate-1-C14 and -2-C14 were prepared and fermented. The data were interpreted to show that 90% of the substrate was decarboxylated to carbon dioxide and pentose phosphate. Pentose phosphate was then fermented to pyruvate through the sedoheptulose diphosphate variation of the pentose phosphate pathway found in this organism. The other 10% of the substrate was converted to pyruvate by way of the Entner-Doudoroff pathway. Calculations of the energy available by the above combination of pathways indicated that about 2.3 moles of adenosine triphosphate per mole of 2-ketogluconate could be obtained if the energy available in acetate formation is conserved through the acetokinase reaction. PMID:14137623

Goddard, J. L.; Sokatch, J. R.

1964-01-01

256

Vacuum Attachment for XRF Scanner  

NASA Technical Reports Server (NTRS)

Vacuum apparatuses have been developed for increasing the range of elements that can be identified by use of x-ray fluorescent (XRF) scanners of the type mentioned in the two immediately preceding articles. As a consequence of the underlying physical principles, in the presence of air, such an XRF scanner is limited to analysis of chlorine and elements of greater atomic number. When the XRF scanner is operated in a vacuum, it extends the range of analysis to lower atomic numbers - even as far as aluminum and sodium. Hence, more elements will be available for use in XRF labeling of objects as discussed in the two preceding articles. The added benefits of the extended capabilities also have other uses for NASA. Detection of elements of low atomic number is of high interest to the aerospace community. High-strength aluminum alloys will be easily analyzed for composition. Silicon, a major contaminant in certain processes, will be detectable before the process is begun, possibly eliminating weld or adhesion problems. Exotic alloys will be evaluated for composition prior to being placed in service where lives depend on them. And in the less glamorous applications, such as bolts and fasteners, substandard products and counterfeit items will be evaluated at the receiving function and never allowed to enter the operation

Schramm, Harry F.; Kaiser, Bruce

2005-01-01

257

Vacuum silicon photomultipliers: Recent developments  

NASA Astrophysics Data System (ADS)

VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an innovative design for a modern hybrid, high gain, silicon based photodetector based on the combination of a SiPM with a hemispherical vacuum glass PMT standard envelope. In such a device photoelectrons emitted by the photocathode are accelerated and focused by an electric field towards a small focal area covered by the SiPM which therefore acts as an amplifier, thus substituting the classical dynode chain of a PMT. With a view to the realization of a first prototype of VSiPMT our group is carrying out a preliminary work aimed at the study of SiPM performances as an electron detector, including an accurate Geant4-based simulation of the interaction between SiPM and electron beams. In order to perform a full characterization of the SiPM we developed an experimental setup for the extraction and the acceleration of a beam of backward secondary electrons emitted after the bombardment of a carbon foil by a proton beam extracted in a TTT-3 accelerator.

Barbarino, Giancarlo; Barbato, Felicia Carla Tiziana; Campajola, Luigi; de Asmundis, Riccardo; De Rosa, Gianfranca; Mollo, Carlos Maximiliano; Vivolo, Daniele

2013-08-01

258

Vacuum systems for the ILC helical undulator  

SciTech Connect

The International Linear Collider (ILC) positron source uses a helical undulator to generate polarized photons of {approx}10 MeV 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 {approx}100 nTorr in a narrow chamber of 4-6 mm inner diameter, with a long length of 100-200 m, 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.

Malyshev, O. B.; Scott, D. J.; Bailey, I. R.; Barber, D. P.; Baynham, E.; Bradshaw, T.; Brummitt, A.; Carr, S.; Clarke, J. A.; Cooke, P.; Dainton, J. B.; Ivanyushenkov, Y.; Malysheva, L. I.; Moortgat-Pick, G. A.; Rochford, J. [ASTeC, STFC Daresbury Laboratory, Warrington, WA4 4AD (United Kingdom); Cockcroft Institute, Warrington WA4 4AD (United Kingdom); ASTeC, STFC Daresbury Laboratory Warrington WA4 4AD (United Kingdom); Cockcroft Institute, Warrington WA4 4AD (United Kingdom) and Department of Physics, University of Liverpool, Oxford St. Liverpool L69 7ZE (United Kingdom); Department of Physics, University of Liverpool Oxford St. Liverpool L69 7ZE (United Kingdom); Cockcroft Institute, Warrington WA4 4AD (United Kingdom); DESY-Hamburg, Notkestrasse 85 22607 Hamburg (Germany); STFC Rutherford Appleton Laboratory Chilton, Didcot Oxfordshire OX11 0QX (United Kingdom); ASTeC, STFC Daresbury Laboratory Warrington WA4 4AD (United Kingdom); Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool Oxford St. Liverpool L69 7ZE (United Kingdom); Cockcroft Institute, Warrington WA4 4AD [United Kingdom and Department of Physics, University of Liverpool, Oxford St., Liverpool L69 7ZE (United Kingdom); STFC Rutherford Appleton Laboratory, Chilton Didcot Oxfordshire OX11 0QX (United Kingdom); Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Department of Physics, University of Liverpool Oxford St. Liverpool L69 7ZE (United Kingdom); Institute of Particle Physics Phenomenology, University of Durham Durham DH1 3LE, (United Kingdom); CERN, CH-1211 Geneva 23 (Switzerland); STFC Rutherford Appleton Laboratory, Chilton Didcot Oxfordshire OX11 0QX (United Kingdom)

2007-07-15

259

The large-scale structure of vacuum  

E-print Network

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.

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

2014-05-15

260

The large-scale structure of vacuum  

E-print Network

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.

Albareti, F D; Maroto, A L

2014-01-01

261

Development of the Vacuum Comparison Standard Device  

NASA Astrophysics Data System (ADS)

The standard device of vacuum comparison is built compared the dynamic method, the static compared method and the static expansion method, this device combined three methods are to meet the wide range of calibrating vacuum gauge. It is used to calibrate 1×105?5×10-4 Pa within the scope of various types of vacuum gauge. The characteristic of this equipment is a simple in structure, easy to operate, high efficiency, practicability of the vacuum standard. Especially suitable for a large number of routine calibrations, the device consists of turbo-molecular pump, calibration container, the standard vacuum gauge and metal expansion valves and other components, and its main technical specifications in line with the International Standards Organization (ISO) and the domestic vacuum standards.

Shufeng, Zhang; Ruihai, Song; Ming, Gao; Huan, Wang; Junwei, Jia; Hulin, Tian

262

Robot design for a vacuum environment  

NASA Technical Reports Server (NTRS)

The cleanliness requirements for many processing and manufacturing tasks are becoming ever stricter, resulting in a greater interest in the vacuum environment. Researchers discuss the importance of this special environment, and the development of robots which are physically and functionally suited to vacuum processing tasks. Work is in progress at the Center for robotic Systems in Microelectronics (CRSM) to provide a robot for the manufacture of a revolutionary new gyroscope in high vacuum. The need for vacuum in this and other processes is discussed as well as the requirements for a vacuum-compatible robot. Finally, researchers present details on work done at the CRSM to modify an existing clean-room compatible robot for use at high vacuum.

Belinski, S.; Trento, W.; Imani-Shikhabadi, R.; Hackwood, S.

1987-01-01

263

Electromagnetic Fields in the QCD Vacuum  

E-print Network

Quarks play an active role in shaping the QCD vacuum structure. Being dual carriers of both `color' and `electric' charges they also respond to externally applied electromagnetic fields. Thus, in principle, the vacuum of strong interactions influences higher order QED processes such as photon-photon scattering. We survey here the current status of the understanding of the vacuum structure of strong interactions, and take a fresh look at its electromagnetic properties.

Johann Rafelski; H. -Thomas Elze

1998-06-16

264

Advanced Photon Source accelerator ultrahigh vacuum guide  

SciTech Connect

In this document the authors summarize the following: (1) an overview of basic concepts of ultrahigh vacuum needed for the APS project, (2) a description of vacuum design and calculations for major parts of APS, including linac, linac waveguide, low energy undulator test line, positron accumulator ring (PAR), booster synchrotron ring, storage ring, and insertion devices, and (3) cleaning procedures of ultrahigh vacuum (UHV) components presently used at APS.

Liu, C.; Noonan, J.

1994-03-01

265

Electrical Strength of Multilayer Vacuum Insulators  

SciTech Connect

The electrical strength of vacuum insulators is a key constraint in the design of particle accelerators and pulsed power systems. Vacuum insulating structures assembled from alternating layers of metal and dielectric can result in improved performance compared to conventional insulators, but previous attempts to optimize their design have yielded seemingly inconsistent results. Here, we present two models for the electrical strength of these structures, one assuming failure by vacuum arcing between adjacent metal layers and the other assuming failure by vacuum surface flashover. These models predict scaling laws which are in agreement with the experimental data currently available.

Harris, J R; Kendig, M; Poole, B; Sanders, D M; Caporaso, G J

2008-07-01

266

Cold vacuum drying facility design requirements  

SciTech Connect

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.

IRWIN, J.J.

1999-07-01

267

Attractor Explosions and Catalyzed Vacuum Decay  

E-print Network

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.

Daniel Green; Eva Silverstein; David Starr

2006-05-04

268

High throughput biotechnology in traditional fermented food industry.  

PubMed

Traditional fermented food is not only the staple food for most of developing countries but also the key healthy food for developed countries. As the healthy function of these foods are gradually discovered, more and more high throughput biotechnologies are being used to promote the old and new industry. As a result, the microflora, manufacturing processes and product healthy function of these foods were pushed forward either in the respect of profundity or extensiveness nowadays. The application and progress of the high throughput biotechnologies into traditional fermented food industries were different from each other, which was reviewed and detailed by the catalogues of fermented milk products (yogurt, cheese), fermented sausages, fermented vegetables (kimchi, sauerkraut), fermented cereals (sourdough) and fermented beans (tempeh, natto). Given the further promotion by high throughput biotechnologies, the middle and/or down-stream process of traditional fermented foods would be optimized and the process of industrialization of local traditional fermented food having many functional factors but in small quantity would be accelerated. The article presents some promising patents on traditional fermented food industry. PMID:20863273

Yang, Yong; Xu, Rong-man; Song, Jia; Wang, Wei-min

2010-11-01

269

Scale-up of rifamycin B fermentation with Amycolatoposis mediterranei.  

PubMed

Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9-25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9-25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation with A. mediterranei XC 9-25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentaion in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous feed from a 15 L fermentor to a 7 m(3) fermentor and further to a 60 m(3) fermentor was realized successfully. The potency of rifamycin B fermentation in the 7 m(3) fermentor and in the 60 m(3) fermentor reached 17.25 g/L and 19.11 g/L, respectively. PMID:15547969

Jin, Zhi-Hua; Lin, Jian-Ping; Cen, Pei-Lin

2004-12-01

270

Laser sealed vacuum insulation window  

DOEpatents

A laser sealed evacuated window panel is comprised of two glass panes held spaced apart in relation to each other by a plurality of spherical glass beads and glass welded around the edges to provide an evacuated space between the glass panes that is completely glass sealed from the exterior. The glass welded edge seal is obtained by welding the edges of the glass panes together with a laser beam while the glass panes and bead spacers are positioned in a vacuum furnace and heated to the annealing point of the glass to avoid stress fracture in the area of the glass weld. The laser welding in the furnace can be directed around the perimeter of the glass panel by a combination of rotating the glass panel and linearly translating or aiming the laser with a relay mirror.

Benson, David K. (Golden, CO); Tracy, C. Edwin (Golden, CO)

1987-01-01

271

Fermion Mass Mixing in Vacuum  

NASA Astrophysics Data System (ADS)

Renormalization group procedure for effective particles is applied to a theory of fermions that interact only through mass mixing terms in their Hamiltonian. Problems with virtual pair production in vacuum are avoided by using the front form of Hamiltonian dynamics. Masses and states of physical fermions emerge at the end of a calculation that is carried out exactly irrespective of the strength of the mass mixing terms. An a priori infinite set of renormalization group equations for all momentum modes of fermion quantum fields is reduced to just one equation for a two-by-two mass matrix. In distinction from scalars, fermions never become tachyons but appear chirally rotated when the mass mixing interaction term is sufficiently strong.

G?azek, Stanis?aw D.

2014-06-01

272

Pressure/vacuum relief valve  

SciTech Connect

This patent describes a pressure/vacuum relief valve for a fluid containing vessel. It comprises: an elongated cylinder having a wall and having end walls closing the cylinder ends, one end portion of the cylinder wall having a first port communicating with the fluid in the vessel and the other end portion of the cylinder having a second port communicating with the atmosphere; a piston in the cylinder normally sealed with the inner wall surface thereof between the first and second ports; a piston rod axially projecting from the piston through the respective cylinder end wall; elongated cage means having a closed end and an open end axially connected with the respective cylinder end wall around the respective end portion of the piston rod; and, pressure responsive elongated pin means interposed between the respective end of the piston rod and the closed end of the respective cage for normally maintaining the piston in valve closed position.

Taylor, J.S.

1990-12-18

273

TRIUMF cyclotron vacuum system refurbishing  

NASA Astrophysics Data System (ADS)

The cyclotron at TRIUMF was commissioned to full energy in 1974. The volume of the cyclotron vacuum tank is about 100 m3 and it operates at 5×10-8 Torr pressure during beam production. The pumping is mainly based on a Phillips B-20 cryogenerator (Stirling cycle 4-cylinder engine). The cryogenerator supplies helium gas at 16 K and 70 K to cryopanels in the tank. The decreasing reliability of the B-20 and demanding maintenance requirements triggered the decision to completely overhaul or replace the cryogenerator. Replacement with the LINDE-1630 helium refrigerator was found to be the most attractive (technically and economically) option. The details of the proposal with installation of the helium refrigerator and with a continuous flow liquid nitrogen shield cooling system are presented.

Sekachev, I.

2008-03-01

274

SXLS Phase 2 vacuum system  

SciTech Connect

Phase 1 of the SXLS (Superconducting X-Ray Lithography Source) is described. It is a room temperature, racetrack-shaped electron storage ring, 8.5 meters in circumference. The Phase 2 design consists of replacing the two room temperature 180{degree} dipole magnets of Phase 1 with superconducting magnets. However, even though superconducting magnets are used, the vacuum chambers within them will operate at room temperature. The chambers are constructed as weldments and are made of INCONEL-625. They are bakeable to 150{degrees}C in-situ and incorporate nine photon beam ports. Each have built-in distributed sputter-ion pumps (DIP), non-evaporable getter (NEG) pumps, beam position monitors, and ion clearing electrodes. R D is underway to optimize the DIP, which much operate at 3.86 Tesla, and to develop a low photo yield coating or treatment for the internal surfaces of the chambers.

Schuchman, J.C.; Chou, T.S.; Halama, H.; Hsieh, H.; Kim, T.; Pjerov, S.; Staicu, F.

1991-01-01

275

Discharge Properties and Emitted Electromagnetic Wave Spectrum in Low Vacuum Region of Vacuum Interrupter  

Microsoft Academic Search

Study on reliability of vacuum interrupter (VI) such as detection method of the slow leak has been extensively carried out, while study on discharge properties in low vacuum of VI is still insufficient. In this report, we experimentally investigated discharge properties inside VI under closed contact and open contact conditions of main contactors in low vacuum of VI to simulate

Mohamad Kamarol; Shinya Ohtsuka; Hitoshi Saitou; Masayuki Sakaki; Masayuki Hikita

2005-01-01

276

Fermentation of wort containing deoxynivalenol and zearalenone.  

PubMed

Wort containing deoxynivalenol and zearalenone, each added at a level of 1.9 ?g/mL, was fermented by 3 strains ofSaccharomyces cerevisiae for 7 or 9 days to make beer. Analysis showed that deoxynivalenol was stable during this process. The major metabolite of zearalenone was ? - zearalenol, which formed in up to 69% of the initial zearalenone concentration, while up to 8.1% of the initial zearalenone was converted to ? - zearalenol. The major part of the metabolism of zearalenone occurred by 1 - 2 days. Control experiments, where the yeasts were omitted and deoxynivalenol, zearalenone and ? - and ? - zearalenol were added, showed good recovery and stability of the mycotoxins over the 7-9 day time period. No deoxynivalenol, zearalenone, ?-zearalenol or ?-zearalenol was detected in control yeast fermentations where they were not added to the wort. PMID:23606000

Scott, P M; Kanhere, S R; Daley, E F; Farber, J M

1992-09-01

277

Optimal temperature control for batch beer fermentation.  

PubMed

Optimal control theory was applied to the process of batch beer fermentation. The performance functional considered was a weighted sum of maximum ethanol production and minimum time. Calculations were based on the model of Engasser et al. modified to include temperature effects. Model parameters were determined from isothermal batch fermentations. The fermentor cooling duty was the single available control. Temperature state variable constraints as well as control variable constraints were considered. The optimal control law is shown to be bang-bang control with the existence of a singular arc corresponding to isothermal operation at the maximum temperature constraint. An iterative algorithm is presented for computing appropriate switching times using a penalty-function-augmented performance functional. PMID:18584597

Gee, D A; Ramirez, W F

1988-02-20

278

Extraction chemistry of fermentation product carboxylic acids.  

PubMed

Within the framework of a program aiming to improve the existing extractive recovery technology of fermentation products, the state of the art is critically reviewed. The acids under consideration are propionic, lactic, pyruvic, succinic, fumaric, maleic, malic, itaconic, tartaric, citric, and isocitric, all obtained by the aerobic fermentation of glucose via the glycolytic pathway and glyoxylate bypass. With no exception, it is the undissociated monomeric acid that is extracted into carbon-bonded and phosphorus-bonded oxygen donor extractants. In the organic phase, the acids are usually dimerized. The extractive transfer process obeys the Nernst law, and the measured partition coefficients range from about 0.003 for aliphatic hydrocarbons to about 2 to 3 for aliphatic alcohols and ketones to about 10 or more for organophosphates. Equally high distribution ratios are measured when long-chain tertiary amines are employed as extractants, forming bulky salts preferentially soluble in the organic phase. PMID:18555324

Kertes, A S; King, C J

1986-02-01

279

Production of clean pyrolytic sugars for fermentation.  

PubMed

This study explores the separate recovery of sugars and phenolic oligomers produced during fast pyrolysis with the effective removal of contaminants from the separated pyrolytic sugars to produce a substrate suitable for fermentation without hydrolysis. The first two stages from a unique recovery system capture "heavy ends", mostly water-soluble sugars and water-insoluble phenolic oligomers. The differences in water solubility can be exploited to recover a sugar-rich aqueous phase and a phenolic-rich raffinate. Over 93?wt?% of the sugars is removed in two water washes. These sugars contain contaminants such as low-molecular-weight acids, furans, and phenols that could inhibit successful fermentation. Detoxification methods were used to remove these contaminants from pyrolytic sugars. The optimal candidate is NaOH overliming, which results in maximum growth measurements with the use of ethanol-producing Escherichia coli. PMID:24706373

Rover, Marjorie R; Johnston, Patrick A; Jin, Tao; Smith, Ryan G; Brown, Robert C; Jarboe, Laura

2014-06-01

280

Engineering the Escherichia coli Fermentative Metabolism  

NASA Astrophysics Data System (ADS)

Fermentative metabolism constitutes a fundamental cellular capacity for industrial biocatalysis. Escherichia coli is an important microorganism in the field of metabolic engineering for its well-known molecular characteristics and its rapid growth. It can adapt to different growth conditions and is able to grow in the presence or absence of oxygen. Through the use of metabolic pathway engineering and bioprocessing techniques, it is possible to explore the fundamental cellular properties and to exploit its capacity to be applied as industrial biocatalysts to produce a wide array of chemicals. The objective of this chapter is to review the metabolic engineering efforts carried out with E. coli by manipulating the central carbon metabolism and fermentative pathways to obtain strains that produce metabolites with high titers, such as ethanol, alanine, lactate and succinate.

Orencio-Trejo, M.; Utrilla, J.; Fernández-Sandoval, M. T.; Huerta-Beristain, G.; Gosset, G.; Martinez, A.

281

Mixed fermentation for natural product drug discovery  

Microsoft Academic Search

Natural products continue to play a major role in drug discovery and development. However, chemical redundancy is an ongoing\\u000a problem. Genomic studies indicate that certain groups of bacteria and fungi have dozens of secondary metabolite pathways that\\u000a are not expressed under standard laboratory growth conditions. One approach to more fully access the metabolic potential of\\u000a cultivatable microbes is mixed fermentation,

Robin K. Pettit

2009-01-01

282

Fermentation of sorghum dough by genus Lactobacillus  

E-print Network

was studied using baker's yeast, isolated pure Lactobacillus, a combination of baker's yeast and isolated pure Lactobaci llus, and microorganisms that occur naturally in sorghum flour. Changes in pH and percent acidity caused by growth of the var- ious... cultures in sorghum flour were measured. Generally, the dough fermented by pure Lactobacillus had lower final pH values and higher final percent acidity compared to the other starter cultures, except for one strain of isolated Lactobacillus which...

Clark, Susie Hong Nguyen

2012-06-07

283

Recovery of succinic acid from fermentation broth  

Microsoft Academic Search

Succinic acid is of high interest as bio-feedstock for the chemical industry. It is a precursor for a variety of many other\\u000a chemicals, e.g. 1,4-butandiol, tetrahydrofuran, biodegradable polymers and fumaric acid. Besides optimized production strains\\u000a and fermentation processes it is indispensable to develop cost-saving and energy-effective downstream processes to compete\\u000a with the current petrochemical production process. Various methods such as

Tanja Kurzrock; Dirk Weuster-Botz

2010-01-01

284

Mould?fermented foods: Recent developments  

Microsoft Academic Search

Mould?ripened foods are used worldwide by tradition. Especially in Asia a variety of foods are produced applying various fungal genera. In Europe mould?ripened foods are predominantly cheeses and meats, fermented with Penicillia. Penicillium roquefortii is used for blue cheese, P. camembertii for white cheese, and P. nalgiovense for salami and certain raw hams.It is required that moulds employed for foods

L. Leistner

1990-01-01

285

A review of antifoam mechanisms in fermentation  

Microsoft Academic Search

  Antifoam (defoamer) chemicals are a crucial part of many commercial fermentation processes. Reviewed are the types of defoamers\\u000a and their mode of operation. Also presented is a simple model, which simulates foam growth as functions of defoamer concentration,\\u000a air hold-up, reactor volume and air flow rate. Journal of Industrial Microbiology & Biotechnology (2002) 29, 149–154 doi:10.1038\\/sj.jim.7000293

R Pelton

2002-01-01

286

Energy Utilization in Fermentation Ethanol Production  

E-print Network

ENERGY UTILIZATION IN FERMENTATION ETHANOL PRODUCTION CHARLES E. EASLEY Vice President Raphael Katzen Associates International, Inc. Cincinnati, Ohio ABSTRACT The fuel ethanol industry has put into practice several techniques for min... consumption. The second reason relates to the net energy production of a fuel ethanol plant. Since ethanol has a heating value of about 76,000 Btu per gallon (LHV) , it can be argued that fuel ethanol should not require more than this amount of energy...

Easley, C. E.

287

Enzyme conversion of biomass to fermentable sugars  

SciTech Connect

Saccharification studies indicated the suitability of Trichoderma viride 253 crude enzyme preparation as a promising agent for saccharifying sugarcane baggase hemicellulose, treated ..cap alpha..-cellulose, and alkali-treated bagasse. Utilization of sugarcane bagasse for the fermentative production of cellulases, hemicellulases, and single cell protein (SCP) by T. viride 253 can be outlined as follows: (a) Production of extracellular cellulases and hemicellulases in a forced aeration-stirred tank fermentor using crude bagasse as the sole carbon source in Dox's culture medium. (b) Treatment of the remaining biodegraded bagasse with NaOH. (c) Refermentation in static culture of bagasse as the sole carbon source in Dox's culture medium for production of SCP material. The yeast, Pachysolen tannophilus, is capable of converting xylose and glucose to ethanol. Fermentation of the crude hydrolyzate from straw revealed low efficiencies of 40 to 60%. As anticipated, interfering substances are present in these crude substrates. Further procedures for optimization of both processing of hydrolyzates and fermentation are being investigated. Endoglucanase and cellobiase are inhibited by glucose, and cellobiose inhibits exoglucanase. A yeast (Candida wickerhamii) was isolated which ferments water soluble oligosaccharides. Because oligosaccharides (cellulodxtrins) are easier to prepare than glucose from cellulose, attention has been directed toward substrate preparation and organism characterization. While the literature contains several methods for preparing cellulodextrins, all the methods involve several steps or involve the removal or neutralization of strong acids. A simple method has been developed using trifluoroacetic acid (TFA)-water for the hydrolysis. Analysis by TLC and HPLC shows a series of cellulodextrins (DP1-6) which are completely converted to ethanol by Candida wickerhamii in 4 to 5 days.

Bagby, M.O. (comp.)

1983-01-01

288

Improving the yield from fermentative hydrogen production  

Microsoft Academic Search

Efforts to increase H2 yields from fermentative H2 production include heat treatment of the inoculum, dissolved gas removal, and varying the organic loading rate. Although\\u000a heat treatment kills methanogens and selects for spore-forming bacteria, the available evidence indicates H2 yields are not maximized compared to bromoethanesulfonate, iodopropane, or perchloric acid pre-treatments and spore-forming\\u000a acetogens are not killed. Operational controls (low

Jeremy T. Kraemer; David M. Bagley

2007-01-01

289

Optical contamination during thermal testing in vacuum  

NASA Technical Reports Server (NTRS)

Comparative tests are described for optical degradation in vacuum systems served by oil-type or ion-type pumping operation. Results show that degradation occurs only during ultraviolet irradiation in vacuum systems with oil-type pumping systems and that it increases with exposure time. Degradation does not occur with ion systems.

Zwiener, J. M.

1970-01-01

290

Thermal versus vacuum magnetization in QED  

Microsoft Academic Search

The magnetized relativistic Fermi and Bose gases are studied at finite temperature and density.In the case of the Fermi gas, the contribution to the magnetization from the vacuum becomes dominant for high magnetic fields, when the thermal contribution saturates. In the case of the charged Bose gas, the (paramagnetic) vacuum--magnetization becomes dominant when the gas changes from a diamagnetic to

P Elmfors; P Liljenberg; D Persson; B S Skagerstam

1994-01-01

291

Vacuum in Gas and Fluid Dynamics  

Microsoft Academic Search

\\u000a In this paper, we review some interesting problems of vacuum states arising in hyperbolic conservations laws with applications\\u000a to gas and fluid dynamics. We present the current status of the understanding of compressible Euler flows near vacuum and\\u000a discuss related open problems.

Juhi Jang; Nader Masmoudi

292

Vacuum pyrolysis of PVC I. Kinetic study  

Microsoft Academic Search

Vacuum pyrolysis of PVC has been studied emphasizing two aspects: the kinetics of PVC pyrolysis reactions and the yields of pyrolysis products. The purpose of the kinetic study is to identify each apparent reaction involved in PVC pyrolysis. Three stages of weight loss have been evidenced by TG analysis during PVC decomposition both under vacuum and in nitrogen atmosphere, while

Rosa Miranda; Jin Yang; Christian Roy; Cornelia Vasile

1999-01-01

293

Vacuum chamber for an undulator straight section  

SciTech Connect

A prototype aluminum extruded vacuum chamber for an undulator straight section of the Advanced Photon Source is described. The 52.-m long vacuum system is designed so that the undulator gap variation does not interfere with it. The chamber is gripped in a stiff close toleranced mounting structure to insure dimensional tolerance of the chamber height.

Kim, S.; Wehrle, R.; Genens, L.

1987-01-01

294

Dark energy and quantum vacuum fluctuations  

E-print Network

It is suggested that the vacuum expectation of the quantum vacuum energy-momentum is zero, but quantum fluctuations give rise to a space-time curvature equivalent to that of a cosmological constant or dark energy. Calculations within quantized gravity, following a few plausible hypotheses, provide results compatible with cosmological observations.

Emilio Santos

2009-02-25

295

Vacuum structure and high-energy scattering  

E-print Network

This short review deals with the manifestations of the vacuum structure of non-Abelian gauge theories in high-energy scattering. Specifically, it concentrates on instanton-induced hard scattering processes, both in the electroweak gauge theory and in QCD. Soft scattering processes in QCD and their connection to models of semi-hard vacuum fluctuations are also briefly discussed.

A. Ringwald

2002-10-15

296

Vacuum Energy: If Not Now, Then When?  

E-print Network

We review the cosmological evidence for a low matter density universe and a cosmological constant or dynamical vacuum energy and address the cosmolog$ coincidence problem: why is the matter density about one-half the vacuum energy {\\em now}. This is reasonble, following the anthropic argument of Efstathiou and of Martel, Schapiro & Weinberg.

Sidney A. Bludman

1999-07-13

297

On the Vacuum Propagation of Gravitational Waves  

E-print Network

We show that, for any local, causal quantum field theory which couples covariantly to gravity, and which admits Minkowski spacetime vacuum(a) invariant under the inhomogeneous proper orthochronous Lorentz group, plane gravitational waves propagating in such Minkowski vacuum(a) do not dissipate energy or momentum via quantum field theoretic effects.

Xiao Liu

2007-06-04

298

On Gauge Invariance and Vacuum Polarization  

Microsoft Academic Search

This paper is based on the elementary remark that the extraction of gauge invariant results from a formally gauge invariant theory is ensured if one employs methods of solution that involve only gauge covariant quantities. We illustrate this statement in connection with the problem of vacuum polarization by a prescribed electromagnetic field. The vacuum current of a charged Dirac field,

Julian Schwinger

1951-01-01

299

Vacuum vessel and pumping system of TEXTOR  

Microsoft Academic Search

The designs of the vacuum vessel and pumping system of the TEXTOR toroidal plasma experiment are presented. The vacuum vessel is an all-metal welded torus consisting of four large and four small rigid sections connected by eight bellows sections, and can be heated up to 400 C. Numerous portholes are provided for diagnostics, as well as pumping units, divertors and

D. A. Butzek; K. Derichs; W. Graf; A. Cosler; K. H. Dippel; M. Schuerer; W. Bieger

1979-01-01

300

Preliminary Study on Arc Welding in Vacuum  

Microsoft Academic Search

Welding technology in space is required to repair the space station. Arc welding in vacuum should be more conventional than electron beam welding because of low voltage operation. Preliminary study on vacuum arc welding is presented in this paper. Arc was ignited by separating an arcing electrode (cathode) from the welding piece (anode). The former is composed of a rod

H. Toya; K. Hieda; T. Saitou

2006-01-01

301

ALUMINUM ALLOY VACUUM CHAMBERS FOR SSRF  

Microsoft Academic Search

The antechamber type vacuum system design is chosen in the SSRF storage ring. Each vacuum chamber is machined from two thick plates of A5083-H321 aluminum alloy and welded at their perimeter. The complex structure and the high dimensional precision requirement are the features of these chambers. Some new ideas are adopted in the structure design to decrease the deflection. The

Lixin Yin; Dikui Jiang; Hanwen Du; Xiaoli Jiang

302

String Field Theory Around the Tachyon Vacuum  

Microsoft Academic Search

Assuming that around the tachyon vacuum the kinetic term of cubic open string field theory is made purely of ghost operators we are led to gauge invariant actions which manifestly implement the absence of open string dynamics around this vacuum. We test this proposal by showing the existence of lump solutions of arbitrary codimension in this string field theory. The

Leonardo Rastelli; Ashoke Sen; Barton Zwiebach

2000-01-01

303

Physicochemical Properties Changes of Donuts During Vacuum Frying  

Microsoft Academic Search

Vacuum frying was explored to cook donuts and compared to the conventional atmospheric frying. A temperature of 190°C was used for atmospheric frying. Three vacuum levels (3, 6, and 9 kPa vacuum) with three temperature levels (150, 165, and 180°C) were used for vacuum frying. The effects of initial moisture content (IMC), vacuum level and frying temperature on physicochemical properties,

K. J. Tan; G. S. Mittal

2006-01-01

304

Genetic analysis of geraniol metabolism during fermentation.  

PubMed

Geraniol produced by grape is the main precursor of terpenols which play a key role in the floral aroma of white wines. We investigated the fate of geraniol during wine fermentation by Saccharomyces cerevisiae. The volatile compounds produced during fermentation of a medium enriched with geraniol were extracted by Stir-bar sorptive extraction and analysed by GC-MS. We were able to detect and quantify geranyl acetate but also citronellyl- and neryl-acetate. The presence of these compounds partly explains the disparition of geraniol. The amounts of terpenyl esters are strain dependant. We demonstrated both by gene overexpression and gene-deletion the involvement of ATF1 enzyme but not ATF2 in the acetylation of terpenols. The affinity of ATF1 enzyme for several terpenols and for isoamyl alcohol was compared. We also demonstrated that OYE2 is the enzyme involved in geraniol to citronellol reduction. Fermenting strain deleted from OYE2 gene produces far less citronellol than wild type strain. Moreover lab strain over-expressing OYE2 allows 87% geraniol to citronellol reduction in bioconversion experiment compared to about 50% conversion with control strain. PMID:23200656

Steyer, Damien; Erny, Claude; Claudel, Patricia; Riveill, Geneviève; Karst, Francis; Legras, Jean-Luc

2013-04-01

305

Simultaneous saccharification: fermentation with Zymomonas mobilis  

SciTech Connect

In recent years, an ethanol production process has been developed which utilizes Trichoderma reesei cellulase and Candida brassicae IFO 1664 in the simultaneous saccharification/fermentation (SSF) of cellulose to ethanol. The direct production of ethanol from cellulose in an SSF process alleviates the problem of end production inhibition. Glucose does not accumulate in this system, but rather is fermented to ethanol immediately following saccharification. The result is an increase in yield of 25% or greater as compared with separate processes of saccharification and fermentation. An alternative organisms which might be used in place of yeasts in ethanol production processes is Zymomonas mobilis. The optimum temperature for hydrolysis of cellulose by Trichoderma reesei cellulases is 50/sup 0/C. Since this hydrolysis is the rate limiting step in the SSF process, it is advantageous to utilize the most temperature tolerant ethanol producer available. Candida brassicae is currently the organism of choice due to its ability to produce ethanol efficiently at 40/sup 0/C. This investigation reports on the screening of Zymomonas strains and evaluating the feasibility of utilizing the most temperature tolerant strain in place of C. brassicae in SSF.

Spangler, D.J.; Emert, G.H.

1986-01-01

306

Kombucha fermentation and its antimicrobial activity.  

PubMed

Kombucha was prepared in a tea broth (0.5% w/v) supplemented with sucrose (10% w/v) by using a commercially available starter culture. The pH decreased steadily from 5 to 2.5 during the fermentation while the weight of the "tea fungus" and the OD of the tea broth increased through 4 days of the fermentation and remained fairly constant thereafter. The counts of acetic acid-producing bacteria and yeasts in the broth increased up to 4 days of fermentation and decreased afterward. The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. Staphylococcus aureus, Shigella sonnei, Escherichia coli, Aeromonas hydrophila, Yersinia enterolitica, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermis, Campylobacter jejuni, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Helicobacterpylori, and Listeria monocytogenes were found to be sensitive to Kombucha. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha. PMID:10888589

Sreeramulu, G; Zhu, Y; Knol, W

2000-06-01

307

Challenges in industrial fermentation technology research.  

PubMed

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 maturity as traditional chemical processes, particularly when it comes to using engineering tools such as mathematical models and optimization techniques. This perspective starts with a brief overview of these engineering tools. However, the main focus is on a description of some of the most important 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 of their wide applications as cell factories and therefore their relevance in a White Biotechnology context. Computational fluid dynamics (CFD) is introduced as a promising tool that can be used to support the scaling up and scaling down of bioreactors, and for studying mixing and the potential occurrence of gradients in a tank. PMID:24846823

Formenti, Luca Riccardo; Nørregaard, Anders; Bolic, Andrijana; Hernandez, Daniela Quintanilla; Hagemann, Timo; Heins, Anna-Lena; Larsson, Hilde; Mears, Lisa; Mauricio-Iglesias, Miguel; Krühne, Ulrich; Gernaey, Krist V

2014-06-01

308

Bioethanol production from fermentable sugar juice.  

PubMed

Bioethanol production from renewable sources to be used in transportation is now an increasing demand worldwide due to continuous depletion of fossil fuels, economic and political crises, and growing concern on environmental safety. Mainly, three types of raw materials, that is, sugar juice, starchy crops, and lignocellulosic materials, are being used for this purpose. This paper will investigate ethanol production from free sugar containing juices obtained from some energy crops such as sugarcane, sugar beet, and sweet sorghum that are the most attractive choice because of their cost-effectiveness and feasibility to use. Three types of fermentation process (batch, fed-batch, and continuous) are employed in ethanol production from these sugar juices. The most common microorganism used in fermentation from its history is the yeast, especially, Saccharomyces cerevisiae, though the bacterial species Zymomonas mobilis is also potentially used nowadays for this purpose. A number of factors related to the fermentation greatly influences the process and their optimization is the key point for efficient ethanol production from these feedstocks. PMID:24715820

Zabed, Hossain; Faruq, Golam; Sahu, Jaya Narayan; Azirun, Mohd Sofian; Hashim, Rosli; Boyce, Amru Nasrulhaq

2014-01-01

309

Bioethanol Production from Fermentable Sugar Juice  

PubMed Central

Bioethanol production from renewable sources to be used in transportation is now an increasing demand worldwide due to continuous depletion of fossil fuels, economic and political crises, and growing concern on environmental safety. Mainly, three types of raw materials, that is, sugar juice, starchy crops, and lignocellulosic materials, are being used for this purpose. This paper will investigate ethanol production from free sugar containing juices obtained from some energy crops such as sugarcane, sugar beet, and sweet sorghum that are the most attractive choice because of their cost-effectiveness and feasibility to use. Three types of fermentation process (batch, fed-batch, and continuous) are employed in ethanol production from these sugar juices. The most common microorganism used in fermentation from its history is the yeast, especially, Saccharomyces cerevisiae, though the bacterial species Zymomonas mobilis is also potentially used nowadays for this purpose. A number of factors related to the fermentation greatly influences the process and their optimization is the key point for efficient ethanol production from these feedstocks. PMID:24715820

Zabed, Hossain; Faruq, Golam; Sahu, Jaya Narayan; Azirun, Mohd Sofian; Hashim, Rosli; Nasrulhaq Boyce, Amru

2014-01-01

310

[The antihypertensive effect of fermented milks].  

PubMed

There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown. PMID:24721277

Domínguez González, Karina N; Cruz Guerrero, Alma E; Márquez, Humberto González; Gómez Ruiz, Lorena C; García-Garibay, Mariano; Rodríguez Serrano, Gabriela M

2014-01-01

311

Vacuum deposition and curing of liquid monomers  

DOEpatents

The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of standard polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

Affinito, J.D.

1993-11-09

312

Vacuum deposition and curing of liquid monomers  

DOEpatents

The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of "standard" polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

Affinito, John D. (Richland, WA)

1993-01-01

313

Vacuum deposition and curing of liquid monomers  

DOEpatents

The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of "standard" polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal or oxide may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

Affinito, John D. (Kennewick, WA)

1995-01-01

314

Vacuum deposition and curing of liquid monomers  

DOEpatents

The present invention is the formation of solid polymer layers under vacuum. More specifically, the present invention is the use of ``standard`` polymer layer-making equipment that is generally used in an atmospheric environment in a vacuum, and degassing the monomer material prior to injection into the vacuum. Additional layers of polymer or metal or oxide may be vacuum deposited onto solid polymer layers. Formation of polymer layers under a vacuum improves material and surface characteristics, and subsequent quality of bonding to additional layers. Further advantages include use of less to no photoinitiator for curing, faster curing, fewer impurities in the polymer electrolyte, as well as improvement in material properties including no trapped gas resulting in greater density, and reduced monomer wetting angle that facilitates spreading of the monomer and provides a smoother finished surface.

Affinito, J.D.

1995-03-07

315

The Vacuum Energy from a New Perspective  

E-print Network

It is commonly believed that the vacuum energy problem points to the need for (1) a radically new formulation of gravitational physics and (2) a new principle which forces the vacuum stress-energy tensor (as measured by gravity) to be nearly zero. Here we point out that a new fundamental theory contains both features: (1) In this theory the vierbein is interpreted as the "superfluid velocity" associated with the order parameter for a GUT-scale Higgs condensate. (2) The vacuum stress-energy tensor is exactly zero in the vacuum state, because the action is extremalized with respect to variations in the order parameter. With inhomogeneously-distributed matter present, the vacuum stress-energy tensor is shifted away from zero.

A. R. Mondragon; R. E. Allen

2001-03-12

316

Lactic acid fermented foods and their benefits in Asia  

Microsoft Academic Search

This paper reviews many types of the world's lactic acid fermented foods and discusses the beneficial effects of lactic acid fermentation of food by focusing on two examples taken from Korean cuisine, kimchi and sikhae.Sikhae is the generic name for a class of Korean lactic acid fermented fish products that contain 6–8% salt and generally are at pH 4–5. Koreans

Cherl-Ho Lee

1997-01-01

317

Effects of cooking on sweet sorghum juice fermentation  

SciTech Connect

Full scale ethanol plant and laboratory fermentation on sweet sorghum juice show not cooking prior to fermentation results in poor sugar to alcohol conversion. Sugar conversion was much higher when heating for microbial control to 60/sup 0/C and 85/sup 0/C with no significant difference between the two. Changes in sugar content of the juice through the season had no effect on fermentation efficiency.

Rein, B.; Ogden, R.; Walker, C.

1982-12-01

318

Influence of Gap Distance on Vacuum Arc Characteristics of Cup Type AMF Electrode in Vacuum Interrupters  

NASA Astrophysics Data System (ADS)

The greenhouse effect of SF6 is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling technique are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device (CCD) video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 mm. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.

Cheng, Shaoyong; Xiu, Shixin; Wang, Jimei; Shen, Zhengchao

2006-11-01

319

[Review of traditional Chinese medicine processed by fermentation].  

PubMed

The fermentation processing of traditional Chinese medicines (TCMs), as an important processing method for TCM, originated from the ancient brewing technology. It has a long history in China. Fermented TCMs (FTCMs) are widely applied among folks for preventing and treating many diseases. There are many kinds of TCM processed by spontaneous fermentation, including Massa Medicata Fermentata, Rhizoma Pinelliae Fermentata, Red fermented rice, Semen Sojae Praepaaratum, Mass Galla chinesis et camelliae Fermentata and Pien Tze Huang. This essay summarizes historical origin, main varieties, the effect of microbial strains, current processing techniques and existing problems of FTCM, and look into the prospect of modern development of FTCMs. PMID:23627162

Zhang, Li-Xia; Gao, Wen-Yuan; Wang, Hai-Yang

2012-12-01

320

Effect of mixing during fermentation in yogurt manufacturing.  

PubMed

In traditional yogurt manufacturing, the yogurt is not agitated during fermentation. However, stirring could be beneficial, particularly for improving heat and mass transport across the fermentation tank. In this contribution, we studied the effect of low-speed agitation during fermentation on process time, acidity profile, and microbial dynamics during yogurt fermentation in 2 laboratory-scale fermenters (3 and 5 L) with different heat-transfer characteristics. Lactobacillus bulgaricus and Streptococcus thermophilus were used as fermenting bacteria. Curves of pH, lactic acid concentration, lactose concentration, and bacterial population profiles during fermentation are presented for static and low-agitation conditions during fermentation. At low-inoculum conditions, agitation reduced the processing time by shortening the lag phase. However, mixing did not modify the duration or the shape of the pH profiles during the exponential phase. In fermentors with poor heat-transfer characteristics, important differences in microbial dynamics were observed between the agitated and nonagitated fermentation experiments; that is, agitation significantly increased the observable specific growth rate and the final microbial count of L. bulgaricus. PMID:19038920

Aguirre-Ezkauriatza, E J; Galarza-González, M G; Uribe-Bujanda, A I; Ríos-Licea, M; López-Pacheco, F; Hernández-Brenes, C M; Alvarez, M M

2008-12-01

321

Stability of high cell density brewery fermentations during serial repitching.  

PubMed

The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e. higher inoculum size). However, the decreased yeast net growth observed in these high cell density brewery fermentations can adversely affect the physiological stability throughout subsequent yeast generations. Therefore, different O(2) conditions (wort aeration and yeast preoxygenation) were applied to high cell density fermentation and eight generations of fermentations were evaluated together with conventional fermentations. Freshly propagated high cell density populations adapted faster to the fermentative conditions than normal cell density populations. Preoxygenating the yeast was essential for the yeast physiological and beer flavor compound stability of high cell density fermentations during serial repitching. In contrast, the use of non-preoxygenated yeast resulted in inadequate growth which caused (1) insufficient yield of biomass to repitch all eight generations, (2) a 10% decrease in viability, (3) a moderate increase of yeast age, (4) and a dramatic increase of the unwanted flavor compounds acetaldehyde and total diacetyl during the sequence of fermentations. Therefore, to achieve sustainable high cell density fermentations throughout the economical valuable process of serial repitching, adequate yeast growth is essential. PMID:19565190

Verbelen, Pieter J; Dekoninck, Tinne M L; Van Mulders, Sebastiaan E; Saerens, Sofie M G; Delvaux, Filip; Delvaux, Freddy R

2009-11-01

322

Use of a continuous multistage bioreactor to mimic winemaking fermentation.  

PubMed

Continuous fermentation set-ups are of great interest for studying the physiology of microorganisms. In winemaking conditions, yeasts go through a growth phase and a stationary phase during which more than half of the sugar is fermented. A comprehensive study of wine-yeast physiology must therefore include yeasts in a non-growing phase. This condition is impossible to achieve within a chemostat, which led us to design a multi-stage fermentation device. In this study, we evaluated the ability of such a device to reproduce, in a series of steady states, the conditions of batch fermentation. Two-stage and four-stage fermentations were carried out with two different strains of Saccharomyces cerevisiae. The main characteristics of the fermentation process (biomass growth, by-product content of the medium) were compared with those observed in batch mode at the same stage of fermentation, which was defined by glucose uptake. The four-stage configuration showed a better ability to reproduce batch fermentation characteristics than the two-stage set-up. It also allowed to uncouple the variations of environmental parameters and proved to be a promising tool to gain new insights into yeast metabolism during alcoholic fermentation. PMID:21839532

Clement, T; Perez, M; Mouret, J R; Sablayrolles, J M; Camarasa, C

2011-10-17

323

Short communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation with  

E-print Network

Kimchi is a fermented vegetable product made of various vegetables such as Chinese cabbage, radishShort communication Metatranscriptome analysis of lactic acid bacteria during kimchi fermentation microbial diversity and biological activity during the fermentation of kimchi, a traditional Korean

Bae, Jin-Woo

324

SCALING RELATIONSHIP BETWEEN BODY WEIGHT AND FERMENTATION GUT CAPACITY IN AXIS DEER  

E-print Network

SCALING RELATIONSHIP BETWEEN BODY WEIGHT AND FERMENTATION GUT CAPACITY IN AXIS DEER DAWN M 78666, USA The scaling relationship between body weight and fermentation gut capacity presumably impacts dietary patterns of ruminants. Interspecific scaling relationships between body weight and fermentation

Aspbury, Andrea S. - Department of Biology, Texas State University

325

Low temperatures and fermentative metabolism limit peptidoglycan digestion of Bacillus cereus. Impact on colony forming unit counts.  

PubMed

The impact of fermentative metabolism at low temperature on cell division of Bacillus cereus was studied. Fermentation at 37 °C had no influence on the division of bacteria. Aerobic cultures at 15 °C produced larger cells than at 37 °C, but cell division was normal. In fermentative cultures at 15 °C, no increase in CFU ml(-1) was observed. However, A(600) increased, due to formation of long filaments. Transmission electronic microscopy and light microscopy with fluorescent staining showed several nucleic acid entities separated by a hydrophobic membrane, indicating that each filament contained several individual cells attached by peptidoglycan. When left in air at room temperature, one filament gave several daughter cells, this means that one CFU formed by one filament may represent a greater contamination potential than one CFU formed by a single cell. Division was observed in cultures at 15 °C with anaerobic respiration in the presence of nitrates. Possible filamentous growth must thus be taken into account to avoid underestimating B. cereus growth in vacuum or modified atmosphere packaged foods stored at low temperature. PMID:23200654

de Sarrau, Benoît; Clavel, Thierry; Bornard, Isabelle; Nguyen-the, Christophe

2013-04-01

326

Vacuum System Transient Simulator and Its Application to TFTR.  

National Technical Information Service (NTIS)

The vacuum system transient simulator (VSTS) models transient gas transport throughout complex networks of ducts, valves, traps, vacuum pumps, and other related vacuum system components. VSTS is capable of treating gas models of up to 10 species, for all ...

J. edniawski

1977-01-01

327

High vacuum facility for hydrazine thruster testing  

NASA Technical Reports Server (NTRS)

An ongoing modification is described of a large vacuum chamber to accommodate the ignition of an arcjet hydrazine thruster while maintaining a vacuum level of 1 x 10(exp -5) torr or less. The vacuum facility consists of a 20 ft stainless steel vacuum tank with an internal LN2 shroud, four 35 in. cryopumps and an 8 in. turbopump. To maintain a vacuum level of 1 x 10(exp -5) torr or less, 900 sq ft of liquid helium (LHe) shroud surface was installed to maintain the vacuum level and pumping requirements. A vacuum level of 1 x 10(exp -5) torr or less will allow the hydrazine thrust to exit the thruster nozzle and radiate into a space type environment so that the plume flow field can be analyzed and compared to the analytical model density distribution profile. Some other arcjet thruster characteristics measured are the electromagnetic interference (EMI) and exhaust contamination. This data is used to evaluate if the arcjet thruster with its high specific impulse in comparison to current chemical propulsion thruster can be used for the next generation of communication satellites.

Neary, Patrick F.

1990-01-01

328

Characteristics of Spoilage-Associated Secondary Cucumber Fermentation  

PubMed Central

Secondary fermentations during the bulk storage of fermented cucumbers can result in spoilage that causes a total loss of the fermented product, at an estimated cost of $6,000 to $15,000 per affected tank. Previous research has suggested that such fermentations are the result of microbiological utilization of lactic acid and the formation of acetic, butyric, and propionic acids. The objectives of this study were to characterize the chemical and environmental conditions associated with secondary cucumber fermentations and to isolate and characterize potential causative microorganisms. Both commercial spoilage samples and laboratory-reproduced secondary fermentations were evaluated. Potential causative agents were isolated based on morphological characteristics. Two yeasts, Pichia manshurica and Issatchenkia occidentalis, were identified and detected most commonly concomitantly with lactic acid utilization. In the presence of oxygen, yeast metabolic activities lead to lactic acid degradation, a small decline in the redox potential (Eh, Ag/AgCl, 3 M KCl) of the fermentation brines, and an increase in pH to levels at which bacteria other than the lactic acid bacteria responsible for the primary fermentation can grow and produce acetic, butyric, and propionic acids. Inhibition of these yeasts by allyl isothiocyanate (AITC) resulted in stabilization of the fermented medium, while the absence of the preservative resulted in the disappearance of lactic and acetic acids in a model system. Additionally, three Gram-positive bacteria, Lactobacillus buchneri, a Clostridium sp., and Pediococcus ethanolidurans, were identified as potentially relevant to different stages of the secondary fermentation. The unique opportunity to study commercial spoilage samples generated a better understanding of the microbiota and environmental conditions associated with secondary cucumber fermentations. PMID:22179234

Franco, Wendy; Johanningsmeier, Suzanne D.; McFeeters, Roger F.

2012-01-01

329

Performance tests of large thin vacuum windows  

SciTech Connect

Tests of thin composition vacuum windows of the type used for the Tagger in Hall B at the Thomas Jefferson National Accelerator Facility are described. Three different tests have been performed. These include: (1) measurement of the deformation and durability of a window under long term (>8 years) almost continuous vacuum load, (2) measurement of the deformation as a function of flexing of the window as it is cycled between vacuum and atmosphere, and (3) measurement of the relative diffusion rate of gas through a variety of thin window membranes.

Hall Crannell

2011-02-01

330

Transient Molecular Transfer During Vacuum Testing  

NASA Technical Reports Server (NTRS)

A common question in contamination budgeting involves the loss of collected volatiles during ambient I&T activity under vacuum and the resultant cross-contamination from outgassing. (1) How much of the material collected under ambient conditions evaporates under vacuum? (2) Why do pristine surfaces sometimes show increased molecular contamination after vacuum bakeout? (3) How much of the collected molecular contamination is transient (i.e. migratory) and how much is permanent? Measuring the transient deposition may be accomplished using a thermally passive QCM

Perry, Radford L.

2011-01-01

331

Is the Free Vacuum Energy Infinite?  

E-print Network

We want to show that the vacuum energy of any free space is simply regularized based on the fundamental cutoff applied by the uncertainty relations limit on virtual particles frequency in the quantum vacuum. Specifically, it is shown that the vacuum energy is proportional to the inverse of the forth power of the dimensional distance of the space under consideration and thus automatically regularized to zero value for an infinitely large free space. This can be used in regularizing a number of unwanted infinities happen in the Casimir effect, the cosmological constant problem and so on without needing usual mathematical (not so reasonable) techniques and tricks.

H. Razmi; S. M. Shirazi

2013-02-05

332

Quantum Vacuum Experiments Using High Intensity Lasers  

E-print Network

The quantum vacuum constitutes a fascinating medium of study, in particular since near-future laser facilities will be able to probe the nonlinear nature of this vacuum. There has been a large number of proposed tests of the low-energy, high intensity regime of quantum electrodynamics (QED) where the nonlinear aspects of the electromagnetic vacuum comes into play, and we will here give a short description of some of these. Such studies can shed light, not only on the validity of QED, but also on certain aspects of nonperturbative effects, and thus also give insights for quantum field theories in general.

Mattias Marklund; Joakim Lundin

2008-12-16

333

Vacuum Structure and Boundary Renormalization Group  

E-print Network

The vacuum structure is probed by boundary conditions. The behaviour of thermodynamical quantities like free energy, boundary entropy and entanglement entropy under the boundary renormalization group flow are analysed in 2D conformal field theories. The results show that whereas vacuum energy and boundary entropy turn out to be very sensitive to boundary conditions, the vacuum entanglement entropy is independent of boundary properties when the boundary of the entanglement domain does not overlap the boundary of the physical space. In all cases the second law of thermodynamics holds along the boundary renormalization group flow.

M. Asorey; J. M. Munoz-Castaneda

2007-12-28

334

Controlling engine exhaust gas recirculation and vacuum inverter  

SciTech Connect

Engine manifold vacuum is inverted by an in-line vacuum inverter which provides a power source for an egr valve actuator for providing desired egr flow in a predetermined range of engine power loading and egr flow is cut off outside the range. The invention utilizes a vacuum inverter employing a pair of spaced diaphragms for controlling an atmospheric air bleed valve to a vacuum chamber powered by manifold vacuum. The diaphragms are spring loaded so as to seek equilibrium positions as vacuum in the chamber varies force. The inverter produces a vacuum output signal which changes inversely with changes in engine manifold vacuum.

Bradshaw, C.E.; Uitvlugt, M.W.

1982-12-28

335

Anti-inflammatory effects of fermented and non-fermented Sophora flavescens: a comparative study  

PubMed Central

Background The roots of Sophora flavescens (Leguminosae) have been used in East Asian countries as an herbal medicine and a food ingredient for thousands of years. The aim of the present study was to investigate the effects of S. flavescens fermentation on endotoxin-induced uveitis (EIU) in rats. Methods EIU was induced in rats via a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS inoculation, fermented and non-fermented extracts of S. flavescens (FSE and NFSE, respectively) were administered orally, and the aqueous humor was collected from both eyes 24 hours later. The anti-inflammatory effects of FSE and NFSE were examined in terms of regulation of nuclear factor kappa B (NF-?B) activation and the expression of interleukin-1? (IL-1?), tumor necrosis factor-? (TNF-?), inducible nitric oxide synthase (iNOS), intercellular cell adhesion molecule (ICAM)-1, and cyclooxygenase-2 (COX-2). The regulation of maleic dialdehyde (MDA) levels and polymorphonuclear cell (PMN) infiltration by FSE and NFSE were also examined. Results Treatment with FSE significantly inhibited LPS-induced increases in IL-1? and TNF-? production and the expression of iNOS, ICAM-1 and COX-2. Moreover, FSE suppressed LPS-induced NF-?B activation, and reduced both MDA levels and infiltration by PMN. Conclusion These results indicate that solid state fermentation may enhance the anti-inflammatory effects of S. flavescens. PMID:22026927

2011-01-01

336

Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii (CBS 5512)  

Microsoft Academic Search

A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated

D. D. Spindler; K. Grohmann; C. E. Wyman

1991-01-01

337

Simultaneous saccharification and fermentation (SSF) using cellobiose fermenting yeast Brettanomyces custersii  

Microsoft Academic Search

A process for producing ethanol from plant biomass includes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose. A species of the yeast Brettanomyces custersii (CBS 5512), which has the ability to ferment both cellobiose and glucose to ethanol, is then selected and isolated. The substrate is inoculated with this yeast, and the inoculated

D. D. Spindler; K. Grohmann; C. E. Wyman

1992-01-01

338

SHINE Vacuum Pump Test Verification  

SciTech Connect

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 scroll pump will be used to back the booster pump. In this case the ''booster pump'' is an Adixen Molecular Drag Pump (MDP 5011) and the backing pump is an Edwards (nXDS15iC) scroll pump. Various configurations of the two pumps and associated lengths of 3/4 inch tubing (0 feet to 300 feet) were used in combination with hydrogen and nitrogen flow rates ranging from 25-400 standard cubic centimeters per minute (sccm) to determine whether the proposed pump configuration meets the design criteria for SHINE. The results of this study indicate that even under the most severe conditions (300 feet of tubing and 400 sccm flow rate) the Adixen 5011 MDP can serve as a booster pump to transport gases from the accelerator (NDAS) to the TPS. The Target Gas Receiving System pump (Edwards nXDS15iC) located approximately 300 feet from the accelerator can effectively back the Adixen MDP. The molecular drag pump was able to maintain its full rotational speed even when the flow rate was 400 sccm hydrogen or nitrogen and 300 feet of tubing was installed between the drag pump and the Edwards scroll pump. In addition to maintaining adequate rotation, the pressure in the system was maintained below the target pressure of 30 torr for all flow rates, lengths of tubing, and process gases. This configuration is therefore adequate to meet the SHINE design requirements in terms of flow and pressure.

Morgan, Gregg A; Peters, Brent

2013-09-30

339

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

NASA Astrophysics Data System (ADS)

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

Martín-Moruno, Prado; Visser, Matt

2013-08-01

340

Fermentative and aerobic metabolism in Rhizobium etli.  

PubMed Central

Strains of Rhizobium etli, Rhizobium meliloti, and Rhizobium tropici decreased their capacity to grow after successive subcultures in minimal medium, with a pattern characteristic for each species. During the growth of R. etli CE 3 in minimal medium (MM), a fermentation-like response was apparent: the O2 content was reduced and, simultaneously, organic acids and amino acids were excreted and poly-beta-hydroxybutyrate (PHB) was accumulated. Some of the organic acids excreted into the medium were tricarboxylic acid (TCA) cycle intermediates, and, concomitantly, the activities of several TCA cycle and auxiliary enzymes decreased substantially or became undetectable. Optimal and sustained growth and a low PHB content were found in R. etli CE 3 when it was grown in MM inoculated at a low cell density with O2 maintained at 20% or with the addition of supplements that have an effect on the supply of substrates for the TCA cycle. In the presence of supplements such as biotin or thiamine, no amino acids were excreted and the organic acids already excreted into the medium were later reutilized. Levels of enzyme activities in cells from supplemented cultures indicated that carbon flux through the TCA cycle was maintained, which did not happen in MM. It is proposed that the fermentative state in Rhizobium species is triggered by a cell density signal that results in the regulation of some of the enzymes responsible for the flux of carbon through the TCA cycle and that this in turn determines how much carbon is available for the synthesis and accumulation of PHB. The fermentative state of free-living Rhizobium species may be closely related to the metabolism that these bacteria express during symbiosis. PMID:7768801

Encarnación, S; Dunn, M; Willms, K; Mora, J

1995-01-01

341

Feeding Fermented Cottonseed Meal to Hogs.  

E-print Network

. / Average 1 Averwe Average 1 Pounds ' Cost Number , Welqht Total Feed Total Dally $am Daily 0aln1 Feed per 1 per Hoas I Anrll 1 Eaten 1 Gain I F~rst Last Pound Pound I 3rl 43 Days 40 Days Gain Ga~n During the first forty-three days Lot I ate 25 pounds... 111.-FEED EATEN AND GAINS MADE BY LOT 11, RECEIVING CORN CHOPS FERMENTED. Average Average Average ' Pounds Cost Number Weight Total Feed 1 Total Dally Gain Dally Gain Feed per per Hogs Aprd Eaten Ga~n F~rut Last Pound Pound I 3d I 41 Days 40 Days...

Marshall, F. R. (Frederick Rupert)

1905-01-01

342

FERMENTATION PROCESS MONITORING THROUGH MEASUREMENT OF AEROSOL RELEASE  

EPA Science Inventory

Fermentation involves many complex biological processes some of which are sometimes difficult to monitor. n this study, aerosol measurement was explored as an additional technique for monitoring a batch aerobic fermentation process using Escherichia coli strain W3110. sing this t...

343

Indigenous Fermented Foods of the Himalayas: Microbiology and Food Safety  

Microsoft Academic Search

Different ethnic people in the Himalayan regions of India, Nepal, Bhutan and China (Tibet) use indigenous fermented food products to provide basic components of diet with diverse characteristics of nutrition, flavour, palatability and texture. For many centuries, the people of these regions prepared and consumed more than forty varieties of common as well as lesser-known indigenous fermented foods and beverages.

Jyoti Prakash TAMANG

344

27 CFR 24.212 - High fermentation wine.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false High fermentation wine. 24.212 Section 24.212 Alcohol, Tobacco...BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.212 High fermentation wine....

2010-04-01

345

Antidiabetic effects of fermented soybean products on type 2 diabetes  

Microsoft Academic Search

Historically, the incidence of type 2 diabetes has been lower in Asian populations compared with those in Western countries. One possible reason for the lower incidence among Asians is that they consume fermented soybean products, which are unique to the traditional Asian diet. Some have hypothesized that dietary phytoestrogens and soy peptides in fermented soybean foods consumed in traditional Asian

Dae Young Kwon; James W. Daily III; Hyun Jin Kim; Sunmin Park

2010-01-01

346

How-to-Do-It: A Simple Demonstration of Fermentation.  

ERIC Educational Resources Information Center

Described is a simple demonstration of fermentation. The materials needed, the basic experimental set-up, and various projects are outlined. Included are a diagram of an apparatus for measuring carbon dioxide production and a table showing typical results of the effect of pH on fermentation. (RT)

Yurkiewicz, William J.; And Others

1989-01-01

347

ORIGINAL PAPER Post-processing of concentrated fermented milk: influence  

E-print Network

-dimensional network. In the milk gel, the clusters fuse to roughly homogeneous strands and cannot be (wellORIGINAL PAPER Post-processing of concentrated fermented milk: influence of temperature and holding of particle clusters in concentrated, fermented milk (protein content 8.2% (w/w)) during post

Paris-Sud XI, Université de

348

?-linolenic acid production by Cunninghamella japonica in solid state fermentation  

Microsoft Academic Search

The production of lipid and ?-linolenic acid (GLA) by Cunninghamella japonica was studied in solid state fermentations (SSF) on cereal substrates. A number of cereals were used as sources of nutrients for fungal SSF and the substrate which favoured the highest accumulation of lipid and GLA in fermented substrate was determined. The treatment of cereals, addition of nutrients to the

Elena V. Emelyanova

1996-01-01

349

The microbial ecology of cocoa bean fermentations in Indonesia  

Microsoft Academic Search

Cocoa beans are the principal raw material of chocolate manufacture. The beans are subject to a microbial fermentation as the first stage in chocolate production. The microbial ecology of bean fermentation (Forastero and Trinitario cultivars) was investigated at three commercial fermentaries in East Java, Indonesia by determining the populations of individual species at 12-h intervals throughout the process. The first

Made M. Ardhana; Graham H. Fleet

2003-01-01

350

Fermented liquid feed reduces susceptibility of broilers for Salmonella enteriditis  

Microsoft Academic Search

The presence of Salmonella in chickens is a problem because poultry meat is recognized as a source of human salmonellosis. Fermented feed has characteris- tics like a high number of lactobacilli and high concentra- tion of lactic acid, which could make chickens less suscep- tible for infection with Salmonella. Fermented feed might therefore prevent the colonization of chickens with Salmo-

L. Heres; B. Engel; F. van Knapen; M. C. M. de Jong; J. A. Wagenaar; B. A. P. Urlings

2003-01-01

351

Kimchi: The famous fermented vegetable product in Korea  

Microsoft Academic Search

Literature on kimchi was reviewed with emphasis on preparation of kimchi, microorganisms involved in the fermentation, changes in the composition during ripening, methods to extend shelflife, and commercial production of kimchi. Kimchi is a traditional Korean fermented vegetable product with a historical background of over 1000 years. The variety of kimchi changes according to the main raw materials and minor

Young C. Lee

1991-01-01

352

Folates in fermented vegetables—a pilot study  

Microsoft Academic Search

The present work aimed to evaluate whether lactic acid fermentation can increase folate concentrations in vegetables making these foods superior to similar foods produced by the more common preservation techniques. The concentrations of folates present in raw vegetables, usually root vegetables, were followed during pre-treatment and fermentation with the purpose to improve the folate retention. Commercial starter cultures aimed for

M Jägerstad; J Jastrebova; U Svensson

2004-01-01

353

Distribution and development of bacterial colonies in fermented sausages  

Microsoft Academic Search

For fermented sausages the growth of microorganisms is essential for stable and safe products. It is important to note that the natural flora as well as added starter cultures are not evenly distributed in the interior of fermented sausages, but are immobilised in cavities or nests within the sausage matrix. A fact which must be taken into account when investigating

K. Katsaras; L. Leistner

1991-01-01

354

Fermentation of Fructooligosaccharides by Lactic Acid Bacteria and Bifidobacteria  

Microsoft Academic Search

Lactic acid bacteria and bifidobacteria were screened of their ability to ferment fructooligosaccharides (FOS) on MRS agar. Of 28 strains of lactic acid bacteria and bifidobacteria examined, 12 of 16 Lactobacillus strains and 7 of 8 Bifidobacterium strains fermented FOS. Only strains that gave a positive reaction by the agar method reached high cell densities in broth containing FOS.

Handan Kaplan; Robert W. Hutkins

2000-01-01

355

The Selective Recovery of Alcohols from Fermentation Broths by Pervaporation  

Microsoft Academic Search

Pervaporation can be successfully utilized to recover various alcohols from fermentation broths and dilute process streams. Hydrophobic membranes, such as silicone-based polymers, have been employed in this application to produce an enriched product. Research in this field has increased dramatically in the past five years and a review of this work is warranted. Fermentations of n-butanol, ethanol, and isopropanol all

Patrick J. Hickey; C. Stewart Slater

1990-01-01

356

Development of clean technology in alcohol fermentation industry  

Microsoft Academic Search

A zero-discharge system for the alcohol fermentation industry was developed by recycling distillery waste (stillage). Stillage was able to be recycled as cooking water for the next fermentation after treating it with appropriate separation processes. Ultrafiltration with a ceramic membrane played a key role in the separation processes. When the permeate from the ultrafiltration of stillage was recycled to the

Jae-Sok Kim; Byung-Gee Kim; Chung-Hak Lee; Sang-Won Kim; Hae-Sung Jee; Jong-Ho Koh; A. G. Fane

1997-01-01

357

Feasibility of Continuous Main Fermentation of Beer Using Immobilized Yeast.  

National Technical Information Service (NTIS)

Fermentation is the most time consuming step in the production of beer and therefore the effective use of fermentation vessels is a crucial element in brewing economy. One means of increasing the productivity of a batch process is to convert it to a conti...

I. Virkajaervi

2001-01-01

358

Innovations in Indian Fermented Milk Products — A Review  

Microsoft Academic Search

Dahi is considered the oldest Indian fermented milk product and is equivalent to Western yogurt from which derivatives such as shrikhand (sweetened concentrated curd) and lassi (stirred curd) are derived. Dietetic significance of Indian fermented milk products has been established due to its various nutritional and therapeutic properties. Acceptable quality dahi could be obtained with the application of acid producing

S. Sarkar

2008-01-01

359

Fermentation and Electrohydrogenic Approaches to Hydrogen Production (Presentation)  

SciTech Connect

This work describes the development of a waste biomass fermentation process using cellulose-degrading bacteria for hydrogen production. This process is then integrated with an electrohydrogenesis process via the development of a microbial electrolysis cell reactor, during which fermentation waste effluent is further converted to hydrogen to increase the total output of hydrogen from biomass.

Maness, P. C.; Thammannagowda, S.; Magnusson, L.; Logan, B.

2010-06-01

360

Fibrous Material in Feedlot Waste Fermented by Trichoderma viride1  

PubMed Central

Trichoderma viride QM9123 fermented fiber isolated from feedlot waste at concentrations up to 16.7% solids. The fermented fiber solids decreased by 32%, and carbohydrate decreased by 60%. Cellulolytic enzyme production was better with fiber substrates that had been alkali pretreated and had a lower hemicellulose-to-cellulose ratio. PMID:1239235

Kaneshiro, T.; Kelson, B. F.; Sloneker, J. H.

1975-01-01

361

SLAC All Access: Vacuum Microwave Device Department  

ScienceCinema

The Vacuum Microwave Device Department (VMDD) builds the devices that make SLAC's particle accelerators go. These devices, called klystrons, generate intense waves of microwave energy that rocket subatomic particles up to nearly the speed of light.

Haase, Andy

2014-06-13

362

Gravity and the Quantum Vacuum Inertia Hypothesis  

E-print Network

In previous work it has been shown that the electromagnetic quantum vacuum, or electromagnetic zero-point field, makes a contribution to the inertial reaction force on an accelerated object. We show that the result for inertial mass can be extended to passive gravitational mass. As a consequence the weak equivalence principle, which equates inertial to passive gravitational mass, appears to be explainable. This in turn leads to a straightforward derivation of the classical Newtonian gravitational force. We call the inertia and gravitation connection with the vacuum fields the quantum vacuum inertia hypothesis. To date only the electromagnetic field has been considered. It remains to extend the hypothesis to the effects of the vacuum fields of the other interactions. We propose an idealized experiment involving a cavity resonator which, in principle, would test the hypothesis for the simple case in which only electromagnetic interactions are involved. This test also suggests a basis for the free parameter $\\eta(\

Alfonso Rueda; Bernard Haisch

2005-04-13

363

The QED vacuum magnetic birefringence experiment  

Microsoft Academic Search

In this contribution we present the status of the BMV experiment whose goal is to measure the vacuum magnetic birefringence. The measurement of this birefringence to a precision of a few ppm will represent a pure QED test.

M. Fouche; P. Berceau; R. Battesti; C. Rizzo

2010-01-01

364

Vacuum Birefringence in Strong Magnetic Fields  

Microsoft Academic Search

Table of Contents 1. One-loop effective Lagrangian in spinor QED. 2. Dispersion effects for low-frequency photons. 3. Vacuum birefringence in magnetic fields. 4. Light cone condition, effective Lagrangian approach.

Walter Dittrich; Holger Gies

1998-01-01

365

Cold vacuum drying facility design requirements  

SciTech Connect

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.

Irwin, J.J.

1997-09-24

366

14 CFR 25.1433 - Vacuum systems.  

Code of Federal Regulations, 2013 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2013-01-01

367

14 CFR 29.1433 - Vacuum systems.  

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2014-01-01

368

14 CFR 25.1433 - Vacuum systems.  

Code of Federal Regulations, 2011 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2011-01-01

369

14 CFR 25.1433 - Vacuum systems.  

Code of Federal Regulations, 2012 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2012-01-01

370

14 CFR 25.1433 - Vacuum systems.  

Code of Federal Regulations, 2010 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2010-01-01

371

14 CFR 29.1433 - Vacuum systems.  

Code of Federal Regulations, 2013 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2013-01-01

372

14 CFR 29.1433 - Vacuum systems.  

Code of Federal Regulations, 2010 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2010-01-01

373

14 CFR 25.1433 - Vacuum systems.  

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2014-01-01

374

14 CFR 29.1433 - Vacuum systems.  

Code of Federal Regulations, 2012 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...addition to the normal pressure relief, to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe....

2012-01-01

375

Quantized electromagnetic tornado in pulsar vacuum gap  

E-print Network

Quantized electromagnetic tornado in pulsar vacuum gap Giant pulses Regular radiation 1937+21 By A of the electromagnetic tornado. The quasi-classical and exact quantization of this rotation is possible. 9 #12;Possible

Fominov, Yakov

376

REVIEWS OF TOPICAL PROBLEMS: Cosmic vacuum  

NASA Astrophysics Data System (ADS)

Recent observational studies of distant supernovae have suggested the existence of cosmic vacuum whose energy density exceeds the total density of all the other energy components in the Universe. The vacuum produces the field of antigravity that causes the cosmological expansion to accelerate. It is this accelerated expansion that has been discovered in the observations. The discovery of cosmic vacuum radically changes our current understanding of the present state of the Universe. It also poses new challenges to both cosmology and fundamental physics. Why is the density of vacuum what it is? Why do the densities of the cosmic energy components differ in exact value but agree in order of magnitude? On the other hand, the discovery made at large cosmological distances of hundreds and thousands Mpc provides new insights into the dynamics of the nearby Universe, the motions of galaxies in the local volume of 10 - 20 Mpc where the cosmological expansion was originally discovered.

Chernin, Artur D.

2001-11-01

377

Thermally actuated MEMS seal for vacuum applications  

E-print Network

This thesis presents the design, fabrication and testing of a new, leak-free, permanently sealable MEMS valve for use in vacuum applications. This device is different from existing MEMS valves in that it is leak-free in ...

Dighe, Aalap (Aalap Shirish)

2011-01-01

378

Electrospray emitters For diffusion vacuum pumps  

E-print Network

Following similar principles as regular diffusion vacuum pumps, an electrospray emitter is set to produce a jet of charged particles that will drag air molecules out of a volume. To be a feasible concept, the emitted ...

Diaz Gómez Maqueo, Pablo (Pablo Ly)

2011-01-01

379

Mass spectrometer vacuum housing and pumping system  

DOEpatents

A vacuum housing and pumping system is described for a portable gas chromatograph/mass spectrometer (GC/MS). The vacuum housing section of the system has minimum weight for portability while designed and constructed to utilize metal gasket sealed stainless steel to be compatible with high vacuum operation. The vacuum pumping section of the system consists of a sorption (getter) pump to remove atmospheric leakage and outgassing contaminants as well as the gas chromatograph carrier gas (hydrogen) and an ion pump to remove the argon from atmospheric leaks. The overall GC/MS system has broad application to contaminants, hazardous materials, illegal drugs, pollution monitoring, etc., as well as for use by chemical weapon treaty verification teams, due to the light weight and portability thereof. 7 figs.

Coutts, G.W.; Bushman, J.F.; Alger, T.W.

1996-07-23

380

Characterization of lactic acid bacteria isolated from a Thai low-salt fermented fish product and the role of garlic as substrate for fermentation.  

PubMed

Lactic acid bacteria (LAB) isolated from raw materials (fish, rice, garlic and banana leaves) and processed som-fak (a Thai low-salt fermented fish product) were characterized by API 50-CH and other phenotypic criteria. Lactococcus lactis subsp. lactis and Leuconostoc citreum were specifically associated with fish fillet and minced fish, Lactobacillus paracasei subsp. paracasei with boiled rice and Weisella confusa with garlic mix and banana leaves. In addition, Lactobacillus plantarum, Lactobacillus pentosus and Pediococcus pentosaceus were isolated from raw materials. A succession of aciduric, homofermentative lactobacillus species, dominated by Lb. plantarum/pentosus, was found during fermentation. In total, 9% of the strains fermented starch and 19% fermented garlic, the two main carbohydrate components in som-fak. The ability to ferment garlic was paralleled by a capacity to ferment inulin. An increased percentage of garlic fermenting strains was found during fermentation of som-fak, from 8% at day 1 to 40% at day 5. No starch fermenting strains were isolated during fermentation. Three mixed LAB cultures, composed of either starch fermenting Lc. lactis subsp. lactis and Lb. paracasei subsp. paracasei, or garlic fermenting Lb. plantarum and Pd. pentosaceus, or a combination of these strains were inoculated into laboratory prepared som-fak with or without garlic. In som-fak without garlic, pH was above 4.8 after three days, irrespective of addition of mixed LAB cultures. The starch fermenting LAB were unable to ferment som-fak and sensory spoilage occurred after three days. Fermentation with the combined mix of starch and garlic fermenting strains led to production of 2.5% acid and a decrease in pH to 4.5 in two days. The fermentation was slightly slower with the garlic fermenting strains alone. This is the first report describing the role of garlic as carbohydrate source for LAB in fermented fish products. PMID:10100902

Paludan-Müller, C; Huss, H H; Gram, L

1999-02-18

381

Distillation of vacuum entanglement to EPR pairs  

E-print Network

It is shown that by means of local interactions between a quantized relativistic field and a pair of non-entangled atoms, entanglement can be extracted from the vacuum and delivered to the atoms. The resulting mixed state of the atoms can be further distilled to EPR pairs. Therefore, in principle, teleportation and other entanglement assisted quantum communication tasks can rely on the vacuum alone as a resource for entanglement.

Benni Reznik

2000-08-01

382

Distillation of vacuum entanglement to EPR pairs  

E-print Network

It is shown that by means of local interactions between a quantized relativistic field and a pair of non-entangled atoms, entanglement can be extracted from the vacuum and delivered to the atoms. The resulting mixed state of the atoms can be further distilled to EPR pairs. Therefore, in principle, teleportation and other entanglement assisted quantum communication tasks can rely on the vacuum alone as a resource for entanglement.

Reznik, B

2000-01-01

383

Reliable vacuum system cuts steam requirements 50%  

SciTech Connect

In choosing a new high-vacuum system for fractional distillation, Polarome Manufacturing Company, New York, NY and Newark, NJ, a producer of high-quality flavor and fragrance chemicals, considered reliability and performance and steam consumption to be the most important factors. Distillation is carried out under vacuum to minimize thermal degradation. For stable operation, the vacuum system for the distillation column has to be ultra-reliable, and has to be able to go on-line quickly. Fluctuations in vacuum affect operating temperature and fractionation and cause deterioration of the product quality. Polarome's process requires a gas removal rate from the distillation column of 7.5 lg/hr of air plus 7.5 lb/hr of condensible vapors at 0.5 mm Hg absolute pressure at 105/sup 0/F. Polarome chose a combination ejector/liquid ring pump system that combines the two distinctly different types of equipment to improve high-vacuum efficiency. The unit requires only 400 lb/hr of motive steam at 125 psig, and the liquid ring pump only draws 5.7 brake hp. Polarome purchased two virtually identical four-stage systems, each composed of two ejector stages, a shell-and-tube condenser, and a two-stage liquid ring vacuum pump. The fully packaged systems were delivered skid-mounted, ready to pipe and operate. Polarome found a number of advantages with their combined system. Steam savings are considerable - up to 50% over a conventional ejector system - because the liquid-ring pump is substituted for the less efficient final two ejector stages. In Polarome's vacuum range of 0.5 mm Hg, this was considered the most efficient way of drawing vacuum, with lowest investment and operating costs for the greatest capacity.

Not Available

1985-12-01

384

Vacuum Misalignment in High Energy Collisions  

E-print Network

We study a recent proposal to observe the disoriented chiral condensate in high energy collisions. In order to produce a large fluctuation in pion probability distribution, a large size of the correlated region is essential. We study the role of the intrinsic symmetry breaking and suggest that a negative (mass)^2 of mesons arising from a misaligned vacuum may be a candidate for such a mechanism. We further point out a possibility to observe unsuppressed strong $CP$ violation in the disoriented vacuum phase.

Zheng Huang

1993-10-04

385

Towards a QED-Based Vacuum Energy  

E-print Network

A QED-based mechanism, breaking translational invariance of the vacuum at sufficiently small distance scales, is suggested as an explanation for the vacuum energy pressure that accelerates the universe. Very-small-scale virtual vacuum currents are assumed to generate small-scale electromagnetic fields corresponding to the appearance of a 4-potential $A_{\\mu}^{ext} (x)$, which is itself equal to the vev of the operator $ A_{\\mu}(x)$ in the presence of that $A_{\\mu}^{ext}(x)$. The latter condition generates a bootstrap-like equation for $A_{\\mu}^{ext}(x)$ which has an approximate, tachyonic-like solution corresponding to propagation outside the light cone, and damping inside; this solution is given in terms of a mass parameter M that turns out to be on the order of the Planck mass if only the simplest, electron vacuum-bubble is included; if the muon and tau bubbles are included, M decreases to $\\sim 10^6 - 10^7$ GeV. A multiplicative 4-vector $v_{\\mu}$, whose magnitude is determined by a comparison with the average mass density needed to produce the observed acceleration is introduced, and characterizes the distance d over which the fields so produced may be expected to be coherent; the present analysis suggests that d can lie anywhere in the range from $10^{-5} cm$ (corresponding to a "spontaneous vacuum phase change") to $10^{-13}cm$ (representing a "polarization of the QED vacuum" by quark-antiquark pairs of the QCD vacuum). Near the light-cone, such electric fields become large, introducing the possibility of copious charged-particle pair production, whose back-reaction-fields tend to diminish the vacuum electric field. The possibility of an experimental test of the resulting plasma at large momentum transfers is discussed.

H. M. Fried

2003-03-12

386

Residual Antibiotics Disrupt Meat Fermentation and Increase Risk of Infection  

PubMed Central

ABSTRACT Fermented sausages, although presumed safe for consumption, sometimes cause serious bacterial infections in humans that may be deadly. Not much is known about why and when this is the case. We tested the hypothesis that residual veterinary antibiotics in meat can disrupt the fermentation process, giving pathogenic bacteria a chance to survive and multiply. We found that six commercially available starter cultures were susceptible to commonly used antibiotics, namely, oxytetracycline, penicillin, and erythromycin. In meat, statutorily tolerable levels of oxytetracycline and erythromycin inhibited fermentation performance of three and five of the six starter cultures, respectively. In model sausages, the disruption of meat fermentation enhanced survival of the pathogens Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium compared to successful fermentations. Our work reveals an overlooked risk associated with the presence of veterinary drugs in meat. PMID:22930338

Kjeldgaard, Jette; Cohn, Marianne T.; Casey, Pat G.; Hill, Colin; Ingmer, Hanne

2012-01-01

387

Processing ethanol fermentation broths and stillage with ceramic membranes  

SciTech Connect

The manufacture of ethanol from biomass requires several separation operations, many of which can benefit by the appropriate membrane technology. This paper discusses applications which may perhaps be done best with inorganic membranes. After the fermentation, the microbial (e.g., yeast) are usually separated from the fermentation broth and may be recycled for fermentation. The ethanol is stripped away from the fermentation broth by steam, leaving behind the {open_quotes}stillage{close_quotes}. This stillage is then separated into a high-solids fraction and a {open_quotes}thin{close_quotes} stillage; the latter forming as much as 60-80% of the total liquid throughput in an ethanol plant, could be stream to conserve water. Traditional separation methods used today include sedimentation, centrifugation and cake filtration. The authors have been studying the application of ceramic membranes for the separation (and possible recycling) of yeast (Saccharomyces cerevisiae) in ethanol fermentation broths, and for the clarification of thin stillage.

Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)

1994-12-31

388

Koji--where East meets West in fermentation.  

PubMed

Almost all biotechnological processes originate from traditional food fermentations, i.e. the many indigenous processes that can be found already in the written history of thousands of years ago. We still consume many of these fermented foods and beverages on a daily basis today. The evolution of these traditional processes, in particular since the 19th century, stimulated and influenced the development of modern biotechnological processes. In return, the development of modern biotechnology and related advanced techniques will no doubt improve the process, the product quality and the safety of our favourite fermented foods and beverages. In this article, we describe the relationship between these traditional food fermentations and modern biotechnology. Using Koji and its derived product soy sauce as examples, we address the mutual influences that will provide us with a better future concerning the quality, safety and nutritional effect of many fermented food products. PMID:23850857

Zhu, Yang; Tramper, Johannes

2013-12-01

389

Sterilization of fermentation vessels by ethanol/water mixtures  

DOEpatents

A method is described for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process. 2 figs.

Wyman, C.E.

1999-02-09

390

Sterilization of fermentation vessels by ethanol/water mixtures  

DOEpatents

A method for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process.

Wyman, Charles E. (Lakewood, CO)

1999-02-09

391

The microbial diversity of traditional spontaneously fermented lambic beer.  

PubMed

Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration. PMID:24748344

Spitaels, Freek; Wieme, Anneleen D; Janssens, Maarten; Aerts, Maarten; Daniel, Heide-Marie; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

2014-01-01

392

The Microbial Diversity of Traditional Spontaneously Fermented Lambic Beer  

PubMed Central

Lambic sour beers are the products of a spontaneous fermentation that lasts for one to three years before bottling. The present study determined the microbiota involved in the fermentation of lambic beers by sampling two fermentation batches during two years in the most traditional lambic brewery of Belgium, using culture-dependent and culture-independent methods. From 14 samples per fermentation, over 2000 bacterial and yeast isolates were obtained and identified. Although minor variations in the microbiota between casks and batches and a considerable species diversity were found, a characteristic microbial succession was identified. This succession started with a dominance of Enterobacteriaceae in the first month, which were replaced at 2 months by Pediococcus damnosus and Saccharomyces spp., the latter being replaced by Dekkera bruxellensis at 6 months fermentation duration. PMID:24748344

Spitaels, Freek; Wieme, Anneleen D.; Janssens, Maarten; Aerts, Maarten; Daniel, Heide-Marie; Van Landschoot, Anita; De Vuyst, Luc; Vandamme, Peter

2014-01-01

393

Sterilization of fermentation vessels by ethanol/water mixtures  

SciTech Connect

This invention is comprised of a method for sterilizing process fermentation vessels with a concentrated alcohol and water mixture integrated in a fuel alcohol or other alcohol production facility. Hot, concentrated alcohol is drawn from a distillation or other purification stage and sprayed into the empty fermentation vessels. This sterilizing alcohol/water mixture should be of a sufficient concentration, preferably higher than 12% alcohol by volume, to be toxic to undesirable microorganisms. Following sterilization, this sterilizing alcohol/water mixture can be recovered back into the same distillation or other purification stage from which it was withdrawn. The process of this invention has its best application in, but is not limited to, batch fermentation processes, wherein the fermentation vessels must be emptied, cleaned, and sterilized following completion of each batch fermentation process.

Wyman, C.E.

1991-03-20

394

Homotopy Operators and One-Loop Vacuum Energy at the Tachyon Vacuum  

E-print Network

We construct the homotopy operators for the BRST operator in the theory around the identity-based solutions, which are believed to represent the tachyon vacuum in cubic bosonic open string field theory. Using the homotopy operators, we find that the one-loop vacuum energy at the tachyon vacuum is independent of moduli such as interbrane distances, which are included in the BRST operator. We also revisit the cohomology problem, which was solved earlier without the homotopy operators.

Shoko Inatomi; Isao Kishimoto; Tomohiko Takahashi

2011-06-27

395

Physical Vacuum Properties and Internal Space Dimension  

E-print Network

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 considerations consist in the condition of maximum vacuum energy density and vacuum fluctuation energy density.

M. V. Gorbatenko; A. V. Pushkin

2004-09-25

396

Cosmological Evolution of Vacuum and Cosmic Acceleration  

E-print Network

It is known that the unregularized expressions for the stress-energy tensor components corresponding to subhorizon and superhorizon vacuum fluctuations of a massless scalar field in a Friedmann-Robertson-Walker background are characterized by the equation of state parameters w=1/3 and w=-1/3, which are not sufficient to produce cosmological acceleration. However, the form of the adiabatically regularized finite stress-energy tensor turns out to be completely different. By using the fact that vacuum subhorizon modes evolve nearly adiabatically and superhorizon modes have w=-1/3, we approximately determine the regularized stress-energy tensor, whose conservation is utilized to fix the time dependence of the vacuum energy density. We then show that vacuum energy density grows from zero up to H^4 in about one Hubble time, vacuum fluctuations give positive acceleration of the order of H^4/M_p^2 and they can completely alter the cosmic evolution of the universe dominated otherwise by cosmological constant, radiation or pressureless dust. Although the magnitude of the acceleration is tiny to explain the observed value today, our findings indicate that the cosmological backreaction of vacuum fluctuations must be taken into account in early stages of cosmic evolution.

Ali Kaya

2010-06-03

397

Cryogenic Insulation System for Soft Vacuum  

NASA Technical Reports Server (NTRS)

The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

Augustynowicz, S. D.; Fesmire, J. E.

1999-01-01

398

Surface mycobiota on Argentinean dry fermented sausages.  

PubMed

The diversity of the mycobiota community occurring on the surface of fermented dry sausages and in the environment of the processing plants was studied. The manufacturing plants (five in total) were located in three different areas of southern Buenos Aires province (Argentina). Samples were collected from two types of fermented sausages (short and long ripening time) at two times of the year (winter and summer) and at different types of plants (artisanal and industrial). A total of 342 samples were examined and 822 isolates belonging to six genera and 16 fungal species were identified. In most cases, Penicillium was the genus most frequently isolated. Penicillium nalgiovense, P. nordicum, P. solitum and P. chrysogenum were the most abundant species. The characteristics of the plants and the season were the influencing factors on the composition of the mycobiota. Under conditions of high humidity and in ripening rooms with reduced ventilation, Mucor racemosus was most prevalent. Eurotium amstelodami and Aspergillus spp were detected mainly during the summer when the temperature was higher. A high number of species isolated from the surface of the sausage was also isolated from air samples. Geotrichum candidum, Alternaria infectoria and P. glabrum were found only in air samples. P. chrysogenum, P. nalgiovense and P. nordicum showed different levels of antibacterial activity in sensitive bioassay with Micrococcus luteus. PMID:20643490

Castellari, Claudia; Quadrelli, Ana María; Laich, Federico

2010-08-15

399

Kefir: a multifaceted fermented dairy product.  

PubMed

Kefir is a fermented dairy beverage produced by the actions of the microflora encased in the "kefir grain" on the carbohydrates in the milk. Containing many bacterial species already known for their probiotic properties, it has long been popular in Eastern Europe for its purported health benefits, where it is routinely administered to patients in hospitals and recommended for infants and the infirm. It is beginning to gain a foothold in the USA as a healthy probiotic beverage, mostly as an artisanal beverage, home fermented from shared grains, but also recently as a commercial product commanding shelf space in retail establishments. This is similar to the status of yogurts in the 1970s when yogurt was the new healthy product. Scientific studies into these reported benefits are being conducted into these health benefits, many with promising results, though not all of the studies have been conclusive. Our review provides an overview of kefir's structure, microbial profile, production, and probiotic properties. Our review also discusses alternative uses of kefir, kefir grains, and kefiran (the soluble polysaccharide produced by the organisms in kefir grains). Their utility in wound therapy, food additives, leavening agents, and other non-beverage uses is being studied with promising results. PMID:25261107

Nielsen, Barbara; Gürakan, G Candan; Unlü, Gülhan

2014-12-01

400

Ethanol fermentation kinetics in a continuous and closed-circulating fermentation system with a pervaporation membrane bioreactor.  

PubMed

The kinetics of ethanol fermentation by Saccharomyces cerevisiae was studied in a continuous and closed-circulating fermentation (CCCF) system with a polydimethylsiloxane (PDMS) pervaporation membrane bioreactor. Three sequential 500-h cycles of CCCF experiments were carried out. A glucose volumetric consumption of 3.8 g L(-1) h(-1) and ethanol volumetric productivity of 1.39 g L(-1) h(-1) were obtained in the third cycle, with a specific glucose utilization rate of 0.32 h(-1) and ethanol yield rate of 0.13 h(-1). The prolonged fermentation time and good fermentation performance indicate that the CCCF would be a feasible and promising fermentation process technology. PMID:22446047

Chen, Chunyan; Tang, Xiaoyu; Xiao, Zeyi; Zhou, Yihui; Jiang, Yue; Fu, Shengwei

2012-06-01

401

Vacuum regulation valve in an exhaust gas recirculation system  

Microsoft Academic Search

The vacuum regulation valve operable to regulate the vacuum in the vacuum line of an exhaust gas recirculation system, includes a compact construction and a buffer means which is effective to eliminate the clattering sounds inherent in the conventional vacuum regulation valve.

M. Washio; T. Harada

1978-01-01

402

VACUUM ENERGY IN QUANTUM GRAPHS A Senior Honors Thesis  

E-print Network

VACUUM ENERGY IN QUANTUM GRAPHS A Senior Honors Thesis by JUSTIN HOWARD WILSON Submitted ABSTRACT Vacuum Energy in Quantum Graphs. (April 2007) Justin Howard Wilson Department of Physics the vacuum energy in quantum graphs. Vacuum energy arose in quantum physics but has an independent

403

OPTIMIZATION OF SUGAR CONSUMPTION IN THE FERMENTATION OF TEMULOSE FOR ETHANOL PRODUCTION  

E-print Network

…………………………………….…....... 4 Fermentation Microbes…………………………………. 6 Fermentation Processes………………………..………..... 7 III METHODS AND MATERIALS……….……………...….. 10 Substrate……….……………………………….………… 10 Microorganisms and Culture Conditions………………… 10 Inocula Preparation... of the released sugars is a natural next step. Fermentation Microbes The microorganisms used to carry out the fermentation process are just as important as the substrate, and they have also been the target of much research. Saccharomyces cerevisiae, also...

Michalka, Jacquelyn

2007-07-14

404

Volatile organic compounds from a Tuber melanosporum fermentation system.  

PubMed

A total of 59 volatile organic compounds (VOCs) were identified from Tuber melanosporum fermentation: 53 from its fermented mycelia and 32 from the fermentation broth. Alcohol-derived compounds were predominant in both the fermentation mycelia and the broth, although long chain fatty acids and isoprenoids were, for the first time, also found in the mycelia. The intense wine bouquet properties of the broth arose from several specific flavor substances, including sulfur compounds, pyrazines, furans and jasmones. Comparing the VOCs identified in this work with those previously reported, our results are more similar to the composition of the Tuber fruiting-body than previous Tuber fermentations. The composition and accumulation of flavor volatiles (e.g., pyrazines, sulfur compounds, and esters) and major constituents (e.g., 3-methyl-1-butanol and 2-phenylethanol) in this fermentation were significantly influenced by the sucrose concentration in the medium. The obtained information could therefore be useful in applications to convert the flavors of truffle mycelia similar to those of the fruiting-body by optimising the fermentation process. PMID:22980851

Li, Yuan-Yuan; Wang, Guan; Li, Hong-Mei; Zhong, Jian-Jiang; Tang, Ya-Jie

2012-12-15

405

Immobilized yeast bioreactor systems for continuous beer fermentation  

PubMed

Two different types of immobilized yeast bioreactors were examined for continuous fermentation of high-gravity worts. One of these is a fluidized bed reactor (FBR) that employs porous glass beads for yeast immobilization. The second system is a loop reactor containing a porous silicon carbide cartridge (SCCR) for immobilizing the yeast cells. Although there was some residual fermentable sugar in the SCCR system product, nearly complete attenuation of the wort sugars was achieved in either of the systems when operated as a two-stage process. Fermentation could be completed in these systems in only half the time required for a conventional batch process. Both the systems showed similar kinetics of extract consumption, and therefore similar volumetric productivity. As compared to the batch fermentation, total fusel alcohols were lower; total esters, while variable, were generally higher. The yeast biomass production was similar to that in a conventional fermentation process. As would be expected in an accelerated fermentation system, the levels of vicinal diketones (VDKs) were higher. To remove the VDKs, the young beer was heat-treated to convert the VDK precursors and processed through a packed bed immobilized yeast bioreactor for VDK assimilation. The finished product from the FBR system was found to be quite acceptable from a flavor perspective, albeit different from the product from a conventional batch process. Significantly shortened fermentation times demonstrate the feasibility of this technology for beer production. PMID:9933520

Tata; Bower; Bromberg; Duncombe; Fehring; Lau; Ryder; Stassi

1999-01-01

406

Determining the impacts of fermentative bacteria on wollastonite dissolution kinetics.  

PubMed

Silicate minerals can be a source of calcium and alkalinity, enabling CO2 sequestration in the form of carbonates. For this to occur, the mineral needs to be first dissolved in an acidifying process such as the biological process of anaerobic fermentation. In the present study, the main factors which govern the dissolution process of an alkaline silicate mineral (wollastonite, CaSiO3) in an anaerobic fermentation process were determined. Wollastonite dissolution kinetics was measured in a series of chemical batch experiments in order to be able to estimate the required amount of alkaline silicate that can neutralize the acidifying fermentation process. An anaerobic fermentation of glucose with wollastonite as the neutralizing agent was consequently performed in a fed-batch reactor. Results of this experiment were compared with an abiotic (control) fed-batch reactor in which the fermentation products (i.e. organic acids and alcohols) were externally supplied to the system at comparable rates and proportions, in order to provide chemical conditions similar to those during the biotic (fermentation) experiment. This procedure enabled us to determine whether dissolution of wollastonite was solely enhanced by production of organic acids or whether there were other impacts that fermentative bacteria could have on the mineral dissolution rate. The established pH profiles, which were the direct indicator of the dissolution rate, were comparable in both experiments suggesting that the mineral dissolution rate was mostly influenced by the quantity of the organic acids produced. PMID:23188461

Salek, S S; Kleerebezem, R; Jonkers, H M; Voncken, J H L; van Loosdrecht, M C M

2013-03-01

407

Vacuum arc under axial magnetic fields: experimental and simulation research  

NASA Astrophysics Data System (ADS)

Axial magnetic field (AMF) technology is a most important control method of vacuum arc, particularly for high-current vacuum arcs in vacuum interrupters. In this paper, a review of the state of current research on vacuum arcs under AMF is presented. The major aspects of vacuum arc in an AMF such as arc voltage, the motion of cathode spots, and anode activities are discussed, and the most recent progress both of experimental and simulation research is presented.

Jia, Shenli; Shi, Zongqian; Wang, Lijun

2014-10-01

408

Cold Vacuum Drying (CVD) Set Point Determination  

SciTech Connect

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 (approximately 0.5 psig) to prevent oxygen ingress unless a purge of adequate volume has been completed. During bulk water draining, the MCO must remain above atmospheric pressure.) (7) Seismic event of sufficient magnitude is detected. (Trip point is below the Uniform Building Code levels). Setpoint determination is required for trips C through H. Sensor error determination for additional safety-significant sensors used by the HVAC system or the SCHe system are also required.

PHILIPP, B.L.

2000-09-04

409

Quantum Vacuum Energy in Graphs and Billiards  

E-print Network

The vacuum (Casimir) energy in quantum field theory is a problem relevant both to new nanotechnology devices and to dark energy in cosmology. The crucial question is the dependence of the energy on the system geometry under study. Despite much progress since the first prediction of the Casimir effect in 1948 and its subsequent experimental verification in simple geometries, even the sign of the force in nontrivial situations is still a matter of controversy. Mathematically, vacuum energy fits squarely into the spectral theory of second-order self-adjoint elliptic linear differential operators. Specifically, one promising approach is based on the small-t asymptotics of the cylinder kernel e^(-t sqrt(H)), where H is the self-adjoint operator under study. In contrast with the well-studied heat kernel e^(-tH), the cylinder kernel depends in a non-local way on the geometry of the problem. We discuss some results by the Louisiana-Oklahoma-Texas collaboration on vacuum energy in model systems, including quantum graphs and two-dimensional cavities. The results may shed light on general questions, including the relationship between vacuum energy and periodic or closed classical orbits, and the contribution to vacuum energy of boundaries, edges, and corners.

L. Kaplan

2011-01-03

410

A Resolution of the Vacuum Energy Problem  

E-print Network

A new vision of the beginning and expansion of our universe has produced a solution to the vacuum energy problem (also known as "cosmological constant problem"). A new dynamic of cellular spaces and a discrete time has space being produced by a process called spatial condensation (SC). With generic energy defined as Planck's constant times the rate of cellular space production, both the vacuum energy and mass energy contents contribute to the expansion in the ratio 10^123/1, the same ratio of predicted densities by quantum theory and our astronomers. However, unlike mass energy, vacuum energy, like Casimir vacuum energy, does not carry the attribute of mass and so does not gravitate. A geometric derivation of the vacuum energy expansion rate was followed by a second derivation in terms of the evolution of the contents, from radiation to matter to dark mass (not matter). With a new definition of cosmic time, the second derivation was shown to produce exactly the same expansion rate. Free of singularities and inflation, both derivations also produced reasonable values of the cosmological parameters and the second derivation produced a good fit to the supernova Ia data with no acceleration of the expansion rate.

Charles B. Leffert

2003-08-01

411

Analysis of fermentation selectivity of purified galacto-oligosaccharides by in vitro human faecal fermentation.  

PubMed

The in vitro fermentation of several purified galacto-oligosaccharides (GOS), specifically the trisaccharides 4'-galactosyl-lactose and 6'-galactosyl-lactose and a mixture of the disaccharides 6-galactobiose and allolactose, was carried out. The bifidogenic effect of GOS at 1% (w/v) was studied in a pH-controlled batch culture fermentation system inoculated with healthy adult human faeces. Results were compared with those obtained with a commercial GOS mixture (Bimuno-GOS). Changes in bacterial populations measured through fluorescence in situ hybridization and short-chain fatty acid (SCFA) production were determined. Bifidobacteria increased after 10-h fermentation for all the GOS substrates, but the changes were only statistically significant (P<0.05) for the mixture of disaccharides and Bimuno-GOS. Acetic acid, whose formation is consistent with bifidobacteria metabolism, was the major SCFA synthesized. The acetate concentration at 10 h was similar with all the substrates (45-50 mM) and significantly higher than the observed for formic, propionic and butyric acids. All the purified GOS could be considered bifidogenic under the assayed conditions, displaying a selectivity index in the range 2.1-3.0, which was slightly lower than the determined for the commercial mixture Bimuno-GOS. PMID:23624658

Rodriguez-Colinas, Barbara; Kolida, Sofia; Baran, Magdalena; Ballesteros, Antonio O; Rastall, Robert A; Plou, Francisco J

2013-07-01

412

[Application of process engineering to remove lignocellulose fermentation inhibitors].  

PubMed

Fermentation inhibitors are toxic to cells, which is one of the bottlenecks for lignocellulose bio-refinery process. How to remove those inhibitors serves a key role in the bioconversion of lignocellulose. This article reviews the sources and the types of the inhibitors, especially the updated removal strategies including physical methods, chemical methods, biological methods and inhibitor-tolerant strain construction strategies. Based on these, we introduce a new bio-refinery model named "fractional conversion", which reduces the production of inhibitors at pretreatment stage, and a novel in situ detoxification method named "fermentation promoter exploitation technology". This review could provide new research ideas on the removal of fermentation inhibitors. PMID:25118395

Wang, Lan; Xia, Menglei; Chen, Hongzhang

2014-05-01

413

THERMOCHEMICAL CONVERSION OF FERMENTATION-DERIVED OXYGENATES TO FUELS  

SciTech Connect

At present ethanol generated from renewable resources through fermentation process is the dominant biofuel. But ethanol suffers from undesirable fuel properties such as low energy density and high water solubility. The production capacity of fermentation derived oxygenates are projected to rise in near future beyond the current needs. The conversion of oxygenates to hydrocarbon compounds that are similar to gasoline, diesel and jet fuel is considered as one of the viable option. In this chapter the thermo catalytic conversion of oxygenates generated through fermentation to fuel range hydrocarbons will be discussed.

Ramasamy, Karthikeyan K.; Wang, Yong

2013-06-01

414

Metabolically engineered bacteria for producing hydrogen via fermentation  

PubMed Central

Summary Hydrogen, the most abundant and lightest element in the universe, has much potential as a future energy source. Hydrogenases catalyse one of the simplest chemical reactions, 2H+?+?2e????H2, yet their structure is very complex. Biologically, hydrogen can be produced via photosynthetic or fermentative routes. This review provides an overview of microbial production of hydrogen by fermentation (currently the more favourable route) and focuses on biochemical pathways, theoretical hydrogen yields and hydrogenase structure. In addition, several examples of metabolic engineering to enhance fermentative hydrogen production are presented along with some examples of expression of heterologous hydrogenases for enhanced hydrogen production. PMID:21261829

Vardar-Schara, Gonul; Maeda, Toshinari; Wood, Thomas K.

2008-01-01

415

Lactic Acid Bacterial Fermentation of Burong Dalag1  

PubMed Central

The fermented food, burong dalag, prepared in many Filipino homes, was studied to determine the nature of the microbiological and chemical changes that occur during fermentation. This is a lactic acid bacterial fermentation in which the species Leuconostoc mesenteroides, Pediococcus cerevisiae, and Lactobacillus plantarum played the major acid-producing role. The pH was lowered to below 4.0, and about 0.9% acid as lactic acid was attained in 1 week. It was essential to keep the product covered well to exclude air and subsequent growth of yeasts and mold. PMID:5726145

Orillo, C. A.; Pederson, C. S.

1968-01-01

416

Inflammation, suppuration, putrefaction, fermentation: Joseph Lister's microbiology  

PubMed Central

This paper focuses on Lister's inaugural lecture at King's College, London, in October 1877. As the new Professor of Clinical Surgery, Lister had much to report, including impressively high survival rates from complex operations previously regarded as foolhardy. Instead, he chose to address the processes of fermentation in wine, blood and milk. His reasons are not obvious to a modern audience, just as they probably were not to those who heard him in the Great Hall at King's. Having brought microbiological apparatus from his laboratory to the lecture theatre and presented proof of bacterial variety and specificity, Lister publicly demonstrated the creation of the first pure bacterial culture in the history of microbiology. It was an ingenious and well-thought-out strategy designed to generate a frame of mind among his new colleagues and future students, receptive to the causative role of bacteria in septic diseases. His timing was impeccable.

Richardson, Ruth

2013-01-01

417

Sequestering the Standard Model Vacuum Energy  

NASA Astrophysics Data System (ADS)

We propose a very simple reformulation of general relativity, which completely sequesters from gravity all of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume element of the Universe. For them to be nonzero, the Universe should be finite in spacetime. If this matter is the standard model of particle physics, our mechanism prevents any of its vacuum energy, classical or quantum, from sourcing the curvature of the Universe. The mechanism is consistent with the large hierarchy between the Planck scale, electroweak scale, and curvature scale, and early Universe cosmology, including inflation. Consequences of our proposal are that the vacuum curvature of an old and large universe is not zero, but very small, that wDE?-1 is a transient, and that the Universe will collapse in the future.

Kaloper, Nemanja; Padilla, Antonio

2014-03-01

418

Vacuum polarization tensor in inhomogeneous magnetic fields  

E-print Network

We develop worldline numerical methods, which combine string-inspired with Monte-Carlo techniques, for the computation of the vacuum polarization tensor in inhomogeneous background fields for scalar QED. The algorithm satisfies the Ward identity exactly and operates on the level of renormalized quantities. We use the algorithm to study for the first time light propagation in a spatially varying magnetic field. Whereas a local derivative expansion applies to the limit of small variations compared to the Compton wavelength, the case of a strongly varying field can be approximated by a derivative expansion for the averaged field. For rapidly varying fields, the vacuum-magnetic refractive indices can exhibit a non-monotonic dependence on the local field strength. This behavior can provide a natural limit on the self-focussing property of the quantum vacuum.

Gies, Holger

2011-01-01

419

Vacuum polarization tensor in inhomogeneous magnetic fields  

E-print Network

We develop worldline numerical methods, which combine string-inspired with Monte-Carlo techniques, for the computation of the vacuum polarization tensor in inhomogeneous background fields for scalar QED. The algorithm satisfies the Ward identity exactly and operates on the level of renormalized quantities. We use the algorithm to study for the first time light propagation in a spatially varying magnetic field. Whereas a local derivative expansion applies to the limit of small variations compared to the Compton wavelength, the case of a strongly varying field can be approximated by a derivative expansion for the averaged field. For rapidly varying fields, the vacuum-magnetic refractive indices can exhibit a non-monotonic dependence on the local field strength. This behavior can provide a natural limit on the self-focussing property of the quantum vacuum.

Holger Gies; Lars Roessler

2011-07-01

420

Vacuum polarization tensor in inhomogeneous magnetic fields  

NASA Astrophysics Data System (ADS)

We develop worldline numerical methods, which combine string-inspired with Monte Carlo techniques, for the computation of the vacuum polarization tensor in inhomogeneous background fields for scalar QED. The algorithm satisfies the Ward identity exactly and operates on the level of renormalized quantities. We use the algorithm to study for the first time light propagation in a spatially varying magnetic field. Whereas a local derivative expansion applies to the limit of small variations compared to the Compton wavelength, the case of a strongly varying field can be approximated by a derivative expansion for the averaged field. For rapidly varying fields, the vacuum-magnetic refractive indices can exhibit a nonmonotonic dependence on the local field strength. This behavior can provide a natural limit on the self-focussing property of the quantum vacuum.

Gies, Holger; Roessler, Lars

2011-09-01

421

Invariant classification of vacuum PP-waves  

E-print Network

We solve the equivalence problem for vacuum PP-wave spacetimes by employing the Karlhede algorithm. Our main result is a suite of Cartan invariants that allows for the complete invariant classification of the vacuum pp-waves. In particular, we derive the invariant characterization of the G2 and G3 sub-classes in terms of these invariants. It is known [Collins91] that the invariant classification of vacuum pp-waves requires at most the fourth order covariant derivative of the curvature tensor, but no specific examples requiring the fourth order were known. Using our comprehensive classification, we prove that the q<=4 bound is sharp and explicitly describe all such maximal order solutions.

Robert Milson; David McNutt; Alan Coley

2012-09-23

422

Materials for high vacuum technology, an overview  

E-print Network

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...

Sgobba, Stefano

2007-01-01

423

Giant vacuum forces via transmission lines.  

PubMed

Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line. PMID:25002503

Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon

2014-07-22

424

Sequestering the standard model vacuum energy.  

PubMed

We propose a very simple reformulation of general relativity, which completely sequesters from gravity all of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume element of the Universe. For them to be nonzero, the Universe should be finite in spacetime. If this matter is the standard model of particle physics, our mechanism prevents any of its vacuum energy, classical or quantum, from sourcing the curvature of the Universe. The mechanism is consistent with the large hierarchy between the Planck scale, electroweak scale, and curvature scale, and early Universe cosmology, including inflation. Consequences of our proposal are that the vacuum curvature of an old and large universe is not zero, but very small, that w(DE) ? -1 is a transient, and that the Universe will collapse in the future. PMID:24655240

Kaloper, Nemanja; Padilla, Antonio

2014-03-01

425

Vacuum energy sequestering and cosmic dynamics  

E-print Network

We explicitly compute the dynamics of closed homogeneous and isotropic universes permeated by a single perfect fluid with a constant equation of state parameter $w$ in the context of a recent reformulation of general relativity, proposed in [1], which prevents the vacuum energy from acting as a gravitational source. This is done using an iterative algorithm, taking as an initial guess the background cosmological evolution obtained using standard general relativity in the absence of a cosmological constant. We show that, in general, the impact of the vacuum energy sequestering mechanism on the dynamics of the universe is significant, except for the $w=1/3$ case where the results are identical to those obtained in the context of general relativity with a null cosmological constant. We also show that there are well behaved models in general relativity that do not have a well behaved counterpart in the vacuum energy sequestering paradigm studied in this paper, highlighting the specific case of a quintessence scal...

Avelino, P P

2014-01-01

426

Thermal Versus Vacuum Magnetization in QED  

E-print Network

The magnetized relativistic Fermi and Bose gases are studied at finite temperature and density.In the case of the Fermi gas, the contribution to the magnetization from the vacuum becomes dominant for high magnetic fields, when the thermal contribution saturates. In the case of the charged Bose gas, the (paramagnetic) vacuum--magnetization becomes dominant when the gas changes from a diamagnetic to a paramagnetic behaviour. We furthermore find that the scalar--QED effective coupling constant for a weak non--zero external magnetic field is a decreasing function of the temperature.

Per Elmfors; Per Liljenberg; David Persson; Bo-Sture Skagerstam

1994-07-22

427

Vacuum distillation/vapor filtration water recovery  

NASA Technical Reports Server (NTRS)

The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

Honegger, R. J.; Neveril, R. B.; Remus, G. A.

1974-01-01

428

Evaluation of Dry, Rough Vacuum Pumps  

NASA Technical Reports Server (NTRS)

This document provides information on the testing and evaluation of thirteen dry rough vacuum pumps of various designs and from various manufacturers. Several types of rough vacuum pumps were evaluated, including scroll, roots, and diaphragm pumps. Tests included long term testing, speed curve generation, voltage variance, vibrations emissions and susceptibility, electromagnetic interference emissions and susceptibility, static leak rate, exhaust restriction, response/recovery time tests, and a contamination analysis for scroll pumps. Parameters were found for operation with helium, which often is not provided from the manufacturer

Hunter, Brian

2006-01-01

429

Criteria for vacuum breakdown in rf cavities  

SciTech Connect

A new high-voltage scaling based on Kilpatrick's criterion is presented that suggests that voltages more than twice the Kilpatrick limit can be obtained with identical initial conditions of vacuum and surface cleanliness. The calculations are based on the experimentally observed decrease in secondary electron emission with increasing ion impact energy above 100 keV. A generalized secondary-emission package has been developed to simulate actual cavity dynamics in conjunction with our 2 1/2-dimensional fully electromagnetic particle-in-cell code CEMIT. The results are discussed with application to the suppression of vacuum breakdown in rf accelerator devices.

Peter, W.; Faehl, R.J.; Kadish, A.; Thode, L.E.

1983-08-01

430

Criteria for vacuum breakdown in rf cavities  

SciTech Connect

A new high-voltage scaling based on Kilpatrick's criterion is presented that suggests that voltages more than twice the Kilpatrick limit can be obtained with identical initial conditions of vacuum and surface cleanliness. The calculations are based on the experimentally observed decrease in secondary electron emission with increasing ion-impact energy above 100 keV. A generalized secondary-emission package has been developed to simulate actual cavity dynamics in conjunction with our 2 1/2-dimensional fully electromagnetic particle-in-cell code CEMIT. The results are discussed with application to the suppression of vacuum breakdown in rf accelerator devices.

Peter, W.; Faehl, R.J.; Kadish, A.; Thode, L.E.

1983-01-01

431

Feigel effect: Extraction of momentum from vacuum?  

PubMed

The Green-function formalism for the electromagnetic field in a magnetoelectric (ME) medium is constructed as a generalization of conventional Casimir theory. Zero temperature is assumed. It is shown how the formalism predicts electromagnetic momentum to be extracted from the vacuum field, just analogous to how energy is extracted in the Casimir case. The possibility of extracting momentum from vacuum was discussed recently by Feigel [Phys. Rev. Lett. 92, 020404 (2004)]. In contrast to Feigel's approach, we assume that the ME coupling occurs naturally, rather than being produced by external strong fields. We also find the same effect qualitatively via another route by considering one single electromagnetic mode. PMID:18233935

Birkeland, Ole Jakob; Brevik, Iver

2007-12-01

432

Stationary and nonstationary scalar vacuum field noises  

E-print Network

If stationary, the spectrum of vacuum field noise (VFN) is an important ingredient to get information about the curvature invariants of classical worldlines (relativistic classical trajectories). For scalar quantum field vacua there are six stationary cases as shown by Letaw some time ago, these are reviewed here. However, the non-stationary vacuum noises are not out of reach and can be processed by a few mathematical methods which I briefly comment on. Since the information about the kinematical curvature invariants of the worldlines is of radiometric origin, hints are given on a more useful application to radiation and beam radiometric standards at relativistic energies

H. C. Rosu

1999-12-14

433

The QCD vacuum probed by overlap fermions  

E-print Network

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.

V. Weinberg; E. -M. Ilgenfritz; K. Koller; Y. Koma; G. Schierholz; T. Streuer

2006-10-13

434

Laser-surface impulse delivery in vacuum  

SciTech Connect

Available experimental measurements of impulse delivery to solid surfaces in vacuum by pulsed laser radiation are presented and compared to predictions of simple theoretical models. The trend of impulse coupling coefficient measurements with increasing laser fluence is explained by three regimes of the laser-material interaction process for vacuum or very low pressure conditions. The results indicate that impulsive coupling measurements can be simply scaled over a wide range of laser wavelengths, pulse lengths and focal spot sizes and coupling coefficients can be predicted with fair accuracy if the effective laser-surface absorption coefficient is known.

Lowder, J.E.

1982-01-01

435

A vacuum spacetime with closed null geodesics  

SciTech Connect

Here we present a vacuum spacetime with closed null geodesics (CNGs). These CNGs are obtained by analytically solving the geodesic equations. This spacetime is locally isometric to the plane wave spacetime and has very different global properties from metrics of the latter type. - Highlights: Black-Right-Pointing-Pointer Closed null geodesics are found in a vacuum spacetime. Black-Right-Pointing-Pointer These are obtained by analytically solving the geodesic equations. Black-Right-Pointing-Pointer The nature of the spacetime is fully analysed.

Sarma, Debojit, E-mail: debojitsarma@yahoo.com; Patgiri, Mahadev, E-mail: mahadev@scientist.com; Ahmed, Faiz Uddin, E-mail: faiz4U.enter@rediffmail.com

2013-02-15

436

Vacuum energy on orbifold factors of spheres  

E-print Network

The vacuum energy is calculated for a free, conformally-coupled scalar field on the orbifold space-time \\R$\\times \\S^2/\\Gamma$ where $\\Gamma$ is a finite subgroup of O(3) acting with fixed points. The energy vanishes when $\\Gamma$ is composed of pure rotations but not otherwise. It is shown on general grounds that the same conclusion holds for all even-dimensional factored spheres and the vacuum energies are given as generalised Bernoulli functions (i.e. Todd polynomials). The relevant $\\zeta$- functions are analysed in some detail and several identities are incidentally derived. The general discussion is presented in terms of finite reflection groups.

Peter Chang; J. S. Dowker

1992-10-02

437

Explosion proofing the ``explosion proof`` vacuum cleaner  

SciTech Connect

Because of the low humidity environments required in the fabrication of nuclear explosives, assembly technicians can be charged to tens of kilovolts while operating, for example, compressed air, venturi-type, `explosion proof` vacuum cleaners. Nuclear explosives must be isolated from all sources of, and return paths for, AC power and from any part of the lightning protection system. This requirement precludes the use of static ground conductors to drain any charge accumulations. Accordingly, an experimental study of the basic charging mechanisms associated with vacuum operations were identified, the charge generation efficacies of various commercial cleaners were established, and a simple method for neutralizing the charge was devised.

Jones, R.D.; Chen, K.C.; Holmes, S.W.

1995-07-01

438

The QCD vacuum probed by overlap fermions  

E-print Network

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.

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

2006-01-01

439

Bioethanol production: an integrated process of low substrate loading hydrolysis-high sugars liquid fermentation and solid state fermentation of enzymatic hydrolysis residue.  

PubMed

An integrated process of enzymatic hydrolysis and fermentation was investigated for high ethanol production. The combination of enzymatic hydrolysis at low substrate loading, liquid fermentation of high sugars concentration and solid state fermentation of enzymatic hydrolysis residue was beneficial for conversion of steam explosion pretreated corn stover to ethanol. The results suggested that low substrate loading hydrolysis caused a high enzymatic hydrolysis yield; the liquid fermentation of about 200g/L glucose by Saccharomyces cerevisiae provided a high ethanol concentration which could significantly decrease cost of the subsequent ethanol distillation. A solid state fermentation of enzymatic hydrolysis residue was combined, which was available to enhance ethanol production and cellulose-to-ethanol conversion. The results of solid state fermentation demonstrated that the solid state fermentation process accompanied by simultaneous saccharification and fermentation. PMID:22975252

Chu, Qiulu; Li, Xin; Ma, Bin; Xu, Yong; Ouyang, Jia; Zhu, Junjun; Yu, Shiyuan; Yong, Qiang

2012-11-01

440

27. STAINLESS STEEL FERMENTING CASKS MADE BY ZERO MANG OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. STAINLESS STEEL FERMENTING CASKS MADE BY ZERO MANG OF WASHINGTON, MISSOURI. VIEW LOOKING NORTH TOWARD VAULT OF THE TWELVE APOSTLES - Stone Hill Winery, 401 West Twelfth Street, Hermann, Gasconade County, MO

441

Analysis and behavior of colistin during anaerobic fermentation.  

PubMed

A new analytical method for the determination of colistin in fermenter samples was developed followed by a study on the behavior of this substance during anaerobic fermentation. Analysis of colistin A and B was carried out by liquid chromatography-tandem mass spectrometry. Separation of the analytes was performed on a Security Guard column (4×3mm). Fourteen fermentation tests in batch as well as in continuous reactors were carried out. After 44days of anaerobic digestion of cattle manure, initially spiked with 500mg/kg of colistin sulfate, a considerable decrease of the colistin concentration to less than 1mg/kg could be observed. Furthermore, the daily production of biogas and methane was measured. A correlation between gas production and colistin concentration could not be determined. However, an increase of 10% of the cumulative methane production was observed in those fermenters spiked with an initial bolus of 500mg/kg colistin. PMID:25151074

Riemenschneider, C; Zerr, W; Vater, N; Brunn, H; Mohring, S A I; Hamscher, G

2014-10-01

442

Fermentation of Glucose, Lactose, Galactose, Mannitol, and Xylose by Bifidobacteria  

PubMed Central

For six strains of Bifidobacterium bifidum (Lactobacillus bifidus), fermentation balances of glucose, lactose, galactose, mannitol, and xylose were determined. Products formed were acetate, l(+)-lactate, ethyl alcohol, and formate. l(+)-Lactate dehydrogenase of all strains studied was found to have an absolute requirement for fructose-1,6-diphosphate. The phosphoroclastic enzyme could not be demonstrated in cell-free extracts. Cell suspensions fermented pyruvate to equimolar amounts of acetate and formate. Alcohol dehydrogenase was shown in cell-free extracts. Possible explanations have been suggested for the differences in fermentation balances found for different strains and carbon sources. By enzyme determinations, it was shown that bifidobacteria convert mannitol to fructose-6-phosphate by an inducible polyol dehydrogenase and fructokinase. For one strain of B. bifidum, molar growth yields of glucose, lactose, galactose, and mannitol were determined. The mean value of Y (ATP), calculated from molar growth yields and fermentation balances, was 11.3. PMID:5674058

de Vries, Wytske; Stouthamer, A. H.

1968-01-01

443

Hydrolysis of starch and fermentable hydrolysates obtained therefrom  

SciTech Connect

Starch in slurry was liquefied by strong acid and a-amylase, saccharified in the presence of acid cation exchanger, and neutralized with NH/sub 4/OH to obtain an aqueous solution of fermentable sugar.

Muller, W.C.; Miller, F.D.

1981-05-05

444

Adding value to carbon dioxide from ethanol fermentations  

Microsoft Academic Search

Carbon dioxide (CO2) from ethanol production facilities is increasing as more ethanol is produced for alternative transportation fuels. CO2 produced from ethanol fermentation processes is of high purity and is nearly a saturated gas. Such highly-concentrated source of CO2 is a potential candidate for capture and utilization by the CO2 industry. Quantity, quality and capture of CO2 from ethanol fermentations

Yixiang Xu; Loren Isom; Milford A. Hanna

2010-01-01

445

Separation of lactic acid from fermented broth by reactive extraction.  

PubMed

The separation of lactic acid from complex fermentation broth was examined. Liquid-liquid extraction using reversible chemical complexation for reactive extraction was chosen to be the separation method. Over 50% yield of lactic acid was obtained from fermented broth in a single extraction step, when using the tertiary amine as the extractant, 1-dekanol as the diluent and trimethylamine (TMA) as the stripping solution. The effect of complex media on the extraction behaviour has hardly been examined previously. PMID:11105245

Järvinen, M; Myllykoski, L; Keiski, R; Sohlo, J

2000-01-01

446

Fermentation of Raw Poultry Byproducts for Animal Nutrition  

Microsoft Academic Search

In this study, the fermentation of raw, inedible poultry byproducts mixed with sugarbeet pulp and dextrose and inoculated with Lactobacillus plantarum and( or) Enteroccocus faecium resulted in a drop of pH in the byproducts to approximately 4.0 to 4.5 within 48 h. To keep the fermented product stable for a period of 21 d, the addition of 2 3% (wt\\/wt)

H. A. P. Urlings; P. G. H. Bijker; J. G. van Logtestijn

447

Citrate Fermentation byLactococcus andLeuconostoc spp  

Microsoft Academic Search

converted pyruvate tolactate athighdilution (growth) rates,lowpH,andhighlactose concentrations. Mixed-acid fermentation withformate, ethanol, andacetate asproducts was observed underconditions oflactose limitation incontinuous culture atpH values above6.0.An acetoin\\/butanediol fermentation witha-acetolactate as an intermediate was foundupon mildaeration incontinuous culture andunderconditions ofexcesspyruvate production fromcitrate. Leuconostoc spp.showed a limited metabolic flexibility. A typical heterofermentative conversion oflactose was observed underallconditions inbothcontinuous andbatchcultures. Thepyruvate produced fromeither lactose orcitrate was

MARJO J. C. STARRENBURG; JEROEN HUGENHOLTZ

1991-01-01

448

Main microorganisms involved in the fermentation of Ugandan ghee  

Microsoft Academic Search

Ghee is widely produced from a traditional fermented butter-like product named mashita in western Uganda. However, no detailed studies have been done to identify the microorganisms involved in mashita fermentation. The aim of this study was to identify the microorganisms present at the end of mashita ripening using culture-dependent and culture-independent techniques. The most commonly identified species of lactic acid

Martin Patrick Ongol; Kozo Asano

2009-01-01

449

Isolation and identification of killer yeast from fermented vegetables  

Microsoft Academic Search

Nine samples of fermented vegetables (pak-sein, bamboo shoot, sator and cabbage) taken from Pattani and Narathiwat provinces, were examined. The fermented liquid from these samples had pH and NaCl concentration ranges between 3.3-3.9 and 2.4-8.2%, respectively. Eighty two yeast isolates were collected for the killer activity screening against five sensitive reference strains, Candida tropicalis TISTR 5045, Hansenula anomala TISTR 5113,

Sunee Waema; Jaruwan Maneesri; Payap Masniyom

2009-01-01

450

Preparation and evaluation of sauces from lactic acid fermented vegetables  

Microsoft Academic Search

Different combinations of fermented vegetables like carrot, radish and cucumber with pear and mango pulps were made separately\\u000a and were processed. All the sauces prepared were having a constant TSS of 18°B using different combinations of fermented pulp\\u000a viz., 25, 50, 75 and 100% with fruit pulps of mango and pear. The titratable acidity of carrot, radish and cucumber based

V. K. Joshi; Sharma Somesh

2010-01-01

451

Stability of virginiamycin and penicillin during alcohol fermentation  

Microsoft Academic Search

Studies were conducted to examine the stabilities of virginiamycin (Vm) and penicillin-G (PG) during incubation at 25 or 35°C in sterile malt-glucose-yeast-extract (MGYE) fermentation broth and during alcohol fermentation by Saccharomyces cerevisiae, Davis 522 strain. A 5×2 (five pH levels and two temperatures) factorial design was used to evaluate the stabilities of these two antibiotics. The pH of MGYE used

M Islam; R Toledo; M. K Hamdy

1999-01-01

452

Ethanol fermentation from biomass resources: current state and prospects  

Microsoft Academic Search

In recent years, growing attention has been devoted to the conversion of biomass into fuel ethanol, considered the cleanest\\u000a liquid fuel alternative to fossil fuels. Significant advances have been made towards the technology of ethanol fermentation.\\u000a This review provides practical examples and gives a broad overview of the current status of ethanol fermentation including\\u000a biomass resources, microorganisms, and technology. Also,

Yan Lin; Shuzo Tanaka

2006-01-01

453

Lignocellulolytic enzyme production from submerged fermentation of paddy straw  

Microsoft Academic Search

Five strains of cellulolytic bacteria and four strains of Phanerochaete chrysosporium were evaluated for the lignocellulolytic enzyme production during submerged fermentation (SmF) of paddy straw. Extra-cellular\\u000a enzyme assay for CMCase, FPase, Cellobiase, Xylanase, Lignin peroxidase and Laccase enzymes was performed after 7 and 15 days\\u000a of submerged fermentation. Cellulomonas cellulans MTCC 23, Cytophaga hutchinsonii NCIM 2338 and Phanerochaete chrysosporium MTCC

B. K. Mishra; A. K. Pandey Lata

2007-01-01

454

Volatile Compounds in Cider: Inoculation Time and Fermentation Temperature Effects  

Microsoft Academic Search

J. Inst. Brew. 112(3), 210-214, 2006 A cider fermentation at laboratory scale with controlled inocula- tion with selected yeasts and malolactic bacteria was performed. The composition of the major volatile compounds with low boil- ing points (<145°C) was determined by gas chromatography throughout the fermentation process, under the different operat- ing conditions of inoculation time of the microorganisms (simul- taneous

Mónica Herrero; Luis A. García; Mario Díaz

455

Alcoholic fermentation: on the inhibitory effect of ethanol  

Microsoft Academic Search

The inhibitory effect of ethanol was studied during alcoholic fermentation under strictly anaerobic conditions assured by stripping dissolved oxygen with pure nitrogen. It is shown that ehthanol produced during batch fermentation is more inhibitory than added ethanol in the range of 0 to 76 g\\/liter. Thus, the inhibition constant is 105.2 and 3.8 g\\/liter for added and produced ethanol, respectively.

M. Novak; P. Strehaiano; M. Moreno; G. Goma

1981-01-01

456

Ethanol vapour pressure as a control factor during alcoholic fermentation  

Microsoft Academic Search

Aqueous solutions of glucose\\/fructose mixtures with varying concentrations of ethanol were used to study the effects on fermentation\\u000a of ethanol vapour pressure and water activity. Water vapour pressure was found to increase significantly with temperature\\u000a in the range 15 to 30‡C. The effects on glucose fermentation bySaccharomyces cerevisiae Bg7FL of the variables glucose concentration, Tween 80 concentration, temperature and ammonium

M. E. Guerzoni; M. C. Nicoli; R. Massini; C. R. Lerici

1997-01-01

457

Optimization of batch alcoholic fermentation of glucose syrup substrate  

Microsoft Academic Search

The quantitative effects of substrate concentration, yeast concentration, and nutrient supplementation on ethanol content, fermentation time, and ethanol productivity were investigated in a Box-Wilson central composite design experiment, consisting of five levels of each variable. High substrate concentration, up to 30 degrees Brix, resulted in higher ethanol content (i.e., up to 15.7% w\\/v or 19.6% v\\/v) but longer fermentation time

S. L. Chen

1981-01-01

458

Enhanced product formation in continuous fermentations with microbial cell recycle  

SciTech Connect

The effect of partial recycle of microbial cells on the operation of a chemostat has been investigated for two fermentations. Stable steady states with and without partial cell recycle were obtained for the conversion of d-sorbitol to L-sorbose by Gluconobacter oxydans subsp. suboxydans 1916B and for the conversion of glucose to 2-ketogluconic acid by Serratia marcescens NRRl B-486. The employment of partial cell recycle dramatically increased product formation rates for both fermentations.

Bull, D.N.; Young, M.D.

1981-02-01

459

Simulations and Vacuum Tests of a CLIC Accelerating Structure  

E-print Network

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.

Garion, C

2011-01-01

460

Lightweight Vacuum Jacket for Cryogenic Insulation. Volume 1  

NASA Technical Reports Server (NTRS)

The feasibility of producing a lightweight vacuum jacket using state-of-the-art technology and materials was examined. Design and analytical studies were made on a full-scale, orbital maneuvering system fuel tank. Preliminary design details were made for the tank assembly, including an optimized vacuum jacket and multilayer insulation system. A half-scale LH2 test model was designed and fabricated, and a force/stiffness proof test was conducted on the vacuum jacket. A vacuum leak rate of .000001 atmosphere ml of helium per second was measured, approximately 1500 hours of vacuum pressure were sustained, and 29 vacuum-pressure cycles were experienced prior to failure.

Barclay, D. L.; Bell, J. E.; Brogren, E. W.; Straayer, J. W.

1975-01-01

461

Polarizable vacuum analysis of the gravitational metric tensor  

E-print Network

The gravitational metric tensor implies a variable dielectric tensor of vacuum around gravitational matter. The curved spacetime in general relativity is then associated with a polarizable vacuum. It is found that the number density of the virtual dipoles in vacuum decreases with the distance from the gravitational centre. This result offers a polarizable vacuum interpretation of the gravitational force. Also, the anisotropy of vacuum polarization is briefly discussed, which appeals for observational proof of anisotropic light propagation in a vacuum altered by gravitational or electromagnetic field.

Xing-Hao Ye

2009-03-21

462

In vitro fermentation studies for selection and evaluation of Bacillus strains as starter cultures for the production of okpehe, a traditional African fermented condiment  

Microsoft Academic Search

Selected Bacillus and Enterococcus strains, isolated from traditional okpehe fermentations, were studied for their suitability as starter cultures in laboratory-scale fermentations of Prosopis africana seeds for the production of okpehe, a traditional fermented vegetable product of Nigeria. The strains were selected on the basis of highest proteolytic activity, as determined with the APIZYM (BioMerieux) test. The choice of starter strains

Folarin A. Oguntoyinbo; Abiodun I. Sanni; Charles M. A. P. Franz; Wilhelm H. Holzapfel

2007-01-01

463

Continuous cellulosic bioethanol fermentation by cyclic fed-batch cocultivation.  

PubMed

Cocultivation of cellulolytic and saccharolytic microbial populations is a promising strategy to improve bioethanol production from the fermentation of recalcitrant cellulosic materials. Earlier studies have demonstrated the effectiveness of cocultivation in enhancing ethanolic fermentation of cellulose in batch fermentation. To further enhance process efficiency, a semicontinuous cyclic fed-batch fermentor configuration was evaluated for its potential in enhancing the efficiency of cellulose fermentation using cocultivation. Cocultures of cellulolytic Clostridium thermocellum LQRI and saccharolytic Thermoanaerobacter pseudethanolicus strain X514 were tested in the semicontinuous fermentor as a model system. Initial cellulose concentration and pH were identified as the key process parameters controlling cellulose fermentation performance in the fixed-volume cyclic fed-batch coculture system. At an initial cellulose concentration of 40 g liter(-1), the concentration of ethanol produced with pH control was 4.5-fold higher than that without pH control. It was also found that efficient cellulosic bioethanol production by cocultivation was sustained in the semicontinuous configuration, with bioethanol production reaching 474 mM in 96 h with an initial cellulose concentration of 80 g liter(-1) and pH controlled at 6.5 to 6.8. These results suggested the advantages of the cyclic fed-batch process for cellulosic bioethanol fermentation by the cocultures. PMID:23275517

Jiang, He-Long; He, Qiang; He, Zhili; Hemme, Christopher L; Wu, Liyou; Zhou, Jizhong

2013-03-01

464

Anaerobic fermentation of woody biomass pretreated with supercritical ammonia  

SciTech Connect

The degradability of ground hardwood by thermophilic anaerobic bacteria (Clostridium thermocellum with or without Thermoanaerobacter strain B6A) was greatly enhanced by pretreatment of the substrate with supercritical ammonia. Relative to C. thermocellum monocultures, cocultures of C. thermocellum and Thermoanaerobacter strain B6A degraded 1.5-fold more pretreated soft maple but produced 2- 5-fold more fermentation end products because Thermoanaerobacter sp. removed reducing sugars produced by C. thermocellum during the fermentation. Dry weight losses were not totally accounted for in end products, due to formation of partially degraded material (<0.4 ..mu..m diameter wood particles) during the fermentation. One pretreated hardwood, Southern red oak, was fermented poorly because it released soluble inhibitors at the 60/sup 0/C incubation temperature. Considerable (6- to 11-fold) increases in substrate degradability were also noted for supercritical ammonia-pretreated wood materials fermented in an in vitro rumen digestibility assay. Degradation of pretreated softwoods by either thermophilic or mesophilic fermentation was not measurable under the conditions tested.

Weimer, P.J.; Chou, Y.C.T.

1986-10-01

465

Enhanced fermentation systems with continuous removal of inhibitory products  

SciTech Connect

A variety of advanced bioreactors are being developed to improve production of fuels, solvents, organic acids, and other fermentation products. A major limitation of microbial fermentations is the dilute aqueous product streams that result, largely due to inhibition of the microbes by the desired products. If these inhibitory products can be removed during the ongoing fermentation, the overall rates, yields, and net product formation may be increased. Simultaneous fermentation and separation have been tested with different separation techniques, such as adsorption, liquid extraction, pervaporation, membrane separations, distillation, and others. These separations can occur directly in situ within the fermentor or indirectly using a sidestream separator with recycle of the unused substrate. These approaches are briefly reviewed. At Oak Ridge National Laboratory (ORNL), we have investigated two modified immobilized-cell fluidized-bed bioreactors (FBRs) to remove the inhibitory product directly from the continuous fermentation. One involves the separation by adsorption of tactic acid, and the other uses liquid solvent extraction for the production of butanol. Keywords: extractive fermentation, in situ separation, adsorption, tactic acid, butanol.

Davison, B.H.; Kaufman, E.N.

1994-06-01

466

Production of folates by yeasts in Tanzanian fermented togwa.  

PubMed

We have investigated the impact of different yeasts and fermentation time on folate content and composition in a fermented maize-based porridge, called togwa, consumed in rural areas in Tanzania. The yeasts studied, originally isolated from indigenous togwa, belong to Issatchenkia orientalis, Pichia anomala, Saccharomyces cerevisiae, Klyveromyces marxianus and Candida glabrata. The main folate forms found, detected and quantified by HPLC during the fermentations were 5-methyl-tetrahydrofolate (5-CH(3)-H(4)folate) and tetrahydrofolate (H(4)folate). The content of H(4)folate, per unit togwa, remained fairly stable at a low level throughout the experiment for all strains, whereas the 5-CH(3)-H(4)folate concentration was highly dependent on yeast strain as well as on fermentation time. The highest folate concentration was found after 46 h of fermentation with C. glabrata (TY26) (6.91+/-0.14 microg 100 mL(-1)), corresponding to a 23-fold increase compared with unfermented togwa. The cell concentration per se could not predict the togwa folate level, as shown by the much higher specific folate content (g folate CFU(-1)) in the S. cerevisiae strain (TY08) compared with the other species tested. This study provides useful data when trying to maximize folate content in togwa as well as in other yeast-fermented products. PMID:18547328

Hjortmo, Sofia B; Hellström, Andreas M; Andlid, Thomas A

2008-08-01

467

Husimi Functions of Excited Squeezed Vacuum States  

NASA Astrophysics Data System (ADS)

Based on the Husimi operator in pure state form introduced by Fan et al., which is a squeezed coherent state projector, and the technique of integration within an ordered product (IWOP) of operators, as well as the entangled state representations, we obtain the Husimi functions of the excited squeezed vacuum states (ESVS) and two marginal distributions of the Husimi functions of the ESVS.

Meng, Xiang-Guo; Wang, Ji-Suo; Liang, Bao-Long

2009-09-01

468

Design of the ZTH vacuum liner  

SciTech Connect

The current status of the ZTH vacuum liner design is covered by this report. ZTH will be the first experiment to be installed in the CPRF (Confinement Physics Research Facility) at the Los Alamos National Laboratory and is scheduled to be operational at the rated current of 4 MA in 1992. The vacuum vessel has a 2.4 m major radius and a 40 cm minor radius. Operating parameters which drive the vacuum vessel mechanical design include a 300 C bakeout temperature, an armour support system capable of withstanding 25 kV, a high toroidal resistance, 1250 kPa magnetic loading, a 10 minute cycle time, and high positional accuracy with respect to the conducting shell. The vacuum vessel design features which satisfy the operating parameters are defined. The liner is constructed of Inconel 625 and has a geometry which alternates sections of thin walled bellows with rigid ribs. These composite sections span between pairs of the 16 diagnostic stations to complete the torus. The thin bellows sections maximize the liner toroidal resistance and the ribs provide support and positional accuracy for the armour in relation to the conducting shell. Heat transfer from the vessel is controlled by a blanket wrap of ceramic fiber insulation and the heat flux is dissipated to a water cooling jacket in the conducting shell.

Prince, P.P.; Dike, R.S.

1987-01-01

469

Microminiature thermionic vacuum flat panel display prototype  

SciTech Connect

The authors report on the fabrication and electrical characteristics of low work microminiature thermionic vacuum (MTV) diodes for use in flat panel display applications. In this work advances in the technology and performance of a novel thermionic analog to field emission vacuum microelectronic emitters that will be referred to by the descriptive name microminiature thermionic vacuum (MTV) emitters will be presented. The salient feature of MTV emitter technology is the use of an air-bridge (suspended) filament that greatly reduces the thermal load and stress on the system. MTV devices can be fabricated using conventional semiconductor and micromachining processing techniques on any thermally stable, vacuum compatible substrate for which a high temperature stable insulating layer can be grown or deposited on. In addition, the small (micron to sub-micron) distances between the cathode and anode allow the possibility of intrinsic operation to high frequencies comparable to that of field emitters since these devices will not suffer from solid-state electron transport effects that limit the upper frequency of operation for all semiconductor devices.

Sadwick, L.P.; Baker, B.; Chen, C.C.; Petersen, R.; Johnson, S.; Hwu, R.J. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Electrical Engineering

1996-12-31

470

Vacuum energy of a color magnetic vortex  

Microsoft Academic Search

We calculate the one loop gluon vacuum energy in the background of a color magnetic vortex for SU(2) and SU(3). We use zeta functional regularization to obtain analytic expressions suitable for numerical treatment. The momentum integration is turned to the imaginary axis and fast converging sums or integrals are obtained. We investigate numerically a number of profiles of the background.

M. Bordag

2003-01-01

471

Vacuum polarization tensor in inhomogeneous magnetic fields  

Microsoft Academic Search

We develop worldline numerical methods, which combine string-inspired with Monte Carlo techniques, for the computation of the vacuum polarization tensor in inhomogeneous background fields for scalar QED. The algorithm satisfies the Ward identity exactly and operates on the level of renormalized quantities. We use the algorithm to study for the first time light propagation in a spatially varying magnetic field.

Holger Gies; Lars Roessler

2011-01-01

472

Resin Vacuum Casting System for LED Screen  

Microsoft Academic Search

This paper mainly describes the resin vacuum casting system for LED screen which uses thin film degassing technology and meter mix technology. Thin film degassing technology is currently the most effective method. In this paper, we describe in detail its working model. And meter mix dispensing technology integrates metering pump and mixing pump. It mixes materials according to the demand.

Hong Robin; Wang Hongmei; Hu Ming

2010-01-01

473

ALSEP CASK ASSEMBLY GEARBOX THERMAL VACUUM TEST  

E-print Network

with the results of a thermal vacuum test on the ACA gearbox assembly which was conducted during the ACA prototype test series. The purpose of the test was to verify the operation of the ACA Gearbox Assembly when. = l. 5 in. 0. 75 in. moment arm. 4. Raw data to true force conversion = 3/. 7 5 = 4 5. Wt of ACA Band

Rathbun, Julie A.

474

Vacuum Pyrolysis and Related ISRU Techniques  

NASA Astrophysics Data System (ADS)

A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a ~1m2 Fresnel lens. This system was successfully used to vaporize quantities of ~1g, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system with a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of ~10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

2007-01-01

475

Vacuum Pyrolysis and Related ISRU Techniques  

NASA Technical Reports Server (NTRS)

A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, process modeling, parts manufacturing, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a approx. l square meter Fresnel lens. This system was successfully used to vaporize quantities of approx. lg, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system With a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of approx. 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

2007-01-01

476

Vacuum Pyrolysis of Bark From Pinus Ponderosa  

Microsoft Academic Search

The inner and outer barks of ponderosa pine (P. ponderosa) have been pyrolysed at 350°C in vacuum and the tars analyzed by gas chromatography after tri-O-methylsilylation. The nine major peaks in the gas chromatogram have been identified and quantified and it is concluded that all (except pinitol) originate predominantly from polysaccharide components of the barks. They account for up to

T. L. Lowary; G. N. Richards

1988-01-01

477

Vacuum Technology: Kinetic Theory of Gas  

NSDL National Science Digital Library

This is a PDF version of lecture slides that discuss the kinetic theory of gases. Slide topics include vacuum basics, kinetic pressure of an ideal gas, pressure and molecular velocity, basic equations from kinetic theory, gas laws, and gas transport phenomena. Numerous charts and mathematical formulas are presented. Keywords: Boltzman's constant, collision frequency, molecular velocity, Boyle's law, Charles' law, Dalton's law

Rack, Philip D.

2012-12-14

478

ON EXTRACTING ELECTROMAGNETIC ENERGY FROM THE VACUUM  

Microsoft Academic Search

Generators and batteries do not furnish any of their internal energy to their external circuit, but only dissipate it internally to perform work on their own internal charges to form a source dipole. Once formed, the dipole's broken symmetry extracts observable energy from the virtual particle exchange between dipole charges and active vacuum. The extracted observable energy is reradiated as

Thomas E. Bearden

479

Quantized electromagnetic tornado in pulsar vacuum gap  

E-print Network

The solution for the electromagnetic tornado in a vacuum gap of a pulsar that could serve as an explanation of the observed circular polarization of giant pulses from pulsars and might also explain the frequency strips observed in giant pulses spectrum is found.

Kontorovich, V M

2009-01-01

480

The HIE-ISOLDE Vacuum System  

E-print Network

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...

Vandoni, G; Radwan, K; Chiggiato, P

2014-01-01

481

Statistical mechanics of the vacuum Christian Beck  

E-print Network

Statistical mechanics of the vacuum Christian Beck Queen Mary University of London, School statistical mechanics that distinguishes fundamental constants of nature. 1 arXiv:1112.1583v1[cond-mat.stat-mech]7Dec2011 #12;1 Introduction Statistical mechanics has been applied to a large variety of complex

Beck, Christian

482

Investigations Of A Pulsed Cathodic Vacuum Arc  

NASA Astrophysics Data System (ADS)

Cathodic vacuum arcs are well established as a method for producing thin films for coatings and as a source of metal ions. Research into DC vacuum arcs has been going on for over ten years in the School of Physics at the University of Sydney. Recently a project was undertaken in the school to design and build a pulsed CVA for use in the investigation of plasma sheaths and plasma immersion ion implantation. Pulsed cathodic vacuum arcs generally have a higher current and plasma density and also provide a more stable and reproducible plasma density than their DC counterparts. Additionally it has been shown that if a high repetition frequency can be established the deposition rate of pulsed arcs is equal to or greater than that of DC arcs with a concomitant reduction in the rate of macro-particle formation. We present here results of our investigations into the building of a center-triggered pulsed cathodic vacuum arc. The design of the power supply and trigger mechanism and the geometry of the anode and cathode are examined. Observations of type I and II arc spots using a CCD camera, and cathode spot velocity dependence on arc current will be presented. The role of retrograde motion in a high current pulsed arc is discussed.

Oates, T. W. H.; Pigott, J.; Denniss, P.; Mckenzie, D. R.; Bilek, M. M. M.

2003-06-01

483

APPLICATION OF CFD IN VACUUM DEZINCING PROCESS  

Microsoft Academic Search

Most lead bullion is refined by pyrometallurgical methods - this involves a series of processes that remove the antimony (softening) silver (Parkes process), zinc (vacuum dezincing) and if need be, bismuth (Betterton-Kroll process). The first step, softening, removes the antimony, arsenic and tin by air oxidation in a furnace or by the Harris process. Next, in the Parkes process, zinc

M. K. PATEL; C. BAILEY; G. DJAMBAZOV; J. SHRIMPTON; V. JALILI

484

Modeling of the vacuum plasma spray process  

Microsoft Academic Search

Experimental and analytical studies have been conducted to investigate gas, particle, and coating dynamics in the vacuum plasma spray (VPS) process for a tungsten powder. VPS coatings were examined metallographically and the results compared with the model`s predictions. The plasma was numerically modeled from the cathode tip to the spray distance in the free plume for the experimental conditions of

D. J. Jr. Varacalle; R. A. Neiser; M. F. Smith

1992-01-01

485

Modeling of the vacuum plasma spray process  

Microsoft Academic Search

Experimental and analytical studies have been conducted to investigate gas, particle, and coating dynamics in the vacuum plasma spray (VPS) process for a tungsten powder. VPS coatings were examined metallographically and the results compared with the model's predictions. The plasma was numerically modeled from the cathode tip to the spray distance in the free plume for the experimental conditions of

D. J. Jr. Varacalle; R. A. Neiser; M. F. Smith

1992-01-01

486

FIRE Vacuum Vessel Design and Analysis  

E-print Network

lifetime component - remotely welded joints are double contained - all bellows are double contained · High quality vacuum - outgassing and leak rate welded construction for remote maintenance - Field joints must be capable of remote leak testing and repair - In-vessel re

487