WorldWideScience

Sample records for wire bubble gum

  1. Demonstrating close-packing of atoms using spherical bubble gums ...

    African Journals Online (AJOL)

    In this paper, the use of spherical bubble gums (Gum Balls) to demonstrate the close-packing of atoms and ions is presented. Spherical bubble gums having distinctive colours were used to illustrate the different layers in variety of crystalline packing and the formation of tetrahedral and octahedral holes. Students with ...

  2. demonstrating close-packing of atoms using spherical bubble gums

    African Journals Online (AJOL)

    Admin

    ABSTRACT: In this paper, the use of spherical bubble gums (Gum Balls) to demonstrate the close-packing of atoms and ions is presented. Spherical bubble gums having distinctive colours were used to illustrate the different layers in variety of crystalline packing and the formation of tetrahedral and octahedral holes.

  3. Sliding bubbles on a hot horizontal wire in a subcooled bath

    Science.gov (United States)

    Duchesne, Alexis; Dubois, Charles; Caps, Hervé

    2015-11-01

    When a wire is heated up to the boiling point in a liquid bath some bubbles will nucleate on the wire surface. Traditional nucleate boiling theory predicts that bubbles generate from active nucleate site, grow up and depart from the heating surface due to buoyancy and inertia. However, an alternative scenario is presented in the literature for a subcooled bath: bubbles slide along the horizontal wire before departing. New experiments were performed by using a constantan wire and different liquids, varying the injected power. Silicone oil, water and even liquid nitrogen were tested in order to vary wetting conditions, liquid viscosities and surface tensions. We explored the influence of the wire diameter and of the subcooled bath temperature. We observed, of course, sliding motion, but also a wide range of behaviors from bubbles clustering to film boiling. We noticed that bubbles could change moving sense, especially when encountering with another bubble. The bubble speed is carefully measured and can reach more than 100 mm/s for a millimetric bubble. We investigated the dependence of the speed on the different parameters and found that this speed is, for a given configuration, quite independent of the injected power. We understand these phenomena in terms of Marangoni effects. This project has been financially supported by ARC SuperCool contract of the University of Liège.

  4. Wire-Mesh Tomography Measurements of Void Fraction in Rectangular Bubble Columns

    International Nuclear Information System (INIS)

    Reddy Vanga, B.N.; Lopez de Bertodano, M.A.; Zaruba, A.; Prasser, H.M.; Krepper, E.

    2004-01-01

    Bubble Columns are widely used in the process industry and their scale-up from laboratory scale units to industrial units have been a subject of extensive study. The void fraction distribution in the bubble column is affected by the column size, superficial velocity of the dispersed phase, height of the liquid column, size of the gas bubbles, flow regime, sparger design and geometry of the bubble column. The void fraction distribution in turn affects the interfacial momentum transfer in the bubble column. The void fraction distribution in a rectangular bubble column 10 cm wide and 2 cm deep has been measured using Wire-Mesh Tomography. Experiments were performed in an air-water system with the column operating in the dispersed bubbly flow regime. The experiments also serve the purpose of studying the performance of wire-mesh sensors in batch flows. A 'wall peak' has been observed in the measured void fraction profiles, for the higher gas flow rates. This 'wall peak' seems to be unique, as this distribution has not been previously reported in bubble column literature. Low gas flow rates yielded the conventional 'center peak' void profile. The effect of column height and superficial gas velocity on the void distribution has been investigated. Wire-mesh Tomography also facilitates the measurement of bubble size distribution in the column. This paper presents the measurement principle and the experimental results for a wide range of superficial gas velocities. (authors)

  5. Reduction of Gas Bubbles and Improved Critical Current Density in Bi-2212 Round Wire by Swaging

    CERN Document Server

    Jiang, J; Huang, Y; Hong, S; Parrell, J; Scheuerlein, C; Di Michiel, M; Ghosh, A; Trociewitz, U; Hellstrom, E; Larbalestier, D

    2013-01-01

    Bi-2212 round wire is made by the powder-in-tube technique. An unavoidable property of powder-in-tube conductors is that there is about 30% void space in the as-drawn wire. We have recently shown that the gas present in the as-drawn Bi-2212 wire agglomerates into large bubbles and that they are presently the most deleterious current limiting mechanism. By densifying short 2212 wires before reaction through cold isostatic pressing (CIPping), the void space was almost removed and the gas bubble density was reduced significantly, resulting in a doubled engineering critical current density (JE) of 810 A/mm2 at 5 T, 4.2 K. Here we report on densifying Bi-2212 wire by swaging, which increased JE (4.2 K, 5 T) from 486 A/mm2 for as-drawn wire to 808 A/mm2 for swaged wire. This result further confirms that enhancing the filament packing density is of great importance for making major JE improvement in this round-wire magnet conductor.

  6. A novel method for shape analysis: deformation of bubbles during wire drawing in doped tungsten

    International Nuclear Information System (INIS)

    Harmat, P.; Bartha, L.; Grosz, T.; Rosta, L.

    2001-01-01

    A novel technique has been developed for monitoring shape and size of microscopic pores, bubbles, second phase particles in deformed PM materials. The anisotropic small angle neutron scattering (ASANS) measurement provides direct visualization of the shape of second phase objects after rolling, swaging, wire drawing. Also in case of mixture of different objects e. g. uniformly elongated bubbles and spherical ones they can be separated and their morphological parameters like relative number density, diameter, aspect ratio can be obtained from the quantitative analysis of ASANS data. Rods and wires from K-AI-Si doped tungsten containing residual porosity and K filled bubbles were studied from 6 mm to 0.2 mm in diameter. The increase of the average aspect ratio (∼1/d) was found to be much slower than expected from the usual theory (∼1/d 3 ). Instead of 'constant volume' assumption, the 'constant length' seems to be reliable. The ASANS investigation revealed also the occurrence of a small amount of spherical bubbles after several steps of wire drawing. (author)

  7. Production of cellulase and xylanase in a bubble gum column using immobilized Aspergillus niger KKS

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seong-Woo; Kim, Seung-Woo [Univ. of Suwon (Korea, Republic of); Lee, Jin-Suk [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    1995-05-01

    Aspergillus niger KKS, isolated from a farmland near Suwon, was immobilized on Celite and polyurethane foams. Enzyme activities produced by the immobilized cell system in a bubble column were higher than that of shake-flask culture. The enzyme productivities were twice as high. {Beta}-Glucosidase, {Beta}-xylosidase, and xylanase activities obtained in a bubble column were significant when the ground rice straw was used as a substrate. 9 refs., 2 figs., 3 tabs.

  8. Bubbles

    DEFF Research Database (Denmark)

    Dholakia, Nikhilesh; Turcan, Romeo V.

    2013-01-01

    A goal of our ongoing research stream is to develop a multidisciplinary metatheory of bubbles. In this viewpoint paper we put forward a typology of bubbles by comparing four types of assets – entertainment, commodities, financial securities (stocks), and housing properties – where bubbles could a...

  9. Thermally driven bubble evolution at a heater wire in water characterized by high-speed transmission electron microscopy.

    Science.gov (United States)

    Vance, J R; Dillon, S J

    2017-05-02

    This work investigates the early stage evolution of thermally nucleated microbubbles in water using in situ high-speed, 400 fps, transmission electron microscopy. A Pt wire Joule heater induced bubble nucleation and growth from air-saturated water at different levels of power. For all powers below Pt breakdown, the dissolved gas initiates bubble nucleation at the concave surface defects adjacent to the area of highest temperature. A combination of interfacial forces and stress relaxation drive rapid migration of the bubbles away from the nucleation site. Thermocapillary forces ultimately dominate and drive their return to the region of highest temperature. The dynamic response highlights the importance of this length and time domain, which has until now received limited direct study.

  10. Bubble Formation within Filaments of Melt-Processed Bi2212 wires and its strongly negative effect on the Critical Current Density

    CERN Document Server

    Kametani, F; Jiang, J; Scheuerlein, C; Malagoli, A; Di Michiel, M; Huang, Y; Miao, H; Parrell, J A; Hellstrom, E E; Larbalestier, D C

    2011-01-01

    Most studies of Bi2Sr2CaCu2Ox (Bi2212) show that the critical current density Jc is limited by the connectivity of the filaments, but what determines the connectivity is still elusive. Here we report on the role played by filament porosity in limiting Jc. By a microstructural investigation of wires quenched from the melt state, we find that porosity in the unreacted wire agglomerates into bubbles that segment the Bi2212 melt within the filaments into discrete sections. These bubbles do not disappear during subsequent processing because they are only partially filled by Bi2212 grains as the Bi2212 forms on cooling. Correlating the microstructure of quenched wires to their final, fully processed Jc values shows an inverse relation between Jc and bubble density. Bubbles are variable between conductors and perhaps from sample to sample, but they occur frequently and almost completely fill the filament diameter, so they exert a strongly variable but always negative effect on Jc. Bubbles reduce the continuous Bi221...

  11. Nicotine Gum

    Science.gov (United States)

    Nicotine chewing gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with a ... support groups, counseling, or specific behavioral change techniques. Nicotine gum is in a class of medications called ...

  12. Gums - swollen

    Science.gov (United States)

    ... Swollen gums may be caused by: Inflamed gums ( gingivitis ) Infection by a virus or fungus Malnutrition Poorly ... 2015:chap 12. Chow AW. Infections of the oral cavity, neck, and head. In: Bennett JE, Dolin R, Blaser MJ, eds. ... Health Topics A-Z Read more A.D.A. ...

  13. Bleeding gums

    Science.gov (United States)

    ... line. This will lead to a condition called gingivitis , or inflamed gums. Plaque that is not removed ... deficiency, take vitamin supplements. Avoid aspirin unless your health care ... doctor. Use an oral irrigation device on the low setting to massage ...

  14. Increased gum arabic production after infestation of Acacia senegal ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the correlation between the beetle Agrilus nubeculosus and gum arabic production by Acacia senegal. Some trees were tapped and left open to facilitate infestation by A. nubeculosus and others were covered with wire mesh as control. Gum yield, physical and chemical properties of ...

  15. Gum Disease Symptoms

    Science.gov (United States)

    ... Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal Health and Pregnancy ...

  16. Gum Disease and Women

    Science.gov (United States)

    ... Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal Health and Diabetes Periodontal Health and Pregnancy ...

  17. Science Bubbles

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Pedersen, David Budtz

    2013-01-01

    Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when bubb...... bubbles appear in science, truth and reliability are the first victims. This paper explores how fashions in research funding and research management may turn science into something like a bubble economy.......Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when...

  18. Bubble systems

    CERN Document Server

    Avdeev, Alexander A

    2016-01-01

    This monograph presents a systematic analysis of bubble system mathematics, using the mechanics of two-phase systems in non-equilibrium as the scope of analysis. The author introduces the thermodynamic foundations of bubble systems, ranging from the fundamental starting points to current research challenges. This book addresses a range of topics, including description methods of multi-phase systems, boundary and initial conditions as well as coupling requirements at the phase boundary. Moreover, it presents a detailed study of the basic problems of bubble dynamics in a liquid mass: growth (dynamically and thermally controlled), collapse, bubble pulsations, bubble rise and breakup. Special emphasis is placed on bubble dynamics in turbulent flows. The analysis results are used to write integral equations governing the rate of vapor generation (condensation) in non-equilibrium flows, thus creating a basis for solving a number of practical problems. This book is the first to present a comprehensive theory of boil...

  19. Xanthan - A Versatile Gum

    Indian Academy of Sciences (India)

    transfer agents. ... Why do Microorganisms Produce Gums? .... also useful for xanthan production. GENERAL I ARTICLE. In the biosynthesis of xanthan on the cabbage plant by X. campestris, the cabbage provides the carbohydrate substrates,.

  20. 21 CFR 184.1349 - Karaya gum (sterculia gum).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Karaya gum (sterculia gum). 184.1349 Section 184.1349 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (sterculia gum) is the dried gummy exudate from the trunk of trees of various species of the genus Sterculia...

  1. Cognitive Bubbles

    OpenAIRE

    Ciril Bosch-Rosa; Thomas Meissner; Antoni Bosch-Domènech

    2015-01-01

    Smith et al. (1988) reported large bubbles and crashes in experimental asset markets, a result that has been replicated by a large literature. Here we test whether the occurrence of bubbles depends on the experimental subjects' cognitive sophistication. In a two-part experiment, we first run a battery of tests to assess the subjects' cognitive sophistication and classify them into low or high levels of cognitive sophistication. We then invite them separately to two asset market experimen...

  2. Bubbling away

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Bubble chambers may have almost vanished from the front line of physics research, but the vivid memory of their intricate and sometimes beautiful patterns of particle tracks lives on, and has greatly influenced the computer graphics of track reconstruction in today's big experiments. 'Seeing' an interaction makes it more understandable. Bubble chambers, with their big collaborations of physicists from many widely scattered research institutes, started another ball rolling. The groups formed are even now only surpassed in size by the big collaborations working on today's major detectors at colliding beam machines. From 14-16 July, about 130 physicists gathered at CERN to commemorate the 40th anniversary of the invention of the bubble chamber by Donald Glaser. The meeting, organized by Derek C. Colley from Birmingham, gave a comprehensive overview of bubble chamber contributions to physics, their challenging technology, and the usefulness of bubble chamber photographs in education, both for physics and the public at large. After opening remarks by CERN Director Carlo Rubbia, Donald Glaser began with a brief review of the work which led to his invention - there was much more to it than idly watching beer bubbles rise up the wall of the glass - before turning to his present line of research, biophysics, also very visually oriented

  3. Development of three-dimensional individual bubble-velocity measurement method by bubble tracking

    International Nuclear Information System (INIS)

    Kanai, Taizo; Furuya, Masahiro; Arai, Takahiro; Shirakawa, Kenetsu; Nishi, Yoshihisa

    2012-01-01

    A gas-liquid two-phase flow in a large diameter pipe exhibits a three-dimensional flow structure. Wire-Mesh Sensor (WMS) consists of a pair of parallel wire layers located at the cross section of a pipe. Both the parallel wires cross at 90o with a small gap and each intersection acts as an electrode. The WMS allows the measurement of the instantaneous two-dimensional void-fraction distribution over the cross-section of a pipe, based on the difference between the local instantaneous conductivity of the two-phase flow. Furthermore, the WMS can acquire a phasic-velocity on the basis of the time lag of void signals between two sets of WMS. Previously, the acquired phasic velocity was one-dimensional with time-averaged distributions. The authors propose a method to estimate the three-dimensional bubble-velocity individually WMS data. The bubble velocity is determined by the tracing method. In this tracing method, each bubble is separated from WMS signal, volume and center coordinates of the bubble is acquired. Two bubbles with near volume at two WMS are considered as the same bubble and bubble velocity is estimated from the displacement of the center coordinates of the two bubbles. The validity of this method is verified by a swirl flow. The proposed method can successfully visualize a swirl flow structure and the results of this method agree with the results of cross-correlation analysis. (author)

  4. Xanthan - A Versatile Gum

    Indian Academy of Sciences (India)

    Why do Microorganisms Produce Gums? .... soybean whey are also useful for xanthan production. GENERAL I ARTICLE. In the biosynthesis of xanthan on the cabbage plant by X. campestris, the cabbage provides the carbohydrate substrates, ... a yellow pigment in the wall, which is extractable only with organic solvents.

  5. Temperature measurements in cavitation bubbles

    Science.gov (United States)

    Coutier-Delgosha, Olivier

    2016-11-01

    Cavitation is usually a nearly isothermal process in the liquid phase, but in some specific flow conditions like hot water or cryogenic fluids, significant temperature variations are detected. In addition, a large temperature increase happens inside the cavitation bubbles at the very end of their collapse, due to the fast compression of the gas at the bubble core, which is almost adiabatic. This process is of primary interest in various biomedical and pharmaceutical applications, where the mechanisms of bubble collapse plays a major role. To investigate the amplitude and the spatial distribution of these temperature variations inside and outside the cavitation bubbles, a system based on cold wires has been developed. They have been tested in a configuration of a single bubble obtained by submitting a small air bubble to a large amplitude pressure wave. Some promising results have been obtained after the initial validation tests. This work is funded by the Office of Naval Research Global under Grant N62909-16-1-2116, Dr. Salahuddin Ahmed & Ki-Han Kim program managers.

  6. Basic Wiring.

    Science.gov (United States)

    Kaltwasser, Stan; And Others

    This module is the first in a series of three wiring publications; it serves as the foundation for students enrolled in a wiring program. It is a prerequisite to either "Residential Wiring" or "Commercial and Industrial Wiring." The module contains 16 instructional units that cover the following topics: occupational…

  7. Leverage bubble

    Science.gov (United States)

    Yan, Wanfeng; Woodard, Ryan; Sornette, Didier

    2012-01-01

    Leverage is strongly related to liquidity in a market and lack of liquidity is considered a cause and/or consequence of the recent financial crisis. A repurchase agreement is a financial instrument where a security is sold simultaneously with an agreement to buy it back at a later date. Repurchase agreement (repo) market size is a very important element in calculating the overall leverage in a financial market. Therefore, studying the behavior of repo market size can help to understand a process that can contribute to the birth of a financial crisis. We hypothesize that herding behavior among large investors led to massive over-leveraging through the use of repos, resulting in a bubble (built up over the previous years) and subsequent crash in this market in early 2008. We use the Johansen-Ledoit-Sornette (JLS) model of rational expectation bubbles and behavioral finance to study the dynamics of the repo market that led to the crash. The JLS model qualifies a bubble by the presence of characteristic patterns in the price dynamics, called log-periodic power law (LPPL) behavior. We show that there was significant LPPL behavior in the market before that crash and that the predicted range of times predicted by the model for the end of the bubble is consistent with the observations.

  8. Blowing bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, K.

    1999-04-01

    The article, based on a series of interviews with column flotation equipment suppliers, reviews and comments on the progress of bubble generator design. Developments mentioned include the Air/Water sparger from Cominco, the SparJet and SlamJet from CPT, the CISA sparger from Sevala CISA, Microcel flotation columns from Birtley Engineering, Flotaire column flotation cells from LMC International, and the Variable Gap Sparger from MinnovEX. 1 fig., 2 photo.

  9. Chewing gums for optimal health

    Directory of Open Access Journals (Sweden)

    Nidhi Madan

    2011-01-01

    Full Text Available This article elaborates on the general aspects and health benefits of chewing gum. Chewing gums have been used since the time of prehistoric man as a source of entertainment and relaxation. It has also become a trendsetter with the teenagers. Currently, the health benefits of chewing gums are being studied and used in the treatment of various diseases. Certain medications have also been included in gums to act as an alternative drug delivery system. These gums have been found to be successful for the treatment of diseases, such as peptic ulcers, upper digestive tract cancer, oral candidiasis, and so on. It helps to relieve symptoms of xerostomia, Parkinsonism, tooth sensitivity after bleaching, and oral malodor. It helps in maintaining oral health, relieves stress, helps in weight loss, and improves alertness. Chewing gum may be distracting and irritating in numerous social environments, including schools, colleges, and the workplace. Research into the social effects of chewing gums is also necessary to further our knowledge into the psychosocial aspects of these gums.

  10. Bubble bath soap poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002762.htm Bubble bath soap poisoning To use the sharing features on this page, please enable JavaScript. Bubble bath soap poisoning occurs when someone swallows bubble bath soap. ...

  11. Production of Gum from Cashew Tree Latex

    Directory of Open Access Journals (Sweden)

    O. S. AZEEZ

    2005-06-01

    Full Text Available This research is aimed at producing gum from cashew tree latex, which can act as substitute for gum Arabic. The method used include drying and size reduction of the exudates gum, sieving of the gum to remove impurities, dissolution of the gum in distilled water, filtration to remove polysaccharide waste and finally concentration and stability of the gum. Glycerine, starch and Zinc oxide are some of the additives used in stabilizing the gum. The pH and Viscosity on addition of various percentage concentration of stabilizing agent were determined. Gum of the best quality was obtained with viscosity and pH of 4.52 Ns/m2 and 4.2 respectively; this is because the natural pH of gum from Acacia Senegal ranges between 3.9 - 4.9. The gum can be used as an alternative for synthetic adhesive used presently for stamps and envelopes.

  12. Gum chewing during pre-anesthetic fasting.

    Science.gov (United States)

    Poulton, Thomas J

    2012-03-01

    Many ad hoc fasting guidelines for pre-anesthetic patients prohibit gum chewing. We find no evidence that gum chewing during pre-anesthetic fasting increases the volume or acidity of gastric juice in a manner that increases risk, nor that the occasional associated unreported swallowing of gum risks subsequent aspiration. On the contrary, there is evidence that gum chewing promotes gastrointestinal motility and physiologic gastric emptying. Recommendations against pre-anesthetic gum chewing do not withstand scrutiny and miss an opportunity to enhance comfort and sense of wellbeing for patients awaiting anesthesia. Gum chewing during the pre-anesthetic nil per os (NPO) period would also permit the development of gum-delivered premedications and should be permitted in children old enough to chew gum safely. Gum chewing should cease when sedatives are given and all patients should be instructed to remove any chewing gum from the mouth immediately prior to anesthetic induction. © 2011 Blackwell Publishing Ltd.

  13. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  14. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  15. Discrete Bubble Modeling for Cavitation Bubbles

    Science.gov (United States)

    Choi, Jin-Keun; Chahine, Georges; Hsiao, Chao-Tsung

    2007-03-01

    Dynaflow, Inc. has conducted extensive studies on non-spherical bubble dynamics and interactions with solid and free boundaries, vortical flow structures, and other bubbles. From these studies, emerged a simplified Surface Averaged Pressure (SAP) spherical bubble dynamics model and a Lagrangian bubble tracking scheme. In this SAP scheme, the pressure and velocity of the surrounding flow field are averaged on the bubble surface, and then used for the bubble motion and volume dynamics calculations. This model is implemented using the Fluent User Defined Function (UDF) as Discrete Bubble Model (DBM). The Bubble dynamics portion can be solved using an incompressible liquid modified Rayleigh-Plesset equation or a compressible liquid modified Gilmore equation. The Discrete Bubble Model is a very suitable tool for the studies on cavitation inception of foils and turbo machinery, bubble nuclei effects, noise from the bubbles, and can be used in many practical problems in industrial and naval applications associated with flows in pipes, jets, pumps, propellers, ships, and the ocean. Applications to propeller cavitation, wake signatures of waterjet propelled ships, bubble-wake interactions, modeling of cavitating jets, and bubble entrainments around a ship will be presented.

  16. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  17. Bubbles & Squat

    DEFF Research Database (Denmark)

    Højbjerre Larsen, Signe

    Years Eve they arranged a similar event, and on their facebook event they wrote that ‘Your last training in 2016 might as well be a party’. The concept has been popular, and in the spring of 2017 it evolved into similar events such as ‘Cocktails & Kettlebells’. Our paper aims to contribute......In Denmark a new fitness chain has seen the light of day. It is called Repeat and on their facebook page it is presented as “A new breed of fitness. Metropolitan environment. Flexible terms & prices. Join the revolution.” As part of this ‘fitness revolution’ they introduced, in the autumn of 2016......, a new concept called ‘Bubbles & Squat’, where fitness training is combined with Champagne and a live DJ. One of the invitations for this event describes how “we spice up your friday training with live DJ and lots of refreshing bubbles, to make sure that you are ready for the weekend (...).” Before New...

  18. Responses of interproximal plaque pH to snack foods and effect of chewing sorbitol-containing gum.

    Science.gov (United States)

    Jensen, M E

    1986-08-01

    Interproximal wire-telemetric plaque pH data were obtained from five volunteers after they ate milk chocolate bars, raisins, chocolate wafer cookies with cream filling, cupcakes with icing and cream filling, and cherry pies. All the foods produced rapid decreases in plaque pH for extended periods. In a second set of test sessions, volunteers chewed sugarless gum for 10 minutes, starting 15 minutes after they ate the snack food. In all cases, the gum chewing caused a rapid increase in plaque pH. The pH remained at a level considered safe for teeth for 30 minutes after chewing the gum.

  19. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  20. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  1. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  2. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  3. Take Care of Your Teeth and Gums

    Science.gov (United States)

    ... drink alcohol, drink only in moderation. What causes tooth decay and gum disease? Plaque (“plak”) is a sticky ... your teeth too long, it can lead to tooth decay and gum disease. Brushing and flossing help get ...

  4. Diabetes, Gum Disease, and Other Dental Problems

    Science.gov (United States)

    ... sugars or starches. Some types of plaque cause tooth decay or cavities. Other types of plaque cause gum ... in your mouth, which raises your risk for tooth decay and gum disease dry feeling in your mouth, ...

  5. Elastic properties of Gum Metal

    International Nuclear Information System (INIS)

    Kuramoto, Shigeru; Furuta, Tadahiko; Hwang, Junghwan; Nishino, Kazuaki; Saito, Takashi

    2006-01-01

    In situ X-ray diffraction measurements under tensile loading and dynamic mechanical analysis were performed to investigate the mechanisms of elastic deformation in Gum Metal. Tensile stress-strain curves for Gum Metal indicate that cold working substantially decreases the elastic modulus while increasing the yield strength, thereby confirming nonlinearity in the elastic range. The gradient of each curve decreased continuously to about one-third its original value near the elastic limit. As a result of this decrease in elastic modulus and nonlinearity, elastic deformability reaches 2.5% after cold working. Superelasticity is attributed to stress-induced martensitic transformations, although the large elastic deformation in Gum Metal is not accompanied by a phase transformation

  6. Oral health benefits of chewing gum

    NARCIS (Netherlands)

    Wessel, Stefan

    2016-01-01

    In the last decades sugar-free chewing gum has developed in an oral healthcare product, next to the conventional products such as the toothbrush and mouthrinses. In this thesis we investigate the oral health benefits of chewing gum and the effects of additives to chewing gum, such as antimicrobials.

  7. Differences in salivary flow rate and pH between chewing gum of xylitol and sucrose at 4, 5, and 6 grade of Inpres Toddopuli elementary school in Makassar

    Directory of Open Access Journals (Sweden)

    Sarah Eva Chalid

    2016-06-01

    Full Text Available Chewing xylitol gum has been shown to be effective to produce of saliva between chewing sucrose gum. Other than, pH of saliva after  chewing xylitol gum is base and chewing sucrose gum is acid. Caries can be caused by various factors such as the large number of salivary flow, salivary acidity, etc. Then it needs to be known by chewing gum with xylitol and sucrose are most excellent to preventing caries in children. The aim of this research study was to determine the difference of salivary flow while chewing xylitol gum and bubble gum sucrose on Inpres Toddopuli elementary school in Makassar. The research is a qualitative research with quase experimental studies method, this type of design is pre- and post-test design with control group. Sample determined in accordance with the criteria of the sample is children aged 9-12 years old, has a superficial dental caries and caries media at least three teeth, another chewing gum does not consume about 60 minutes before the investigation, and ready to be research samples and ready to follow the instructions of researchers. After determining the sample then obtained 30 samples respectively at grades 4, 5, and 6. On first day, samples requested to chewing gum with xylitol and on the second day, chewing gum with sucrose each for 5 minutes after that saliva from samples collected on a centrifuge tube, then observed number of saliva and saliva acidity. The results obtained, showed that there are differences in the amount of salivary flow and acidity between  chewing gum with xylitol and sucrose, there is difference in amount of salivary flow (0.002 and for salivary pH value (0.000 which means the value of difference is significant. The research found that children who chewed xylitol gum can produce more saliva than chewed sucrose gum and sucrose gum had higher acidity than xylitol gum.

  8. Real-Time Measurements and Modelling on Dynamic Behaviour of SonoVue Bubbles Based on Light Scattering Technology

    Science.gov (United States)

    Tu, Juan; Guan F., J.; Matula J., T.; Crum A., L.; Wei, Rongjue

    2008-01-01

    The dynamic behaviour of SonoVue microbubbles, a new generation ultrasound contrast agent, is investigated in real time with light scattering method. Highly diluted SonoVue microbubbles are injected into a diluted gel made of xanthan gum and water. The responses of individual SonoVue bubbles to driven ultrasound pulses are measured. Both linear and nonlinear bubble oscillations are observed and the results suggest that SonoVue microbubbles can generate strong nonlinear responses. By fitting the experimental data of individual bubble responses with Sarkar's model, the shell coating parameter of the bubbles and dilatational viscosity is estimated to be 7.0 nm.s.Pa.

  9. The CT appearance of intraoral chewing gum

    Energy Technology Data Exchange (ETDEWEB)

    Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2008-12-15

    When imaged, intraoral chewing gum has the potential to be misdiagnosed. Chewing gum has a characteristic appearance on CT: it is ovoid in shape, hyperdense, and has small internal locules of air. Reports have described the appearance of gum on radiographs and abdominal CT images; however, no reports could be found detailing its appearance within the mouth. This report describes the appearance of intraoral chewing gum as well as the properties of the gum that lead to this appearance. Because of the potential for misdiagnosis, screening for intraoral foreign bodies should be considered prior to imaging. (orig.)

  10. Xanthan-A Versatile Gum

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 10. Xanthan – A Versatile Gum. Anil Lachke. General Article Volume 9 Issue 10 October 2004 pp 25-33. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/10/0025-0033. Keywords. Xanthan ...

  11. GumTree: Data reduction

    International Nuclear Information System (INIS)

    Rayner, Hugh; Hathaway, Paul; Hauser, Nick; Fei, Yang; Franceschini, Ferdi; Lam, Tony

    2006-01-01

    Access to software tools for interactive data reduction, visualisation and analysis during a neutron scattering experiment enables instrument users to make informed decisions regarding the direction and success of their experiment. ANSTO aims to enhance the experiment experience of its facility's users by integrating these data reduction tools with the instrument control interface for immediate feedback. GumTree is a software framework and application designed to support an Integrated Scientific Experimental Environment, for concurrent access to instrument control, data acquisition, visualisation and analysis software. The Data Reduction and Analysis (DRA) module is a component of the GumTree framework that allows users to perform data reduction, correction and basic analysis within GumTree while an experiment is running. It is highly integrated with GumTree, able to pull experiment data and metadata directly from the instrument control and data acquisition components. The DRA itself uses components common to all instruments at the facility, providing a consistent interface. It features familiar ISAW-based 1D and 2D plotting, an OpenGL-based 3D plotter and peak fitting performed by fityk. This paper covers the benefits of integration, the flexibility of the DRA module, ease of use for the interface and audit trail generation

  12. Fama on Bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    2016-01-01

    While Eugene Fama has repeatedly expressed his discontent with the notion of an “irrational bubble,” he has never publicly expressed his opinion on “rational bubbles.” On empirical grounds Fama rejects bubbles by referring to the lack of reliable evidence that price declines are predictable...

  13. Fama on bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    . On empirical grounds Fama rejects bubbles by referring to the lack of reliable evidence that price declines are predictable. However, this argument cannot be used to rule out rational bubbles because such bubbles do not necessarily imply return predictability. On data samples that include the 1990s...

  14. 21 CFR 172.615 - Chewing gum base.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chewing gum base. 172.615 Section 172.615 Food and..., Chewing Gum Bases and Related Substances § 172.615 Chewing gum base. The food additive chewing gum base... substances listed in paragraph (a) of this section, chewing gum base may also include substances generally...

  15. Seeded perturbations in wire array Z-Pinches

    International Nuclear Information System (INIS)

    Robinson, Allen Conrad; Fedin, Dmitry; Kantsyrev, Victor Leonidovich; Wunsch, Scott Edward; Oliver, Bryan Velten; Lebedev, Sergey V.; Coverdale, Christine Anne; Ouart, Nicholas D.; LePell, Paul David; Safronova, Alla S.; Shrestha, I.; McKenney, John Lee; Ampleford, David J.; Rapley, J.; Bott, S.C.; Palmer, J.B.A.; Sotnikov, Vladimir Isaakovich; Bland, Simon Nicholas; Ivanov, Vladimir V.; Chittenden, Jeremy Paul; Jones, B.; Garasi, Christopher Joseph; Hall, Gareth Neville; Yilmaz, M. Faith; Mehlhorn, Thomas Alan; Deeney, Christopher; Pokala, S.; Nalajala, V.

    2005-01-01

    Controlled seeding of perturbations is employed to study the evolution of wire array z-pinch implosion instabilities which strongly impact x-ray production when the 3D plasma stagnates on axis. Wires modulated in radius exhibit locally enhanced magnetic field and imploding bubble formation at discontinuities in wire radius due to the perturbed current path. Wires coated with localized spectroscopic dopants are used to track turbulent material flow. Experiments and MHD modeling offer insight into the behavior of z-pinch instabilities.

  16. Caffeine gum minimizes sleep inertia.

    Science.gov (United States)

    Newman, Rachel A; Kamimori, Gary H; Wesensten, Nancy J; Picchioni, Dante; Balkin, Thomas J

    2013-02-01

    Naps are an effective strategy for maintaining alertness and cognitive performance; however, upon abrupt wakening from naps, sleep inertia (temporary performance degradation) may ensue. In the present study, attenuation of post-nap sleep inertia was attempted by administration of caffeine gum. Using a double-blind, placebo-controlled crossover design, 15 healthy, non-smoking adults were awakened at 1 hr. and again at 6 hr. after lights out (0100 and 0600, respectively) and were immediately administered a gum pellet containing 100 mg of caffeine or placebo. A 5-min. psychomotor vigilance task was administered at 0 min., 6 min., 12 min., and 18 min. post-awakening. At 0100, response speed with caffeine was significantly better at 12 min. and 18 min. post-awakening compared to placebo; at 0600, caffeine's effects were evident at 18 min. post-awakening. Caffeinated gum is a viable means of rapidly attenuating sleep inertia, suggesting that the adenosine receptor system is involved in sleep maintenance.

  17. Isolation and characterization of gum from Chrysophyllum albidum ...

    African Journals Online (AJOL)

    This study describes the morphology, physicochemical and compressional characteristics of a natural gum derived from the fruits of Chrysophyllum albidum. Preliminary phytochemical screening and physicochemical properties of Chrysophyllum albidum gum (in comparison with tragacanth gum) were determined while ...

  18. Dynamics of bubble generated by low energy pulsed electric discharge in water

    International Nuclear Information System (INIS)

    Pinchuk, M E; Kolikov, V A; Rutberg, Ph G; Leks, A G; Dolinovskaya, R V; Snetov, V N; Stogov, A Yu

    2012-01-01

    Results of investigations of bubble formation and dynamics for discharge in water are presented. Experiments were carried out in discharge chamber with axisymmetric electrode system “wire to wire”. Interelectrode gap was varied from 1 to 10 mm. Energy in a pulse was <1 J. Velocity of bubble expantion and collapse is about several hundreds meter per second at early stage of discharge. Bubble pulsation period is 0.5 – 1 ms. Increasing of energy released in the discharge gap will increase bubble pulsation period. Little bubble was formed by reducing energy input into discharge. But the main stage of discharge always followed by bubble formation. Specific erosion is measured for different energy in pulse and matched up with bubble collapse.

  19. Bubble and drop interfaces

    CERN Document Server

    Miller

    2011-01-01

    The book aims at describing the most important experimental methods for characterizing liquid interfaces, such as drop profile analysis, bubble pressure and drop volume tensiometry, capillary pressure technique, and oscillating drops and bubbles. Besides the details of experimental set ups, also the underlying theoretical basis is presented in detail. In addition, a number of applications based on drops and bubbles is discussed, such as rising bubbles and the very complex process of flotation. Also wetting, characterized by the dynamics of advancing contact angles is discussed critically. Spec

  20. Prospects for bubble fusion

    Energy Technology Data Exchange (ETDEWEB)

    Nigmatulin, R.I. [Tyumen Institute of Mechanics of Multiphase Systems (TIMMS), Marx (Russian Federation); Lahey, R.T. Jr. [Rensselaer Polytechnic Institute, Troy, NY (United States)

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  1. Bubbles, Banks, and Financial Stability

    OpenAIRE

    Kosuke Aoki; Kalin Nikolov

    2011-01-01

    This paper asks two main questions: (1) What makes some asset price bubbles more costly for the real economy than others? and (2) When do costly bubbles occur? We construct a model of rational bubbles under credit frictions and show that when bubbles held by banks burst this is followed by a costly financial crisis. In contrast, bubbles held by ordinary savers have relatively muted effects. Banks tend to invest in bubbles when financial liberalisation decreases their profitability.

  2. Xanthan gum production by Xanthomonas campestris pv ...

    African Journals Online (AJOL)

    Cassava starch is a main renewable bio-resource with low price and mass production in Guangxi, China. It was used as carbon source in growing Xanthomonas campestris pv. campestris 8004 (Xcc 8004) for xanthan gum production in this study. The xanthan gum yield of gelatinized cassava starch was higher than that of ...

  3. Gum chewing affects academic performance in adolescents

    Science.gov (United States)

    Chewing gum may have an impact on improved memory during specific tasks of recognition and sustained attention. Research objective was to determine the effect of gum chewing on standardized test scores and math class grades of eighth grade students. Four math classes, 108 students, were randomized i...

  4. Flow visualization using bubbles

    International Nuclear Information System (INIS)

    Henry, J.P.

    1974-01-01

    Soap bubbles were used for visualizing flows. The tests effected allowed some characteristics of flows around models in blow tunnels to be precised at mean velocities V 0 5 . The velocity of a bubble is measured by chronophotography, the bulk envelope of the trajectories is also registered [fr

  5. HCDA bubble experiment, (2)

    International Nuclear Information System (INIS)

    Sakata, Kaoru; Mashiko, Hiroyuki; Oka, Yoshiaki; An, Shigehiro; Isozaki, Tadashi.

    1981-06-01

    An experiment simulating the behavior of the very large steam bubbles generated at the time of an accident of core collapse was carried out with a warm water tank, and the applicability of the theory of very small bubble disappearance known at present was examined. The bubbles generated in HCDA (hypothetical core disruptive accident) are expected to be very large, containing sodium, fuel, FP gas and so on, and play important role in the mechanism of emitting radioactive substances in the safety analysis of LMFBRs. In this experiment, the degree of subcool of the warm water pool, the initial radii of steam bubbles and the blowoff pressure of steam were taken as the parameters. The radius of the steam bubbles generated in the experiment was about 6.5 cm, and the state of disappearance was different above and below the degree of unsaturation of 10 deg C. Comparing the disappearance curve obtained by the experiment with the theory of disappearance of small bubbles, the experimental values were between inertia-controlled disappearance and heat transfer-controlled disappearance, and this result was able to be explained generally with the model taking the pressure change within steam bubbles into account. The rise of bubbles was also observed. (Kako, I.)

  6. Viscosity Destabilizes Sonoluminescing Bubbles

    NARCIS (Netherlands)

    Tögel, R.; Luther, S.; Lohse, Detlef

    2006-01-01

    In single-bubble sonoluminescence (SBSL) microbubbles are trapped in a standing sound wave, typically in water or water-glycerol mixtures. However, in viscous liquids such as glycol, methylformamide, or sulphuric acid it is not possible to trap the bubble in a stable position. This is very peculiar

  7. Bubbles in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Power, Stephen; Lin, Jun

    2015-01-01

    Strain-induced deformations in graphene are predicted to give rise to large pseudomagnetic fields. We examine theoretically the case of gas-inflated bubbles to determine whether signatures of such fields are present in the local density of states. Sharp-edged bubbles are found to induce Friedel...

  8. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  9. Turbulence, bubbles and drops

    NARCIS (Netherlands)

    van der Veen, Roeland

    2016-01-01

    In this thesis, several questions related to drop impact and Taylor-Couette turbulence are answered. The deformation of a drop just before impact can cause a bubble to be entrapped. For many applications, such as inkjet printing, it is crucial to control the size of this entrapped bubble. To study

  10. The emulsifying Properties of Terminalia randii baker F. Gum in ...

    African Journals Online (AJOL)

    Objectives: In this study, the emulsifying properties of Terminalia randii gum were assessed and compared with a standard emulsifier (Tragacanth gum) using castor oil and liquid paraffin . Method: Different concentrations (1-10% w/v) of the mucilages of Terminalia randii gum and Tragacanth were prepared. Using wet gum ...

  11. Theory calculation of combination of 'embryo' bubble growing-up visible bubble in bubble chamber

    International Nuclear Information System (INIS)

    Ye Zipiao; Sheng Xiangdong; Dai Changjiang

    2004-01-01

    By aid of island combination theory of 'embryo' bubble, it is resolved well the question which 'embryo' bubble grows up a visible bubble in the bubble chamber. Through theory calculation it is shown that radius of the big' embryo' bubble combinated not only relates with work matter such as surface tension coefficient, saturation vapour pressure and boiling point of liquid, but also does absorbing quantity of heat and the numbers of 'embryo' bubbles combination. It is explained reasonably that the radius of bubbles in bubble chamber is different for the same energies of neutrons and proton. The track of neutron in bubble chamber is long and thin, and the track of proton in bubble chamber is wide and short. It is also explained reasonably that the bubble radius of the incident particles with more charges which there are the same energies will be wider than that of the incident particles with less charges in the track. (author)

  12. Measurement of the impuslive force generated by colapsing bubble close to a solid boundary

    Directory of Open Access Journals (Sweden)

    Zima Patrik

    2012-04-01

    Full Text Available The article presents experimental results of the acoustical and optical study of cavitation bubble collapse close to a solid boundary in water. The bubble was generated by discharge of low-voltage capacitor into a couple of wires closing a simple circuit. Different distances from the solid wall and different maximum bubble radii were studied. The bubble radius was studied using time-resolved photography and by PVDF film sensor glued on the solid boundary. The illumination was provided by high-power led diode. Synchronization of the system was provided by pulse generator connected to an oscilloscope. The impact power of the bubble to the wall was estimated from the time-resolved photography of the bubble and from the PVDF film sensor signal. The PVDF film sensor calibration was performed by a pendulum test to estimate the impact force.

  13. Noncontextual Wirings

    Science.gov (United States)

    Amaral, Barbara; Cabello, Adán; Cunha, Marcelo Terra; Aolita, Leandro

    2018-03-01

    Contextuality is a fundamental feature of quantum theory necessary for certain models of quantum computation and communication. Serious steps have therefore been taken towards a formal framework for contextuality as an operational resource. However, the main ingredient of a resource theory—a concrete, explicit form of free operations of contextuality—was still missing. Here we provide such a component by introducing noncontextual wirings: a class of contextuality-free operations with a clear operational interpretation and a friendly parametrization. We characterize them completely for general black-box measurement devices with arbitrarily many inputs and outputs. As applications, we show that the relative entropy of contextuality is a contextuality monotone and that maximally contextual boxes that serve as contextuality bits exist for a broad class of scenarios. Our results complete a unified resource-theoretic framework for contextuality and Bell nonlocality.

  14. bubble chamber lens

    CERN Multimedia

    Before the days of electronic detectors, visual techniques were used to detect particles, using detectors such as spark chambers and bubble chambers. This plexiglass lens was used to focus the image of tracks so they could be photographed.

  15. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  16. Design, formulation and evaluation of caffeine chewing gum.

    Science.gov (United States)

    Aslani, Abolfazl; Jalilian, Fatemeh

    2013-01-01

    Caffeine which exists in drinks such as coffee as well as in drug dosage forms in the global market is among the materials that increase alertness and decrease fatigue. Compared to other forms of caffeine, caffeine gum can create faster and more prominent effects. In this study, the main goal is to design a new formulation of caffeine gum with desirable taste and assess its physicochemical properties. Caffeine gum was prepared by softening of gum bases and then mixing with other formulation ingredients. To decrease the bitterness of caffeine, sugar, aspartame, liquid glucose, sorbitol, manitol, xylitol, and various flavors were used. Caffeine release from gum base was investigated by mechanical chewing set. Content uniformity test was also performed on the gums. The gums were evaluated in terms of organoleptic properties by the Latin-Square design at different stages. After making 22 formulations of caffeine gums, F11 from 20 mg caffeine gums and F22 from 50 mg caffeine gums were chosen as the best formulation in organoleptic properties. Both types of gum released about 90% of their own drug content after 30 min. Drug content of 20 and 50 mg caffeine gum was about 18.2-21.3 mg and 45.7-53.6 mg respectively. In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release) were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test.

  17. Magnetic-bubble devices

    International Nuclear Information System (INIS)

    Fairholme, R.J.

    1978-01-01

    Magnetic bubbles were first described only ten years ago when research workers were discussing orthoferrites containing μm diameter bubbles. However, problems of material fabrication limit crystals to a few mm across which severely curtailed device development. Since then materials have changed and rare-earth-iron garnet films can be grown up 3 inches in diameter with bubble diameters down to sizes below 1 μm. The first commercial products have device capacities in the range 64 000 to 100 000 bits with bubble diameters between 4 and 6 μm. Chip capacities of 1 Mbit are presently under development in the laboratory, as are new techniques to use submicrometre bubbles. The operation and fabrication of a bubble device is described using the serial loop devices currently being manufactured at Plessey as models. Chip organization is one important variable which directly affects the access time. A range of access times and capacities is available which offers a wide range of market opportunities, ranging from consumer products to fixed head disc replacements. some of the application areas are described. (author)

  18. Bubble transport in bifurcations

    Science.gov (United States)

    Bull, Joseph; Qamar, Adnan

    2017-11-01

    Motivated by a developmental gas embolotherapy technique for cancer treatment, we examine the transport of bubbles entrained in liquid. In gas embolotherapy, infarction of tumors is induced by selectively formed vascular gas bubbles that originate from acoustic vaporization of vascular droplets. In the case of non-functionalized droplets with the objective of vessel occlusion, the bubbles are transported by flow through vessel bifurcations, where they may split prior to eventually reach vessels small enough that they become lodged. This splitting behavior affects the distribution of bubbles and the efficacy of flow occlusion and the treatment. In these studies, we investigated bubble transport in bifurcations using computational and theoretical modeling. The model reproduces the variety of experimentally observed splitting behaviors. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Maximum shear stresses were found to decrease with increasing Reynolds number. The initial bubble length was found to affect the splitting behavior in the presence of gravitational asymmetry. This work was supported by NIH Grant R01EB006476.

  19. Control of flow past a circular cylinder via a spanwise surface wire: effect of the wire scale

    Energy Technology Data Exchange (ETDEWEB)

    Ekmekci, Alis [University of Toronto Institute for Aerospace Studies, Toronto, ON (Canada); Rockwell, Donald [Lehigh University, Department of Mechanical Engineering, Bethlehem, PA (United States)

    2011-09-15

    Flow phenomena induced by a single spanwise wire on the surface of a circular cylinder are investigated via a cinema technique of particle image velocimetry (PIV). The primary aim of this investigation is to assess the effect of the wire scale. To this end, consideration is given to wires with different diameters that are 0.5, 1.2, and 2.9% of the cylinder diameter. The Reynolds number has a subcritical value of 10,000. Compared to the thickness of the unperturbed boundary layer developing around the cylinder between 5 and 75 from the forward stagnation point, the former two wires have smaller scales and the latter has a larger scale. Two angular locations of the wire, defined with respect to the forward stagnation point of the cylinder, are found to be critical. When the wire is located at these critical angles, either the most significant extension or the contraction of the time-mean separation bubble occurs in the near wake. These critical angles depend on the wire scale: the smaller the wire, the larger the critical angle. The small-scale and large-scale wires that have diameters of 1.2 and 2.9% of the cylinder diameter induce bistable shear-layer oscillations between different separation modes when placed at their respective critical angles corresponding to maximum extension of the near-wake bubble. These oscillations have irregular time intervals that are much longer than the time scale associated with the classical Karman instability. Moreover, the large-scale wire can either significantly attenuate or intensify the Karman mode of vortex shedding at the critical states; in contrast, the small-scale wires do not notably alter the strength of the Karman instability. (orig.)

  20. The Mechanical Behavior Variation of Nickel - Titanium Orthodontic Wires in Different Fluoride Mouthwash

    Directory of Open Access Journals (Sweden)

    Ilnaz haj Hemati

    2016-12-01

    Full Text Available In this study, an orthodontic arch wire of Ni-Ti alloy made by Germany in four different mouthwashes contain fluoride was investigated in mechanical behavior. This research focused on the mechanical behavior changes in different mouthwashes. The Mouthwashes were chosen from most popular one in Iran including Oral-B, Gum, and Behsa Mouthwash. The wires after 3 month in touch with mouthwashes were studied and the result was presented. The result show that the lowest power to reshape the wire, is for the wire in Crest case (3. The maximum power assigns to wire in Behsa case (1. Also, the shortest treatment period is for wire in Behsa mouthwash case (1 with 0.087 Nm strain energy and the maximum duration of therapy is related to case (3 Crest mouthwash with 0.039 Nm. Moreover, the wires in Oral-b (0.095 Nm has the lowest and Gum mouthwash (0.140 Nm has the highest energy intake. The energy absorbed by the wires in Behsa and Crest is in the middle. Finally, it is proposed that patient could used all mouthwash but based on their condition, one product will be useful.

  1. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  2. Gum Producers Can Improve Quality Of Gum Marketed and Get Higher Prices

    Science.gov (United States)

    Ralph W. Clements

    1979-01-01

    Acid waste from over-treatment and old, wornout iron cups have contributed significantly to the generally poor quality of gum marketed. Today producers are reluctant to purchase new cups and gutters and invest up to $1.80 per tree for production when the market price for gum averages 14.54 per pound annually. Guidelines are given for improving the quality by...

  3. Stretched Wire Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, Gordon; /SLAC

    2005-09-06

    Stretched wires are beginning to play an important role in the alignment of accelerators and synchrotron light sources. Stretched wires are proposed for the alignment of the 130 meter long LCLS undulator. Wire position technology has reached sub-micron resolution yet analyses of perturbations to wire straightness are hard to find. This paper considers possible deviations of stretched wire from the simple 2-dimensional catenary form.

  4. Gummed-up memory: chewing gum impairs short-term recall.

    Science.gov (United States)

    Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

    2012-01-01

    Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.

  5. The Fermi Bubbles

    Science.gov (United States)

    Finkbeiner, Douglas P.

    2015-01-01

    The Fermi Bubbles are a pair of giant lobes at the heart of the Milky Way, extending roughly 50 degrees north and south of the Galactic Center, and emitting photons with energies up to 100 GeV. This previously unknown structure could be evidence for past activity of the central supermassive black hole, or enhanced star formation towards the inner Galaxy. We will describe the path to discovery of the Bubbles in multiwavelength data, from the first hints in microwave radiation measured by WMAP and X-rays from ROSAT, to the unveiling of their shape and spectrum using public gamma-ray data from the Fermi Gamma-ray Space Telescope, to more recent measurements by Planck and XMM-Newton. We will outline the current state of knowledge of the Bubbles' spectrum, morphology and internal structure, and discuss theoretical proposals and numerical simulations for their nature and origin.

  6. Rheological and interfacial properties at the equilibrium of almond gum tree exudate (Prunus dulcis) in comparison with gum arabic.

    Science.gov (United States)

    Mahfoudhi, Nesrine; Sessa, Mariarenata; Ferrari, Giovanna; Hamdi, Salem; Donsi, Francesco

    2016-06-01

    Almond gum contains an arabinogalactan-type polysaccharide, which plays an important role in defining its interfacial and rheological properties. In this study, rheological and interfacial properties of almond gum and gum arabic aqueous dispersions were comparatively investigated. The interfacial tension of almond gum and gum arabic aqueous dispersions was measured using the pendant drop method in hexadecane. The asymptotic interfacial tension values for almond gum were significantly lower than the corresponding values measured for gum arabic, especially at high concentration. Rheological properties were characterized by steady and oscillatory tests using a coaxial geometry. Almond gum flow curves exhibited a shear thinning non-Newtonian behavior with a tendency to a Newtonian plateau at low shear rate, while gum arabic flow curves exhibited such behavior only at high shear rate. The influence of temperature (5-50  ℃) on the flow curves was studied at 4% (m/m) gum concentration and the Newtonian viscosities at infinite and at zero shear rate, for gum arabic and almond gum, respectively, were accurately fitted by an Arrhenius-type equation. The dynamic properties of the two gum dispersions were also studied. Both gum dispersions exhibited viscoelastic properties, with the viscous component being predominant in a wider range of concentrations for almond gum, while for gum arabic the elastic component being higher than the elastic one especially at higher concentrations.The rheological and interfacial tension properties of almond gum suggest that it may represent a possible substitute of gum arabic in different food applications. © The Author(s) 2015.

  7. Multivariate bubbles and antibubbles

    Science.gov (United States)

    Fry, John

    2014-08-01

    In this paper we develop models for multivariate financial bubbles and antibubbles based on statistical physics. In particular, we extend a rich set of univariate models to higher dimensions. Changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. Moreover, our multivariate models are able to capture some of the contagious effects that occur during such episodes. We are able to show that declining lending quality helped fuel a bubble in the US stock market prior to 2008. Further, our approach offers interesting insights into the spatial development of UK house prices.

  8. Optimizing gelling parameters of gellan gum for fibrocartilage tissue engineering.

    Science.gov (United States)

    Lee, Haeyeon; Fisher, Stephanie; Kallos, Michael S; Hunter, Christopher J

    2011-08-01

    Gellan gum is an attractive biomaterial for fibrocartilage tissue engineering applications because it is cell compatible, can be injected into a defect, and gels at body temperature. However, the gelling parameters of gellan gum have not yet been fully optimized. The aim of this study was to investigate the mechanics, degradation, gelling temperature, and viscosity of low acyl and low/high acyl gellan gum blends. Dynamic mechanical analysis showed that increased concentrations of low acyl gellan gum resulted in increased stiffness and the addition of high acyl gellan gum resulted in greatly decreased stiffness. Degradation studies showed that low acyl gellan gum was more stable than low/high acyl gellan gum blends. Gelling temperature studies showed that increased concentrations of low acyl gellan gum and CaCl₂ increased gelling temperature and low acyl gellan gum concentrations below 2% (w/v) would be most suitable for cell encapsulation. Gellan gum blends were generally found to have a higher gelling temperature than low acyl gellan gum. Viscosity studies showed that increased concentrations of low acyl gellan gum increased viscosity. Our results suggest that 2% (w/v) low acyl gellan gum would have the most appropriate mechanics, degradation, and gelling temperature for use in fibrocartilage tissue engineering applications. Copyright © 2011 Wiley Periodicals, Inc.

  9. Cohesion of Bubbles in Foam

    Science.gov (United States)

    Ross, Sydney

    1978-01-01

    The free-energy change, or binding energy, of an idealized bubble cluster is calculated on the basis of one mole of gas, and on the basis of a single bubble going from sphere to polyhedron. Some new relations of bubble geometry are developed in the course of the calculation. (BB)

  10. Design, formulation and evaluation of nicotine chewing gum

    Directory of Open Access Journals (Sweden)

    Abolfazl Aslani

    2012-01-01

    Conclusion: Taste enhancement of nicotine gums was achieved where formulations comprised aspartame as the sweetener and cherry and eucalyptus as the flavoring agents. Nicotine gums of pleasant taste may, therefore, be used as NRT to assist smokers quit smoking.

  11. Heavy liquid bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  12. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  13. bubble chamber lens

    CERN Multimedia

    Was used in a PS experiment. Before the days of electronic detectors, visual techniques were used to detect particles, using detectors such as spark chambers and bubble chambers. This plexiglass lens was used to focus the image of tracks so they could be photographed.

  14. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  15. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  16. Critical scattering by bubbles

    International Nuclear Information System (INIS)

    Fiedler-Ferrari, N.; Nussenzveig, H.M.

    1986-11-01

    We apply the complex angular momentum theory to the problem of the critical scattering of light by spherical cavities in the high frequency limit (permittivity greater than the external media) (e.g, air bubble in water) (M.W.O.) [pt

  17. Soap Bubbles and Crystals

    Indian Academy of Sciences (India)

    Jean Taylor is Professor. Emerita at Rutgers. University and currently a. Visitor at the Courant. Institute, NYU. She works on problems related to soap bubble froths, crystals, and how they evolve under various physical laws. Much of her recent research has been interdisciplinary, joint work with materials scientists ...

  18. Bubble properties of heterogeneous bubbly flow in a square bubble column

    NARCIS (Netherlands)

    Bai, Wei; Deen, Niels G.; Kuipers, J.A.M.

    2010-01-01

    The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical

  19. Natural gums and modified natural gums as sustained-release carriers.

    Science.gov (United States)

    Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

    2000-10-01

    Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored.

  20. Rheological Modeling and Characterization of Ficus platyphylla Gum Exudates

    Directory of Open Access Journals (Sweden)

    Nnabuk O. Eddy

    2013-01-01

    Full Text Available Ficus platyphylla gum exudates (FP gum have been analyzed for their physicochemical parameters and found to be ionic, mildly acidic, odourless, and yellowish brown in colour. The gum is soluble in water, sparingly soluble in ethanol, and insoluble in acetone and chloroform. The nitrogen (0.39% and protein (2.44% contents of the gum are relatively low. The concentrations of the cations were found to increase according to the following trend, Mn>Fe>Zn>Pb>Cu>Mg>Cd>Ca. Analysis of the FTIR spectrum of the gum revealed vibrations similar to those found in polysaccharides while the scanning electron micrograph indicated that the gum has irregular molecular shapes, arranged randomly. The intrinsic viscosity of FP gum estimated by extrapolating to zero concentrations in Huggins, Kraemer, Schulz-Blaschke, and Martin plots has an average value of 7 dL/g. From the plots of viscosity versus shear rate/speed of rotation and also that of shear stress versus shear rate, FP gum can be classified as a non-Newtonian gum with characteristics-plastic properties. Development of the Master_s curve for FP gum also indicated that the gum prefers to remain in a dilute domain (Cgum (calculated from Arrhenius-Frenkel-Eyring plot was relatively low and indicated the presence of fewer inter- and intramolecular interactions.

  1. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

  2. Evaluation of the suspending properties of Cola acuminata gum on ...

    African Journals Online (AJOL)

    Many natural gums are employed as suspending agents in the formulation of pharmaceutical suspensions. The search to develop locally available natural gum from apparently a waste product as an alternative suspending agent stimulated the interest in this present study. Cola acuminata gum (CAG) extracted from Cola ...

  3. Design, formulation and evaluation of caffeine chewing gum

    Directory of Open Access Journals (Sweden)

    Abolfazl Aslani

    2013-01-01

    Conclusion: In this study, 20 and 50 mg caffeine gums with suitable and desirable properties (i.e., good taste and satisfactory release were formulated. The best flavor for caffeine gum was cinnamon. Both kinds of 20 and 50 mg gums succeeded in content uniformity test.

  4. Evaluation of the suspending properties of Adansonia digitata gum ...

    African Journals Online (AJOL)

    Sedimentation volume and rate, rheology, and ease of redispersion were employed as evaluation parameters. The results showed that both hot and cold water extracts of the gum used at 2-3 % w/v produced a better suspending property than 4 % w/v Compound Tragacanth gum. The suspending ability of the gums was in ...

  5. Granule properties of paracetamol made with Bombax ceiba gum ...

    African Journals Online (AJOL)

    Bombax ceiba gum was extracted from the calyx of the Bombax flower using both hot and cold water extraction method. The gum was used as binder to prepare paracetamol granules in concentrations of 1, 1.5, 2, and 3 %. Acacia gum was used to prepare the standard at the same concentrations. The granule properties of ...

  6. Dependence on the nicotine gum in former smokers.

    Science.gov (United States)

    Etter, Jean-François

    2009-03-01

    We conducted an Internet survey in 2004-2007 in 526 daily users of the nicotine gum, to assess use of, and dependence on the nicotine gum in former smokers. We used modified versions of the Nicotine Dependence Syndrome Scale (NDSS-G), the Cigarette Dependence Scale (CDS-G) and the Fagerström Test (FTND-G). After 30 days, 155 participants (29%) indicated their gum use. Higher dependence on the gum predicted a lower chance of stopping using it at follow-up (odds ratio=0.36 for each standard deviation unit on CDS-G, p=0.001). More long-term (>3 months) than short-term (dependence on the gum than short-term users, as assessed with NDSS-Gum, CDS-Gum and FTND-Gum (all pdependence on the nicotine gum. Lower levels of dependence on the gum predicted cessation of gum use. However, long term use of the nicotine gum has no known serious adverse consequence, and may be beneficial if it prevents late relapse.

  7. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  8. Enzymatic production of polysaccharides from gum tragacanth

    DEFF Research Database (Denmark)

    2014-01-01

    Plant polysaccharides, relating to the field of natural probiotic components, can comprise structures similar to human milk oligosaccharides. A method for enzymatic hydrolysis of gum tragacanth from the bush-like legumes of the genus Astragalus, using a combination of pectin hydrolases and a xylo......Plant polysaccharides, relating to the field of natural probiotic components, can comprise structures similar to human milk oligosaccharides. A method for enzymatic hydrolysis of gum tragacanth from the bush-like legumes of the genus Astragalus, using a combination of pectin hydrolases...

  9. Waterflooding process using mucilage gum thickeners

    Energy Technology Data Exchange (ETDEWEB)

    Lummus, J.L.

    1967-08-29

    According to the described process, the viscosity of water in a water drive can be increased with a mucilage gum derived from flax meal. This substance has less tendency to be absorbed on clay surfaces than some high molecular weight polymers that have been studied. The water-extracted flax gum can be deactivated with clay to remove the absorbable fraction and the residual solution be used for the ''pusher flood.'' This is said to avoid decreasing permeability around the well bore and keep the solution in contact with the oil at essentially the same viscosity as the injected fluid. (7 claims)

  10. Flavor release measurement from gum model system

    DEFF Research Database (Denmark)

    Ovejero-López, I.; Haahr, Anne-Mette; van den Berg, Frans W.J.

    2004-01-01

    Flavor release from a mint-flavored chewing gum model system was measured by atmospheric pressure chemical ionization mass spectroscopy (APCI-MS) and sensory time-intensity (TI). A data analysis method for handling the individual curves from both methods is presented. The APCI-MS data are ratio...... composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory...

  11. Bubble Dynamics and Shock Waves

    CERN Document Server

    2013-01-01

    This volume of the Shock Wave Science and Technology Reference Library is concerned with the interplay between bubble dynamics and shock waves. It is divided into four parts containing twelve chapters written by eminent scientists. Topics discussed include shock wave emission by laser generated bubbles (W Lauterborn, A Vogel), pulsating bubbles near boundaries (DM Leppinen, QX Wang, JR Blake), interaction of shock waves with bubble clouds (CD Ohl, SW Ohl), shock propagation in polydispersed bubbly liquids by model equations (K Ando, T Colonius, CE Brennen. T Yano, T Kanagawa,  M Watanabe, S Fujikawa) and by DNS (G Tryggvason, S Dabiri), shocks in cavitating flows (NA Adams, SJ Schmidt, CF Delale, GH Schnerr, S Pasinlioglu) together with applications involving encapsulated bubble dynamics in imaging (AA Doinikov, A Novell, JM Escoffre, A Bouakaz),  shock wave lithotripsy (P Zhong), sterilization of ships’ ballast water (A Abe, H Mimura) and bubbly flow model of volcano eruptions ((VK Kedrinskii, K Takayama...

  12. Ring Bubbles of Dolphins

    Science.gov (United States)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  13. Water Desalination with Wires

    NARCIS (Netherlands)

    Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

    2012-01-01

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

  14. Seeded perturbations in wire array z-pinches

    International Nuclear Information System (INIS)

    Robinson, Allen Conrad; Kantsyrev, Victor Leonidovich; Wunsch, Scott Edward; Oliver, Bryan Velten; Lebedev, Sergey V.; Safronova, Alla S.; Maxwell, J.; McKenney, John Lee; Ampleford, David J.; Rapley, J.; Bott, S.C.; Palmer, J.B.A.; Bland, Simon Nicholas; Jones, Brent Manley; Chittenden, Jeremy Paul; Garasi, Christopher Joseph; Hall, Gareth Neville; Mehlhorn, Thomas Alan; Deeney, Christopher

    2004-01-01

    The impact of 3D structure on wire array z-pinch dynamics is a topic of current interest, and has been studied by the controlled seeding of wire perturbations. First, Al wires were etched at Sandia, creating 20% radial perturbations with variable axial wavelength. Observations of magnetic bubble formation in the etched regions during experiments on the MAGPIE accelerator are discussed and compared to 3D MHD modeling. Second, thin NaF coatings of 1 mm axial extent were deposited on Al wires and fielded on the Zebra accelerator. Little or no axial transport of the NaF spectroscopic dopant was observed in spatially resolved K-shell spectra, which places constraints on particle diffusivity in dense z-pinch plasmas. Finally, technology development for seeding perturbations is discussed

  15. Evaluation of mechanical properties of unsaturated polyester-guar gum/hydroxypropyl guar gum composites

    Directory of Open Access Journals (Sweden)

    2007-09-01

    Full Text Available Guar gum is a natural polysaccharide that has been explored for various applications. However, there is a limited number of studies in which guar gum has been used as a filler in a polymer. The effect of guar gum and its hydroxypropyl derivatives in unsaturated polyester composites were investigated with respect to their mechanical and chemical properties. The effect of hydroxypropylation and the degree of hydroxypropylation on the properties of resultant composites were also studied. It was observed that the inclusion of guar gum and its derivatives resulted in composites with increased solvent resistance and mechanical properties. An increase in the degree of substitution resulted in increased polymer-filler interaction reflected by a positive effect on the mechanical properties of the composites. These results open an avenue for the use of polysaccharides and their derivatives as eco-friendly fillers as a replacement of mineral fillers.

  16. Constrained Vapor Bubble Experiment

    Science.gov (United States)

    Gokhale, Shripad; Plawsky, Joel; Wayner, Peter C., Jr.; Zheng, Ling; Wang, Ying-Xi

    2002-11-01

    Microgravity experiments on the Constrained Vapor Bubble Heat Exchanger, CVB, are being developed for the International Space Station. In particular, we present results of a precursory experimental and theoretical study of the vertical Constrained Vapor Bubble in the Earth's environment. A novel non-isothermal experimental setup was designed and built to study the transport processes in an ethanol/quartz vertical CVB system. Temperature profiles were measured using an in situ PC (personal computer)-based LabView data acquisition system via thermocouples. Film thickness profiles were measured using interferometry. A theoretical model was developed to predict the curvature profile of the stable film in the evaporator. The concept of the total amount of evaporation, which can be obtained directly by integrating the experimental temperature profile, was introduced. Experimentally measured curvature profiles are in good agreement with modeling results. For microgravity conditions, an analytical expression, which reveals an inherent relation between temperature and curvature profiles, was derived.

  17. Bubble dynamics in drinks

    Science.gov (United States)

    Broučková, Zuzana; Trávníček, Zdeněk; Šafařík, Pavel

    2014-03-01

    This study introduces two physical effects known from beverages: the effect of sinking bubbles and the hot chocolate sound effect. The paper presents two simple "kitchen" experiments. The first and second effects are indicated by means of a flow visualization and microphone measurement, respectively. To quantify the second (acoustic) effect, sound records are analyzed using time-frequency signal processing, and the obtained power spectra and spectrograms are discussed.

  18. PS wire chamber

    CERN Document Server

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. PHYSICOCHEMICAL AND gabonensis GUM EXUDATES A ...

    African Journals Online (AJOL)

    userpc

    surfaces as revealed by streaming potential measurements, atomic force microscopy, molecular dynamics simulations and contact angle measurements." 77-80. Nep, E. I and Conway, B. R.. (2010).Characterization of Grewia gum, a potential pharmaceutical excipient. Journal of Excipient and Food Chemistry 1(1): 30-. 40.

  20. Mind Your Mouth: Preventing Gum Disease

    Science.gov (United States)

    ... gum disease. Smoking greatly increases your risk for periodontitis—another reason not to smoke. Other factors that boost your risk include hormonal changes in women, certain medications and some illnesses like diabetes, cancer and AIDS. NIH-supported researchers are working ...

  1. 21 CFR 582.3336 - Gum guaiac.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gum guaiac. 582.3336 Section 582.3336 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3336...

  2. 21 CFR 172.665 - Gellan gum.

    Science.gov (United States)

    2010-04-01

    ... molecular weight polysaccharide gum produced from Pseudomonas elodea by a pure culture fermentation process... (glyceryl and acetyl) groups as the O-glycosidically linked esters. (b) The strain of P. elodea is... viable cells of P. elodea. (d) The additive meets the following specifications: (1) Positive for gellan...

  3. 21 CFR 172.695 - Xanthan gum.

    Science.gov (United States)

    2010-04-01

    ... hexose units and is manufactured as the sodium, potassium, or calcium salt. (b) The strain of Xanthomonas... hours for cooling. Examine the cooled beaker contents for a firm rubbery gel formation after the... bean gum). Allow the solution to cool without agitation as before. Formation of a gel on cooling...

  4. gum production by Xanthomonas campestris pv

    African Journals Online (AJOL)

    DR TONUKARI NYEROVWO

    2012-09-11

    Sep 11, 2012 ... Fermentation curve of total sugar and xanthan gum production. living cells, as colony counting method can reflect the counts of living bacteria. The gelatinized cassava starch was viscous at the beginning of the fermentation; the fermentation broth was not well mixed, so the concentration of total sugar was.

  5. Tuliposides and tulipalins in tulip Gum

    NARCIS (Netherlands)

    Lubbe, A.; Verpoorte, R.; Gude, H.; Dijkema, M.H.G.E.

    2013-01-01

    Gummosis in tulip bulbs is one of the negative effects of ethylene gas that is produced during storage by Fusarium-infected bulbs on the healthy bulbs. Several aspects of the gummosis process, like the factors inducing it, the underlying carbohydrate metabolism and the composition of the gum have

  6. Global and Local Hydrodynamics of Bubble Columns – Effect of Gas Distributor.

    Czech Academy of Sciences Publication Activity Database

    Sharaf, S.; Zedníková, Mária; Růžička, Marek; Azzopardi, B.J.

    2016-01-01

    Roč. 288, MAR 15 (2016), s. 489-504 ISSN 1385-8947 R&D Projects: GA MŠk(CZ) LD13018 Grant - others:EPSRC(GB) EP/F016050/1 Institutional support: RVO:67985858 Keywords : bubble columns * wire mesh sensor * void fraction Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 6.216, year: 2016

  7. The effect of chewing gum on dental plaque accumulation

    Directory of Open Access Journals (Sweden)

    Karami Nogourani M

    2010-06-01

    Full Text Available "nBackground and Aims: Studies show that sucrose containing chewing gums are cariogenic. The aim of this study was to evaluate the effect of two commercial chewing gums with and without sucrose on dental plaque accumulation compared with the control group. "nMaterials and Methods: In this clinical study, plaque accumulation during three 7-day periods (with two weeks interval was recorded (Sillness & Loe Index in a group of 23 volunteer male dental students who chewed in the first two periods sugar-free or sugar-containing chewing gums (Olips and Orbit, respectively and in the last period did not chew any gum. Participants were asked to chew daily five gum sticks after meals for about twenty minutes. The data were statistically analyzed using Repeated Measure ANOVA and paired-T test. "nResults: The results showed that chewing any gum even sucrose-containing gum decreased the level of dental plaque accumulation (P<0.001. However, the decreasing effect of sugar-free gums was significantly higher (P<0.001. "nConclusion: Although sugar free gum was more effective than sugar containing gum on reducing dental plaque accumulation, chewing even sugar containing gums could decrease the level of dental plaque.

  8. Flavour-enhanced cortisol release during gum chewing.

    Directory of Open Access Journals (Sweden)

    Yoko Hasegawa

    Full Text Available There is some evidence to suggest that chewing gum reduces chronic stress. However, it remains controversial how the taste and odour properties of chewing gum influence stress. The present study was designed to investigate this issue in human subjects. Using an enzyme-linked immunosorbent assay, we tested salivary cortisol concentration, which is thought to be a stress marker, in 96 adults who chewed gum with different combinations of taste and odour. Subjects could discriminate between the types of gum without prior information. Salivary cortisol concentrations were highest and lowest for the subjects who chewed the most flavourful gum and the least flavourful gum, respectively. These findings suggest that the salivary cortisol level during gum chewing is not a marker of negative emotions (i.e., stressful conditions as traditionally considered but, rather, an index of positive emotions that can facilitate biological responses to overcome stressful conditions.

  9. Intrinsic viscosity of binary gum mixtures with xanthan gum and guar gum: Effect of NaCl, sucrose, and pH.

    Science.gov (United States)

    Bak, J H; Yoo, B

    2017-12-29

    The intrinsic viscosity ([η]) values of binary gum mixtures with xanthan gum (XG) and guar gum (GG) mixed with NaCl and sucrose at different concentrations as well as in the presence of different pH levels were examined in dilute solution as a function of XG/GG mixing ratio (100/0, 75/25, 50/50, and 0/100). Experimental values of concentration (C) and relative viscosity (η rel ) or specific viscosity (η sp ) of gums in dilute solution were fitted to five models to determine [η] values of binary gum mixtures including individual gums. A [η] model (η rel =1+[η]C) of Tanglertpaibul and Rao is recommended as the best model to estimate [η] values for the binary gum mixtures with XG and GG as affected by NaCl, sucrose, and pH. Overall, the synergistic interaction of XG-GG mixtures in the presence of NaCl and sucrose showed a greatly positive variation between measured and calculated values of [η]. In contrast, the binary gum mixtures showed synergy only under an acidic condition (pH3). These results suggest that the NaCl and sucrose addition or acidic condition appears to affect the intermolecular interaction occurred between XG and GG at different gum mixing ratios. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Droplets, Bubbles and Ultrasound Interactions.

    Science.gov (United States)

    Shpak, Oleksandr; Verweij, Martin; de Jong, Nico; Versluis, Michel

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics.

  11. Bubble measuring instrument and method

    Science.gov (United States)

    Kline-Schoder, Robert (Inventor); Magari, Patrick J. (Inventor)

    2003-01-01

    Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer, respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.

  12. Helium bubble bursting in tungsten

    International Nuclear Information System (INIS)

    Sefta, Faiza; Juslin, Niklas; Wirth, Brian D.

    2013-01-01

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz

  13. Neutron detection via bubble chambers.

    Science.gov (United States)

    Jordan, D V; Ely, J H; Peurrung, A J; Bond, L J; Collar, J I; Flake, M; Knopf, M A; Pitts, W K; Shaver, M; Sonnenschein, A; Smart, J E; Todd, L C

    2005-01-01

    Research investigating the application of pressure-cycled bubble chambers to fast neutron detection is described. Experiments with a Halon-filled chamber showed clear sensitivity to an AmBe neutron source and insensitivity to a (137)Cs gamma source. Bubble formation was documented using high-speed photography, and a ceramic piezo-electric transducer element registered the acoustic signature of bubble formation. In a second set of experiments, the bubble nucleation response of a Freon-134a chamber to an AmBe neutron source was documented with high-speed photography.

  14. Neutron detection via bubble chambers

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, D.V. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States)]. E-mail: david.jordan@pnl.gov; Ely, J.H. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Peurrung, A.J. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Bond, L.J. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Collar, J.I. [Department of Physics and Enrico Fermi Institute, University of Chicago, 5640 S. Ellis Ave., LASR 214, Chicago, IL 60637 (United States); Flake, M. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Knopf, M.A. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Pitts, W.K. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Shaver, M. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Sonnenschein, A. [Department of Physics and Enrico Fermi Institute, University of Chicago, 5640 S. Ellis Ave., LASR 214, Chicago, IL 60637 (United States); Smart, J.E. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States); Todd, L.C. [Pacific Northwest National Laboratory, MS P8-20, P.O. Box 999, Richland, WA 99352 (United States)

    2005-12-01

    Research investigating the application of pressure-cycled bubble chambers to fast neutron detection is described. Experiments with a Halon-filled chamber showed clear sensitivity to an AmBe neutron source and insensitivity to a {sup 137}Cs gamma source. Bubble formation was documented using high-speed photography, and a ceramic piezo-electric transducer element registered the acoustic signature of bubble formation. In a second set of experiments, the bubble nucleation response of a Freon-134a chamber to an AmBe neutron source was documented with high-speed photography.

  15. Physico-chemical study on guar gum

    International Nuclear Information System (INIS)

    Mahmoud, Nahla Mubarak

    2000-05-01

    Guar plant is an annual summer plant and it can resist diseases, pests and drought. Guar gum is used in a lot of industries. The present study deals with some physical properties of two commercial grade samples of guar gum cyamopsis tetragonoloba which where produced in 1996 and 1997 seasons (S 1 and S 2 respectively). Our analytical data are compared with those of previous workers in this area and international quality. Guar gum (S 2 ) is separated into water-insoluble components. Three fractions were obtained from the water-soluble components by fractional participation using acetone. Guar gum powder is yellowish white; the water-insoluble component is brownish white. Comparison study between gum samples (S 1 and S 2 ) and water-insoluble fraction (1) and water-soluble fractions are close to each other in their physico-properties. chemical All samples and fractions contain galactomannan polysaccharide as explained by infra-red spectra.Moisture contents for the gum samples were 5.2% and 7.8% and that for the water-insoluble fraction 4.7% while that for fraction samples were 5.2%-7.5% ash contents for the gum samples was 0.81% and 1.14% and for the water-insoluble component 0.88% while the contents in the fractions between 0.5%-0.66%. Nitrogen content determination showed that the gum samples had value of 0.678% and 0.732% and water -insoluble fraction had a value of 0.118%. The values decreased in the water-soluble fractions giving 0.049%, 0.053 and 0.056%. Water-soluble component and its fractions record the following results: pH measurements showed that the water-soluble component had pH 6.70 and 6.84 while its fractions had pH 5.90 and 7.00. Viscosity measurements showed that water-soluble fractions had intrinsic viscosity of 6.4 and 6.8 dL. g -1 . The fractions derived from water-soluble fraction had intrinsic viscosity of 6.6, 7 and 7.5 dl. g -1 . Using Mark-Howink equation, calculated average molecular weights for the water-soluble components were 7.01x10 5

  16. Bubble Coalescence: Effect of Bubble Approach Velocity and Liquid Viscosity

    Czech Academy of Sciences Publication Activity Database

    Orvalho, Sandra; Růžička, Marek; Olivieri, G.; Marzocchella, A.

    2015-01-01

    Roč. 134, SEP 29 (2015), s. 205-216 ISSN 0009-2509 R&D Projects: GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : bubble coalescence * bubble approach velocity * liquid viscosity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.750, year: 2015

  17. Magnetic Bubble Research

    Science.gov (United States)

    1974-09-01

    x-axis intercept in Figure 20 is twice the coercive field, which for this sample is 0.3 oersted . In this experiment, the laser beam diameter was...the ion im- planted region. From the theory of optical waveguides, Namba, et al., have shown that the minimum refractive index change in an...resulting in bubble outputs at both A + B and A • B outputs. Our first devices of this type were found to have 6 to 7 Oersted bias field margins for

  18. Competition in the gum arabic market: a game theoretic modelling approach

    NARCIS (Netherlands)

    Rahim, A.; Ierland, van E.C.; Weikard, H.P.

    2010-01-01

    Gum arabic is mainly produced from two Acacias that are found in the gum belt of Sub-Saharan Africa. These are Acacia senegal that produces high quality gum and Acacia seyal that produces low quality gum. In recent years the gum market structure has changed and Sudan lost its near monopoly position

  19. Towards plant wires

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self...

  20. Stable tridimensional bubble clusters in multi-bubble sonoluminescence (MBSL).

    Science.gov (United States)

    Rosselló, J M; Dellavale, D; Bonetto, F J

    2015-01-01

    In the present work, stable clusters made of multiple sonoluminescent bubbles are experimentally and theoretically studied. Argon bubbles were acoustically generated and trapped using bi-frequency driving within a cylindrical chamber filled with a sulfuric acid aqueous solution (SA85w/w). The intensity of the acoustic pressure field was strong enough to sustain, during several minutes, a large number of positionally and spatially fixed (without pseudo-orbits) sonoluminescent bubbles over an ellipsoidally-shaped tridimensional array. The dimensions of the ellipsoids were studied as a function of the amplitude of the applied low-frequency acoustic pressure (PAc(LF)) and the static pressure in the fluid (P0). In order to explain the size and shape of the bubble clusters, we performed a series of numerical simulations of the hydrodynamic forces acting over the bubbles. In both cases the observed experimental behavior was in excellent agreement with the numerical results. The simulations revealed that the positionally stable region, mainly determined by the null primary Bjerknes force (F→Bj), is defined as the outer perimeter of an axisymmetric ellipsoidal cluster centered in the acoustic field antinode. The role of the high-frequency component of the pressure field and the influence of the secondary Bjerknes force are discussed. We also investigate the effect of a change in the concentration of dissolved gas on the positional and spatial instabilities through the cluster dimensions. The experimental and numerical results presented in this paper are potentially useful for further understanding and modeling numerous current research topics regarding multi-bubble phenomena, e.g. forces acting on the bubbles in multi-frequency acoustic fields, transient acoustic cavitation, bubble interactions, structure formation processes, atomic and molecular emissions of equal bubbles and nonlinear or unsteady acoustic pressure fields in bubbly media. Copyright © 2014 Elsevier B

  1. Photovoltaic Wire, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  2. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  3. Charpak hemispherical wire chamber

    CERN Document Server

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. New mechanism for bubble nucleation: Classical transitions

    International Nuclear Information System (INIS)

    Easther, Richard; Giblin, John T. Jr; Hui Lam; Lim, Eugene A.

    2009-01-01

    Given a scalar field with metastable minima, bubbles nucleate quantum mechanically. When bubbles collide, energy stored in the bubble walls is converted into kinetic energy of the field. This kinetic energy can facilitate the classical nucleation of new bubbles in minima that lie below those of the 'parent' bubbles. This process is efficient and classical, and changes the dynamics and statistics of bubble formation in models with multiple vacua, relative to that derived from quantum tunneling.

  5. 1998 wire development workshop proceedings

    International Nuclear Information System (INIS)

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development

  6. Bubble chamber: colour enhanced tracks

    CERN Document Server

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  7. Bubble coalescence in breathing DNA

    DEFF Research Database (Denmark)

    Novotný, Tomas; Pedersen, Jonas Nyvold; Ambjörnsson, Tobias

    2007-01-01

    We investigate the coalescence of two DNA bubbles initially located at weak segments and separated by a more stable barrier region in a designed construct of double-stranded DNA. The characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribu...

  8. Bubble columns : Structures or stability?

    NARCIS (Netherlands)

    Harteveld, W.K.

    2005-01-01

    The aim of the thesis is to contribute to the understanding of the hydrodynamics of the gravity driven bubbly flow that can be found in bubble columns. Special attention is paid to the large scale structures that have a strong impact on several key parameters such as the degree of mixing, mass and

  9. Sonoporation from jetting cavitation bubbles

    NARCIS (Netherlands)

    Ohl, C.D.; Arora, M.; Ikink, Roy; de Jong, N.; Versluis, Michel; Delius, Michael; Lohse, Detlef

    2006-01-01

    The fluid dynamic interaction of cavitation bubbles with adherent cells on a substrate is experimentally investigated. We find that the nonspherical collapse of bubbles near to the boundary is responsible for cell detachment. High-speed photography reveals that a wall bounded flow leads to the

  10. Sonoporation from jetting cavitation bubbles

    NARCIS (Netherlands)

    C.-D. Ohl (Claus-Dieter); M. Arora (Manish); R. Ikink (Roy); N. de Jong (Nico); M. Versluis (Michel); M. Delius (Michael); D. Lohse (Detlef)

    2006-01-01

    textabstractThe fluid dynamic interaction of cavitation bubbles with adherent cells on a substrate is experimentally investigated. We find that the nonspherical collapse of bubbles near to the boundary is responsible for cell detachment. High-speed photography reveals that a wall bounded flow leads

  11. Sonoluminescing Air Bubbles Rectify Argon

    NARCIS (Netherlands)

    Lohse, Detlef; Brenner, Michael P.; Dupont, Todd F.; Hilgenfeldt, Sascha; Johnston, Blaine

    1997-01-01

    The dynamics of single bubble sonoluminescence (SBSL) strongly depends on the percentage of inert gas within the bubble. We propose a theory for this dependence, based on a combination of principles from sonochemistry and hydrodynamic stability. The nitrogen and oxygen dissociation and subsequent

  12. Gum Arabic authentication and mixture quantification by near infrared spectroscopy

    DEFF Research Database (Denmark)

    Dong, Yongjiang; Sørensen, Klavs Martin; He, Sailing

    2017-01-01

    A rapid and reliable method is developed for Gum Arabic authentication based on Near Infrared (NIR) spectroscopy and chemometric methods. On a large industrial collection of authentic gum Arabics, the two major Acacia gum species, Acacia senegal and Acacia seyal could be assigned perfectly...... by the NIR spectroscopic method. In addition, a partial least squares (PLS) regression model is calibrated to predict the blending percentage of the two pure gum types, producing an accuracy, root mean square error of cross validation (RMSECV) of 2.8%. Sampling of the Gum Arabic ‘tears’ is discussed......, and it was determined that subsamples from three ‘tears’ is required for a representative result. It is concluded that NIR spectroscopy is a very powerful and reliable method for authenticity testing of Gum Arabic species....

  13. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    The effect of the melting temperature on bubble size and bubble formation in an iron bearing calcium aluminosilicate melt is studied by means of in-depth images acquired by optical microscopy. The bubble size distribution and the total bubble volume are determined by counting the number of bubbles...... and their diameter. The variation in melting temperature has little influence on the overall bubble volume. However, the size distribution of the bubbles varies with the melting temperature. When the melt is slowly cooled, the bubble volume increases, implying decreased solubility of the gaseous species. Mass...

  14. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  15. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  16. Antiectoparasitic activity of the gum resin, gum haggar, from the East African plant, Commiphora holtziana.

    Science.gov (United States)

    Birkett, Michael A; Abassi, Sate Al; Kröber, Thomas; Chamberlain, Keith; Hooper, Antony M; Guerin, Patrick M; Pettersson, Jan; Pickett, John A; Slade, Robin; Wadhams, Lester J

    2008-05-01

    The mechanism of ixodid tick (Acari: Ixodidae) repellency by gum haggar, a resin produced by Commiphora holtziana (Burseraceae), was investigated by evaluating activity against the cattle tick, Boophilus microplus. In an arena bioassay, a hexane extract of the resin of C. holtziana exhibited a repellent effect lasting up to 5h. The hydrocarbon fraction of the resin extract was shown to account for the repellent activity, and was analysed by coupled gas chromatography-mass spectrometry (GC-MS). Major sesquiterpene hydrocarbons were tentatively identified as germacrene-D, delta-elemene and beta-bourbonene. The identity and stereochemistry of the former compound was confirmed as the (+)-isomer by peak enhancement using enantioselective GC, whereas the latter 2 compounds, which are most likely degradation products of germacrene-type precursors, were identified through isolation by preparative gas chromatography followed by microprobe-NMR spectroscopy. GC comparison of gum haggar with another resin, C. myrrha, which was inactive in the tick bioassay, showed that the latter contained much lower levels of these hydrocarbons. To assess the suitability of the gum haggar resin as a general acarine repellent, further tests were made on a major acarine pest of European and US animal husbandry systems, the red poultry mite, Dermanyssus gallinae (Acari: Dermanyssidae). Gum haggar extract, and the isolated hydrocarbon fraction, showed strong repellent effects in an olfactometer assay, and again gum myrrh showed no effect. These findings provide a scientific basis for the observed anti-tick properties of gum haggar, and demonstrate the potential for its development as a general acarine repellent for use in animal husbandry systems.

  17. Bubble length affects bubble speed in a rough microfluidic channel

    Science.gov (United States)

    Zhang, Quan; Turitsyn, Konstantin; Witten, Tom

    2010-03-01

    We discuss the creeping motion of bubbles of different length in rough capillary tubes filled with carrier fluids. This extends the results of BrethertonfootnotetextF.P.Bretherton, 1961, J. Fluid Mech., 10, 166. for an infinite-length bubble at small capillary number Ca in a circular tube. We first derive the asymptotic corrections to the speed owing to finite length. This dependence on length is exponentially small, with a decay length much shorter than the tube radius R. Then we discuss the effect of azimuthal roughness of the tube on the bubble speed. Tube roughness leads to a carrier fluid flow in the azimuthal plane; this flow controls the relaxation of the bubble shape to its infinite length limit. For long-wavelength roughness, we find that the above decay length becomes much longer and even comparable to R. This implies a much-enhanced dependence of the bubble velocity on length. A shorter bubble should then catch up with a longer bubble ahead of it in the same channel. This mechanism may explain catch-up effects seen experimentally.footnotetextR.Ismagilov, private communication.

  18. Quantification and qualification of bacteria trapped in chewed gum.

    Directory of Open Access Journals (Sweden)

    Stefan W Wessel

    Full Text Available Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR, yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 10(8 bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing

  19. Phytase application in chewing gum - A technical assessment

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    either prior to ingestion, i.e. in the food, or post ingestion, i.e. in the human gastrointestinal tract. We have assessed the technical aspects of formulation and release of phytase added to chewing gum as a delivery vehicle. Phytases from Aspergillus niger and Escherichia coli incorporated into chewing...... gum were released quantitatively upon chewing and retained phytase activity (50-80% of the enzyme activity added was released within 10 minutes). Initial evaluations of phytase chewing gum shelf life showed good stability after 48 days of storage of the chewing gum at ambient conditions....

  20. "Quarters Are What You Put into the Bubble Gum Machine": Numeracy Interactions during Parentchild Play

    Science.gov (United States)

    Vandermaas­-Peeler, Maureen; Nelson, Jackie; Bumpass, Charity

    2007-01-01

    Literacy has been studied extensively in the context of children's play, but few studies exist of numeracy development through play. The purpose of this study was to investigate the frequency and type of numeracy exchanges that occurred spontaneously during parent-child play. Twenty-six 4-year-olds and their mothers played with a variety of toys,…

  1. Stabilization of emulsions by gum tragacanth (Astragalus spp.) correlates to the galacturonic acid content and methoxylation degree of the gum

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan; Meyer, Anne S.; Abang Zaidel, Dayang Norulfairuz

    2013-01-01

    -soluble (tragacanthin) and water-swellable (bassorin) fractions, their monosaccharide composition, methoxylation, and acetylation degrees. The gums from A. parrowianus and A. fluccosus had relatively high tragacanthin:bassorin ratios of ∼66:34 and ∼75:25, respectively, whereas in the other gums this ratio approached 50......–270 mg/g), and galactose (∼40–140 mg/g), and also contained fucose, rhamnose, and glucose. The ability of the gums to act as stabilizers in whey protein isolate based emulsions varied. The best emulsion stabilization effect, measured as lowest creaming index ratio after 20 days, was obtained with the A....... fluccosus gum. The emulsion stabilization effect correlated linearly and positively to the methoxylation degree, and galacturonic acid content of the gums, but not to acetyl or fucose content. A particularly high correlation was found between methoxyl level in the soluble gum part and emulsion stabilization...

  2. Automating wiring formboard design

    NARCIS (Netherlands)

    Van den Berg, T.

    2013-01-01

    Increase in aircraft wiring complexity call for manufacturing design improvements to reduce cost and lead-time. To achieve such improvements, a joint research project was performed by the Flight Performance and Propulsion (FPP) group and Fokker Elmo BV, the second largest aircraft wiring harness

  3. The bubble legacy

    Science.gov (United States)

    Hecht, Jeff

    2010-05-01

    Imagine an optics company - let's call it JDS Uniphase - with a market capitalization approaching the gross domestic product (GDP) of Ireland. Now imagine it merging with a laser company - say, SDL - that has a stock valuation of 41bn, higher than the GDP of Costa Rica. Finally, imagine a start-up with 109m in venture capital in its pocket but no product to its name (Novalux) turning down an offer of 500m as insufficient. It may be hard to believe, but these tales are true: they occurred in the year 2000 - an era when the laser, fibre-optics and photonics industries were the darlings of the financial world. Such was the madcap nature of that brief period that survivors call it simply "the bubble".

  4. Faraday and Kerr Effects Diagnostics for Underwater Exploding Wires

    Science.gov (United States)

    Sarkisov, G. S.; Fedotov-Gefen, A. V.; Krasik, Ya. E.

    2012-10-01

    Two-channel laser polarimeter was used to measure magnetic and electric fields in vicinity of underwater exploding wire. Nd:YAG Q-switch laser with 532nm wavelength, 100mJ energy and 5ns pulse width was used for probing. Single wire, parallel wires and X and V- shaped wires was used in experiments. Electric and magnetic field induced birefringes in the water results in changing of polarization stage of probing beam after propagation through this anisotropic medium. Magnetic field results in circular anisotropy of the water, while electric field creates linear anisotropy. Magnetic field results in rotation of polarization plan of linear-polarized probing beam. Electric field effect is more complicated- polarization plan of the laser beam subjected to pulsation and changing of ellipticity. Effect of electric field depends on initial probing geometry- angle between electrical field vector E and polarization plane of probing wave. In our exploding wire experiments we found influence of both Faraday and Kerr effects. It was demonstrated existence of Kerr effect inside bubbles at high voltage electrode. Effect of magnetic fields interaction for multi-wire loads was observed.

  5. Formulation development and evaluation of metformin chewing gum with bitter taste masking

    Directory of Open Access Journals (Sweden)

    Sayed Abolfazl Mostafavi

    2014-01-01

    Conclusion: Metfornin chewing gum had suitable appearance and appropriate invitro characteristics that fallow the pharmacopeia suggestions. This chewable gum showed bitterness suppression with a suitable release rate.

  6. Sonochemistry and the acoustic bubble

    CERN Document Server

    Grieser, Franz; Enomoto, Naoya; Harada, Hisashi; Okitsu, Kenji; Yasui, Kyuichi

    2015-01-01

    Sonochemistry and the Acoustic Bubble provides an introduction to the way ultrasound acts on bubbles in a liquid to cause bubbles to collapse violently, leading to localized 'hot spots' in the liquid with temperatures of 5000° celcius and under pressures of several hundred atmospheres. These extreme conditions produce events such as the emission of light, sonoluminescence, with a lifetime of less than a nanosecond, and free radicals that can initiate a host of varied chemical reactions (sonochemistry) in the liquid, all at room temperature. The physics and chemistry behind the p

  7. New evidence on the first financial bubble

    NARCIS (Netherlands)

    Frehen, R.G.P.; Goetzmann, W.; Rouwenhorst, K.G.

    2013-01-01

    The Mississippi Bubble, South Sea Bubble and the Dutch Windhandel of 1720 together represent the world's first global financial bubble. We hand-collect cross-sectional price data and investor account data from 1720 to test theories about market bubbles. Our tests suggest that innovation was a key

  8. Characterization and in vitro drug release studies of a natural polysaccharide Terminalia catappa gum (Badam gum).

    Science.gov (United States)

    Meka, Venkata Srikanth; Nali, Sreenivasa Rao; Songa, Ambedkar Sunil; Kolapalli, Venkata Ramana Murthy

    2012-12-01

    The main objective of the present study is the physicochemical characterization of naturally available Terminalia catappa gum (Badam gum [BG]) as a novel pharmaceutical excipient and its suitability in the development of gastroretentive floating drug delivery systems (GRFDDS) to retard the drug for 12 h when the dosage form is exposed to gastrointestinal fluids in the gastric environment. As BG was being explored for the first time for its pharmaceutical application, physicochemical, microbiological, rheological, and stability studies were carried out on this gum. In the present investigation, the physicochemical properties, such as micromeritic, rheological, melting point, moisture content, pH, swelling index, water absorption, and volatile acidity, were evaluated. The gum was characterized by scanning electron microscopy, differential scanning calorimetry (DSC), powder X-ray diffraction studies (PXRD), and Fourier transform infrared spectroscopy (FTIR). Gastroretentive floating tablets of BG were prepared with the model drug propranolol HCl by direct compression methods. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, in vitro drug release, and rate order kinetics. PBG 04 was selected as an optimized formulation based on its 12-h drug release and good buoyancy characteristics. The optimized formulation was characterized with FTIR, DSC, and PXRD studies, and no interaction between the drug and BG was found. Thus, the study confirmed that BG might be used in the gastroretentive drug delivery system as a release-retarding polymer.

  9. Thermosonic wire bonding of IC devices using palladium wire

    International Nuclear Information System (INIS)

    Shze, J.H.; Poh, M.T.; Tan, R.M.

    1996-01-01

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  10. Towards plant wires.

    Science.gov (United States)

    Adamatzky, Andrew

    2014-08-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self-growing wetware circuits and devices, and integration of plant-based electronic components into future and emergent bio-hybrid systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Increased gum arabic production after infestation of Acacia senegal ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... changes in some physical properties of gum (colour, shape, size, moisture content and optical rotation) and chemical properties .... rotation with long fallow periods (15 to 20 years) of gum cultivation interspersed with short ..... G.A. fiber as a supplement to low protein diet in chronic renal failure patients. In: ...

  12. Intrinsic viscosity of guar gum in sweeteners solutions | Samavati ...

    African Journals Online (AJOL)

    Rheological methods were applied to study the effect of sweeteners on the rheological behavior of guar gum in dilute solutions. The concentration of the sweeteners were 0.1, 0.2%w/v for aspartame, acesulfame-k and cyclamate, and 0.001, 0.002%w/v for neotame. Gum was evaluated for intrinsic viscosity by various ...

  13. Grewia Gum 1: Some Mechanical and Swelling Properties of ...

    African Journals Online (AJOL)

    Purpose: To study the mechanical and dynamic swelling properties of grewia gum, evaluate its compression behaviour and determine the effect of drying methods on its properties. Methods: Compacts (500 mg) of both freeze-dried and air-dried grewia gum were separately prepared by compression on a potassium bromide ...

  14. Gellan Gum: Fermentative Production, Downstream Processing and Applications

    Directory of Open Access Journals (Sweden)

    Ishwar B. Bajaj

    2007-01-01

    Full Text Available The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C. P. Kelco in Japan and the USA. Further research and development in biopolymer technology is expected to expand its use. This article presents a critical review of the available information on the gellan gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production and downstream processing. Rheological behaviour of fermentation broth during fermentative production of gellan gum and problems associated with mass transfer have been addressed. Information on the biosynthetic pathway of gellan gum, enzymes and precursors involved in gellan gum production and application of metabolic engineering for enhancement of yield of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties, rheology of its solutions and gel formation behaviour are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries.

  15. Current evidence on the anticancer potential of Chios mastic gum.

    Science.gov (United States)

    Giaginis, Constantinos; Theocharis, Stamatios

    2011-11-01

    Chios mastic gum derived from the plant Pistacia lentiscus L. variation chia has been shown to exert beneficial effects on a wide range of human disorders. The most comprehensive data so far have indicated that mastic gum provides protection against gastrointestinal malfunctions and bacterial infections. Substantial evidence has also suggested that mastic gum exhibits hepatoprotective and cardioprotective, antiinflammatory/antioxidant, and antiatherogenic properties. In the last decade, an increasing number of studies further evaluated the potential antiproliferative properties of mastic gum against several types of human neoplasia. The present review aims to summarize the current data concerning the anticancer activities of mastic gum and their major constituents, highlighting also the molecular mechanisms through which they exert anticancer function. Mastic gum constituents that belong to the chemical class of triterpenoids appear to be mainly responsible for its anticancer potential. Thus, a brief discussion is dedicated to the anticancer activity of synthetic and naturally occurring triterpenoid analogues with similar chemical structure to mastic gum constituents. Taking into consideration the available data so far, Chios mastic gum could be considered as a conglomeration of effective anticancer drugs.

  16. Entandophragma angolense Gum as a Novel Binder and ...

    African Journals Online (AJOL)

    Michael

    the development of oral controlled release dosage forms. These semisynthetic polymers are quite expensive when compared with natural polymers such as guar gum and alginates, while the natural polymers are nontoxic and readily available [18]. The present study was designed to evaluate the hydrophilic natural gum ...

  17. Evaluation of the bioadhesive property of Grewia gum in ...

    African Journals Online (AJOL)

    The bioadhesive property of grewia gum for sustained release of Indomethacin from tablets was evaluated using pig gastric mucus as substrate. The tablets formulated by wet granulation contained 75 mg of the drug and 15 or 20 %w/w of the gum. Similar tablets made differently with carbopol 934, tragacanth and sodium ...

  18. Evaluation of the suspending properties of Abizia zygia gum on ...

    African Journals Online (AJOL)

    Method: The suspending properties of Albizia zygia gum (family Mimosoideae) were evaluated comparatively with those of Compound Tragacanth, Acacia and Gelatin at concentration range of 0.5 – 4.0%w/v in Sulphadimidine suspension. Characterization tests were carried out on purified Albizia zygia gum. Sedimentation ...

  19. Bubble nucleation in stout beers

    Science.gov (United States)

    Lee, W. T.; McKechnie, J. S.; Devereux, M. G.

    2011-05-01

    Bubble nucleation in weakly supersaturated solutions of carbon dioxide—such as champagne, sparkling wines, and carbonated beers—is well understood. Bubbles grow and detach from nucleation sites: gas pockets trapped within hollow cellulose fibers. This mechanism appears not to be active in stout beers that are supersaturated solutions of nitrogen and carbon dioxide. In their canned forms these beers require additional technology (widgets) to release the bubbles which will form the head of the beer. We extend the mathematical model of bubble nucleation in carbonated liquids to the case of two gases and show that this nucleation mechanism is active in stout beers, though substantially slower than in carbonated beers and confirm this by observation. A rough calculation suggests that despite the slowness of the process, applying a coating of hollow porous fibers to the inside of a can or bottle could be a potential replacement for widgets.

  20. Holography in small bubble chambers

    International Nuclear Information System (INIS)

    Lecoq, P.

    1984-01-01

    This chapter reports on an experiment to determine the total charm cross section at different incident momenta using the small, heavy liquid bubble chamber HOBC. Holography in liquid hydrogen is also tested using the holographic lexan bubble chamber HOLEBC with the aim of preparing a future holographic experiment in hydrogen. The high intensity tests show that more than 100 incident tracks per hologram do not cause a dramatic effect on the picture quality. Hydrogen is more favorable than freon as the bubble growth is much slower in hydrogen. An advantage of holography is to have the maximum resolution in the full volume of the bubble chamber, which allows a gain in sensitivity by a factor of 10 compared to classical optics as 100 tracks per hologram look reasonable. Holograms are not more difficult to analyze than classical optics high-resolution pictures. The results show that holography is a very powerful technique which can be used in very high resolution particle physics experiments

  1. Gum Arabic as a Cause of Occupational Allergy

    Directory of Open Access Journals (Sweden)

    Arja Viinanen

    2011-01-01

    Full Text Available Background. Gum arabic is a potential sensitizer in food industry. Methods. We examined 11 candy factory workers referred to examinations due to respiratory and skin symptoms paying attention to exposure and sensitization to gum arabic. Skin tests, pulmonary function tests, and respiratory provocation tests were carried out as indicated by the symptoms and findings. Results. Occupational asthma, caused by gum arabic was diagnosed in 4/11 candy factory workers and two of them had also occupational contact urticaria and one had occupational rhinitis. One of them had oral symptoms associated with ingestion of products containing gum arabic. Conclusions. Airborne exposure to gum arabic may cause sensitization leading to allergic rhinitis, asthma, and urticaria.

  2. From rational bubbles to crashes

    Science.gov (United States)

    Sornette, D.; Malevergne, Y.

    2001-10-01

    We study and generalize in various ways the model of rational expectation (RE) bubbles introduced by Blanchard and Watson in the economic literature. Bubbles are argued to be the equivalent of Goldstone modes of the fundamental rational pricing equation, associated with the symmetry-breaking introduced by non-vanishing dividends. Generalizing bubbles in terms of multiplicative stochastic maps, we summarize the result of Lux and Sornette that the no-arbitrage condition imposes that the tail of the return distribution is hyperbolic with an exponent μbubble model to arbitrary dimensions d: a number d of market time series are made linearly interdependent via d× d stochastic coupling coefficients. We derive the no-arbitrage condition in this context and, with the renewal theory for products of random matrices applied to stochastic recurrence equations, we extend the theorem of Lux and Sornette to demonstrate that the tails of the unconditional distributions associated with such d-dimensional bubble processes follow power laws, with the same asymptotic tail exponent μmodel and the non-stationary growth rate model) of the RE bubble model that provide two ways of reconciliation with the stylized facts of financial data.

  3. Bubble bursting at an interface

    Science.gov (United States)

    Kulkarni, Varun; Sajjad, Kumayl; Anand, Sushant; Fezzaa, Kamel

    2017-11-01

    Bubble bursting is crucial to understanding the life span of bubbles at an interface and more importantly the nature of interaction between the bulk liquid and the outside environment from the point of view of chemical and biological material transport. The dynamics of the bubble as it rises from inside the liquid bulk to its disappearance on the interface after bursting is an intriguing process, many aspects of which are still being explored. In our study, we make detailed high speed imaging measurements to examine carefully the hole initiation and growth in bursting bubbles that unearth some interesting features of the process. Previous analyses available in literature are revisited based on our novel experimental visualizations. Using a combination of experiments and theory we investigate the role of various forces during the rupturing process. This work aims to further our current knowledge of bubble dynamics at an interface with an aim of predicting better the bubble evolution from its growth to its eventual integration with the liquid bulk.

  4. Cryogenic Pressure Seal for Wires

    Science.gov (United States)

    Ciana, J. J.

    1984-01-01

    High-pressure-seal formed by forcing polyurethane into space surrounding wire or cable in special fitting. Wire or cable routed through fitting then through a tightly fitting cap. Wire insulation left intact. Cap filled with sealant and forced onto the fitting: this pushes sealant into fitting so it seals wire or cable in fitting as well as in cap.

  5. Measuring online social bubbles

    Directory of Open Access Journals (Sweden)

    Dimitar Nikolov

    2015-12-01

    Full Text Available Social media have become a prevalent channel to access information, spread ideas, and influence opinions. However, it has been suggested that social and algorithmic filtering may cause exposure to less diverse points of view. Here we quantitatively measure this kind of social bias at the collective level by mining a massive datasets of web clicks. Our analysis shows that collectively, people access information from a significantly narrower spectrum of sources through social media and email, compared to a search baseline. The significance of this finding for individual exposure is revealed by investigating the relationship between the diversity of information sources experienced by users at both the collective and individual levels in two datasets where individual users can be analyzed—Twitter posts and search logs. There is a strong correlation between collective and individual diversity, supporting the notion that when we use social media we find ourselves inside “social bubbles.” Our results could lead to a deeper understanding of how technology biases our exposure to new information.

  6. Beyond the gas bubble

    International Nuclear Information System (INIS)

    Hilt, R.H.

    1990-01-01

    The deliverability issue currently being discussed within the natural gas industry involves both near-term and long-term questions. In the near-term, over the next two or three years, it is probable that the natural gas industry will need to mobilize for much greater levels of investment than have been the experience over the past few years. In the longer-term, it is expected that new opportunities for gas will arise as the nation seeks to meet increasing energy requirements within new environmental constraints. Methane for emissions control, CNG vehicles, expanded gas-fired electricity generation, and increased efficiency of traditional energy services are just a few examples. The issues in the longer-term center on the ability of the gas industry to meet increasing supply requirements reliably and at cost-competitive prices for these markets. This paper begins by reviewing the historical situation of gas deliverability that is the capability of the gas producing and transportation portions of the industry. The delivery system's ability to handle shifts in the centers of consumption and production is discussed, with an emphasis on regional problems of gas deliverability and potential bottlenecks. On the production side, the paper reviews the capability and the required investment necessary to handle an orderly transition to a stable supply and demand balance once the elusive bubble had finally disappeared

  7. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  8. Progress in American Superconductor’s HTS wire and optimization for fault current limiting systems

    Energy Technology Data Exchange (ETDEWEB)

    Malozemoff, Alexis P., E-mail: amalozemoff@amsc.com

    2016-11-15

    Highlights: • AMSC HTS wire critical current needed for rotating machinery is doubled by 16 MeV Au irradiation. • Nonuniformity of HTS wires in power devices causes hot spot formation during power system faults. • Lower normal-state resistivity and critical current lower HTS wire hot spot heating during faults. • HTS wire hot spot heating in HTS cables during faults must stay below lN{sub 2} bubble nucleation point. • HTS wire can be designed to meet hot spot heating limits in fault current limiting cables. - Abstract: American Superconductor has developed composite coated conductor tape-shaped wires using high temperature superconductor (HTS) on a flexible substrate with laminated metal stabilizer. Such wires enable many applications, each requiring specific optimization. For example, coils for HTS rotating machinery require increased current density J at 25–50 K. A collaboration with Argonne, Brookhaven and Los Alamos National Laboratories and several universities has increased J using an optimized combination of precipitates and ion irradiation defects in the HTS. Major commercial opportunities also exist to enhance electric power grid resiliency by linking substations with distribution-voltage HTS power cables [10]. Such links provide alternative power sources if one substation's transmission-voltage power is compromised. But they must also limit fault currents which would otherwise be increased by such distribution-level links. This can be done in an HTS cable, exploiting the superconductor-to-resistive transition when current exceeds the wires’ critical J. A key insight is that such transitions are usually nonuniform; so the wire must be designed to prevent localized hot spots from damaging the wire or even generating gas bubbles in the cable causing dielectric breakdown. Analysis shows that local heating can be minimized by increasing the composite tape's total thickness, decreasing its total resistance in the normal state and

  9. Occurrence of gum spots in black cherry after partial harvest cutting

    Science.gov (United States)

    Charles O. Rexrode; H. Clay Smith; H. Clay Smith

    1990-01-01

    Bark beetles, primarily the bark beetle Phlosotribus liminori (Harris), are the major cause of gum spots in sawtimber-size black cherry Prunus serotina Ehrh. Approximately 90 percent of all gum spots in the bole sections are caused by bark beetles. Gum spots were studied in 95 black cherry trees near Parsons, West Virginia. Over 50 percent of the bark beetle-caused gum...

  10. Flavor-Enhanced Modulation of Cerebral Blood Flow during Gum Chewing.

    Directory of Open Access Journals (Sweden)

    Yoko Hasegawa

    Full Text Available Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior.WE TESTED CEREBRAL BLOOD FLOW (CBF IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no odor gum (C-gum, sweet taste/no odor gum (T-gum, and sweet taste/lemon odor gum (TO-gum. Simultaneous recordings of transcranial Doppler ultrasound (TCD and near infrared spectrometer (NIRS were used to measure CBF during gum chewing in 25 healthy volunteers. Bilateral masseter muscle activity was also monitored.We found that subjects could discriminate the type of gum without prior information. Subjects rated the TO-gum as the most flavorful gum and the C-gum as the least flavorful. Analysis of masseter muscle activity indicated that masticatory motor output during gum chewing was not affected by taste and odor. The TCD/NIRS measurements revealed significantly higher hemodynamic signals when subjects chewed the TO-gum compared to when they chewed the C-gum and T-gum.These data suggest that taste and odor can influence brain activation during chewing in sensory, cognitive, and motivational processes rather than in motor control.

  11. Effect of sorbitol gum chewing on plaque pH response after ingesting snacks containing predominantly sucrose or starch.

    Science.gov (United States)

    Park, K K; Schemehorn, B R; Bolton, J W; Stookey, G K

    1990-10-01

    The purpose of this study was to determine the effect of chewing a sorbitol gum (Trident) for 10 minutes on interproximal plaque pH changes following ingestion of selected sucrose- or starch-containing foods. The snacks containing predominantly sucrose (and/or simple sugars) were chocolate bar, cream-filled cupcakes, cream-filled sandwich cookie, cherry pie and raisins. The snacks containing predominantly starch were oat cereal, granola bars, pretzels, potato chips and corn chips. Plaque pH responses were monitored using an indwelling wire-telemetry system in five adult panelists. The test design involved two sets of 5 x 5 Latin square randomization in which each set consisted of two series of tests. In the first series of tests, the fasted, resting plaque pH was recorded for 5 minutes, panelists ingested the designated snacks for 2 minutes, and the pH response was monitored for the remainder of a 2-hour period. In the second series of tests, the same procedure was followed through the snack ingestion. After the pH response to the snack was monitored for 15 minutes, the panelists were asked to chew one stick of sorbitol gum for 10 minutes and the pH response was then monitored for the balance of the 2-hour period. Results indicated that both the sugar- and starch-containing snacks tested in this study caused significant decreases in interproximal plaque pH. Chewing a sorbitol gum after ingestion of the snacks significantly reduced the demineralizing potential of the plaque. The chewing of sorbitol gum following the ingestion of snacks can be recommended as an adjunct to other caries-preventive oral hygiene measures.

  12. The rheological properties of tara gum (Caesalpinia spinosa).

    Science.gov (United States)

    Wu, Yanbei; Ding, Wei; Jia, Lirong; He, Qiang

    2015-02-01

    The rheological properties of tara gum, as affected by concentration, temperature, pH and the presence of salts and sucrose, were investigated by using steady and dynamic shear measurements and atomic force microscope observation. Tara gum exhibited non-Newtonian, pseudoplastic behaviour without thixotropy at tested concentrations (0.2-1.0%, w/v). Salts (CaCl2 and NaCl) led to a viscosity reduction, which was more sensitive to Ca(2+) than to Na(+). The gum had stable viscosity over a wide pH range (pH 3-11), and the influence of sucrose was concentration dependent. Increasing temperature from 20°C to 80°C decreased the gum viscosity. Frequency sweeps indicated that tara gum (1.0% w/v) behaved as a liquid at low frequency, and acted more like a gel at high frequency. With the decrease of concentration, tara gum may show a viscous property rather than an elastic one. These results are potentially useful for the application of tara gum in food processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Carboxymethylation of Cassia angustifolia seed gum: synthesis and rheological study.

    Science.gov (United States)

    Rajput, Gaurav; Pandey, I P; Joshi, Gyanesh

    2015-03-06

    The seeds of Cassia angustifolia are a rich source of galactomannan gum. The seed gums possess a wide variety of industrial applications. To utilize C. angustifolia seed gum for broader industrial applications, the carboxymethyl-Cassia angustifolia seed gum (CM-CAG) was synthesized. The gum was etherified with sodium monochloroacetate (SMCA) in a methanol-water system in presence of alkali (NaOH) at different reaction conditions. The variables studied includes alkali concentration, SMCA concentration, methanol:water ratio, liquor:gum ratio, reaction temperature and time. The extent of carboxymethylation was determined as degree of substitution (DS). The optimum conditions for preparing CM-CAG (DS=0.474) comprised 0.100 mol of NaOH, 0.05 mol of SMCA, 80% of methanol:water ratio (as % methanol) and liquor:gum ratio (v/w) of 10:1 at 75 °C for 60 min using 0.03 mol (as AGU) of CAG. Rheological studies showed CM-CAG to exhibit non-Newtonian pseudoplastic behaviour, relatively high viscosity, cold water solubility and solution stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

    Full Text Available The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.

  15. On the Inception of Financial Representative Bubbles

    Directory of Open Access Journals (Sweden)

    Massimiliano Ferrara

    2017-11-01

    Full Text Available In this work, we aim to formalize the inception of representative bubbles giving the condition under which they may arise. We will find that representative bubbles may start at any time, depending on the definition of a behavioral component. This result is at odds with the theory of classic rational bubbles, which are those models that rely on the fulfillment of the transversality condition by which a bubble in a financial asset can arise just at its first trade. This means that a classic rational bubble (differently from our model cannot follow a cycle since if a bubble exists, it will burst by definition and never arise again.

  16. Gum chewing modulates heart rate variability under noise stress.

    Science.gov (United States)

    Ekuni, Daisuke; Tomofuji, Takaaki; Takeuchi, Noriko; Morita, Manabu

    2012-12-01

    Gum chewing may relieve stress, although this hypothesis has not been proven. Heart-rate variability (HRV) is commonly used to measure stress levels. However, it is not known if gum chewing modulates HRV under acute stress. The aim of this study was to investigate the effects of gum chewing on HRV under acute stress. A cross-over study involving 47 non-smoking healthy subjects, aged 22-27 years, was carried out. The subjects received a stress procedure with gum chewing (GS group) and without gum chewing (S group). Additionally, the other 20 subjects were allocated to the gum chewing without stress group (G group). The GS and S groups were exposed to noise for 5 min (75 dBA) as stress. Before and after stress exposure/gum chewing, participants completed the state portion of the State-Trait Anxiety Inventory (STAI-s) and a single Stress Visual Analogue Scale (VAS) measurement. HRV measurement was performed before and during stress/gum chewing for 5 min. After the stress procedure, VAS score significantly increased in the GS and S groups. During the stress procedure, the GS group showed a significantly lower level of high frequency (HF) and higher levels of low frequency (LF) and LF/HF than the S group. However, there were no significant differences in the scores of the state portion of the State-Trait Anxiety Inventory (STAI-s) and VAS between the two stress groups. These findings suggest that gum chewing modulates HRV, but may not relieve acute stress caused by noise.

  17. Ethnic diversity deflates price bubbles.

    Science.gov (United States)

    Levine, Sheen S; Apfelbaum, Evan P; Bernard, Mark; Bartelt, Valerie L; Zajac, Edward J; Stark, David

    2014-12-30

    Markets are central to modern society, so their failures can be devastating. Here, we examine a prominent failure: price bubbles. Bubbles emerge when traders err collectively in pricing, causing misfit between market prices and the true values of assets. The causes of such collective errors remain elusive. We propose that bubbles are affected by ethnic homogeneity in the market and can be thwarted by diversity. In homogenous markets, traders place undue confidence in the decisions of others. Less likely to scrutinize others' decisions, traders are more likely to accept prices that deviate from true values. To test this, we constructed experimental markets in Southeast Asia and North America, where participants traded stocks to earn money. We randomly assigned participants to ethnically homogeneous or diverse markets. We find a marked difference: Across markets and locations, market prices fit true values 58% better in diverse markets. The effect is similar across sites, despite sizeable differences in culture and ethnic composition. Specifically, in homogenous markets, overpricing is higher as traders are more likely to accept speculative prices. Their pricing errors are more correlated than in diverse markets. In addition, when bubbles burst, homogenous markets crash more severely. The findings suggest that price bubbles arise not only from individual errors or financial conditions, but also from the social context of decision making. The evidence may inform public discussion on ethnic diversity: it may be beneficial not only for providing variety in perspectives and skills, but also because diversity facilitates friction that enhances deliberation and upends conformity.

  18. Modification mechanism of sesbania gum, and preparation, property, adsorption of dialdehyde cross-linked sesbania gum.

    Science.gov (United States)

    Tang, Hongbo; Gao, Shiqi; Li, Yanping; Dong, Siqing

    2016-09-20

    This paper studied the modification mechanism of Sesbania gum (SG) by means of the variations in the numbers of surface hydroxyl groups on the granules, Schiff's agent coloration of aldehyde groups, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), energy dispersive spectrum (EDS), etc., and also examined the preparation, property and adsorption of dialdehyde cross-linked sesbania gum (DCLSG). The results showed that the surface hydroxyl numbers of cross-linked sesbania gum (CLSG) decreased with increasing the cross-linking degree. The distribution of the aldehyde groups on the DCLSG particles was nonuniform because most of aldehyde groups mainly located on the edge of particles. The cross-linking occurred only on the surface of SG particles. The oxidization occurred not only on the surface of SG particles, but also in the interior of particles. The cross-linking or oxidization changed the thermal properties, and reduced the swelling power, viscosity, alkali and acid resistance of SG. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Electron beam irradiation effects on xanthan gum, rheological aspects

    International Nuclear Information System (INIS)

    Mastro, N.L. del; Vieira, F.F.

    2003-01-01

    Food ingredients to be used for food processing should be decontaminated in order to prevent food spoilage and food-borne diseases. Xanthan gum is a well-known microbial polysaccharide produced by Xanthomonas campestris used in the hydrocolloid market. This paper describes the application of electron beam (EB) irradiation to xanthan gum as used as ingredient by the food or cosmetics industry in order to establish their radiosensitivity. Viscosity of 1% xanthan gum solutions prepared with the irradiated powder decreased with the increase of the EB irradiation dose. The radiation-induced viscosity detriment of this additive must be considered for practical applications. (author)

  20. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva.

    Science.gov (United States)

    Moore, Michael; Hasler-Nguyen, Nathalie; Saroea, Geoffrey

    2008-08-11

    Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B) on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C) and human saliva (D). Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances) using the L*a*b scale: lightness (L*), red-green (a) and yellow-blue (b). Medicated chewing gums (A and B) removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C) had a milder whitening effect as evaluated by quantitative and qualitative assessment. The tested Nicotine Replacement Therapy (NRT) chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

  1. Rheological properties of grouts with viscosity modifying agents as diutan gum and welan gum incorporating pulverised fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed Sonebia [Queen' s University Belfast, Belfast (United Kingdom). School of Planning, Architecture and Civil Engineering

    2006-09-15

    This investigation was undertaken to evaluate the influence of the dosage of the second generation of viscosity modifying agent (diutan gum) on fluidity and rheological parameters of cement-based materials grout compared to welan gum. All grouts were made with 0.40 water-to-binder ratio (W/B). The fresh properties of control grouts made without any viscosity modifying agent (VMA) and with superplasticizer (SP) were compared to those of grouts made with 0.02, 0.04, 0.06 and 0.08% diutan gum by mass of binder. Similar mixes made with welan gum were compared to those containing diutan gums. The effect of admixtures on fluidity and rheological parameters are discussed in this paper. The effect of the replacement of cement by pulverised fly ash (PFA) was also investigated. Grouts with replacements of PFA of 5, 13 and 20% by mass were used with the same W/B. Similar control grouts and mixes incorporated different dosages of PFA made with welan gum were made in order to compare the fluidity and the rheological parameters to the previous grouts made with diutan gum.

  2. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    Directory of Open Access Journals (Sweden)

    Saroea Geoffrey

    2008-08-01

    Full Text Available Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C and human saliva (D. Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances using the L*a*b scale: lightness (L*, red-green (a and yellow-blue (b. Results Medicated chewing gums (A and B removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

  3. Hamiltonian description of bubble dynamics

    International Nuclear Information System (INIS)

    Maksimov, A. O.

    2008-01-01

    The dynamics of a nonspherical bubble in a liquid is described within the Hamiltonian formalism. Primary attention is focused on the introduction of the canonical variables into the computational algorithm. The expansion of the Dirichlet-Neumann operator in powers of the displacement of a bubble wall from an equilibrium position is obtained in the explicit form. The first three terms (more specifically, the second-, third-, and fourth-order terms) in the expansion of the Hamiltonian in powers of the canonical variables are determined. These terms describe the spectrum and interaction of three essentially different modes, i.e., monopole oscillations (pulsations), dipole oscillations (translational motions), and surface oscillations. The cubic nonlinearity is analyzed for the problem associated with the generation of Faraday ripples on the wall of a bubble in an acoustic field. The possibility of decay processes occurring in the course of interaction of surface oscillations for the first fifteen (experimentally observed) modes is investigated.

  4. Wired to freedom

    DEFF Research Database (Denmark)

    Jepsen, Kim Sune Karrasch; Bertilsson, Margareta

    2017-01-01

    dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...... new access to social life, continuous communicative challenges, common practices, and experiences. In looking at their lives as “wired to freedom,” we hope to promote a wider spectrum of civic participation in the benefit of future life science developments within and beyond the field of Cochlear...

  5. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  6. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  7. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  8. Bubble dynamics equations in Newton fluid

    International Nuclear Information System (INIS)

    Xiao, J

    2008-01-01

    For the high-speed flow of Newton fluid, bubble is produced and expanded when it moves toward the surface of fluid. Bubble dynamics is a very important research field to understand the intrinsic feature of bubble production and motion. This research formulates the bubble expansion by expansion-local rotation transformation, which can be calculated by the measured velocity field. Then, the related dynamic equations are established to describe the interaction between the fluid and the bubble. The research shows that the bubble production condition can be expressed by critical vortex value and fluid pressure; and the bubble expansion rate can be obtained by solving the non-linear dynamic equation of bubble motion. The results may help the related research as it shows a special kind of fluid motion in theoretic sense. As an application example, the nanofiber radium-voltage relation and threshold voltage-surface tension relation in electrospinning process are discussed

  9. Fluid dynamics of bubbly flows

    International Nuclear Information System (INIS)

    Ziegenhein, Thomas

    2016-01-01

    Bubbly flows can be found in many applications in chemical, biological and power engineering. Reliable simulation tools of such flows that allow the design of new processes and optimization of existing one are therefore highly desirable. CFD-simulations applying the multi-fluid approach are very promising to provide such a design tool for complete facilities. In the multi-fluid approach, however, closure models have to be formulated to model the interaction between the continuous and dispersed phase. Due to the complex nature of bubbly flows, different phenomena have to be taken into account and for every phenomenon different closure models exist. Therefore, reliable predictions of unknown bubbly flows are not yet possible with the multi-fluid approach. A strategy to overcome this problem is to define a baseline model in which the closure models including the model constants are fixed so that the limitations of the modeling can be evaluated by validating it on different experiments. Afterwards, the shortcomings are identified so that the baseline model can be stepwise improved without losing the validity for the already validated cases. This development of a baseline model is done in the present work by validating the baseline model developed at the Helmholtz-Zentrum Dresden-Rossendorf mainly basing on experimental data for bubbly pipe flows to bubble columns, bubble plumes and air-lift reactors that are relevant in chemical and biological engineering applications. In the present work, a large variety of such setups is used for validation. The buoyancy driven bubbly flows showed thereby a transient behavior on the scale of the facility. Since such large scales are characterized by the geometry of the facility, turbulence models cannot describe them. Therefore, the transient simulation of bubbly flows with two equation models based on the unsteady Reynolds-averaged Navier-Stokes equations is investigated. In combination with the before mentioned baseline model these

  10. Modification of Portland cement mortars with cactus gum

    OpenAIRE

    Hernandez-Zaragoza, Juan-Bosco; Caballero-Badillo, Carlos-Eduardo; Rosas-Juarez, Arnulfo; Lopez-Lara, Teresa; Hinojosa-Torres, Jaime; Castano, Victor-Manuel

    2007-01-01

    ????????, ?? ?????????? ??????? ?? ?????? ????????-???????, ??? ???????????????? ? ????????? ???????????, ???????????? ?????????? ?????????? ??????, ????????? ? ????????? ?????????????? ???????. ???????? ?????????? ???????? ??? ????????? ???????? ??? ????????? ?? 65 %, ????????? ?? ???????????? ?????????. Portland cement-based mortars of the standard type used for modern constructions, were modified by adding liophilized cactus gum, extracted froman indigenous Mexican cactus. The results show...

  11. Use of Natural Gums and Mucilages as Pharmaceutical Excipients.

    Science.gov (United States)

    Hamman, Hannlie; Steenekamp, Jan; Hamman, Josias

    2015-01-01

    Polysaccharide rich gums and mucilages are produced by different natural sources such as plants, animals and microbial organisms to fulfil structural and physiological functions. Their diverse structural compositions with a broad range of physicochemical properties make them useful for inclusion in dosage forms for different purposes such as to improve manufacturing processes and/or to facilitate drug delivery. A number of natural gums and mucilages have been investigated for inclusion in pharmaceutical formulations for a variety of reasons. The search for new excipients continues to be an active topic in dosage form design and drug delivery research. The aim of this review article is to give an overview of the chemical nature of natural gums and mucilages and to discuss their applications in the formulation of pharmaceutical dosage forms. Special emphasis will be placed on the use of gums and mucilages in novel drug delivery systems, such as modified release dosage forms and delivery systems that target specific sites of delivery.

  12. Ask a Periodontist (Frequently Asked Questions about Gum Disease)

    Science.gov (United States)

    ... doing their job. Periodontists may also correct gum recession and cover up exposed root surfaces which can ... seeing a periodontist for a consultation is a great first step. There are a few ways to ...

  13. Studies on some Physicochemical Properties of the Plant Gum ...

    African Journals Online (AJOL)

    A. senegal, A. sieberiana and A. nilotica) in Batagarawa, Katsina State, were determined and compared. Data generated from the study confirm that there are a number of physicochemical differences between the gum exudates.

  14. Physicochemical and functional parameters of Cochlospermum vitifolium (bototo gum exudate

    Directory of Open Access Journals (Sweden)

    Maritza Coromoto Martínez

    2016-12-01

    Full Text Available The physicochemical parameters of Cochlospermum vitifolium they were evaluated and were linked to certain functional properties of industrial interest. The physicochemical parameters were determined by the classic methodology used for carbohydrates and the functional properties, as reported in the literature. The results obtained showed that the gum object of this study is low soluble in water, which corresponds with relatively high values of swelling indexes and water absorption capacity. Also, the intrinsic viscosity of the C. vitifolium exudate was related to a high molar mass, in the order of 106. Its emulsifying capacity is high, which is attributed to hydrophobic groups present in its structure. The gum gels at a minimum concentration, similar to that of the gum karaya (4.5%, but the gel that forms agglomerates, it is not uniform. The C. vitifolium gum exhibits important physicochemical and functional parameters which could serve as a criterion for testing its use in various industries.

  15. Oxidation of cashew tree gum exudate polysaccharide with TEMPO reagent

    OpenAIRE

    Cunha, Pablyana L. R.; Maciel, Jeanny S.; Sierakowski, Maria Rita; Paula, Regina C. M. de; Feitosa, Judith P. A.

    2007-01-01

    Cashew gum (CG), an exudate polysaccharide from Anacardium ocidentale trees, was oxidized with TEMPO reagent and the 7product (CGOX) characterized by spectroscopic techniques (FT-IR and NMR), chromatographic analyses (HPLC and GPC), viscosity measurements and thermal analysis (TGA). The yield of the reaction product was 96%. The uronic acid content in starting gum (7.2 m%) was increased to 36 m%. The degree of oxidation based on free galactose and glucose units was 68%. NMR data show that oxi...

  16. Natural polymers, gums and mucilages as excipients in drug delivery.

    Science.gov (United States)

    Kumar, Shobhit; Gupta, Satish Kumar

    2012-01-01

    Use of natural polymers, gums and mucilages in drug delivery systems has been weighed down by the synthetic materials. Natural based excipients offered advantages such as non-toxicity, less cost and abundantly availablity. Aqueous solubility of natural excipients plays an important role in their selection for designing immediate, controlled or sustained release formulations. This review article provide an overview of natural gum, polymers and mucilages as excipients in dosage forms as well as novel drug delivery systems.

  17. Extraction and characterization of artocarpus integer gum as pharmaceutical excipient.

    Science.gov (United States)

    Farooq, Uzma; Malviya, Rishabha; Sharma, Pramod Kumar

    2014-01-01

    Natural polymers are widely used as excipients in pharmaceutical formulations. They are easily available, cheap and less toxic as compared to synthetic polymers. This study involves the extraction and characterization of kathal (Artocarpus integer) gum as a pharmaceutical excipient. Water was used as a solvent for extraction of the natural polymer. Yield was calculated with an aim to evaluate the efficacy of the process. The product was screened for the presence of Micrometric properties, and swelling index, flow behavior, surface tension, and viscosity of natural polymers were calculated. Using a water based extraction method, the yield of gum was found to be 2.85%. Various parameters such as flow behavior, organoleptic properties, surface tension, viscosity, loss on drying, ash value and swelling index together with microscopic studies of particles were done to characterize the extracted gum. The result showed that extracted kathal gum exhibited excellent flow properties. The gum was investigated for purity by carrying out chemical tests for different phytochemical constituents and only carbohydrates were found to be present. It had a good swelling index (13 ± 1). The pH and surface tension of the 1% gum solution were found to be 6 ± 0.5 and 0.0627 J/m2, respectively. The ash values such as total ash, acid insoluble ash, and water soluble ash were found to be 18.9%, 0.67% and 4% respectively. Loss on drying was 6.61%. The extracted gum was soluble in warm water and insoluble in organic solvents. The scanning electron micrograph (SEM) revealed rough and irregular particles of the isolated polymer. The results of the evaluated properties showed that kathal-derived gum has acceptable pH and organoleptic properties and can be used as a pharmaceutical excipient to formulate solid oral dosage forms.

  18. Xylitol Chewing Gums on the Market: Do They Prevent Caries?

    Science.gov (United States)

    Alanzi, Abrar; Soderling, Eva; Varghese, Anisha; Honkala, Eino

    To measure the xylitol content in sugar-free chewing gums available on the market in Gulf Cooperation Council (GCC) countries in the Middle East, in order to identify those products that can provide the recommended daily dose of xylitol for caries prevention (6-7 g). Acid production from chewing gums was also measured in vitro and in vivo. Twenty-one chewing gums containing xylitol were identified and collected from the GCC market (Kuwait, Bahrain, Qatar, Saudi Arabia, UAE and Oman). Xylitol was extracted and its concentration was analysed using a special enzymatic kit. The pH of extracts was measured during 30-min incubation with Streptococcus mutans. Changes in saliva and plaque pH were noted in four subjects after the consumption of highly concentrated xylitol gums. The xylitol content in grams was clearly mentioned only on one product's label. Twelve products stated the percentage of xylitol (3.5% to 35%). The rest did not specify the amount. The mean measured weight of one piece of gum was 1.67 ± 0.38 g. The mean measured xylitol content/piece was 0.33 ± 0.21 g. Xylitol content was 0.5 g in 5 products. None of the highly concentrated xylitol gums showed a pH drop in vitro or in vivo. One chewing gum, containing xylitol and glucose, resulted in a low pH level (xylitol chewing gums sold on the GCC market do not provide the consumers with the recommended daily dose of xylitol for caries prevention. Clear, accurate labeling is recommended.

  19. Computing bubble-points of CO

    NARCIS (Netherlands)

    Ramdin, M.; Balaji, S.P.; Vicent Luna, J.M.; Torres-Knoop, A; Chen, Q.; Dubbeldam, D.; Calero, S; de Loos, T.W.; Vlugt, T.J.H.

    2016-01-01

    Computing bubble-points of multicomponent mixtures using Monte Carlo simulations is a non-trivial task. A new method is used to compute gas compositions from a known temperature, bubble-point pressure, and liquid composition. Monte Carlo simulations are used to calculate the bubble-points of

  20. Mechanics of gas-vapor bubbles

    NARCIS (Netherlands)

    Hao, Yue; Zhang, Yuhang; Prosperetti, Andrea

    2017-01-01

    Most bubbles contain a mixture of vapor and incondensible gases. While the limit cases of pure vapor and pure gas bubbles are well studied, much less is known about the more realistic case of a mixture. The bubble contents continuously change due to the combined effects of evaporation and

  1. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  2. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  3. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  4. Command Wire Sensor Measurements

    Science.gov (United States)

    2012-09-01

    CFAR Constant False Alarm Rate CWIE Command Wire-Improvised Explosive Device EMI Electromagnetic Induction GPR Ground Penetrating Radar...this, some type of constant false alarm rate ( CFAR ) receiver is required. CFAR automatically raises the threshold level to keep clutter echoes and

  5. Transport in quantum wires

    Indian Academy of Sciences (India)

    Transport in quantum wires. SIDDHARTHA LAL, SUMATHI RAO£ and DIPTIMAN SEN. Centre for Theoretical Studies, Indian Institute of Science, Bangalore 560 012, India. £ Harish-chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India. Abstract. With a brief introduction to one-dimensional channels ...

  6. Wire chamber conference

    International Nuclear Information System (INIS)

    Bartl, W.; Neuhofer, G.; Regler, M.

    1986-02-01

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  7. GumTree-An integrated scientific experiment environment

    International Nuclear Information System (INIS)

    Lam, Tony; Hauser, Nick; Goetz, Andy; Hathaway, Paul; Franceschini, Fredi; Rayner, Hugh; Zhang, Lidia

    2006-01-01

    GumTree is an open source and multi-platform graphical user interface for performing neutron scattering and X-ray experiments. It handles the complete experiment life cycle from instrument calibration, data acquisition, and real time data analysis to results publication. The aim of the GumTree Project is to create a highly Integrated Scientific Experiment Environment (ISEE), allowing interconnectivity and data sharing between different distributed components such as motors, detectors, user proposal database and data analysis server. GumTree is being adapted to several instrument control server systems such as TANGO, EPICS and SICS, providing an easy-to-use front-end for users and simple-to-extend model for software developers. The design of GumTree is aimed to be reusable and configurable for any scientific instrument. GumTree will be adapted to six neutron beam instruments for the OPAL reactor at ANSTO. Other European institutes including ESRF, ILL and PSI have shown interest in using GumTree as their workbench for instrument control and data analysis

  8. Characterization of Grewia Gum, a Potential Pharmaceutical Excipient

    Directory of Open Access Journals (Sweden)

    Elijah.I.Nep

    2010-03-01

    Full Text Available Grewia gum was extracted from the inner stem bark of Grewia mollis and characterized by several techniques such as gas chromatography (GC, gel permeation chromatography (GPC, scanning electron microscopy (SEM, differential scanning calorimetry (DSC and thermogravimetric analysis of the extracted sample. Spectroscopic techniques such as x-ray photoelectron spectroscopy (XPS, fourier-transformed infrared (FT-IR, solid-state nuclear magnetic resonance (NMR, and 1H and 13C NMR techniques were also used to characterize the gum. The results showed that grewia gum is a typically amorphous polysaccharide gum containing glucose, rhamnose, galactose, arabinose and xylose as neutral sugars. It has an average molecular weight of 5925 kDa expressed as the pullulan equivalent. The gum slowly hydrated in water, dispersing and swelling to form a highly viscous dispersion exhibiting pseudoplastic flow behaviour. The polysaccharide gum is thermally stable and may have application as stabilizer or suspending agent in foods, cosmetics and in pharmaceuticals. It may have application as a binder or sustained-release polymer matrix in tablets or granulations.

  9. Fabrication and characterization of gum Arabic bonded Rhizophora spp. particleboards

    International Nuclear Information System (INIS)

    Abuarra, Ali; Hashim, Rokiah; Bauk, Sabar; Kandaiya, Sivamany; Tousi, Ehsan Taghizadeh

    2014-01-01

    Highlights: • Exploring gum Arabic as a binder for Rhizophora sp. particleboards. • The addition of gum Arabic improved overall properties. • Gum Arabic could be added to manufacture particleboards. - Abstract: Gum Arabic (GA) was used as a binder for the fabrication of Rhizophora spp. particleboards. The physical and mechanical properties of the bioadhesive bonded particleboards, including moisture content, internal bond (IB) strength, thickness swelling (TS), water absorption (WA) and field-emission scanning electron microscopy (FESEM) were used to characterize the manufactured particleboards. Three different particle sizes of the Rhizophora spp. with four adhesive levels were utilized. Results revealed that the addition of GA into the particleboards noticeably improved panel overall properties. The GA bonded particleboards resulted in smoother surfaces, more rigid texture and better internal bonding strength compared to binderless particleboards made without using any adhesive. All specimens had internal bond strength of more than the minimum requirement of the Japanese Industrial Standard JIS A-5908 Type-8 of 0.15 N/mm 2 and were noticed to increase by increasing the adhesive level. However the GA bonded particleboards had higher percentage of WA and the TS compared with the binderless boards. Microscopic study also revealed that particleboards bonded with the gum had better contact compared to the binderless boards. Based on these results, it could be concluded that gum Arabic is an effective natural substance that could be added to manufacture particleboards to improve some of panels’ physical and mechanical properties

  10. Oxidized Xanthan Gum and Chitosan as Natural Adhesives for Cork

    Directory of Open Access Journals (Sweden)

    Diana Paiva

    2016-07-01

    Full Text Available Natural cork stopper manufacturing produces a significant amount of cork waste, which is granulated and combined with synthetic glues for use in a wide range of applications. There is a high demand for using biosourced polymers in these composite materials. In this study, xanthan gum (XG and chitosan (CS were investigated as possible natural binders for cork. Xanthan gum was oxidized at two different aldehyde contents as a strategy to improve its water resistance. This modification was studied in detail by 1H and 13C nuclear magnetic resonance (NMR, and the degree of oxidation was determined by the hydroxylamine hydrochloride titration method. The performance of the adhesives was studied by tensile tests and total soluble matter (TSM determinations. Xanthan gum showed no water resistance, contrary to oxidized xanthan gum and chitosan. It is hypothesized that the good performance of oxidized xanthan gum is due to the reaction of aldehyde groups—formed in the oxidation process—with hydroxyl groups on the cork surface during the high temperature drying. Combining oxidized xanthan gum with chitosan did not yield significant improvements.

  11. Droplets, Bubbles and Ultrasound Interactions

    NARCIS (Netherlands)

    Shpak, O.; Verweij, M.; de Jong, N.; Versluis, Michel; Escoffre, J.M.; Bouakaz, A.

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to

  12. Electrolysis Bubbles Make Waterflow Visible

    Science.gov (United States)

    Schultz, Donald F.

    1990-01-01

    Technique for visualization of three-dimensional flow uses tiny tracer bubbles of hydrogen and oxygen made by electrolysis of water. Strobe-light photography used to capture flow patterns, yielding permanent record that is measured to obtain velocities of particles. Used to measure simulated mixing turbulence in proposed gas-turbine combustor and also used in other water-table flow tests.

  13. Impurity bubbles in a BEC

    Science.gov (United States)

    Timmermans, Eddy; Blinova, Alina; Boshier, Malcolm

    2013-05-01

    Polarons (particles that interact with the self-consistent deformation of the host medium that contains them) self-localize when strongly coupled. Dilute Bose-Einstein condensates (BECs) doped with neutral distinguishable atoms (impurities) and armed with a Feshbach-tuned impurity-boson interaction provide a unique laboratory to study self-localized polarons. In nature, self-localized polarons come in two flavors that exhibit qualitatively different behavior: In lattice systems, the deformation is slight and the particle is accompanied by a cloud of collective excitations as in the case of the Landau-Pekar polarons of electrons in a dielectric lattice. In natural fluids and gases, the strongly coupled particle radically alters the medium, e.g. by expelling the host medium as in the case of the electron bubbles in superfluid helium. We show that BEC-impurities can self-localize in a bubble, as well as in a Landau-Pekar polaron state. The BEC-impurity system is fully characterized by only two dimensionless coupling constants. In the corresponding phase diagram the bubble and Landau-Pekar polaron limits correspond to large islands separated by a cross-over region. The same BEC-impurity species can be adiabatically Feshbach steered from the Landau-Pekar to the bubble regime. This work was funded by the Los Alamos LDRD program.

  14. Neutron Detection via Bubble Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, David V.; Ely, James H.; Peurrung, Anthony J.; Bond, Leonard J.; Collar, J. I.; Flake, Matthew; Knopf, Michael A.; Pitts, W. K.; Shaver, Mark W.; Sonnenschein, Andrew; Smart, John E.; Todd, Lindsay C.

    2005-10-06

    The results of a Pacific Northwest National Laboratory (PNNL) exploratory research project investigating the feasibility of fast neutron detection using a suitably prepared and operated, pressure-cycled bubble chamber are described. The research was conducted along two parallel paths. Experiments with a slow pressure-release Halon chamber at the Enrico Fermi Institute at the University of Chicago showed clear bubble nucleation sensitivity to an AmBe neutron source and insensitivity to the 662 keV gammas from a 137Cs source. Bubble formation was documented via high-speed (1000 frames/sec) photography, and the acoustic signature of bubble formation was detected using a piezo-electric transducer element mounted on the base of the chamber. The chamber’s neutron sensitivity as a function of working fluid temperature was mapped out. The second research path consisted of the design, fabrication, and testing of a fast pressure-release Freon-134a chamber at PNNL. The project concluded with successful demonstrations of the PNNL chamber’s AmBe neutron source sensitivity and 137Cs gamma insensitivity. The source response tests of the PNNL chamber were documented with high-speed photography.

  15. Soliton bubbles and phase transformations

    International Nuclear Information System (INIS)

    Masperi, L.

    1989-01-01

    It is shown that no topological classical solutions in form of bubbles of a real scalar field theory with Lagrangian of quartet and sextet self interactions in 1+1 dimensions are responsible to discontinue transitions in the quantum problem between phases with degenerated and disordered excited level. (M.C.K.)

  16. Models of cylindrical bubble pulsation.

    Science.gov (United States)

    Ilinskii, Yurii A; Zabolotskaya, Evgenia A; Hay, Todd A; Hamilton, Mark F

    2012-09-01

    Three models are considered for describing the dynamics of a pulsating cylindrical bubble. A linear solution is derived for a cylindrical bubble in an infinite compressible liquid. The solution accounts for losses due to viscosity, heat conduction, and acoustic radiation. It reveals that radiation is the dominant loss mechanism, and that it is 22 times greater than for a spherical bubble of the same radius. The predicted resonance frequency provides a basis of comparison for limiting forms of other models. The second model considered is a commonly used equation in Rayleigh-Plesset form that requires an incompressible liquid to be finite in extent in order for bubble pulsation to occur. The radial extent of the liquid becomes a fitting parameter, and it is found that considerably different values of the parameter are required for modeling inertial motion versus acoustical oscillations. The third model was developed by V. K. Kedrinskii [Hydrodynamics of Explosion (Springer, New York, 2005), pp. 23-26] in the form of the Gilmore equation for compressible liquids of infinite extent. While the correct resonance frequency and loss factor are not recovered from this model in the linear approximation, it provides reasonable agreement with observations of inertial motion.

  17. "Financial Bubbles" and Monetary Policy

    Science.gov (United States)

    Tikhonov, Yuriy A.; Pudovkina, Olga E.; Permjakova, Juliana V.

    2016-01-01

    The relevance of this research is caused by the need of strengthening a role of monetary regulators to prevent financial bubbles in the financial markets. The aim of the article is the analysis of a problem of crisis phenomena in the markets of financial assets owing to an inadequate growth of their cost, owing to subjective reasons. The leading…

  18. Axial stability of Taylor bubbles

    NARCIS (Netherlands)

    Lu, X.; Prosperetti, Andrea

    2006-01-01

    Long gas bubbles rising in a vertical tube are observed to lose axial symmetry and become unstable in a downward liquid flow. In this paper an approximate linear stability analysis of this phenomenon is presented. It is found that, under the combined effect of gravity and the pressure gradient which

  19. Effect of guar and xanthan gums on functional properties of mango (Mangifera indica) kernel starch.

    Science.gov (United States)

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid

    2016-12-01

    The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Bubble fusion: fact or fiction?

    Energy Technology Data Exchange (ETDEWEB)

    Pennicott, Katie

    2002-04-01

    Physicists in the US claim to have seen nuclear fusion in a table-top experiment but their work has met with a hostile reaction from other researchers. In sonoluminescence, flashes of light are emitted by bubbles that are forced to expand and then collapse by sound waves, although this process is still not fully understood (see Physics World May 1998 pp38-42, print version). Physicists have long speculated that the considerable compression forces inside the collapsing bubbles could be large enough to spark nuclear reactions. If this was the case, it could lead to a new source of clean energy. In their experiment, Taleyarkhan and co-workers at Oak Ridge, the Rensselaer Polytechnic Institute in the US, and the Russian Academy of Sciences used 14 MeV neutrons to create bubbles about 10 nano metres across in acetone in which the ordinary hydrogen atoms had been replaced by deuterium atoms (C{sub 3}D{sub 6O}). An acoustic signal then forced these bubbles - and the acetone vapour inside them - to first expand to about a millimetre in size, and then collapse. Two deuterium nuclei can fuse to produce either a tritium nucleus and a proton, or a helium-3 nucleus and a neutron with an energy of 2.45 MeV. Taleyarkhan and co-workers claim to have seen evidence for both tritium and 2.45 MeV neutrons in their experiments. They have also calculated that temperatures of a million or even 10 million degrees - the temperature at the Sun's core - must have existed inside the bubbles for these reactions to proceed. Some other experiments and the controversy discussions of the researchers are summarized. (U.K.)

  1. Hydrodynamics in a swarm of rising bubbles

    International Nuclear Information System (INIS)

    Riboux, G.

    2007-04-01

    In many applications, bubbles are used to agitate a liquid in order to enhance mixing and transfer. This work is devoted to the study of the hydrodynamics in a stable bubble column. Experimentally, we have determined the properties of the velocity fluctuations inside and behind a homogeneous swarm of rising bubbles for different bubble sizes and gas volume fractions α: self-similarity in α 0,4 , spectrum in k -3 and integral length scale controlled by buoyancy. Numerically, we have reproduced these properties by means of large-scale simulations, the bubbles being modeled by volume-forces. This confirms that the dynamics is controlled by wake interactions. (author)

  2. Bubble Universe Dynamics After Free Passage

    Energy Technology Data Exchange (ETDEWEB)

    Ahlqvist, Pontus [Department of Physics, Columbia University, New York, New York 10027 (United States); Eckerle, Kate [Department of Applied Mathematics, Columbia University, New York, New York 10027 (United States); Greene, Brian [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2015-03-06

    We consider bubble collisions in single scalar field theories with multiple vacua. Recent work has argued that at sufficiently high impact velocities, collisions between such bubble vacua are governed by ‘free passage’ dynamics in which field interactions can be ignored during the collision, providing a systematic process for populating local minima without quantum nucleation. We focus on the time period that follows the bubble collision and provide evidence that, for certain potentials, interactions can drive significant deviations from the free-passage bubble profile, thwarting the production of bubbles with different field values.

  3. Lidar signature from bubbles in the sea.

    Science.gov (United States)

    Churnside, James H

    2010-04-12

    The lidar signature from a collection of bubbles is proportional to the volume backscatter coefficient at a scattering angle of 180 degrees . This quantity, calculated using a combination of geometric optics and diffraction, is proportional to the void fraction of the bubbles in the water for any bubble size distribution. The constant of proportionality is 233 m(-1) sr(-1)for clean bubbles, slightly less for bubbles coated with a thin layer of organic material, and as large as 1445 m(-1) sr(-1) for a thick coating of protein.

  4. Solar drying of uruguayan red gum

    Directory of Open Access Journals (Sweden)

    Andrés Ono

    2011-04-01

    Full Text Available he use of solar energy as an alternative to non-renewable energy sources has been widely researched in the last decades. Compared to air drying, solar drying kilns can better control the drying process, resulting in a higher quality of the dry wood and lower final wood moisture content values. Investment and running costs for a solar drying kiln are lower than those of a conventional kiln. Moreover, the solar drying process can be advantageous for drying hardwoods which are traditionally considered difficult to dry such as eucalyptus wood of medium and high density (Red gums, known in Spanish as “Eucaliptos colorados”. The solar drying kiln naturally incorporates a daily high relative humidity period that can be similar to a conditioning or steaming step, although at a lower temperature.This results in fewer defects due to the drying process.A pilot scale 2.5 m3 semi-greenhouse type solar wood drying kiln was constructed at LATU (Uruguay Technological Laboratory in Montevideo, Uruguay. The operating conditions and the results from two drying runs are presented. Two species of red gum (Eucalyptus tereticornis Sm., ADD 870 kg/m3, and Eucalyptus camaldulensis Dehnh., ADD 800 kg/m3 were dried from initial average moisture contents (WMC of around 60% down to 10.0% and 12.7% in 108 days and 76 days, respectively. Boards were provided by the Grupo Forestal San Gregorio from trees harvested at Tacuarembo and Paysandu Departments from cattle shelter forests 60 and 70 years old.Mean volume shrinkage was 18% for E. tereticornis, and 16% for E. camaldulensis, and the level of defects was moderate. Residual stresses and moisture content gradients were observed for both species. Final moisture content values were similar compared to those obtained in conventional drying kilns but with longer drying periods and lower operating costs. This would make the solar drying process attractive to small and medium sized forest products industries in a small country

  5. Analytical studies on the gum exudate from Anogeissus leiocarpus

    International Nuclear Information System (INIS)

    Ahmed, Samia Eltayeb

    1999-04-01

    Anogeissus leiocarpus gum samples were collected as natural exudate nodules, from three different location. Physicochemical properties of gum samples were studied. results showed significant differences within each location in most parameters studied except refractive index value which was found to be constant in all samples. The effect of location on the properties of gum samples was also studied and the analysis of variance showed insignificant differences (P≤0.05) in all properties studied except in ash content. Inter nodule variations of gum from two different location were studied individually. Results showed significant differences for each parameter studied except for the refractive index value. The properties studied of all gum samples were as follows: 9.2% moisture, 3.4% ash, 0.72% nitrogen, 4.74% protein, -35.5 specific rotation, 1.68 relative viscosity, 4.2 pH, 1.334 refractive index, 14.3 uronic acid, 0.44% reducing sugar, 1336.0 equivalent weight and 0.68% tannin content. UV absorption spectra of gum samples and gum nodules were determined. Cationic composition of gum samples was also determined and the results showed that (Mg) has highest value in all samples studied followed by Fe, Na, K, Ca, Zn and trace amount of Mn, Co, Ni, Cd and Pb. The water holding capacity was found to be 65.5% and emulsifying stability was found to be 1.008. The component sugars of gum were examined by different methods followed by qualitative and quantitative analysis. Analysis of hydrolysate crude gum sample by HPLC show L-rhamnose (6.82), L-arabinose (48.08), D-galactose (11.26) and two unknown oligosaccharides having values (0.22 and 32.61). Some physicochemical properties were studied. Results showed significant differences in nitrogen and protein contents, specific rotation, relative viscosity, equivalent weight and pH of fractions, where as insignificant differences were observed in uronic acid content and refractive index values

  6. An equation of motion for bubble growth

    International Nuclear Information System (INIS)

    Lesage, F.J.; Cotton, J.S.; Robinson, A.J.

    2009-01-01

    A mathematical model is developed which describes asymmetric bubble growth, either during boiling or bubble injection from submerged orifices. The model is developed using the integral form of the continuity and momentum equations, resulting in a general expression for the acceleration of the bubble's centre of gravity. The proposed model highlights the need to include acceleration due to an asymmetric gain or loss of mass in order to accurately predict bubble motion. Some scenarios are posed by which the growth of bubbles, particularly idealized bubbles that remain a section of a sphere, must include the fact that bubble growth can be asymmetric. In particular, for approximately hemispherical bubble growth the sum of the forces acting on the bubble is negligible compared with the asymmetric term. Further, for bubble injection from a submerged needle this component in the equation of motion is very significant during the initial rapid growth phase as the bubble issues from the nozzle changing from a near hemisphere to truncated sphere geometry. (author)

  7. Agitation, Mixing, and Transfers Induced by Bubbles

    Science.gov (United States)

    Risso, Frédéric

    2018-01-01

    Bubbly flows involve bubbles randomly distributed within a liquid. At large Reynolds number, they experience an agitation that can combine shear-induced turbulence (SIT), large-scale buoyancy-driven flows, and bubble-induced agitation (BIA). The properties of BIA strongly differ from those of SIT. They have been determined from studies of homogeneous swarms of rising bubbles. Regarding the bubbles, agitation is mainly caused by the wake-induced path instability. Regarding the liquid, two contributions must be distinguished. The first one corresponds to the anisotropic flow disturbances generated near the bubbles, principally in the vertical direction. The second one is the almost isotropic turbulence induced by the flow instability through a population of bubbles, which turns out to be the main cause of horizontal fluctuations. Both contributions generate a k‑3 spectral subrange and exponential probability density functions. The subsequent issue will be to understand how BIA interacts with SIT.

  8. The deformation of 'Gum Metal' in nanoindentation

    International Nuclear Information System (INIS)

    Withey, E.; Jin, M.; Minor, A.; Kuramoto, S.; Chrzan, D.C.; Morris, J.W.

    2008-01-01

    'Gum Metal' describes a newly developed set of alloys with nominal composition Ti-24(Nb + V + Ta)-(Zr,Hf)-O. In the cold-worked condition these alloys have exceptional elastic elongation and high-strength; the available evidence suggests that they do not yield until the applied stress approaches the ideal strength of the alloy, and then deform by mechanisms that do not involve conventional crystal dislocations. The present paper reports research on the nanoindentation of this material in both the cold-worked and annealed conditions. Nanoindentation tests were conducted in situ in a transmission electron microscope (TEM) stage that allows the deformation process to be observed in real time, and ex situ in a Hysitron nanoindenter, with samples subsequently extracted for high-resolution TEM study. The results reveal unusual deformation patterns beneath the nanoindenter that are, to our knowledge, unique to this material. In the cold-worked alloy deformation is confined to the immediate neighborhood of the indentation, with no evidence of dislocation, twin or fault propagation into the bulk. The deformed volume is highly inhomogeneous; the deformation is accomplished by a series of incremental rotations that are ordinarily resolved into discrete nanodomains. The annealed material deforms in a similar way within the nanoindentation pit, but dislocations emanate from the pit boundary. These are pinned by microstructural barriers only a few nanometers apart, a condition that recent theory suggests is necessary for the material to achieve ideal strength

  9. Dental Arch Wire

    Science.gov (United States)

    1979-01-01

    Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

  10. Wire chamber gases

    International Nuclear Information System (INIS)

    Va'vra, J.

    1992-04-01

    In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging

  11. Vienna Wire Chamber Conference

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    After those of 1978 and 1980, a third Wire Chamber Conference was held from 15-18 February in the Technical University of Vienna. Eight invited speakers covered the field from sophisticated applications in biology and medicine, via software, to the state of the art of gaseous detectors. In some forty other talks the speakers tackled in more detail the topics of gaseous detectors, calorimetry and associated electronics and software

  12. Flavor improvement does not increase abuse liability of nicotine chewing gum.

    Science.gov (United States)

    Houtsmuller, Elisabeth J; Fant, Reginald V; Eissenberg, Thomas E; Henningfield, Jack E; Stitzer, Maxine L

    2002-06-01

    Because the taste of nicotine gum has impeded compliance with dosing recommendations, nicotine gum with improved taste (mint, orange) was developed and marketed. Prior to marketing, the Food and Drug Administration (FDA) required a rigorous abuse liability assessment to examine whether enhanced palatability of nicotine gum would increase its abuse liability. Subjective, physiological, and psychomotor effects of mint flavor and original nicotine gum were tested in adult smokers (22-55 years old); a group of younger subjects (18-21 years old) was also included to allow for assessment of abuse liability in young adults specifically. Amphetamine and confectionery gum served as positive controls for abuse liability and palatability. Subjects rated palatability of mint gum higher than original nicotine gum, but substantially lower than confectionery gum. Palatability decreased with increasing dose of nicotine. Neither original nor mint gum increased ratings of traditional abuse liability predictors [Good Effect, Like Effect, Morphine-Benzedrine Group (MBG) scales of Addiction Research Center Inventory (ARCI)], while amphetamine increased ratings of all these measures. Both flavors of nicotine gum decreased craving during 2 h of abstinence. These effects were more pronounced in the adult group and mint gum was more effective than original gum. Younger subjects reported fewer withdrawal symptoms and lower ratings for drug effects and flavor. Improved flavor of nicotine gum does not increase abuse liability, but may be associated with enhanced craving reduction.

  13. Physicochemical properties of cissus gum powder extracted with the aid of edible starches.

    Science.gov (United States)

    Iwe, M O; Obaje, P O; Akpapunam, M A

    2004-01-01

    Gum powder was extracted from the stem and root of the cissus (Cissus populnea Guill and perr Ampelidacae) plant using water. Extraction was facilitated by the incorporation of 25-50% edible starches of sweet cassava, sweet potato, and maize. Dry samples were milled and sieved through a 250-microm sieve. Proximate and physicochemical properties of the gum samples were determined using standard methods. Results of the proximate analyses showed that protein and ash contents of the root gum were appreciably higher than those of the stem gum. Values of the crude fiber and ether extract of the root gum were lower than those of the stem gum. Inclusion of edible starches in the extraction process appreciably lowered proximate values. Results of the physicochemical properties showed that cissus gum samples did not form true gel but a "putty-like" mass. Addition of starches at various levels did not alter the characteristic putty-like nature of the gum. The gum samples had a remarkably low oil absorption capacity. Cissus gum samples had appreciably higher emulsion capacity and stability than the samples containing starch. The pH of the cissus gum powder and those of the starch-containing samples lie in the low-acid range (5.69-6.49). Cissus gum samples were highly hygroscopic; however, the addition of starch lowered the hygroscopicity. Incorporation of 25% starch into cissus mucilage enhanced extraction of the gum without adverse alteration of the physicochemical properties.

  14. Bubble entrapment through topological change

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2010-05-03

    When a viscousdrop impacts onto a solid surface, it entraps a myriad of microbubbles at the interface between liquid and solid. We present direct high-speed video observations of this entrapment. For viscousdrops, the tip of the spreading lamella is separated from the surface and levitated on a cushion of air. We show that the primary mechanism for the bubble entrapment is contact between this precursor sheet of liquid with the solid and not air pulled directly through cusps in the contact line. The sheet makes contact with the solid surface,forming a wetted patch, which grows in size, but only entraps a bubble when it meets the advancing contact line. The leading front of this wet patch can also lead to the localized thinning and puncturing of the liquid film producing strong splashing of droplets.

  15. BEBC Big European Bubble Chamber

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  16. Informational pathologies and interest bubbles

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Wiewiura, Joachim Schmidt

    2017-01-01

    This article contends that certain configurations of information networks facilitate specific cognitive states that are instrumental for decision and action on social media. Group-related knowledge and belief states—in particular common knowledge and pluralistic ignorance—may enable strong public...... signals. Indeed, some network configurations and attitude states foster informational pathologies that may fuel interest bubbles affecting agenda-setting and the generation of narratives in public spheres....

  17. A NEW SPECIES OF INVASIVE GALL WASP (HYMENOPTERA: EULOPHIDAE: TETRASTICHINAE) ON BLUE GUM (EUCALYPTUS GLOBULUS) IN CALIFORNIA

    Science.gov (United States)

    The blue gum gall wasp, Selitrichodes globulus La Salle & Gates (Hymenoptera: Eulophidae: Tetrastichinae), is described as an invasive gall inducer on blue gum, Eucalyptus globulus (Myrtaceae), in California....

  18. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  19. Soap bubbles in paintings: Art and science

    Science.gov (United States)

    Behroozi, F.

    2008-12-01

    Soap bubbles became popular in 17th century paintings and prints primarily as a metaphor for the impermanence and fragility of life. The Dancing Couple (1663) by the Dutch painter Jan Steen is a good example which, among many other symbols, shows a young boy blowing soap bubbles. In the 18th century the French painter Jean-Simeon Chardin used soap bubbles not only as metaphor but also to express a sense of play and wonder. In his most famous painting, Soap Bubbles (1733/1734) a translucent and quavering soap bubble takes center stage. Chardin's contemporary Charles Van Loo painted his Soap Bubbles (1764) after seeing Chardin's work. In both paintings the soap bubbles have a hint of color and show two bright reflection spots. We discuss the physics involved and explain how keenly the painters have observed the interaction of light and soap bubbles. We show that the two reflection spots on the soap bubbles are images of the light source, one real and one virtual, formed by the curved surface of the bubble. The faint colors are due to thin film interference effects.

  20. When Will Occur the Crude Oil Bubbles?

    International Nuclear Information System (INIS)

    Su, Chi-Wei; Li, Zheng-Zheng; Chang, Hsu-Ling; Lobonţ, Oana-Ramona

    2017-01-01

    In this paper, we apply a recursive unit root test to investigate whether there exist multiple bubbles in crude oil price. The method is best suited for a practical implementation of a time series and delivers a consistent date-stamping strategy for the origination and termination of multiple bubbles. The empirical result indicates that there exist six bubbles during 1986–2016 when the oil price deviate from its intrinsic value based on market fundamentals. Specifically, oil price contains the fundamentals and bubble components. The dates of the bubbles correspond to specific events in the politics and financial markets. The authorities should actively fight speculative bubbles or just observe their evolutions and speculation activities may decrease, which is favour of the stabilisation of the staple commodities including crude oil price. These findings have important economic and policy implications to recognise the cause of bubbles and take corresponding measures to reduce the impact on the real economy cause of the fluctuation of crude oil price. - Highlights: • Investigate multiple bubbles in crude oil price. • Indicate six bubbles deviate from its intrinsic value based on market fundamentals. • The bubbles correspond to specific events in the politics and financial markets. • Reduce the impact on the real economy cause of the fluctuation of crude oil price.

  1. Armoring confined bubbles in concentrated colloidal suspensions

    Science.gov (United States)

    Yu, Yingxian; Khodaparast, Sepideh; Stone, Howard

    2016-11-01

    Encapsulation of a bubble with microparticles is known to significantly improve the stability of the bubble. This phenomenon has recently gained increasing attention due to its application in a variety of technologies such as foam stabilization, drug encapsulation and colloidosomes. Nevertheless, the production of such colloidal armored bubble with controlled size and particle coverage ratio is still a great challenge industrially. We study the coating process of a long air bubble by microparticles in a circular tube filled with a concentrated microparticles colloidal suspension. As the bubble proceeds in the suspension of particles, a monolayer of micro-particles forms on the interface of the bubble, which eventually results in a fully armored bubble. We investigate the phenomenon that triggers and controls the evolution of the particle accumulation on the bubble interface. Moreover, we examine the effects of the mean flow velocity, the size of the colloids and concentration of the suspension on the dynamics of the armored bubble. The results of this study can potentially be applied to production of particle-encapsulated bubbles, surface-cleaning techniques, and gas-assisted injection molding.

  2. STUDIES ON SOME PHYSICOCHEMICAL PROPERTIES OF LEUCAENA LEUCOCEPHALA BARK GUM

    Directory of Open Access Journals (Sweden)

    Vijetha Pendyala

    2010-06-01

    Full Text Available Gum exudates from Leucaena Leucocephala (Family: Fabaceae plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C. At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns.

  3. Aplikasi Campuran Alginat Dari Sargassum Crassifolium Dan Gum Sebagai Pengental Textile Printing

    Directory of Open Access Journals (Sweden)

    Subaryono Subaryono

    2015-12-01

    Full Text Available Penelitian aplikasi campuran alginat dari Sargassum crassifolium dan gum untuk meningkatkan viskositas alginat sebagai pengental pada textile printing telah dilakukan. Viskositas campuran alginat dengan guar gum, gum arab, dan locust bean gum diamati pada penyimpanan selama 8 jam. Produk terbaik diujikan sebagai pengental pada textile printing. Campuran alginat dengan guar gum pada perbandingan 90:10 dan 80:20 meningkatkan viskositas dan stabilitas alginat selama penyimpanan. Campuran alginat dengan gum arab dan locust bean gum akan menurunkan viskositas alginat sehingga tidak sesuai untuk aplikasi textile printing. Aplikasi campuran alginat dengan guar gum 90:10 dan 80:20 sebagai pengental pada tekstil printing menghasilkan produk akhir yang setara dengan pengental komersial manutex.

  4. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  5. The KEK 1 m hydrogen bubble chamber

    International Nuclear Information System (INIS)

    Doi, Yoshikuni; Araoka, Osamu; Hayashi, Kohei; Hayashi, Yoshio; Hirabayashi, Hiromi.

    1978-03-01

    A medium size hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition time of the accelerator, by utilizing a hydraulic expansion system. The bubble chamber has a one meter diameter and a visible volume of about 280 l. A three-view stereo camera system is used for taking photographic pictures of the chamber. A 2 MW bubble chamber magnet is constructed. The main part of the bubble chamber vessel is supported by the magnet yoke. The magnet gives a maximum field of 18.4 kG at the centre of the fiducial volume of the chamber. The overall system of the KEK 1 m hydrogen bubble chamber facility is described in some detail. Some operational characteristics of the facility are also reported. (auth.)

  6. Formation of soap bubbles by gas jet

    Science.gov (United States)

    Zhou, Maolei; Li, Min; Chen, Zhiyuan; Han, Jifeng; Liu, Dong

    2017-12-01

    Soap bubbles can be easily generated by various methods, while their formation process is complicated and still worth studying. A model about the bubble formation process was proposed in the study by Salkin et al. [Phys. Rev. Lett. 116, 077801 (2016)] recently, and it was reported that the bubbles were formed when the gas blowing velocity was above one threshold. However, after a detailed study of these experiments, we found that the bubbles could be generated in two velocity ranges which corresponded to the laminar and turbulent gas jet, respectively, and the predicted threshold was only effective for turbulent gas flow. The study revealed that the bubble formation was greatly influenced by the aerodynamics of the gas jet blowing to the film, and these results will help to further understand the formation mechanism of the soap bubble as well as the interaction between the gas jet and the thin liquid film.

  7. Development of controlled release spheroids using Buchananiacochinchinesis gum

    Directory of Open Access Journals (Sweden)

    Narayan Babulal Gaikwad

    2013-03-01

    Full Text Available Chirauli nut gum was isolated from the bark of Buchanania cochinchinesis (fam. Anacadiacea and was used as a release modifier for the preparation of Diclofenac sodium spheroids using the extrusion spheronization technique. The process was studied for the effects on variables when making spheroids with satisfactory particle shape, size and size distribution. The prepared spheroids were characterized for surface morphology, qualitative surface porosity, friability, bulk density and flow properties. In vitro studies demonstrated that the release exhibited Fickian diffusion kinetics which was confirmed by the Higuchi and the Korsmeyer-Peppas models. The physico-chemical parameters of the gum could be correlated to the in vitro dissolution profile of the spheroids. The spheroids were not able to sustain the drug releases over 12 hours. A greater concentration of Chirauli nut gum and a process that can accommodate such greater concentrations may produce a formulation capable of significant sustained release.

  8. Cetirizine release from cyclodextrin formulated compressed chewing gum

    DEFF Research Database (Denmark)

    Stojanov, Mladen; Larsen, Kim Lambertsen

    2012-01-01

    Beside the efficient effect on masking cetirizine bitter taste, the cyclodextrins (CDs) as well could have influence on the release from the formulation. In vitro release profiles of cetirizine from compressed chewing gums containing α-, β- and γ-CD were investigated using a three cell chewing...... instead the complexes with respect to release yield. Thus unnecessary expenses for the complex preformulation may be avoided. Keywords: Cetirizine, chewing gum, cyclodextrin, complex, drug release...... apparatus. Different cetirizine/CD formulations were produced and analysed with respect to type of CD (α-, β- and γ-CD), the molar ratio between cetirizine and CD and the formulation of cetirizine (complex or physical mixture). Release experiments from all compressed chewing gum formulations gave similar...

  9. Asset Bubbles, Endogenous Growth, and Financial Frictions

    OpenAIRE

    Hirano, Tomohiro; Yanagawa, Noriyuki

    2016-01-01

    This paper analyzes the effects of bubbles in an infinitely-lived agent model of endogenous growth with financial frictions and heterogeneous agents. We provide a complete characterization on the relationship between financial frictions and the existence of bubbles. Our model predicts that if the degree of pledgeability is sufficiently high or sufficiently low, bubbles can not exist. They can only arise at an intermediate degree. This suggests that improving the financial market condition mig...

  10. Bubbles, Financial Crises, and Systemic Risk

    OpenAIRE

    Markus K. Brunnermeier; Martin Oehmke

    2012-01-01

    This chapter surveys the literature on bubbles, financial crises, and systemic risk. The first part of the chapter provides a brief historical account of bubbles and financial crisis. The second part of the chapter gives a structured overview of the literature on financial bubbles. The third part of the chapter discusses the literatures on financial crises and systemic risk, with particular emphasis on amplification and propagation mechanisms during financial crises, and the measurement of sy...

  11. On Bubble Rising in Countercurrent Flow

    Czech Academy of Sciences Publication Activity Database

    Večeř, M.; Leštinský, P.; Wichterle, K.; Růžička, Marek

    2012-01-01

    Roč. 10, č. 2012 (2012), A30 ISSN 1542-6580 R&D Projects: GA ČR GA104/09/0972; GA ČR GA104/07/1110 Grant - others:GA MŠMT(CZ) CZ.1.05/2.1.00/03.0069 Institutional support: RVO:67985858 Keywords : ellipsoidal bubble * bubble shape * bubble velocity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.790, year: 2011

  12. Design, formulation and evaluation of Aloe vera chewing gum

    Science.gov (United States)

    Aslani, Abolfazl; Ghannadi, Alireza; Raddanipour, Razieh

    2015-01-01

    Background: Aloe vera has antioxidant, antiinflammatory, healing, antiseptic, anticancer and antidiabetic effects. The aim of the present study was to design and evaluate the formulation of Aloe vera chewing gum with an appropriate taste and quality with the indications for healing oral wounds, such as lichen planus, mouth sores caused by cancer chemotherapy and mouth abscesses as well as reducing mouth dryness caused by chemotherapy. Materials and Methods: In Aloe vera powder, the carbohydrate content was determined according to mannose and phenolic compounds in terms of gallic acid. Aloe vera powder, sugar, liquid glucose, glycerin, sweeteners and different flavors were added to the soft gum bases. In Aloe vera chewing gum formulation, 10% of dried Aloe vera extract entered the gum base. Then the chewing gum was cut into pieces of suitable sizes. Weight uniformity, content uniformity, the organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer (pH, 6.8) and taste evaluation were examined by Latin square method. Results: One gram of Aloe vera powder contained 5.16 ± 0.25 mg/g of phenolic compounds and 104.63 ± 4.72 mg/g of carbohydrates. After making 16 Aloe vera chewing gum formulations, the F16 formulation was selected as the best formulation according to its physicochemical and organoleptic properties. In fact F16 formulation has suitable hardness, lack of adhesion to the tooth and appropriate size and taste; and after 30 min, it released more than 90% of its drug content. Conclusion: After assessments made, the F16 formulation with maltitol, aspartame and sugar sweeteners was selected as the best formulation. Among various flavors used, peppermint flavor which had the most acceptance between consumers was selected. PMID:26605214

  13. Metabolic Effects of Nicotine Gum and Cigarette Smoking: Potential Implications for Postcessation Weight Gain?

    Science.gov (United States)

    Klesges, Robert C.; And Others

    1991-01-01

    Twenty smoking women participated in nicotine gum and smoking administration, after which resting energy expenditures (REEs) were measured. Results indicated acute increase in REE for both nicotine gum and cigarettes. Metabolic rates for nicotine gum slowly returned to baseline; rates for cigarettes quickly fell significantly below baseline.…

  14. The role of time on task performance in modifying the effects of gum chewing on attention

    NARCIS (Netherlands)

    Tucha, Lara; Simpson, William

    Recent research examined the effects of chewing gum on attention and reported a significant interaction of gum chewing with time. Using a crossover within-subject design, the present study examined the effect of gum chewing on sustained attention in healthy adults over a period of 30 min. The

  15. Evaluation of the Binding Effect of Local Gum of Boswellia papyrifera ...

    African Journals Online (AJOL)

    In this work, B. papyrifera gum has been evaluated for its binding effect in paracetamol granules and tablet formulations in comparison with the commonly used binders, Acacia BP and PVP K-30. Some physicochemical properties of the extracted gum indicated that the gum exhibited solubility in water, absence of tannin and ...

  16. investigation of the effect of zinc oxide-modified gum arabic on polar ...

    African Journals Online (AJOL)

    BARTH EKWUEME

    Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was ... starch and dextrin, polyvinyl alcohol, cellulose nitrate, .... Zinc oxide-modified gum Arabic improved bond strength on ceramic due to dipole-dipole interactions as well as electrovalent bonds formed between gum ...

  17. Wire communication engineering

    International Nuclear Information System (INIS)

    Son, Byeong Tae

    1997-02-01

    This book describes wire telecommunication engineering/ It is divided into eleven chapter, which deal with Introduction with development of telecommunication, voice and sound wave and communication network, Telegraphy with summary of telegraphy, code of telegraphy, communication speed, morse and telex, Telephone on structure, circuit and image telephone, Traffic on telecommunication traffic, transmission of line about theory, cable line and loaded cable, carrier communication with carrier telegraphy and carrier telephone, optical communication with types, structure, specialty, laser and equipment, DATA, Mobile telecommunication on summary, mobile telephone, radio paging and digital mobile telecommunication, ISDN with channel of ISDN, and service of ISDN, and design of telecommunication.

  18. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  19. The Micro Wire Detector

    Energy Technology Data Exchange (ETDEWEB)

    Adeva, B.; Gomez, F.; Pazos, A.; Pfau, R.; Plo, M. E-mail: maximo.plo@cern.ch; Rodriguez, J.M.; Vazquez, P.; Labbe, J.C

    1999-10-11

    We present the performance of a new proportional gas detector. Its geometry consists of a cathode plane with 70x70 {mu}m{sup 2} apertures, crossed by 25 {mu}m anode strips to which it is attached by 50 {mu}m kapton spacers. In the region where the avalanche takes place, the anode strips are suspended in the gas mixture as in a standard wire chamber. This detector exhibits high rate capability and large gains, introducing very little material. (author)

  20. Epitaxial semiconductor quantum wires.

    Science.gov (United States)

    Wu, J; Chen, Y H; Wang, Z G

    2008-07-01

    The investigation on the direct epitaxial quantum wires (QWR) using MBE or MOCVD has been persuited for more than two decades, more lengthy in history as compared with its quantum dot counterpart. Up to now, QWRs with various structural configurations have been produced with different growth methods. This is a reviewing article consisting mainly of two parts. The first part discusses QWRs of various configurations, together with laser devices based on them, in terms of the two growth mechanisms, self-ordering and self-assembling. The second part gives a brief review of the electrical and optical properties of QWRs.

  1. Improvised bubble continuous positive airway pressure (BCPAP ...

    African Journals Online (AJOL)

    Improvised bubble continuous positive airway pressure (BCPAP) device at the National Hospital Abuja gives immediate improvement in respiratory rate and oxygenation in neonates with respiratory distress.

  2. Multiple Spark-Generated Bubble Interactions

    Science.gov (United States)

    Khoo, Boo Cheong; Adikhari, Deepak; Fong, Siew Wan; Klaseboer, Evert

    The complex interactions of two and three spark-generated bubbles are studied using high speed photography. The corresponding simulations are performed using a 3D Boundary Element Method (BEM) code. The bubbles generated are between 3 to 5 mm in radius, and they are either in-phase or out-of-phase with one another. The possible interaction phenomena between two identically sized bubbles are summarized. Depending on their relative distances and phase differences, they can coalesce, jet towards or away from one another, split into smaller bubbles, or 'catapult' away from one another. The 'catapult' effect can be utilized to generated high speed jet in the absence of a solid boundary or shockwave. Also three bubble interactions are highlighted. Complicated phenomena such as bubble forming an elliptical shape and bubble splitting are observed. The BEM simulations provide insight into the physics of the phenomena by providing details such as detailed bubble shape changes (experimental observations are limited by the temporal and spatial resolution), and jet velocity. It is noted that the well-tested BEM code [1,2] utilized here is computationally very efficient as compared to other full-domain methods since only the bubble surface is meshed.

  3. Safety Assessment of Microbial Polysaccharide Gums as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2016-07-01

    The Cosmetic Ingredient Review Expert Panel assessed the safety of 34 microbial polysaccharide gums for use in cosmetics, finding that these ingredients are safe in cosmetic formulations in the present practices of use and concentration. The microbial polysaccharide gums named in this report have a variety of reported functions in cosmetics, including emulsion stabilizer, film former, binder, viscosity-increasing agent, and skin-conditioning agent. The Panel reviewed available animal and clinical data in making its determination of safety. © The Author(s) 2016.

  4. Locust bean gum: Exploring its potential for biopharmaceutical applications.

    Science.gov (United States)

    Dionísio, Marita; Grenha, Ana

    2012-07-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed.

  5. 46 CFR 111.60-11 - Wire.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Wire. 111.60-11 Section 111.60-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-11 Wire. (a) Wire must be in an enclosure. (b) Wire must be...

  6. Fluorescence spectral studies of Gum Arabic: Multi-emission of Gum Arabic in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Dhenadhayalan, Namasivayam, E-mail: ndhena@gmail.com [Department of Chemistry, National Taiwan University, Taipei, Taiwan (China); Mythily, Rajan, E-mail: rajanmythily@gmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India); Kumaran, Rajendran, E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India)

    2014-11-15

    Gum Arabic (GA), a food hydrocolloid is a natural composite obtained from the stems and branches of Acacia Senegal and Acacia Seyal trees. GA structure is made up of highly branched arabinogalactan polysaccharides. Steady-state absorption, fluorescence, and time-resolved fluorescence spectral studies of acid hydrolyzed GA solutions were carried out at various pH conditions. The fluorescence in GA is predominantly attributed to the presence of tyrosine and phenylalanine amino acids. The presence of multi-emissive peaks at different pH condition is attributed to the exposure of the fluorescing amino acids to the aqueous phase, which contains several sugar units, hydrophilic and hydrophobic moieties. Time-resolved fluorescence studies of GA exhibits a multi-exponential decay with different fluorescence lifetime of varying amplitude which confirms that tyrosine is confined to a heterogeneous microenvironment. The existence of multi-emissive peaks with large variation in the fluorescence intensities were established by 3D emission contour spectral studies. The probable location of the fluorophore in a heterogeneous environment was further ascertained by constructing a time-resolved emission spectrum (TRES) and time-resolved area normalized emission spectrum (TRANES) plots. Fluorescence spectral technique is used as an analytical tool in understanding the photophysical properties of a water soluble complex food hydrocolloid containing an intrinsic fluorophore located in a multiple environment is illustrated. - Highlights: • The Manuscript deals with the steady state absorption, emission, fluorescence lifetime and time-resolved emission spectrum studies of Gum Arabic in aqueous medium at various pH conditions. • The fluorescence emanates from the tyrosine amino acid present in GA. • Change in pH results in marked variation in the fluorescence spectral properties of tyrosine. • Fluorescence spectral techniques are employed as a tool in establishing the

  7. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  8. Liquid jet formation through the interactions of a laser-induced bubble and a gas bubble

    Directory of Open Access Journals (Sweden)

    Bing Han

    2017-10-01

    Full Text Available The mechanisms of the liquid jet formation from the interaction of the laser-induced and gas bubble pair are investigated and compared with the jet formation from the interaction of the laser-induced anti-phase bubble pair. The strobe photography experimental method and numerical simulations are implemented to obtain the parameter space of the optimum liquid jet, i.e. highest speed and lowest diameter. It is found that due to the enhanced “catapult effect”, which is induced by the protrusion of the first bubble into the second bubble and the flip back of the elongated part of the first bubble, the optimum liquid jet of the second bubble of the laser-induced anti-phase bubble pair compared to that of the laser-induced and gas bubble pair is 54 %, 65 % and 11 % faster in speed, and 4 %, 44 % and 64 % smaller in diameter, for the 500 μm, 50 μm and 5 μm sized bubbles, respectively. The optimum dimensionless distance for the optimum jet of the laser-induced and the gas bubble is around 0.7, when the maximum bubble radius increases from ∼ 5μm to ∼500 μm, which is different from the laser-induced anti-phase bubble pairs. Besides, the optimum jet of the laser-induced bubble appeared when the bubbles are equal sized, while that of the gas bubble is independent of the relative bubble size, i.e. the liquid jet of the gas bubble has higher robustness in real liquid jet assisted applications when the laser-induced bubble size varies. However, the jet of bubble 2 could maintain a high speed (20 m/s - 35 m/s and a low diameter (∼5 % of the maximum bubble diameter over a big range of the dimensionless distance (0.6 - 0.9 for both of the 50 μm and 500 μm sized laser-induced equal sized anti-phase bubble pairs.

  9. Liquid jet formation through the interactions of a laser-induced bubble and a gas bubble

    Science.gov (United States)

    Han, Bing; Liu, Liu; Zhao, Xiong-Tao; Ni, Xiao-Wu

    2017-10-01

    The mechanisms of the liquid jet formation from the interaction of the laser-induced and gas bubble pair are investigated and compared with the jet formation from the interaction of the laser-induced anti-phase bubble pair. The strobe photography experimental method and numerical simulations are implemented to obtain the parameter space of the optimum liquid jet, i.e. highest speed and lowest diameter. It is found that due to the enhanced "catapult effect", which is induced by the protrusion of the first bubble into the second bubble and the flip back of the elongated part of the first bubble, the optimum liquid jet of the second bubble of the laser-induced anti-phase bubble pair compared to that of the laser-induced and gas bubble pair is 54 %, 65 % and 11 % faster in speed, and 4 %, 44 % and 64 % smaller in diameter, for the 500 μm, 50 μm and 5 μm sized bubbles, respectively. The optimum dimensionless distance for the optimum jet of the laser-induced and the gas bubble is around 0.7, when the maximum bubble radius increases from ˜ 5μm to ˜500 μm, which is different from the laser-induced anti-phase bubble pairs. Besides, the optimum jet of the laser-induced bubble appeared when the bubbles are equal sized, while that of the gas bubble is independent of the relative bubble size, i.e. the liquid jet of the gas bubble has higher robustness in real liquid jet assisted applications when the laser-induced bubble size varies. However, the jet of bubble 2 could maintain a high speed (20 m/s - 35 m/s) and a low diameter (˜5 % of the maximum bubble diameter) over a big range of the dimensionless distance (0.6 - 0.9) for both of the 50 μm and 500 μm sized laser-induced equal sized anti-phase bubble pairs.

  10. Grewia gum as a potential aqueous film coating agent. I: Some physicochemical characteristics of fractions of grewia gum

    Directory of Open Access Journals (Sweden)

    Ikoni J Ogaji

    2013-01-01

    Full Text Available Background: Grewia gum has received attention as a polymeric pharmaceutical excipient in the recent times, being employed as a suspending, film coating, mucoadhesive, and binding agent. The low aqueous solubility, however, has limited its characterization and application. Objective: The purpose of this study was to fractionate and evaluate some physicochemical properties of the gum. Materials and Methods: Aqueous dispersion of the gum was treated at 80΀C for 30 min in the presence of sodium chloride and was subsequently fractionated by successively centrifuging it at 3445 rpm for 30 min. Skeletal density, solubility, particle size, and rheological as well as thermal characteristics of the fractions were evaluated. The 1 H nuclear magnetic resonance (NMR and near infrared (NIR profiles of the fractions were also investigated. The solubility of the gum increased up to fourfold while the viscosity decreased from 244 to as low as70 cP at 40 rpm with some fractions. Results: Grewia gum and the fractions showed good thermal stability exhibiting no thermal events, but charred irreversibly at 297΀C irrespective of the fraction. The molecular weight averages by weight and by number of the fractions were between 233,100 and 235,000. The 1 H nuclear magnetic resonance (NMR spectra showed broad peaks. The NMR and NIR spectra suggested the presence of -OH and -OCH 3 functional groups in this gum. Conclusion: The fractionation improved solubility and facilitated further investigations on its characteristics that may have implication on its processing, application, and optimization as a potential pharmaceutical excipient.

  11. Improved superconducting magnet wire

    Science.gov (United States)

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  12. Bubble size distribution in flow boiling of aqueous boric acid under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nakath, Richard, E-mail: Richard.Nakath@tu-dresden.de; Schuster, Christoph, E-mail: Christoph.Schuster@tu-dresden.de; Hurtado, Antonio, E-mail: Antonio.Hurtado@tu-dresden.de

    2013-09-15

    The focus of this study lies on the effect of boric acid and lithium hydroxide on the bubble size distribution in flow boiling with special regard to pressurized water reactors (PWRs). Previous studies proposed effects similar to those of surface active agents. Transient and stationary measurements of the bubble size distribution with a wire-mesh sensor in a boiling loop with up to 40 bar were taken. The experiments approximated many aspects of reactor conditions. In addition, the physical properties – especially surface tension – at atmospheric pressure of boric acid solutions were determined. The equilibrium surface tension was measured with the Wilhelmy plate method and the dynamic surface tension with the maximum bubble pressure method. Both measurements showed no difference to pure water, which contradicts previously published data. Two types of experiments were performed: transient experiments with the aim to simulate a fast pressure increase in a PWR and stationary experiments simulating normal, i.e. stable, operating conditions. The transient measurements of the bubble-size distribution yielded no detectable difference between deionized water and boric acid solutions. The stationary measurements showed only minor deviations in the range of small gas mass fractions, which decreased with increasing gas mass fraction. The addition of lithium hydroxide seemed to counter this effect.

  13. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  14. Neutron Detection with Bubble Chambers

    Science.gov (United States)

    Ghilea, M. C.; Lerche, R. A.; Disdier, L.

    2005-10-01

    To improve neutron imaging resolution, we have developed a general imaging design tool for inertial confinement fusion facilities that can simulate aperture errors, generate arbitrary neutron source distributions, simulate arbitrary aperture shapes, calculate point-spread functions using ray tracing, and reconstruct source images using a variety of filter functions. Predicted system performance can be compared to various concepts before construction. This software design tool is being developed for the UR/LLE OMEGA laser and the NIF as part of a process to design and build an imaging system based on a bubble chamber detectorootnotetextR. A. Lerche et al., Rev. Sci. Instrum. 74, 1709 (2003). for the UR/LLE OMEGA laser. This talk will present the latest results on aperture contributions to system performance and review the conceptual design of the bubble chamber-based imaging system, its conceptual design being reviewed in the second part of the presentation. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460.

  15. Evaluation of the suspending property of grewia gum in ...

    African Journals Online (AJOL)

    The suspending properties evaluated included the sedimentation rate, sedimentation volume, ease of redispersibility, apparent viscosity and degree of flocculation. Results obtained after 8 weeks of storage showed that the optimum suspending concentration for grewia gum in the drug was 1% w/v. The sedimentation rate ...

  16. Evaluation of Local Gum of Acacia polyacantha as a Suspending ...

    African Journals Online (AJOL)

    The local gum of Acacia polyacantha was evaluated as a suspending agent in metronidazole benzoate suspensions in comparison with Acacia senegal and NaCMC at concentration range of 1-4% (w/v). The resulting suspensions were evaluated for their sedimentation volume (%), degree of flocculation, rheology, ...

  17. Isolated congenital fusion of the gums | Chiabi | African Journal of ...

    African Journals Online (AJOL)

    Isolated congenital fusion of the gums is a rare anomaly. Early surgical treatment is indicated, as longstanding cases will impair normal feeding leading to nutritional and growth problems. We report the fi rst case in the Yaoundé Gynaeco-Obstetric and Paediatric Hospital, which was successfully managed surgically

  18. Guar gum: a miracle therapy for hypercholesterolemia, hyperglycemia and obesity.

    Science.gov (United States)

    Butt, Masood Sadiq; Shahzadi, Naureen; Sharif, Mian Kamran; Nasir, Muhammad

    2007-01-01

    The number of hypercholesterolemic and hyperglycemic people is increasing rapidly in the world. The prevention against these health problems is related to a complex management of conventional and non-conventional risk factors. The inclusion of dietary fiber in the diet is the right approach to reduce these risks. Cholesterol and glucose lowering effects are most often associated with gelling, mucilaginous, and viscous fibers such as guar gum, an edible thickening agent. It has widespread applications in the food industry due to its ability to hydrate without heating. The demand for guar gum is still growing rapidly because in addition to its indispensable role in lowering serum cholesterol and glucose levels, it is also considered helpful in weight loss programs. The main thrust of therapeutic and medicinal properties lies in the soluble dietary fiber content of guar gum to improve the serum biochemical profile of human and non-human primates, reducing total serum cholesterol, triglycerides, increasing the high density lipoprotein cholesterol level, and the management of glycemic indices and obesity. Among the various intervention strategies, diet diversification is the right approach to overcome these problems. Composite flours containing wheat and legumes have proven practical uses and are being utilized in many parts of the world to improve the nutritional and functional properties of flour. The main focus of this manuscript is to review the available information on various aspects of guar gum with special reference to its effectiveness in reducing the cardiovascular disease risk, diabetes and weight loss programs.

  19. Original Article Gum Arabic in treatment of functional constipation in ...

    African Journals Online (AJOL)

    Background: Constipation represents a common problem in children. The worldwide prevalence of functional constipation in children varies from 0.7% to 29.6%. Objective: The aim of this study is to assess the response to Gum Arabic in addition to laxative in management of functional constipation. Methods: All children less ...

  20. Gellan gum fluid gels for topical administration of diclofenac.

    Science.gov (United States)

    Mahdi, Mohammed H; Conway, Barbara R; Mills, Thomas; Smith, Alan M

    2016-12-30

    Diclofenac topical formulations are often preferred for drug administration to patients who experience serious GIT problems. Absorption of the drug through the skin, however, can be challenging due to the natural protective feature of the stratum corneum (SC). In this article, fluid gels prepared from gellan gum were explored as a topical drug delivery vehicle. Rheological analysis of the formulations showed that it was possible to produce a topical gel with a viscosity and the mechanical strength similar to that of the commercially available Voltaren ® gel using 1% w/w of a 50:50 low acyl/high acyl (LA/HA) gellan blend. Soft-tribology was used to assess the lubrication properties of gellan fluid gels. The lubrication of the gellan gum fluid gel formulations at high rubbing speeds was similar to the lubrication of the Voltaren ® gel. The use of gellan gum dramatically increased skin permeation of diclofenac when compared with the commercially available formulation and could be controlled by changing the gellan gum concentration and/or sodium ion concentration in the formulation. This study highlights the potential use of fluid gels that can be easily tuned to have physical properties suitable for topical formulations with the added advantage of increasing drug permeation. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. 21 CFR 172.780 - Acacia (gum arabic).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acacia (gum arabic). 172.780 Section 172.780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... exudate from stems and branches of trees of various species of the genus Acacia, family Leguminosae. (b...

  2. Radiation induced degradation of xanthan gum in aqueous solution

    Science.gov (United States)

    Hayrabolulu, Hande; Demeter, Maria; Cutrubinis, Mihalis; Güven, Olgun; Şen, Murat

    2018-03-01

    In our previous study, we have investigated the effect of gamma rays on xanthan gum in the solid state and it was determined that dose rate was an important factor effecting the radiation degradation of xanthan gum. In the present study, in order to provide a better understanding of how ionizing radiation effect xanthan gum, we have investigated the effects of ionizing radiation on aqueous solutions of xanthan at various concentrations (0.5-4%). Xanthan solutions were irradiated with gamma rays in air, at ambient temperature, at different dose rates (0.1-3.3-7.0 kGy/h) and doses (2.5-50 kGy). Change in their molecular weights was followed by size exclusion chromatography (SEC). Chain scission yield (G(S)), and degradation rate constants (k) were calculated. It was determined that, solution concentration was a factor effecting the degradation chemical yield and degradation rate of xanthan gum. Chain scission reactions were more effective for lower solution concentrations.

  3. Improvement of xanthan gum production in batch culture using ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... In this study, the effect of acetic acid on the improvement of xanthan biosynthesis by Xanthomonas campestris b82 was investigated. ... have been considered to improve xanthan productivity, which include improvement of culture ..... continuous production of xanthan gum. Paper presented at the Fifth.

  4. Investigation of Transport Properties of a New Biomaterials - GUM Mangosteen

    Science.gov (United States)

    Pradhan, Sourav S.; Sarkar, A.

    2006-06-01

    Biomaterial has occupied leading position in material science for various scientific and technological applications. This present work is carried out over a natural gum extracted from raw fruit of Mangosteen, an east Indian tree (Gercinia Mangostana) following extraction and purification process. Solid specimen of the said gum is developed following sol-gel like process. AC and DC electrical analysis on the dried solid specimen of the gum were carried out and showed high electrical conduction with σ ~ 1 E-03 S/cm, of which ionic and electronic contributions are 70% and 30% respectively. Analysis shows that origin of high electrical conductivity is due to presence of substantial amount of organic acid unit in its polysaccharide background. In fact the observed σ is about 1000 times of that observed in gum Arabica. Optical absorption of this new bio- materials are also studied using UV-VIS analysis. The results show its high absorption co-efficient in UV and blue part of analysed range. A complete electrical characterization of the material have been made. It has also been observed that the electronic conduction can be enhanced to 70% of the total electrical conductivity by forming complex with Iodine and organic (Citric) acid from Lemon fruit. This high potential material is being studied for development of electronic device application.

  5. The efficacy of chewing gum on postoperative ileus following ...

    African Journals Online (AJOL)

    Background: Postoperative ileus (POI) is a common complication following caesarean section. It impairs patients comfort; delays wound healing and prolong duration of hospital stay. Several methods have been used in the management of this condition with varying efficacy. Chewing gum postoperatively is a recent concept ...

  6. Formulation and In vitro Evaluation of Natural Gum-Based ...

    African Journals Online (AJOL)

    Nigeria. The collection, purification and characterization of the natural gums have been described elsewhere [5,9]. All other reagents were of analytical grade. Preformulation studies. Preformulation studies were carried out using different chelating agents in order to optimize the formulation and physicochemical properties of.

  7. Cashew gum and gelatin blend for food packaging application

    Science.gov (United States)

    Cashew gum (CG) and gelatin (G) films were developed using the casting method and response surface methodology. The objective was produce packaging films from CG/G blends that exhibit effective barrier properties. A study of zeta potential versus pH was first carried out to determine the isoelectric...

  8. Electrospinning of guar gum/corn starch blends

    Science.gov (United States)

    In this study, electrospun nanofibers were prepared for the first time from aqueous blends of guar gum (GG) and corn starch with amylose contents of 27.8% (CS28) and 50% (CS50). The fiber morphology and fiber diameter sizes (FDS) were correlated with solution rheology. The spinning solutions were pr...

  9. Binding Properties Of A Polymeric Gum From Cola accuminata ...

    African Journals Online (AJOL)

    However all the tablets produced with 1 % w/w binder; Sodium carboxyl methyl cellulose (SCMC) and Cola accuminata failed the hardness test. Hardness increased while friability decreased as tablet binder concentration increased. However, the tablets produced with Cola accuminata gum had long disintegration times ...

  10. Iron microencapsulation in gum tragacanth using solvent evaporation method.

    Science.gov (United States)

    Asghari-Varzaneh, Elham; Shahedi, Mohammad; Shekarchizadeh, Hajar

    2017-10-01

    In this study iron salt (FeSO 4 ·7H 2 O) was microencapsulated in gum tragacanth hydrogel using solvent evaporation method. Three significant parameters (ferrous sulfate content, content of gum tragacanth, and alcohol to mixture ratio) were optimized by response surface methodology to obtain maximum encapsulation efficiency. Ferrous sulfate content, 5%, content of gum tragacanth, 22%, and alcohol to mixture ratio, 11:1 was determined to be the optimum condition to reach maximum encapsulation efficiency. Microstructure of iron microcapsules was thoroughly monitored using scanning electron microscopy (SEM). The microphotographs indicated two distinct crystalline and amorphous structures in the microcapsules. This structure was confirmed by X-ray diffraction (XRD) pattern of microcapsules. Fourier transform infrared (FTIR) spectra of iron microcapsules identified the presence of iron in the tragacanth microcapsules. The average size of microcapsules was determined by particle size analyzer. Release assessment of iron in simulated gastric fluid showed its complete release in stomach which is necessary for its absorption in duodenum. However, the use of encapsulated iron in gum tragacanth in watery foods is rather recommended due to the fast release of iron in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. blue gums fortress observation post simon's bay fire command 1942 ...

    African Journals Online (AJOL)

    In a letter dated 21 July 1942 the General Staff. Officer I at the Castle requested that accommo- dation for one White NCO and 20 members of 1. Battalion, Native Military Corps be provided at. Blue Gums. Ten days later the Fortress Com- mander submitted the request to the Quarter- master-General and advised him that the ...

  12. Wire metamaterials: physics and applications.

    Science.gov (United States)

    Simovski, Constantin R; Belov, Pavel A; Atrashchenko, Alexander V; Kivshar, Yuri S

    2012-08-16

    The physics and applications of a broad class of artificial electromagnetic materials composed of lattices of aligned metal rods embedded in a dielectric matrix are reviewed. Such structures are here termed wire metamaterials. They appear in various settings and can operate from microwaves to THz and optical frequencies. An important group of these metamaterials is a wire medium possessing extreme optical anisotropy. The study of wire metamaterials has a long history, however, most of their important and useful properties have been revealed and understood only recently, especially in the THz and optical frequency ranges where the wire media correspond to the lattices of microwires and nanowires, respectively. Another group of wire metamaterials are arrays and lattices of nanorods of noble metals whose unusual properties are driven by plasmonic resonances. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Acoustic Energy Storage in Single Bubble Sonoluminescence

    NARCIS (Netherlands)

    Brenner, Michael P.; Hilgenfeldt, Sascha; Lohse, Detlef; Rosales, Rodolfo R.

    1996-01-01

    Single bubble sonoluminescence is understood in terms of a shock focusing towards the bubble center. We present a mechanism for significantly enhancing the effect of shock focusing, arising from the storage of energy in the acoustic modes of the gas. The modes with strongest coupling are not

  14. Steady State Vapor Bubble in Pool Boiling.

    Science.gov (United States)

    Zou, An; Chanana, Ashish; Agrawal, Amit; Wayner, Peter C; Maroo, Shalabh C

    2016-02-03

    Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

  15. Microfluidics with ultrasound-driven bubbles

    NARCIS (Netherlands)

    Marmottant, P.; Marmottant, P.G.M.; Raven, J.P.; Gardeniers, Johannes G.E.; Bomer, Johan G.; Hilgenfeldt, Sascha; Hilgenfeldt, S.

    2006-01-01

    Microstreaming from oscillating bubbles is known to induce vigorous vortex flow. Here we show how to harness the power of bubble streaming in an experiment to achieve directed transport flow of high velocity, allowing design and manufacture of microfluidic MEMS devices. By combining oscillating

  16. Laminar separation bubbles: Dynamics and control

    Indian Academy of Sciences (India)

    surface of a flat plate by appropriately contouring the top wall of the wind tunnel. First, a basic ... of thin aerofoils, on gas turbine blades and on low Reynolds number micro-aero-vehicle wings. Presence of bubbles ... ied its effect on the loss reduction in a gas turbine blade due to periodic quenching of the separation bubble.

  17. The life and death of film bubbles

    Science.gov (United States)

    Poulain, S.; Villermaux, E.; Bourouiba, L.

    2017-11-01

    Following its burst, the fragmentation of a large bubble (film bubble) at the air-water interface can release hundreds of micrometer-sized film-drops in the air we breathe. This mechanism of droplet formation is one of the most prominent sources of sea spray. Indoor or outdoor, pathogens from contaminated water are transported by these droplets and have also been linked to respiratory infection. The lifetime and thickness of bubbles govern the number and size of the droplets they produce. Despite these important implications, little is known about the factors influencing the life and death of surface film bubbles. In particular, the fundamental physical mechanisms linking bubble aging, thinning, and lifetime remain poorly understood. To address this gap, we present the results of an extensive investigation of the aging of film-drop-producing bubbles in various ambient air, water composition, and temperature conditions. We present and validate a generalized physical picture and model of bubble cap thickness evolution. The model and physical picture are linked to the lifetime of bubbles via a series of cap rupture mechanisms of increasing efficiency.

  18. Bubble Swarm Rise Velocity in Fluidized Beds.

    Czech Academy of Sciences Publication Activity Database

    Punčochář, Miroslav; Růžička, Marek; Šimčík, Miroslav

    2016-01-01

    Roč. 152, OCT 2 (2016), s. 84-94 ISSN 0009-2509 R&D Projects: GA ČR(CZ) GA15-05534S Institutional support: RVO:67985858 Keywords : bubbling fluidized bed * gas-solid * bubble swarm velocity Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.895, year: 2016

  19. A New Statistical Parameter for Identifying the Main Transition Velocities in Bubble Columns.

    Science.gov (United States)

    Nedeltchev, Stoyan; Rabha, Swapna; Hampel, Uwe; Schubert, Markus

    2015-11-01

    The identification of the main flow regime boundaries in bubble columns is essential since the degrees of mixing and mass and heat transfer vary with the flow regime. In this work, a new statistical parameter was extracted from the time series of the cross-sectional averaged gas holdup. The measurements were performed in bubble columns by means of conductivity wire-mesh sensors at very high sampling frequency. The columns were operated with an air/deionized water system under ambient conditions. As a flow regime indicator, a new dimensionless statistical parameter called "relative maximum number of visits in a region" was introduced. This new parameter is a function of the difference between the maximum numbers of visits in a region, calculated from two different division schemes of the signal range.

  20. Galactic Teamwork Makes Distant Bubbles

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    During the period of reionization that followed the dark ages of our universe, hydrogen was transformed from a neutral state, which is opaque to radiation, to an ionized one, which is transparent to radiation. But what generated the initial ionizing radiation? The recent discovery of multiple distant galaxies offers evidence for how this process occurred.Two Distant GalaxiesWe believe reionization occurred somewhere between a redshift of z = 6 and 7, because Ly-emitting galaxies drop out at roughly this redshift. Beyond this distance, were generally unable to see the light from these galaxies, because the universe is no longer transparent to their emission. This is not always the case, however: if a bubble of ionized gas exists around a distant galaxy, the radiation can escape, allowing us to see the galaxy.This is true of two recently-discovered Ly-emitting galaxies, confirmed to be at a redshift of z~7 and located near one another in a region known as the Bremer Deep Field. The fact that were able to see the radiation from these galaxies means that they are in an ionized HII region presumably one of the earlier regions to have become reionized in the universe.But on their own, neither of these galaxies is capable of generating an ionized bubble large enough for their light to escape. So what ionized the region around them, and what does this mean for our understanding of how reionization occurred in the universe?A Little Help From FriendsLocation in different filters of the objects in the Hubble Bremer Deep Field catalog. The z~7 selection region is outlined by the grey box. BDF-521 and BDF-3299 were the two originally discovered galaxies; the remaining red markers indicate the additional six galaxies discovered in the same region. [Castellano et al. 2016]A team of scientists led by Marco Castellano (Rome Observatory, INAF) investigated the possibility that there are other, faint galaxies near these two that have helped to ionize the region. Performing a survey

  1. Mango kernel starch-gum composite films: Physical, mechanical and barrier properties.

    Science.gov (United States)

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Lutfi, Zubala; Hasnain, Abid

    2017-05-01

    Composite films were developed by the casting method using mango kernel starch (MKS) and guar and xanthan gums. The concentration of both gums ranged from 0% to 30% (w/w of starch; db). Mechanical properties, oxygen permeability (OP), water vapor permeability (WVP), solubility in water and color parameters of composite films were evaluated. The crystallinity and homogeneity between the starch and gums were also evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The scanning electron micrographs showed homogeneous matrix, with no signs of phase separation between the components. XRD analysis demonstrated diminished crystalline peak. Regardless of gum type the tensile strength (TS) of composite films increased with increasing gum concentration while reverse trend was noted for elongation at break (EAB) which found to be decreased with increasing gum concentration. The addition of both guar and xanthan gums increased solubility and WVP of the composite films. However, the OP was found to be lower than that of the control with both gums. Furthermore, addition of both gums led to changes in transparency and opacity of MKS films. Films containing 10% (w/w) xanthan gum showed lower values for solubility, WVP and OP, while film containing 20% guar gum showed good mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Effect of bubble size on internal characteristics of upward bubble flow

    International Nuclear Information System (INIS)

    Matsui, Goichi; Kumazawa, Toshio; Yamashita, Yutaka.

    1987-01-01

    Bubble flow characteristics were investigated experimentally in nitrogen gas-water in a spuare channel using a laser Doppler anemometer and a double-sensor conductance probe under the same flow rate conditions. The size of the bubbles was controlled by changing the mixing conditions and by adding a surface active agent to water. Thus, four sets of experiments were conducted. Experimental results show that the reduction in bubble size flattens the gas-phase distribution and increases the number density of bubbles. The reduction in bubble size leads to a decrease in turbulence and an increase in water and bubble velocities, but an extreme reduction does not bring about a further increase in both velocities, although it leads to a further decrease in turbulence. Turbulence suppression was observed in layer-type bubble flows. This type of flow has a peculiar profile of water velocity. (author)

  3. Enzymatic depolymerization of gum Tragacanth: Bifidogenic potential of low molecular weight oligosaccharides

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan; Michalak, Malwina; Meyer, Anne S.

    2013-01-01

    Gum tragacanth derived from the plant “goat’s horn” (Astragalus sp.) has a long history of use as a stabilizing, viscosity-enhancing agent in food emulsions. The gum contains pectinaceous arabinogalactans and fucose-substituted xylogalacturonans. In this work, gum tragacanth from Astragalus gossy...... that on galactan (control). HAG3 completely inhibited the growth of the Cl. perfringens strain. Tragacanth gum is thus a potential source of prebiotic carbohydrates that exert no viscosity effects and which may find use as natural functional food ingredients.......Gum tragacanth derived from the plant “goat’s horn” (Astragalus sp.) has a long history of use as a stabilizing, viscosity-enhancing agent in food emulsions. The gum contains pectinaceous arabinogalactans and fucose-substituted xylogalacturonans. In this work, gum tragacanth from Astragalus...

  4. The Role of Xylitol Gum Chewing in Restoring Postoperative Bowel Activity After Cesarean Section.

    Science.gov (United States)

    Lee, Jian Tao; Hsieh, Mei-Hui; Cheng, Po-Jen; Lin, Jr-Rung

    2016-03-01

    The goal of this study was to evaluate the effects of xylitol gum chewing on gastrointestinal recovery after cesarean section. Women who underwent cesarean section (N = 120) were randomly allocated into Group A (xylitol gum), Group B (nonxylitol gum), or the control group (no chewing gum). Every 2 hr post-cesarean section and until first flatus, Groups A and B received two pellets of chewing gum and were asked to chew for 15 min. The times to first bowel sounds, first flatus, and first defecation were then compared among the three groups. Group A had the shortest mean time to first bowel sounds (6.9 ± 1.7 hr), followed by Group B (8 ± 1.6 hr) and the control group (12.8 ± 2.5 hr; one-way analysis of variance, p xylitol-containing gum may be superior to xylitol-free gum. © The Author(s) 2015.

  5. Constraining hadronic models of the Fermi bubbles

    Science.gov (United States)

    Razzaque, Soebur

    2018-01-01

    The origin of sub-TeV gamma rays detected by Fermi-LAT from the Fermi bubbles at the Galactic center is unknown. In a hadronic model, acceleration of protons and/or nuclei and their subsequent interactions with gas in the bubble volume can produce observed gamma ray. Such interactions naturally produce high-energy neutrinos, and detection of those can discriminate between a hadronic and a leptonic origin of gamma rays. Additional constraints on the Fermi bubbles gamma-ray flux in the PeV range from recent HAWC observations restrict hadronic model parameters, which in turn disfavor Fermi bubbles as the origin of a large fraction of neutrino events detected by IceCube along the bubble directions. We revisit our hadronic model and discuss future constraints on parameters from observations in very high-energy gamma rays by CTA and in neutrinos.

  6. Primordial black hole formation by vacuum bubbles

    Science.gov (United States)

    Deng, Heling; Vilenkin, Alexander

    2017-12-01

    Vacuum bubbles may nucleate during the inflationary epoch and expand, reaching relativistic speeds. After inflation ends, the bubbles are quickly slowed down, transferring their momentum to a shock wave that propagates outwards in the radiation background. The ultimate fate of the bubble depends on its size. Bubbles smaller than certain critical size collapse to ordinary black holes, while in the supercritical case the bubble interior inflates, forming a baby universe, which is connected to the exterior region by a wormhole. The wormhole then closes up, turning into two black holes at its two mouths. We use numerical simulations to find the masses of black holes formed in this scenario, both in subcritical and supercritical regime. The resulting mass spectrum is extremely broad, ranging over many orders of magnitude. For some parameter values, these black holes can serve as seeds for supermassive black holes and may account for LIGO observations.

  7. Bubble mobility in mud and magmatic volcanoes

    Science.gov (United States)

    Tran, Aaron; Rudolph, Maxwell L.; Manga, Michael

    2015-03-01

    The rheology of particle-laden fluids with a yield stress, such as mud or crystal-rich magmas, controls the mobility of bubbles, both the size needed to overcome the yield stress and their rise speed. We experimentally measured the velocities of bubbles and rigid spheres in mud sampled from the Davis-Schrimpf mud volcanoes adjacent to the Salton Sea, Southern California. Combined with previous measurements in the polymer gel Carbopol, we obtained an empirical model for the drag coefficient and bounded the conditions under which bubbles overcome the yield stress. Yield stresses typical of mud and basaltic magmas with sub-mm particles can immobilize millimeter to centimeter sized bubbles. At Stromboli volcano, Italy, a vertical yield stress gradient in the shallow conduit may immobilize bubbles with diameter ≲ 1 cm and hinder slug coalescence.

  8. Bubble streams rising beneath an inclined surface

    Science.gov (United States)

    Bird, James; Brasz, Frederik; Kim, Dayoung; Menesses, Mark; Belden, Jesse

    2017-11-01

    Bubbles released beneath a submerged inclined surface can tumble along the wall as they rise, dragging the surrounding fluid with them. This effect has recently regained attention as a method to mitigate biofouling in marine environment, such as a ship hull. It appears that the efficacy of this approach may be related to the velocity of the rising bubbles and the extent that they spread laterally as they rise. Yet, it is unclear how bubble stream rise velocity and lateral migration depend on bubble size, flow rate, and inclination angle. Here we perform systematic experiments to quantify these relationships for both individual bubble trajectories and ensemble average statistics. Research supported by the Office of Naval Research under Grant Number award N00014-16-1-3000.

  9. Gas Bubble Dynamics under Mechanical Vibrations

    Science.gov (United States)

    Mohagheghian, Shahrouz; Elbing, Brian

    2017-11-01

    The scientific community has a limited understanding of the bubble dynamics under mechanical oscillations due to over simplification of Navier-Stockes equation by neglecting the shear stress tensor and not accounting for body forces when calculating the acoustic radiation force. The current work experimental investigates bubble dynamics under mechanical vibration and resulting acoustic field by measuring the bubble size and velocity using high-speed imaging. The experimental setup consists of a custom-designed shaker table, cast acrylic bubble column, compressed air injection manifold and an optical imaging system. The mechanical vibrations resulted in accelerations between 0.25 to 10 times gravitational acceleration corresponding to frequency and amplitude range of 8 - 22Hz and 1 - 10mm respectively. Throughout testing the void fraction was limited to definition of Bjerknes force in combination with Rayleigh-Plesset equation. Physical behavior of the system was capture and classified. Bubble size, velocity as well as size and spatial distribution will be presented.

  10. 3D Wire 2015

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias

    , therefore, we’ve drawn conclusions and recommendations for future editions of the event, also generalizable to other experiences of gamification especially in events. This report details the methodology and working elements from the design phase, human resources and organization of production......This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and have...... proposed new ones (viralization of the event on social networks and improvement of the integration of international attendees). On the other hand we defined a set of research objectives related to the study of gamification in an eminently social place like an event. Most of the goals have been met and...

  11. Relationships Between Gum Chewing and Stroop Test: A Pilot Study.

    Science.gov (United States)

    Kawakami, Y; Takeda, T; Konno, M; Suzuki, Y; Kawano, Y; Ozawa, T; Kondo, Y; Sakatani, K

    2017-01-01

    Cognitive function tends to decrease with aging, therefore maintenance of this function in an aging society is an important issue. The role of chewing in nutrition is important. Although several studies indicate that gum chewing is thought to improve cognitive function, it remains debatable whether gum-chewing does in fact improve cognitive function. The Stroop test is a psychological tool used to measure cognition. A shorter reaction time indicates a mean higher behavioral performance and higher levels of oxy-Hb concentration. fNIRS is a powerful, non-invasive imaging technique offering many advantages, including compact size, no need for specially equipped facilities, and the potential for real-time measurement. The left dorsolateral prefrontal cortex (DLPFC) seems to be mainly involved in the Stroop task.The aim of the present study was to investigate the hypothesis that gum-chewing changes cerebral blood flow in the left DLPFC during the Stroop test, and also changes the reaction time. Fourteen healthy volunteers (mean age 26.9 years) participated in this study after providing written informed consent. A piece of tasteless gum weighing 1.0 g was used. Each session was designed in a block manner, i.e. 4 rests (30 s) and 3 blocks of task (30 s). A computerized Stroop test was used (including both congruent and incongruent Stroop tasks) which calculates a response time automatically. The Binominal test was used for comparisons (p Stroop task and that gum chewing significantly increases responses/oxy-Hb concentration and significantly shortens the reaction time.

  12. Naturalistic assessment of demand for cigarettes, snus, and nicotine gum.

    Science.gov (United States)

    Stein, Jeffrey S; Wilson, A George; Koffarnus, Mikhail N; Judd, Michael C; Bickel, Warren K

    2017-01-01

    Behavioral economic measures of demand provide estimates of tobacco product abuse liability and may predict effects of policy-related price regulation on consumption of existing and emerging tobacco products. In the present study, we examined demand for snus, a smokeless tobacco product, in comparison to both cigarettes and medicinal nicotine. We used both a naturalistic method in which participants purchased these products for use outside the laboratory, as well as laboratory-based self-administration procedures. Cigarette smokers (N = 42) used an experimental income to purchase their usual brand of cigarettes and either snus or gum (only one product available per session) across a range of prices, while receiving all products they purchased from one randomly selected price. In a separate portion of the study, participants self-administered these products during laboratory-based, progressive ratio sessions. Demand elasticity (sensitivity of purchasing to price) was significantly greater for snus than cigarettes. Elasticity for gum was intermediate between snus and cigarettes but was not significantly different than either. Demand intensity (purchasing unconstrained by price) was significantly lower for gum compared to cigarettes, with no significant difference observed between snus and cigarettes. Results of the laboratory-based, progressive ratio sessions were generally discordant with measures of demand elasticity, with significantly higher "breakpoints" for cigarettes compared to gum and no significant differences between other study products. Moreover, breakpoints and product purchasing were generally uncorrelated across tasks. Under naturalistic conditions, snus appears more sensitive to price manipulation than either cigarettes or nicotine gum in existing smokers.

  13. Investigation of air-water flow in a horizontal pipe with 90 degree bends using wire mesh sensors

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, R.C.; Yang, S.K., E-mail: robert.bowden@cnl.ca, E-mail: sun-kyu.yang@cnl.ca [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

    2015-07-01

    Wire mesh sensors were used to investigate the void fraction distribution along a 9 meter long, 50.8 mm diameter, horizontal test section that contained two 90 degree bends. Deionised water and compressed air were used as the working fluids, with the bubbly flow regime achieved at a superficial liquid velocity of 3.5 m/s and superficial gas velocities that varied between 0.1 and 1.2 m/s. The effects of superficial gas velocity and axial location on the void fraction distribution were investigated. Bubble and slug flow patterns were identified using a probability density function analysis based on a Gaussian mixture model. (author)

  14. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  15. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years....... The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model...... and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes....

  16. Numerical modeling of bubble dynamics in magmas

    Science.gov (United States)

    Huber, Christian; Su, Yanqing; Parmigiani, Andrea

    2014-05-01

    Understanding the complex non-linear physics that governs volcanic eruptions is contingent on our ability to characterize the dynamics of bubbles and its effect on the ascending magma. The exsolution and migration of bubbles has also a great impact on the heat and mass transport in and out of magma bodies stored at shallow depths in the crust. Multiphase systems like magmas are by definition heterogeneous at small scales. Although mixture theory or homogenization methods are convenient to represent multiphase systems as a homogeneous equivalent media, these approaches do not inform us on possible feedbacks at the pore-scale and can be significantly misleading. In this presentation, we discuss the development and application of bubble-scale multiphase flow modeling to address the following questions : How do bubbles impact heat and mass transport in magma chambers ? How efficient are chemical exchanges between the melt and bubbles during magma decompression? What is the role of hydrodynamic interactions on the deformation of bubbles while the magma is sheared? Addressing these questions requires powerful numerical methods that accurately model the balance between viscous, capillary and pressure stresses. We discuss how these bubble-scale models can provide important constraints on the dynamics of magmas stored at shallow depth or ascending to the surface during an eruption.

  17. Average properties of bidisperse bubbly flows

    Science.gov (United States)

    Serrano-García, J. C.; Mendez-Díaz, S.; Zenit, R.

    2018-03-01

    Experiments were performed in a vertical channel to study the properties of a bubbly flow composed of two distinct bubble size species. Bubbles were produced using a capillary bank with tubes with two distinct inner diameters; the flow through each capillary size was controlled such that the amount of large or small bubbles could be controlled. Using water and water-glycerin mixtures, a wide range of Reynolds and Weber number ranges were investigated. The gas volume fraction ranged between 0.5% and 6%. The measurements of the mean bubble velocity of each species and the liquid velocity variance were obtained and contrasted with the monodisperse flows with equivalent gas volume fractions. We found that the bidispersity can induce a reduction of the mean bubble velocity of the large species; for the small size species, the bubble velocity can be increased, decreased, or remain unaffected depending of the flow conditions. The liquid velocity variance of the bidisperse flows is, in general, bound by the values of the small and large monodisperse values; interestingly, in some cases, the liquid velocity fluctuations can be larger than either monodisperse case. A simple model for the liquid agitation for bidisperse flows is proposed, with good agreement with the experimental measurements.

  18. Bubbles in live-stranded dolphins.

    Science.gov (United States)

    Dennison, S; Moore, M J; Fahlman, A; Moore, K; Sharp, S; Harry, C T; Hoppe, J; Niemeyer, M; Lentell, B; Wells, R S

    2012-04-07

    Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, kidneys, eyes and blubber-muscle interface of live-stranded and capture-release dolphins were scanned with B-mode ultrasound. Gas was identified in kidneys of 21 of 22 live-stranded dolphins and in the hepatic portal vasculature of 2 of 22. Nine then died or were euthanized and bubble presence corroborated by computer tomography and necropsy, 13 were released of which all but two did not re-strand. Bubbles were not detected in 20 live wild dolphins examined during health assessments in shallow water. Off-gassing of supersaturated blood and tissues was the most probable origin for the gas bubbles. In contrast to marine mammals repeatedly diving in the wild, stranded animals are unable to recompress by diving, and thus may retain bubbles. Since the majority of beached dolphins released did not re-strand it also suggests that minor bubble formation is tolerated and will not lead to clinically significant decompression sickness.

  19. MAGNETIC TOPOLOGY OF BUBBLES IN QUIESCENT PROMINENCES

    International Nuclear Information System (INIS)

    Dudík, J.; Aulanier, G.; Schmieder, B.; Zapiór, M.; Heinzel, P.

    2012-01-01

    We study a polar-crown prominence with a bubble and its plume observed in several coronal filters by the SDO/AIA and in Hα by the MSDP spectrograph in Białków (Poland) to address the following questions: what is the brightness of prominence bubbles in EUV with respect to the corona outside of the prominence and the prominence coronal cavity? What is the geometry and topology of the magnetic field in the bubble? What is the nature of the vertical threads seen within prominences? We find that the brightness of the bubble and plume is lower than the brightness of the corona outside of the prominence, and is similar to that of the coronal cavity. We constructed linear force-free models of prominences with bubbles, where the flux rope is perturbed by inclusion of parasitic bipoles. The arcade field lines of the bipole create the bubble, which is thus devoid of magnetic dips. Shearing the bipole or adding a second one can lead to cusp-shaped prominences with bubbles similar to the observed ones. The bubbles have complex magnetic topology, with a pair of coronal magnetic null points linked by a separator outlining the boundary between the bubble and the prominence body. We conjecture that plume formation involves magnetic reconnection at the separator. Depending on the viewing angle, the prominence can appear either anvil-shaped with predominantly horizontal structures, or cusp-shaped with predominantly vertical structuring. The latter is an artifact of the alignment of magnetic dips with respect to the prominence axis and the line of sight.

  20. The Minnaert bubble: an acoustic approach

    Energy Technology Data Exchange (ETDEWEB)

    Devaud, Martin; Hocquet, Thierry; Bacri, Jean-Claude [Laboratoire Matiere et Systemes Complexes, Universite Paris Diderot and CNRS UMR 7057, 10 rue Alice Domont et Leonie Duquet, 75013 Paris (France); Leroy, Valentin [Laboratoire Ondes et Acoustique, Universite Paris 7 and CNRS UMR 7587, ESPCI, 10 rue Vauquelin, 75005 Paris (France)], E-mail: martin.devaud@univ-paris-diderot.fr

    2008-11-15

    We propose an ab initio introduction to the well-known Minnaert pulsating bubble at graduate level. After a brief recall of the standard stuff, we begin with a detailed discussion of the radial movements of an air bubble in water. This discussion is managed from an acoustic point of view, and using the Lagrangian rather than the Eulerian variables. In unbounded water, the air-water system has a continuum of eigenmodes, some of them correspond to regular Fabry-Perot resonances. A singular resonance, the lowest one, is shown to coincide with that of Minnaert. In bounded water, the eigenmodes spectrum is discrete, with a finite fundamental frequency. A spectacular quasi-locking of the latter occurs if it happens to exceed the Minnaert frequency, which provides an unforeseen one-bubble alternative version of the famous 'hot chocolate effect'. In the (low) frequency domain in which sound propagation inside the bubble reduces to a simple 'breathing' (i.e. inflation/deflation), the light air bubble can be 'dressed' by the outer water pressure forces, and is turned into the heavy Minnaert bubble. Thanks to this unexpected renormalization process, we demonstrate that the Minnaert bubble definitely behaves like a true harmonic oscillator of the spring-bob type, but with a damping term and a forcing term in apparent disagreement with those commonly admitted in the literature. Finally, we underline the double role played by the water. In order to tell the water motion associated with water compressibility (i.e. the sound) from the simple incompressible accompaniment of the bubble breathing, we introduce a new picture analogous to the electromagnetic radiative picture in Coulomb gauge, which naturally leads us to split the water displacement in an instantaneous and a retarded part. The Minnaert renormalized mass of the dressed bubble is then automatically recovered.

  1. Dynamics of two-dimensional bubbles

    Science.gov (United States)

    Piedra, Saúl; Ramos, Eduardo; Herrera, J. Ramón

    2015-06-01

    The dynamics of two-dimensional bubbles ascending under the influence of buoyant forces is numerically studied with a one-fluid model coupled with the front-tracking technique. The bubble dynamics are described by recording the position, shape, and orientation of the bubbles as functions of time. The qualitative properties of the bubbles and their terminal velocities are described in terms of the Eötvos (ratio of buoyancy to surface tension) and Archimedes numbers (ratio of buoyancy to viscous forces). The terminal Reynolds number result from the balance of buoyancy and drag forces and, consequently, is not an externally fixed parameter. In the cases that yield small Reynolds numbers, the bubbles follow straight paths and the wake is steady. A more interesting behavior is found at high Reynolds numbers where the bubbles follow an approximately periodic zigzag trajectory and an unstable wake with properties similar to the Von Karman vortex street is formed. The dynamical features of the motion of single bubbles are compared to experimental observations of air bubbles ascending in a water-filled Hele-Shaw cell. Although the comparison is not strictly valid in the sense that the effect of the lateral walls is not incorporated in the model, most of the dynamical properties observed are in good qualitative agreement with the numerical calculations. Hele-Shaw cells with different gaps have been used to determine the degree of approximation of the numerical calculation. It is found that for the relation between the terminal Reynolds number and the Archimedes number, the numerical calculations are closer to the observations of bubble dynamics in Hele-Shaw cells of larger gaps.

  2. The Minnaert bubble: an acoustic approach

    International Nuclear Information System (INIS)

    Devaud, Martin; Hocquet, Thierry; Bacri, Jean-Claude; Leroy, Valentin

    2008-01-01

    We propose an ab initio introduction to the well-known Minnaert pulsating bubble at graduate level. After a brief recall of the standard stuff, we begin with a detailed discussion of the radial movements of an air bubble in water. This discussion is managed from an acoustic point of view, and using the Lagrangian rather than the Eulerian variables. In unbounded water, the air-water system has a continuum of eigenmodes, some of them correspond to regular Fabry-Perot resonances. A singular resonance, the lowest one, is shown to coincide with that of Minnaert. In bounded water, the eigenmodes spectrum is discrete, with a finite fundamental frequency. A spectacular quasi-locking of the latter occurs if it happens to exceed the Minnaert frequency, which provides an unforeseen one-bubble alternative version of the famous 'hot chocolate effect'. In the (low) frequency domain in which sound propagation inside the bubble reduces to a simple 'breathing' (i.e. inflation/deflation), the light air bubble can be 'dressed' by the outer water pressure forces, and is turned into the heavy Minnaert bubble. Thanks to this unexpected renormalization process, we demonstrate that the Minnaert bubble definitely behaves like a true harmonic oscillator of the spring-bob type, but with a damping term and a forcing term in apparent disagreement with those commonly admitted in the literature. Finally, we underline the double role played by the water. In order to tell the water motion associated with water compressibility (i.e. the sound) from the simple incompressible accompaniment of the bubble breathing, we introduce a new picture analogous to the electromagnetic radiative picture in Coulomb gauge, which naturally leads us to split the water displacement in an instantaneous and a retarded part. The Minnaert renormalized mass of the dressed bubble is then automatically recovered

  3. A comparison of corn fiber gum, hydrophobically modified starch, gum arabic and soybean soluble polysaccharide: interfacial dynamics, viscoelastic response at oil/water interfaces and emulsion stabilization mechanisms

    Science.gov (United States)

    The interfacial rheology of polysaccharide adsorption layers of corn fiber gum (CFG), octenyl succinate anhydride-modified starch (OSA-s), gum arabic (GA) and soybean soluble polysaccharides (SSPS) at the oil/water interface and their emulsifying properties in oil-in-water (O/W) emulsions were compa...

  4. Numerical investigation of bubble nonlinear dynamics characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jie, E-mail: shijie@hrbeu.edu.cn; Yang, Desen; Shi, Shengguo; Hu, Bo [Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001 (China); Zhang, Haoyang; Jiang, Wei [College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001 (China)

    2015-10-28

    The complicated dynamical behaviors of bubble oscillation driven by acoustic wave can provide favorable conditions for many engineering applications. On the basis of Keller-Miksis model, the influences of control parameters, including acoustic frequency, acoustic pressure and radius of gas bubble, are discussed by utilizing various numerical analysis methods, Furthermore, the law of power spectral variation is studied. It is shown that the complicated dynamic behaviors of bubble oscillation driven by acoustic wave, such as bifurcation and chaos, further the stimulated scattering processes are revealed.

  5. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  6. Primordial bubbles of colour superconducting quark matter

    International Nuclear Information System (INIS)

    Masperi, L.; Orsaria, M.

    2004-01-01

    We analyze the possibility that bubbles of quark matter surviving the confinement phase transition might have become superconducting due to the enormous compression they suffer. Because of the relatively high temperature of the process we compare the initially unpaired quark matter with the colour-flavour locked alternative when the extremely large chemical potential could have increased the critical temperature sufficiently and find that this latter phase would be more stable before the bubble compression stops. If other physical effects had not affected completely their stability, these bubbles might still exist today and perhaps be observed as strangelets

  7. Dynamics of bubbles in general relativity

    International Nuclear Information System (INIS)

    Berezin, V.A.; Kuzmin, V.A.; Tkachev, I.I.

    1987-01-01

    This is a systematic study of the evolution of thin shell bubbles in general relativity. We develop the general thin-wall formalism first elaborated by Israel and apply it to the investigation of the motion of various bubbles arising in the course of phase transitions in the very early Universe including new phase bubbles, old phase remnants, and domains. We consider metric junction conditions and derive constraints both on the decay of metastable states and on the evolution of non- equilibrium scalar field configurations (fluctuations) following from the global geometry of spacetime

  8. Blackbody spectra for sonoluminescing hydrogen bubbles.

    Science.gov (United States)

    Vazquez, George; Camara, C; Putterman, S J; Weninger, K

    2002-05-13

    The dynamical motion of sonoluminescing bubbles formed from a mixture of water and hydrogen gas indicates that these bubbles contain hydrogen. Their spectrum is well matched by an ideal 6000 K blackbody radiating from a surface with a radius less than 1/4 microm. According to this model, the state of matter inside the collapsed bubble is so stressed that the photon mean free path is much smaller than 1 microm. Implications for various theories of the light-emitting mechanism and the role of chemical reactions are discussed.

  9. Holography in a freon bubble chamber

    International Nuclear Information System (INIS)

    Lecoq, P.; Olivier, P.

    1982-01-01

    After some tests in a PS beam in the summer of 1981, the run took place in October 1981 in the H2 beam of the SPS. Although some problems of heat dissipation in freon limited the expansion rate of the bubble chamber, more than 11000 holograms were taken, showing 10 μm bubble tracks, with very good image quality and contrast. More than 100 tracks can be stored on a hologram without affecting the quality if all the bubbles are small. In addition, the analysis of the holograms does not look more complex than the exploitation of conventional high-resolution pictures. (orig./HSI)

  10. Bubble detectors in individual neutron dosimetry

    International Nuclear Information System (INIS)

    Spurny, F.; Votockova, I.

    1996-01-01

    Bubble detectors be able to fulfill requirements following from the ICRP 60 recommendations as far as individual neutron dosemeter is concerned. Particularly, the lowest limit of detection seems to be decreased down to about 10 μSv or even lower. At the moment there are two types of such detectors commercially available: bubble damage neutron detectors (BDNDs -Bubble Technology Industries, Chalk River) and superheated drop detectors (SDDs - Apfel Enterpr., New Haven). Both these types have been tested in our studies from the point of view of personal dosimetry. Particular attention is devoted their energetic dependences and their responses in the fields in which they should be wed to determine occupational exposures. (author)

  11. A model established of a 'Embryo' bubble growing-up some visible bubble in bubble chamber and its primary theory calculation

    International Nuclear Information System (INIS)

    Ye Zipiao; Sheng Xiangdong

    2006-01-01

    A model of a 'embryo' bubble growing up a visible bubble in the bubble chamber is established. Through primary theory calculation it is shown that the 'embryo' bubble is not only absorbing quantity of heat, but also some molecules get into the 'embryo' bubble from its environment. It is explained reasonably that the radius of bubbles in bubble camber is different for the same energies of neutrons and proton. The track of neutron in bubble camber is long and thin, and the track of proton in bubble camber is wide and short. It is explained reasonably that the bubble radius of the incident particles with more charges which there are the same energies will be wider than that of the incident particles with less charges in the track. It is also explained reasonably that there are a little different radius of the bubbles of a track at the some region. It can be predicted theoretically that there should be big bubbles to burst when incident particles enter the bubble chamber at first. The sensitivity and the detective efficiency of bubble camber can be enhanced by choosing appropriate work matter. (authors)

  12. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring systems. Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor...

  13. Modeling birds on wires.

    Science.gov (United States)

    Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

    2017-02-21

    In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Conservation of bubble size distribution during gas reactive absorption in bubble column reactors

    Directory of Open Access Journals (Sweden)

    P. L.C. LAGE

    1999-12-01

    Full Text Available Conservation of the bubble size distribution function was applied to the reactive absorption of carbon dioxide in a bubble column reactor. The model developed was solved by the method of characteristics and by a Monte Carlo method. Simulations were carried out using simplified models for the liquid phase and for the gas-liquid mass transfer. Predictions of gas holdup and outlet gas composition showed that the concept of a mean bubble diameter is not applicable when the bubble size distribution is reasonably polydispersed. In these cases, the mass mean velocity and the numerical mean velocity of the bubbles are very different. Therefore, quantification of the polydispersion of bubbles was shown to be essential to gas-phase hydrodynamics modeling.

  15. Interactions of multiple spark-generated bubbles with phase differences

    Science.gov (United States)

    Fong, Siew Wan; Adhikari, Deepak; Klaseboer, Evert; Khoo, Boo Cheong

    2009-04-01

    This paper aims to study the complex interaction between multiple bubbles, and to provide a summary and physical explanation of the phenomena observed during the interaction of two bubbles. High-speed photography is utilized to observe the experiments involving multiple spark-generated bubbles. Numerical simulations corresponding to the experiments are performed using the Boundary Element Method (BEM). The bubbles are typically between 3 and 5 mm in radius and are generated either in-phase (at the same time) or with phase differences. Complex phenomena are observed such as bubble splitting, and high-speed jetting inside a bubble caused by another collapsing bubble nearby (termed the ‘catapult’ effect). The two-bubble interactions are broadly classified in a graph according to two parameters: the relative inter-bubble distance and the phase difference (a new parameter introduced). The BEM simulations provide insight into the physics, such as bubble shape changes in detail, and jet velocities. Also presented in this paper are the experimental results of three bubble interactions. The interesting and complex observations of multiple bubble interaction are important for a better understanding of real life applications in medical ultrasonic treatment and ultrasonic cleaning. Many of the three bubble interactions can be explained by isolating bubble pairs and classifying their interaction according to the graph for the two bubble case. This graph can be a useful tool to predict the behavior of multiple bubble interactions.

  16. Stability of a Bubble Expanding and Translating Through an Inviscid ...

    Indian Academy of Sciences (India)

    A bubble expands adiabatically and translates in an incompressible and inviscid liquid. We investigate the number of equilibrium points of the bubble and the nature of stability of the bubble at these points. We find that there is only one equilibrium point and the bubble is stable there.

  17. Tropical Bubbles : Asset Prices in Latin America, 1980-2001

    OpenAIRE

    Herrera, Santiago; Perry, Guillermo

    2001-01-01

    The authors test for the existence of asset price bubbles in Latin America in 1980-2001, focusing mainly on stock prices. Based on unit root and cointegration tests, they find that they cannot reject the hypothesis of bubbles. They arrive at the same conclusion using Froot and Obstfeld's intrinsic bubbles model. To examine empirical regularities of these bubble episodes in the region, the ...

  18. MARANGONI CONVECTION AROUND A VENTILATED AIR BUBBLE UNDER MICROGRAVITY CONDITIONS

    NARCIS (Netherlands)

    HOEFSLOOT, HCJ; JANSSEN, LPBM; HOOGSTRATEN, HW

    Under microgravity conditions in both parabolic and sounding rocket flights, the mass-transfer-induced Marangoni convection around an air bubble was studied. To prevent the bubble from becoming saturated, the bubble was ventilated. It turned out that the flow rate of the air through the bubble

  19. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  20. Composite conductor containing superconductive wires

    Energy Technology Data Exchange (ETDEWEB)

    Larson, W.L.; Wong, J.

    1974-03-26

    A superconductor cable substitute made by coworking multiple rods of superconductive niobium--titanium or niobium--zirconium alloy with a common copper matrix to extend the copper and rods to form a final elongated product which has superconductive wires distributed in a reduced cross-section copper conductor with a complete metallurgical bond between the normal-conductive copper and the superconductor wires contained therein is described. The superconductor cable can be in the form of a tube.

  1. 30 CFR 75.701-4 - Grounding wires; capacity of wires.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding wires; capacity of wires. 75.701-4... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.701-4 Grounding wires; capacity of wires. Where grounding wires are used to ground metallic sheaths, armors, conduits, frames...

  2. Black Hole Blows Big Bubble

    Science.gov (United States)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  3. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  4. IMPLEMENTATION OF SERIAL AND PARALLEL BUBBLE SORT ON FPGA

    Directory of Open Access Journals (Sweden)

    Dwi Marhaendro Jati Purnomo

    2016-06-01

    Full Text Available Sorting is common process in computational world. Its utilization are on many fields from research to industry. There are many sorting algorithm in nowadays. One of the simplest yet powerful is bubble sort. In this study, bubble sort is implemented on FPGA. The implementation was taken on serial and parallel approach. Serial and parallel bubble sort then compared by means of its memory, execution time, and utility which comprises slices and LUTs. The experiments show that serial bubble sort required smaller memory as well as utility compared to parallel bubble sort. Meanwhile, parallel bubble sort performed faster than serial bubble sort

  5. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  6. Sulfomethylated graft copolymers of xanthan gum and polyacrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, I.W.; Empey, R.A.; Racciato, J.S.

    1978-08-08

    A water-soluble anionic graft copolymer of xanthan gum and polyacrylamide is described in which at least part of the amide function of the acrylamide portion of the copolymer is sulfomethylated and the xanthan gum portion of the copolymer is unreacted with formaldehyde. The copolymer is sulfomethylated by reaction with formaldehyde and sodium metabisulfite. The formaldehyde does not cause any appreciable cross-linking between hydroxyl groups of the xanthan moieties. The sulfomethylation of the acrylamido group takes place at temperatures from 35 to 70 C. The pH is 10 or higher, typically from 12 to 13. The degree of anionic character may be varied by adjusting the molar ratio of formaldehyde and sodium metabisulfite with respect to the copolymer. 10 claims.

  7. Microwave Assisted Grafting of Gums and Extraction of Natural Materials.

    Science.gov (United States)

    Singh, Inderbir; Rani, Priya; Kumar, Pradeep

    2017-01-01

    Microwave assisted modification of polymers has become an established technique for modifying the functionality of polymers. Microwave irradiation reduces reaction time as well as the use of toxic solvents with enhanced sensitivity and yields of quality products. In this review article instrumentation and basic principles of microwave activation have been discussed. Microwave assisted grafting of natural gums, characterization of grafted polymers and their toxicological parameters have also been listed. Pharmaceutical applications viz. drug release retardant, mucoahesion and tablet superdisintegrant potential of microwave assisted gums has also been discussed. An overview of microwave assisted extraction of plant based natural materials has also been presented. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Locust bean gum: Exploring its potential for biopharmaceutical applications

    Directory of Open Access Journals (Sweden)

    Marita Dionísio

    2012-01-01

    Full Text Available Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua. This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed.

  9. Lattice Boltzmann Simulation of Multiple Bubbles Motion under Gravity

    Directory of Open Access Journals (Sweden)

    Deming Nie

    2015-01-01

    Full Text Available The motion of multiple bubbles under gravity in two dimensions is numerically studied through the lattice Boltzmann method for the Eotvos number ranging from 1 to 12. Two kinds of initial arrangement are taken into account: vertical and horizontal arrangement. In both cases the effects of Eotvos number on the bubble coalescence and rising velocity are investigated. For the vertical arrangement, it has been found that the coalescence pattern is similar. The first coalescence always takes place between the two uppermost bubbles. And the last coalescence always takes place between the coalesced bubble and the bottommost bubble. For four bubbles in a horizontal arrangement, the outermost bubbles travel into the wake of the middle bubbles in all cases, which allows the bubbles to coalesce. The coalescence pattern is more complex for the case of eight bubbles, which strongly depends on the Eotvos number.

  10. Optimization of the bubble radius in a moving single bubble sonoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Mirheydari, Mona; Sadighi-Bonabi, Rasoul; Rezaee, Nastaran; Ebrahimi, Homa, E-mail: sadighi@sharif.ir [Department of Physics, Sharif University of Technology, 11365-91, Tehran (Iran, Islamic Republic of)

    2011-05-01

    A complete study of the hydrodynamic force on a moving single bubble sonoluminescence in N-methylformamide is presented in this work. All forces exerted, trajectory, interior temperature and gas pressure are discussed. The maximum values of the calculated components of the hydrodynamic force for three different radii at the same driving pressure were compared, while the optimum bubble radius was determined. The maximum value of the buoyancy force appears at the start of bubble collapse, earlier than the other forces whose maximum values appear at the moment of bubble collapse. We verified that for radii larger than the optimum radius, the temperature peak value decreases.

  11. Optimization of the bubble radius in a moving single bubble sonoluminescence

    International Nuclear Information System (INIS)

    Mirheydari, Mona; Sadighi-Bonabi, Rasoul; Rezaee, Nastaran; Ebrahimi, Homa

    2011-01-01

    A complete study of the hydrodynamic force on a moving single bubble sonoluminescence in N-methylformamide is presented in this work. All forces exerted, trajectory, interior temperature and gas pressure are discussed. The maximum values of the calculated components of the hydrodynamic force for three different radii at the same driving pressure were compared, while the optimum bubble radius was determined. The maximum value of the buoyancy force appears at the start of bubble collapse, earlier than the other forces whose maximum values appear at the moment of bubble collapse. We verified that for radii larger than the optimum radius, the temperature peak value decreases.

  12. Enhancement of electrical conductivity in the Gum Arabica complex

    International Nuclear Information System (INIS)

    Pradhan, Sourav S.; Sarkar, A.

    2009-01-01

    Gum Arabica is a natural biopolymer obtained from plant Acacia Arabica. In this present study the electro-active nature of its complex has been investigated. The complexes were developed using pure Gum Arabica and pure Citric acid by the sol-gel process. The scope of complex formation has been investigated and their natures were examined experimentally. The experiments which were carried out in this work are namely d.c V-I characteristics, d.c Arrhenius, ion transference number measurement, UV-VIS and IR photo-absorption. Solid specimen of the complex at various concentration of Citric acid has been developed for d.c experiments and adequate specimens were also developed for UV-VIS experiment. The result of d.c V-I characteristics on specimens at different Citric acid concentrations shows that d.c conductivity increases with concentration of the acid. The said enhancement is observed to be about 100 times that of pure hosts. The ion transference number measurement shows that the total conductivity increases with external acid concentration of which d.c conductivity enhance many times compared to that of ionic part. The result from d.c Arrhenius study shows that electro-thermal activation energy decreases with increasing acid concentration leading to enhancement of electronic conductivity of the complex. The result of UV-VIS study confirms the formation of the acid complex of Gum Arabica. The nature of photo-absorption indicates very clearly that main absorption region shows gradual shifts towards longer wavelength with increase of acid concentration. The result of FTIR absorption shows the structural concepts of electro-activity and complex formation indication of pure Gum Arabica. The overall analysis shows that the electro-activity of the mentioned biopolymer may be tailored.

  13. Carboxy methylation of cashew nut tree exudate gum

    International Nuclear Information System (INIS)

    Silva, Durcilene A. da; Paula, Regina C.M.

    2001-01-01

    Anacardium occidentale exudate polysaccharide was carboxymethylated with monochloroacetic acid. The samples were characterized by NMR, solution viscometry, GPC and thermal analysis. Carboxymethylated cashew gum (CMGC) with a degree of substitution between 0,1-0,16 was obtained. Solution viscometry and GPC analysis showed that polymer molar mass degradation occurred. Sample with higher DS shows higher peak molar mass, intrinsic viscosity and thermal stability. NMR spectrum indicated that the carboxy methylation reaction occurs preferentially in C-6 of galactose residue. (author)

  14. Cryoextraction: A novel approach to remove aspirated chewing gum

    Directory of Open Access Journals (Sweden)

    Edmundo Rubio

    2013-01-01

    Full Text Available The extraction of aspirated foreign bodies can prove challenging at times, requiring even rigid bronchoscopy. Cryotherapy probes have been reported to help with extraction of foreign bodies. We present a case where successful "cryoextraction" was performed on an aspirated chewing gum. The case highlights the fact that this technique is useful to extract all materials that have water content. This technique can be performed through flexible bronchoscopy and can save patients from more aggressive approaches.

  15. Chewing gum and lozenges as delivery systems for noscapine

    DEFF Research Database (Denmark)

    Norgaard Jensen, L.; Christrup, Lona Louring; Menger, N.

    1991-01-01

    base. The release characteristics of the preparations were evaluated both in vitro and in vivo, and their taste properties examined. Only the formulations containing noscapine base were without any appreciable taste. Chewing gum containing this compound showed, however, a low level of drug release both...... in vitro and in vivo and is therefore not a suitable dosage form. Only a lozenge formulation containing noscapine base fulfilled the requirements of taste acceptability and adequate release properties....

  16. Bubble collisions and measures of the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Salem, Michael P., E-mail: salem@cosmos.phy.tufts.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2012-01-01

    To compute the spectrum of bubble collisions seen by an observer in an eternally-inflating multiverse, one must choose a measure over the diverging spacetime volume, including choosing an ''initial'' hypersurface below which there are no bubble nucleations. Previous calculations focused on the case where the initial hypersurface is pushed arbitrarily deep into the past. Interestingly, the observed spectrum depends on the orientation of the initial hypersurface, however one's ability observe the effect rapidly decreases with the ratio of inflationary Hubble rates inside and outside one's bubble. We investigate whether this conclusion might be avoided under more general circumstances, including placing the observer's bubble near the initial hypersurface. We find that it is not. As a point of reference, a substantial appendix reviews relevant aspects of the measure problem of eternal inflation.

  17. Loop exponent in DNA bubble dynamics

    Science.gov (United States)

    Kaiser, Vojtěch; Novotný, Tomáš

    2014-08-01

    Dynamics of DNA bubbles are of interest for both statistical physics and biology. We present exact solutions to the Fokker-Planck equation governing bubble dynamics in the presence of a long-range entropic interaction. The complete meeting time and meeting position probability distributions are derived from the solutions. Probability distribution functions (PDFs) reflect the value of the loop exponent of the entropic interaction. Our results extend previous results which concentrated mainly on the tails of the PDFs and open a way to determining the strength of the entropic interaction experimentally which has been a matter of recent discussions. Using numerical integration, we also discuss the influence of the finite size of a DNA chain on the bubble dynamics. Analogous results are obtained also for the case of subdiffusive dynamics of a DNA bubble in a heteropolymer, revealing highly universal asymptotics of meeting time and position probability functions.

  18. Why do bubbles in Guinness sink?

    Science.gov (United States)

    Benilov, E. S.; Cummins, C. P.; Lee, W. T.

    2013-02-01

    Stout beers show the counter-intuitive phenomena of sinking bubbles, while the beer is settling. Previous research suggests that this phenomenon is due to the small size of the bubbles in these beers and the presence of a circulatory current, directed downwards near the side of the wall and upwards in the interior of the glass. The mechanism by which such a circulation is established and the conditions under which it will occur has not been clarified. In this paper, we use simulations and experiments to demonstrate that the flow in a glass of stout beer depends on the shape of the glass. If it narrows downwards (as the traditional stout glass, the pint, does), the flow is directed downwards near the wall and upwards in the interior and sinking bubbles will be observed. If the container widens downwards, the flow is opposite to that described above and only rising bubbles will be seen.

  19. The 2008 oil bubble: Causes and consequences

    International Nuclear Information System (INIS)

    Tokic, Damir

    2010-01-01

    We argue that 'the 2008 Oil Bubble' was directly and indirectly created by the Federal Reserve in response to deflationary risks that resurfaced after the housing bubble burst and the resulting credit crisis of 2008. Deflationary risks first appeared after the dot.com bubble burst in 2000 and after the terrorist attacks on September 11, 2001. Manipulation of the US dollar value has been one of the key emergency tools in the Fed's arsenal. During the entire period from 2000 to 2008, the US dollar has been falling, while the price of crude oil has been rising, with the culmination in July 2008. If other global central banks embrace the Fed's anti-deflationary strategies, the consequences could be dire for the global economy, potentially resulting in an ultimate gold bubble.

  20. Universe out of a breathing bubble

    International Nuclear Information System (INIS)

    Guendelman, Eduardo I.; Sakai, Nobuyuki

    2008-01-01

    We consider the model of a false-vacuum bubble with a thin wall where the surface energy density is composed of two different components, 'domain-wall' type and 'dust' type, with opposite signs. We find stably oscillating solutions, which we call 'breathing bubbles'. By decay to a lower mass state, such a breathing bubble could become either (i) a child universe or ii) a bubble that 'eats up' the original universe, depending on the sign of the surface energy of the domain-wall component. We also discuss the effect of the finite-thickness corrections to the thin-wall approximation and possible origins of the energy contents of our model

  1. Modelling of large-scale dense gas-solid bubbling fluidised beds using a novel discrete bubble model

    NARCIS (Netherlands)

    Bokkers, G.A.; Laverman, J.A.; van Sint Annaland, M.; Kuipers, J.A.M.

    2006-01-01

    In order to model the complex hydrodynamic phenomena prevailing in industrial scale gas–solid bubbling fluidised bed reactors and especially the macro-scale emulsion phase circulation patterns induced by bubble–bubble interactions and bubble coalescence, a discrete bubble model (DBM) has been

  2. Preparation and characterization of tragacanth-locust bean gum edible blend films.

    Science.gov (United States)

    Mostafavi, Fatemeh Sadat; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Koocheki, Arash

    2016-03-30

    The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT-LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum

    Science.gov (United States)

    Segura-Campos, Maira Rubi; Ciau-Solís, Norma; Rosado-Rubio, Gabriel; Chel-Guerrero, Luis; Betancur-Ancona, David

    2014-01-01

    Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submitted to fat extraction, producing two fractions: gum with fat (FCG) and gum partly defatted (PDCG). Proximal composition and physicochemical characterization showed these fractions to be different (P pseudoplastic type. PDCG had more viscosity than FCG. Chia seed is an excellent natural source of gum with good physicochemical and functional qualities, and is very promising for use in food industry. PMID:26904622

  4. Efficacy of baking soda-containing chewing gum in removing natural tooth stain.

    Science.gov (United States)

    Mankodi, S M; Conforti, N; Berkowitz, H

    2001-07-01

    A 14-week, double-blind, randomized clinical trial was conducted with 126 healthy volunteers to compare the efficacy of twice-daily use of 3 baking soda-containing chewing gums in removing natural tooth stain when used in conjunction with a program of regular oral hygiene. All 3 chewing gums significantly reduced extrinsic stain (P Baking Soda Gum (AHDC) reduced dental stain by 70.8%, compared to reductions of 71.9% and 65.3%, after use of 2 experimental gum formulations. Whitened appearance improved by 1.73 shade tabs using AHDC gum, and up to 2.49 shade tabs with the experimental formulations. These results suggest that the use of baking soda-containing gum after meals, in conjunction with good oral hygiene, can improve both extrinsic dental staining and the whitened appearance of teeth.

  5. An insight into the emerging exopolysaccharide gellan gum as a novel polymer.

    Science.gov (United States)

    Prajapati, Vipul D; Jani, Girish K; Zala, Bhumi S; Khutliwala, Tohra A

    2013-04-02

    The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C.P. Kelco in Japan and the USA. This article presents a critical review of the available information on the gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production. Factors affecting the fermentative production of gellan gum and problems associated with mass transfer have been addressed. Classification and trade names of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Influence of tragacanth gum in egg white based bioplastics: Thermomechanical and water uptake properties.

    Science.gov (United States)

    López-Castejón, María Luisa; Bengoechea, Carlos; García-Morales, Moisés; Martínez, Inmaculada

    2016-11-05

    This study aims to extend the range of applications of tragacanth gum by studying its incorporation into bioplastics formulation, exploring the influence that different gum contents (0-20wt.%) exert over the thermomechanical and water uptake properties of bioplastics based on egg white albumen protein (EW). The effect of plasticizer nature was also evaluated through the modification of the water/glycerol ratio within the plasticizer fraction (fixed at 40wt.%). The addition of tragacanth gum generally yielded an enhancement of the water uptake capacity, being doubled at the highest content. Conversely, presence of tragacanth gum resulted in a considerable decrease in the bioplastic mechanical properties: both tensile strength and maximum elongation were reduced up to 75% approximately when compared to the gum-free system. Ageing of selected samples was also studied, revealing an important effect of storage time when tragacanth gum is present, possibly due to its hydrophilic character. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Electron acceleration in the bubble regime

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Oliver

    2014-02-03

    The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

  8. THE MORPHOLOGY OF THE GUM AND OF THE DESMODONTIUM

    Directory of Open Access Journals (Sweden)

    M. NICULESCU

    2003-01-01

    Full Text Available The gum and the desmodontium are constituent parts of the morpho-functional complex of the parodontium. Depending on its topographic situation, we can describe three portions of the gum: alveolar, marginal and interdental, each one having its features. Within the gum, the collagen fibres from the subepihtelial net are grouped in alveologingival, dentogingival, circular and interdental, the last ones being seen by us as a single group, called peridental fibres. The desmodontium or the alveolodental ligament or the parodontal ligament makes the relation between the alveolar bone and the radicular cement within the dentoalveolar articulation, articulation known under the name of gomphosis, a syndesmose that does not allow any movement to the tooth. Depending on their topographic situation, the collagen fibres in the constitution of the alveolodental ligament, also called cemento-alveolar fibres, can be divided in marginal, intermediary and apical. The alveolodental ligament has the important role in the transmission of the chewing forces to the resistance structures within the functional architectonics of the cranium.

  9. Long-term effects of guar gum on blood lipids.

    Science.gov (United States)

    McIvor, M E; Cummings, C C; Van Duyn, M A; Leo, T A; Margolis, S; Behall, K M; Michnowski, J E; Mendeloff, A I

    1986-04-01

    While guar gum has been shown to lower total cholesterol and low density lipoprotein cholesterol (LDL-C) in diabetic patients over the short-term, the long-term effects are less well studied and may be unpredictable. Granola bars with and without 6.6 g guar gum were developed and fed to 16 adult volunteers with Type II diabetes mellitus who had been randomized in a double-blind fashion into guar and placebo groups of equal size. Four to six bars were consumed daily with an ad lib diet over a 6-month period. Total cholesterol, total high density lipoprotein cholesterol (HDL-C), subfractions HDL2-C and HDL3-C, LDL-C, and beta-apoprotein were measured at 0 and 6 months. Although LDL-C was lower and triglycerides higher at 6 months than at baseline, these changes were of equal magnitude and direction in both guar and placebo groups. Using each subject as his own control, only the change in triglycerides was statistically significant (P less than 0.025). When male subjects alone were analyzed, the guar group showed a statistically significant decrease in LDL, while the placebo group did not. Other lipid parameters were not significantly changed during the study, despite a positive effect on carbohydrate metabolism from the guar bars. The data suggest either that the hypolipemic effects of guar gum in patients with Type II diabetes mellitus are not sustained for 6 months, or the effects occur only in men.

  10. Sono-chemiluminescence from a single cavitation bubble in water

    International Nuclear Information System (INIS)

    Brotchie, Adam; Shchukin, Dmitry; Moehwald, Helmuth; Schneider, Julia; Pflieger, Rachel

    2012-01-01

    In summary, this study has revealed the conditions required for a single bubble to be sono-chemically active. Evidence of radical-induced processes surrounding the bubble was only observed below the SL threshold, where the bubble was not spatially stable, and did not correlate with emission from excited molecular states inside the bubble. Moreover, this work substantiates recent progress that has been made in bridging the gap between single and multi-bubble cavitation. (authors)

  11. Test ventilation with smoke, bubbles, and balloons

    International Nuclear Information System (INIS)

    Pickering, P.L.; Cucchiara, A.L.; McAtee, J.L.; Gonzales, M.

    1987-01-01

    The behavior of smoke, bubbles, and helium-filled balloons was videotaped to demonstrate the mixing of air in the plutonium chemistry laboratories, a plutonium facility. The air-distribution patterns, as indicated by each method, were compared. Helium-filled balloons proved more useful than bubbles or smoke in the visualization of airflow patterns. The replay of various segments of the videotape proved useful in evaluating the different techniques and in identifying airflow trends responsible for air mixing. 6 refs

  12. Numerical simulation of single bubble boiling behavior

    Directory of Open Access Journals (Sweden)

    Junjie Liu

    2017-06-01

    Full Text Available The phenomena of a single bubble boiling process are studied with numerical modeling. The mass, momentum, energy and level set equations are solved using COMSOL multi-physics software. The bubble boiling dynamics, the transient pressure field, velocity field and temperature field in time are analyzed, and reasonable results are obtained. The numeral model is validated by the empirical equation of Fritz and could be used for various applications.

  13. Bubble nonlinear dynamics and stimulated scattering process

    Science.gov (United States)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  14. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

  15. Bayesian Analysis of Bubbles in Asset Prices

    OpenAIRE

    Andras Fulop; Jun Yu

    2017-01-01

    We develop a new model where the dynamic structure of the asset price, after the fundamental value is removed, is subject to two different regimes. One regime reflects the normal period where the asset price divided by the dividend is assumed to follow a mean-reverting process around a stochastic long run mean. The second regime reflects the bubble period with explosive behavior. Stochastic switches between two regimes and non-constant probabilities of exit from the bubble regime are both all...

  16. Beer tapping: dynamics of bubbles after impact

    Science.gov (United States)

    Mantič-Lugo, V.; Cayron, A.; Brun, P.-T.; Gallaire, F.

    2015-12-01

    Beer tapping is a well known prank where a bottle of beer is impacted from the top by a solid object, usually another bottle, leading to a sudden foam overflow. A description of the shock-driven bubble dynamics leading to foaming is presented based on an experimental and numerical study evoking the following physical picture. First, the solid impact produces a sudden downwards acceleration of the bottle creating a strong depression in the liquid bulk. The existing bubbles undergo a strong expansion and a sudden contraction ending in their collapse and fragmentation into a large amount of small bubbles. Second, the bubble clouds present a large surface area to volume ratio, enhancing the CO2 diffusion from the supersaturated liquid, hence growing rapidly and depleting the CO2. The clouds of bubbles migrate upwards in the form of plumes pulling the surrounding liquid with them and eventually resulting in the foam overflow. The sudden pressure drop that triggers the bubble dynamics with a collapse and oscillations is modelled by the Rayleigh-Plesset equation. The bubble dynamics from impact to collapse occurs over a time (tb ≃ 800 μs) much larger than the acoustic time scale of the liquid bulk (tac = 2H/c ≃ 80 μs), for the experimental container of height H = 6 cm and a speed of sound around c ≃ 1500 m/s. This scale separation, together with the comparison of numerical and experimental results, suggests that the pressure drop is controlled by two parameters: the acceleration of the container and the distance from the bubble to the free surface.

  17. Bubbles on the river of time

    International Nuclear Information System (INIS)

    Gribbin, J.

    1988-01-01

    The paper is concerned with modern cosmology, and the possibility that our Universe is just one bubble among many in some greater suprauniverse. These ideas are connected with the concept of inflation; inflation occurred shortly after the moment of creation of the Universe and just before the fireball stage that represents the big bang proper. A description is given of inflation and its use to explain the creation of the Universe from bubbles of mass-energy. (U.K.)

  18. Bubble parameters analysis of gas-liquid two-phase sparse bubbly flow based on image method

    International Nuclear Information System (INIS)

    Zhou Yunlong; Zhou Hongjuan; Song Lianzhuang; Liu Qian

    2012-01-01

    The sparse rising bubbles of gas-liquid two-phase flow in vertical pipe were measured and studied based on image method. The bubble images were acquired by high-speed video camera systems, the characteristic parameters of bubbles were extracted by using image processing techniques. Then velocity variation of rising bubbles were drawn. Area and centroid variation of single bubble were also drawn. And then parameters and movement law of bubbles were analyzed and studied. The test results showed that parameters of bubbles had been analyzed well by using image method. (authors)

  19. Fearless versus fearful speculative financial bubbles

    Science.gov (United States)

    Andersen, J. V.; Sornette, D.

    2004-06-01

    Using a recently introduced rational expectation model of bubbles, based on the interplay between stochasticity and positive feedbacks of prices on returns and volatility, we develop a new methodology to test how this model classifies nine time series that have been previously considered as bubbles ending in crashes. The model predicts the existence of two anomalous behaviors occurring simultaneously: (i) super-exponential price growth and (ii) volatility growth, that we refer to as the “fearful singular bubble” regime. Out of the nine time series, we find that five pass our tests and can be characterized as “fearful singular bubbles”. The four other cases are the information technology Nasdaq bubble and three bubbles of the Hang Seng index ending in crashes in 1987, 1994 and 1997. According to our analysis, these four bubbles have developed with essentially no significant increase of their volatility. This paper thus proposes that speculative bubbles ending in crashes form two groups hitherto unrecognized, namely those accompanied by increasing volatility (reflecting increasing risk perception) and those without change of volatility (reflecting an absence of risk perception).

  20. FORMULATION OF ACECLOFENAC SUSTAINED RELEASE MATRIX TABLET USING HYDROPHILIC NATURAL GUM

    OpenAIRE

    Parasuram Rajam Radhika; Pankaj R. Kharkate; Thangavel Sivakumar

    2011-01-01

    In order to reduce production costs, a simple, direct compression sustained release formulation consisting of drug Aceclofenac and by using hydrophilic polymer guar gum and tamarind gum as the release modifier was investigated. No interaction between drug and polymer was confirmed by FTIR, which shows the suitability of all excipients with the drug to formulate the sustained release matrix tablets. Five batches of sustained release matrix tablets of Aceclofenac with both guar gum and tamarind...

  1. Effects of Chewing Different Flavored Gums on Salivary Flow Rate and pH

    Directory of Open Access Journals (Sweden)

    Maryam Karami Nogourani

    2012-01-01

    Full Text Available Chewing gum increases salivary flow rate (SFR and pH, but differences in preferences of gum flavor may influence SFR and pH. The aim of this paper was to assess the effect of five different flavors of sucrose-free chewing gum on the salivary flow rate and pH in healthy dental students in Isfahan, Iran. Fifteen (7 men and 8 women healthy dental student volunteers collected unstimulated saliva and then chewed one of five flavored gums for 6 min. The whole saliva was collected and assessed for 6 consecutive days. After unstimulated saliva was collected, stimulated saliva was collected at interval of 0-1, 1–3, and 3–6 minutes after the start of different flavored chewing gums. The SFR and salivary pH were measured. The SFR increased in all five flavored gums at 1, 3, and 6 minutes after start of chewing gums (<0.001. The flow rate of all products reached peak in the 1st minute of stimulation, except spearmint-flavored gums which reached peak in the 6th minute. In the 1st minute, the strawberry-flavored gums showed the highest SFR. During 1–3 minutes, strawberry- and apple-flavored gums showed higher SFR, respectively. Only the spearmint- and cinnamon-flavored gum significantly increased salivary pH. Gum flavored can affect the SFR and pH and special flavors can be advised for different individuals according to their oral conditions.

  2. Chemical and Functional Properties of Chia Seed (Salvia hispanica L.) Gum

    OpenAIRE

    Segura-Campos, Maira Rubi; Ciau-Sol?s, Norma; Rosado-Rubio, Gabriel; Chel-Guerrero, Luis; Betancur-Ancona, David

    2014-01-01

    Chia (Salvia hispanica L.) constitutes a potential alternative raw material and ingredient in food industry applications due to its dietary fiber content. Gum can be extracted from its dietary fiber fractions for use as an additive to control viscosity, stability, texture, and consistency in food systems. The gum extracted from chia seeds was characterized to determine their quality and potential as functional food additives. The extracted chia gum contained 26.2% fat and a portion was submit...

  3. One thousand and one bubbles

    Science.gov (United States)

    Ávila, Jesús; Ramírez, Pedro F.; Ruipérez, Alejandro

    2018-01-01

    We propose a novel strategy that permits the construction of completely general five-dimensional microstate geometries on a Gibbons-Hawking space. Our scheme is based on two steps. First, we rewrite the bubble equations as a system of linear equations that can be easily solved. Second, we conjecture that the presence or absence of closed timelike curves in the solution can be detected through the evaluation of an algebraic relation. The construction we propose is systematic and covers the whole space of parameters, so it can be applied to find all five-dimensional BPS microstate geometries on a Gibbons-Hawking base. As a first result of this approach, we find that the spectrum of scaling solutions becomes much larger when non-Abelian fields are present. We use our method to describe several smooth horizonless multicenter solutions with the asymptotic charges of three-charge (Abelian and non-Abelian) black holes. In particular, we describe solutions with the centers lying on lines and circles that can be specified with exact precision. We show the power of our method by explicitly constructing a 50-center solution. Moreover, we use it to find the first smooth five-dimensional microstate geometries with arbitrarily small angular momentum.

  4. Effects of filament size on critical current density in overpressure processed Bi-2212 round wire.

    Science.gov (United States)

    Jiang, Jianyi; Francis, Ashleigh; Alicea, Ryan; Matras, Maxime; Kametani, Fumitake; Trociewitz, Ulf P; Hellstrom, Eric E; Larbalestier, David C

    2017-06-01

    Bi 2 Sr 2 CaCu 2 O x (Bi-2212) conductor is the only high temperature superconductor manufactured as a round wire and is a very promising conductor for very high field applications. One of the key design parameters of Bi-2212 wire is its filament size, which has been previously reported to affect the critical current density ( J c ) and ac losses. Work with 1 bar heat treatment showed that the optimal filament diameter was about 15 μm but it was not well understood at that time that gas bubbles were the main current limiting mechanism. Here we investigated a recent Bi-2212 wire with a 121×18 filament architecture with varying wire diameter (1.0 to 1.5 mm) using 50 bar overpressure processing. This wire is part of a 1.2 km piece length of 1.0 mm diameter made by Oxford Superconducting Technology. We found that J c is independent of the filament size in the range from 9 to 14 μm, although the n value increased with increasing filament size. A new record J c (4.2 K, 15 T) of 4200 A/mm 2 and J E (4.2 K, 15 T) of 830 A/mm 2 were achieved.

  5. Single-Dose and Multiple-Dose Pharmacokinetics of Nicotine 6 mg Gum.

    Science.gov (United States)

    Hansson, Anna; Rasmussen, Thomas; Kraiczi, Holger

    2017-04-01

    Under-dosing is a recognized problem with current nicotine replacement therapy (NRT). Therefore, a new 6mg nicotine gum has been developed. To compare the nicotine uptake from the 6mg gum versus currently available NRT products, two pharmacokinetic studies were performed. In one randomized crossover study, 44 healthy adult smokers received single doses of 6, 4, and 2mg nicotine gum, and 4mg nicotine lozenge on separate occasions. In a separate randomized crossover multiple-dose study over 11 hours, 50 healthy adult smokers received one 6mg gum every hour and 90 minutes, respectively, one 4mg gum every hour, and one 4mg lozenge every hour. In both studies, blood samples were collected over 12 hours to determine single-dose and multiple-dose pharmacokinetic variables. In the single-dose study, the amount of nicotine released from the 2, 4, and 6mg gums (1.44, 3.36, and 4.94mg) as well as the resulting maximum concentration and area under the curve (5.9, 10.1, and 13.8ng/mL, and 17.1, 30.7, 46.2ng/mL × h, respectively) increased with dose. The maximum concentration and area under the curve of the 6mg gum were 44% and 30% greater, respectively, than those for 4mg lozenge. Upon hourly administration, the steady-state average plasma nicotine concentration with 6mg gum (37.4ng/mL) was significantly higher than those for 4mg lozenge (28.3ng/mL) and 4mg gum (27.1ng/mL). Nicotine delivery via the 6mg gum results in higher plasma nicotine concentrations after a single dose and at steady state than with currently available oral NRT. Under-dosing is a recognized problem with current NRT. Therefore, a new 6mg nicotine gum has been developed. Our studies show that upon single-dose and multiple-dose administration, the 6mg gum releases and delivers more nicotine to the systemic circulation than 2mg gum, 4mg gum, and 4mg lozenge. Thus, each 6mg nicotine gum provides a higher degree of nicotine substitution and/or lasts for a longer period of time than currently available nicotine

  6. Fabrication of electrospun almond gum/PVA nanofibers as a thermostable delivery system for vanillin.

    Science.gov (United States)

    Rezaei, Atefe; Tavanai, Hossein; Nasirpour, Ali

    2016-10-01

    In this study, the fabrication of vanillin incorporated almond gum/polyvinyl alcohol (PVA) nanofibers through electrospinning has been investigated. Electrospinning of only almond gum was proved impossible. It was found that the aqueous solution of almond gum/PVA (80:20, concentration=7% (w/w)) containing 3% (w/w) vanillin could have successfully electrospun to uniform nanofibers with diameters as low as 77nm. According to the thermal analysis, incorporated vanillin in almond gum/PVA nanofibers showed higher thermal stability than free vanillin, making this composite especially suitable for high temperature applications. XRD and FTIR analyses proved the presence of vanillin in the almond gum/PVA nanofibers. It was also found that vanillin was dispersed as big crystallites in the matrix of almond gum/PVA nanofibers. FTIR analysis showed almond gum and PVA had chemical cross-linking by etheric bonds between COH groups of almond gum and OH groups of PVA. Also, in the nanofibers, there were no major interaction between vanillin and either almond gum or PVA. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The development of a simple objective test of mastication suitable for older people, using chewing gums.

    Science.gov (United States)

    Anastassiadou, V; Heath, M R

    2001-12-01

    To develop and assess a simple test for evaluating the mastication of visco-elastic foods and prosthodontic success subsequent to treatment of older people. The weight lost from chewing gum during mastication tests and the saliva secreted is weighed. The percentage of the original gum weight that is chewed out in a defined number of strokes is termed the Masticatory Effectiveness (ME) MATERIAL: Five edentate and three dentate volunteers were selected to provide a range of dental states and age. Four commercially available chewing gums of different origins and perceived hardness were tested, one without sweetener acted as a control for salivary stimulation. Pre-weighed samples of each gum were chewed, each for defined numbers of strokes. The saliva secreted was collected and weighed. The chewed gum was desiccated and the total weight loss of sweeteners chewed out provided an objective measure of chewing performance. Weight loss showed large differences between gums, between subjects and the number of strokes. ME was significantly correlated with salivary secretion rates for two subjects. The interaction between subject and gum was statistically significant, established by an ANOVA model, the value of which is shown for multivariate studies. Differential success between gums of different thickness may provide evaluation of denture stability. Measuring the weight lost from gums during chewing provides a simple test of masticatory effectiveness of visco-elastic foods. This has particular value both in functional assessment of older people and in physiological research.

  8. Compositional analysis and rheological characterization of gum tragacanth exudates from six species of Iranian Astragalus

    DEFF Research Database (Denmark)

    Balaghi, Sima; Mohammadifar, Mohammad Amin; Zargaraan, Azizollaah

    2011-01-01

    The sugar composition and viscoelastic behaviour of Iranian gum tragacanth exuded by six species of Astragalus was investigated at a concentration of 1.3% and varying ionic strength using a controlled shear-rate rheometer. Compositional analysis of the six species of gum tragacanth by high......-performance anion-exchange chromatography with pulsed amperometric detection suggested the occurrence of arabinose, xylose, glucose, galactose, fucose, rhamnose and galacturonic acid residues in the gum structure; however, the proportions of each sugar varied significantly among the gums from the different species...

  9. Whole and crushed nutlets of chia (Salvia hispanica from Mexico as a source of functional gums

    Directory of Open Access Journals (Sweden)

    Maira Segura-Campos

    2014-12-01

    Full Text Available The objective of this study was to characterize the chemical and functional properties of Mexican chia (Salvia hispanica gums extracted from defatted whole and crushed nutlets using the Soxhlet and SFE-CO2 methods. Chia gums have interesting chemical and functional properties for the food industry. The oil and gum yields were in the range of 1.98-16.42% and 5.81-12.60%, respectively. The defatting procedure did not affect significantly the oil and gum extraction; the nutlet type (whole or crushed was the only parameter influencing the yield. The proximate composition and the protein and fiber contents of chia gum were evaluated. Low contents of protein and fiber and high NFE levels were found in whole nutlet gums. The functional properties of chia gum extracted from whole and crushed nutlets with the Soxhlet and SFE-COs methods showed the following ranges of water absorption capacity of 62.64 to 143.66 g/g, water adsorption capacity of 0.69 to 1.35 g/g, and water and oil holding capacity of 100 to 149.28 g/g and19.5 to 40.4 g/g, respectively. The rheological behavior exhibited by the gums was pseudoplastic or shear thinning. From a functional perspective, chia gum is an important food component due its emulsifier and stabilizer potentials.

  10. Chemical and Physical Properties, Safety and Application of Partially Hydrolized Guar Gum as Dietary Fiber

    OpenAIRE

    Yoon, Seon-Joo; Chu, Djong-Chi; Raj Juneja, Lekh

    2007-01-01

    The ideal water-soluble dietary fiber for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clear solutions in beverages. Partially hydrolyzed guar gum (PHGG) produced from guar gum by enzymatic process has the same chemical structure with intact guar gum but less than one-tenth the original molecular length of guar gum, which make available to be used as film former, foam stabilizer and swelling agent. The viscosity of PHGG is about 10 mPa·s...

  11. Locust bean gum: processing, properties and food applications--a review.

    Science.gov (United States)

    Barak, Sheweta; Mudgil, Deepak

    2014-05-01

    Locust bean gum or carob gum is a galactomannan obtained from seed endosperm of carob tree i.e. Ceratonia siliqua. It is widely utilized as an additive in various industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Industrial applications of locust bean gum are due to its ability to form hydrogen bonding with water molecule. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer due to its dietary fiber action. This article focuses on production, processing, composition, properties, food applications and health benefits of locust bean gum. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. MASS-TRANSFER AND BUBBLE-SIZE IN A BUBBLE-COLUMN UNDER PRESSURE

    NARCIS (Netherlands)

    WILKINSON, PM; HARINGA, H; VANDIERENDONCK, LL

    The influence of pressure on the gas hold-up in a bubble column is determined for a sodium sulphite solution in combination with the volumetric mass transfer coefficient. Furthermore, for the same conditions the bubble size is also estimated from photos. The results of these experiments show that

  13. Application of coalescence and breakup models in a discrete bubble model for bubble columns

    NARCIS (Netherlands)

    van den Hengel, E.I.V.; Deen, N.G.; Kuipers, J.A.M.

    2005-01-01

    In this work, a discrete bubble model (DBM) is used to investigate the hydrodynamics, coalescence, and breakup occurring in a bubble column. The DBM, originally developed by Delnoij et al. (Chem. Eng. Sci. 1997, 52, 1429-1458; Chem. Eng. Sci. 1999, 54, 2217-2226),1,2 was extended to incorporate

  14. Financial Bubbles, Real Estate Bubbles, Derivative Bubbles, and the Financial and Economic Crisis

    Science.gov (United States)

    Sornette, Didier; Woodard, Ryan

    The financial crisis of 2008, which started with an initially well-defined epicenter focused on mortgage backed securities (MBS), has been cascading into a global economic recession, whose increasing severity and uncertain duration has led and is continuing to lead to massive losses and damage for billions of people. Heavy central bank interventions and government spending programs have been launched worldwide and especially in the USA and Europe, with the hope to unfreeze credit and bolster consumption. Here, we present evidence and articulate a general framework that allows one to diagnose the fundamental cause of the unfolding financial and economic crisis: the accumulation of several bubbles and their interplay and mutual reinforcement have led to an illusion of a "perpetual money machine" allowing financial institutions to extract wealth from an unsustainable artificial process. Taking stock of this diagnostic, we conclude that many of the interventions to address the so-called liquidity crisis and to encourage more consumption are ill-advised and even dangerous, given that precautionary reserves were not accumulated in the "good times" but that huge liabilities were. The most "interesting" present times constitute unique opportunities but also great challenges, for which we offer a few recommendations.

  15. Convective mass transfer around a dissolving bubble

    Science.gov (United States)

    Duplat, Jerome; Grandemange, Mathieu; Poulain, Cedric

    2017-11-01

    Heat or mass transfer around an evaporating drop or condensing vapor bubble is a complex issue due to the interplay between the substrate properties, diffusion- and convection-driven mass transfer, and Marangoni effects, to mention but a few. In order to disentangle these mechanisms, we focus here mainly on the convective mass transfer contribution in an isothermal mass transfer problem. For this, we study the case of a millimetric carbon dioxide bubble which is suspended under a substrate and dissolved into pure liquid water. The high solubility of CO2 in water makes the liquid denser and promotes a buoyant-driven flow at a high (solutal) Rayleigh number (Ra˜104 ). The alteration of p H allows the concentration field in the liquid to be imaged by laser fluorescence enabling us to measure both the global mass flux (bubble volume, contact angle) and local mass flux around the bubble along time. After a short period of mass diffusion, where the boundary layer thickens like the square root of time, convection starts and the CO2 is carried by a plume falling at constant velocity. The boundary layer thickness then reaches a plateau which depends on the bubble cross section. Meanwhile the plume velocity scales like (dV /d t )1 /2 with V being the volume of the bubble. As for the rate of volume loss, we recover a constant mass flux in the diffusion-driven regime followed by a decrease in the volume V like V2 /3 after convection has started. We present a model which agrees well with the bubble dynamics and discuss our results in the context of droplet evaporation, as well as high Rayleigh convection.

  16. Non-intuitive bubble effects in reactor and containment technology

    International Nuclear Information System (INIS)

    Moody, F.J.

    1991-01-01

    Most people know a lot about bubbles, including how they rise in liquids and the way they appear when the cap is removed from a bottle of carbonated beverage. A lot of bubble knowledge is obtained from bubbling air through water in aquariums to keep the fish alive and happy, or watching scuba divers feed the sharks in large glass tanks at the local zoo. But innocent bubbles can be sources of structural loadings and sometimes destructive fluid behavior. In fact, there are many non-intuitive effects associated with bubbles which have been discovered by experiments and analyses. It has been necessary to design various reactor and containment components in the nuclear energy industry to accommodate the fact that bubbles can expand like compressed springs, or oscillate, or collapse abruptly, and create structural loads. This paper describes several important phenomena associated with bubble action in nuclear reactor and containment systems and the associated loads exerted. An awareness of these effects can help to avoid unwelcome surprises in general thermal-hydraulic applications when a system is disturbed by bubble behavior. Major topics discussed include expanding and collapsing submerged bubbles, steam chugging and ringout, bubble shattering, surprising hot bubble action in a saturated pool, bubble effects on fluid-structure-interaction, waterhammer from collapsing bubble in pipes, and vapor bubble effects on sound speed in saturated mixtures

  17. A grid-independent EMMS/bubbling drag model for bubbling and turbulent fluidization

    DEFF Research Database (Denmark)

    Luo, Hao; Lu, Bona; Zhang, Jingyuan

    2017-01-01

    The EMMS/bubbling drag model takes the effects of meso-scale structures (i.e. bubbles) into modeling of drag coefficient and thus improves coarse-grid simulation of bubbling and turbulent fluidized beds. However, its dependence on grid size has not been fully investigated. In this article, we adopt...... a periodic domain show the new drag model is less sensitive to grid size because of the additional dependence on local slip velocity. When applying the new drag model to simulations of realistic bubbling and turbulent fluidized beds, we find grid-independent results are easier to obtain for high......-velocity turbulent fluidized bed cases. The simulation results indicate that the extended EMMS/bubbling drag model is a potential method for coarse-grid simulations of large-scale fluidized beds....

  18. The release of vitamin C from chewing gum and its effects on supragingival calculus formation.

    Science.gov (United States)

    Lingström, Peter; Fure, Solveig; Dinitzen, Bettina; Fritzne, Christina; Klefbom, Carin; Birkhed, Dowen

    2005-02-01

    The aims of this study were to evaluate (i): whether vitamin C in chewing gum, alone or in combination with carbamide, influences calculus formation, and (ii) whether carbamide affects the release, stability and uptake of vitamin C in a chewing gum. In two test series (Series I and II), 30 subjects, all calculus formers, participated. They were instructed to chew on five (Series I) or 10 (Series II) pieces of gum per day for a period of 3 months. The chewing gums were: vitamin C (60 mg, Series I), non-vitamin C (Series I) and vitamin C + carbamide (30 mg + 30 mg, Series II). In both series, no gum was used as a negative control. Calculus formation was scored on three lingual sites on the six anterior mandibular teeth according to the Volpe-Manhold index. The effect on plaque and gingivitis was also determined. A significant reduction in the total calculus score was observed after the use of vitamin C (33%) and vitamin C + carbamide (12%) gums compared with no gum use; this reduction was most pronounced in the heavy calculus formers. A reduced amount of visible plaque was also observed after use of vitamin C and non-vitamin C gum, but only the vitamin C gum reduced the number of bleeding sites (37%). In a separate study, the release, stability and uptake of vitamin C were evaluated using the iodine titration method in both saliva and urine after exposure to the following gums: vitamin C + carbamide (30 mg + 30 mg) and vitamin C (30 mg). There was no indication that carbamide affected the release, stability or uptake of vitamin C when used in a chewing gum.

  19. Wire Rupture Optimization in Wire Electrical Discharge Machining using Taguchi Approach

    Directory of Open Access Journals (Sweden)

    Maher Ibrahem

    2017-01-01

    Full Text Available Wire electrical discharge machining (WEDM is one of the most important nontraditional machining process that is well-known for cutting difficult to machine materials. The wire electrode along with machining parameters control the WEDM process. This research work focuses on optimizing WEDM parameters using Taguchi technique to minimize wire rupture. Experiments have been done using the L18 orthogonal array. Each experiment is repeated three times to ensure accurate readings of the wire rupture. The statistical methods of signal to noise ratio (S/N ratio is applied to study effects of peak current, pulse width, charging time, wire speed, and wire tension on wire rupture. As a results, the peak current, pulse width, and wire tension have the most significant effect on wire rupture followed by charging time and wire speed. The developed analysis can be used in the metal cutting field to identify the optimum machining parameters for less wire rupture.

  20. Enhancing wire-composite bond strength of bonded retainers with wire surface treatment.

    Science.gov (United States)

    Oesterle, L J; Shellhart, W C; Henderson, S

    2001-06-01

    Bonded orthodontic retainers with wires embedded in composite resin are commonly used for orthodontic retention. The purpose of this study was to test, in vitro, various wire surface treatments to determine the optimal method of enhancing the wire-composite bond strength. Coaxial wires and stainless steel wires with different surface treatments were bonded to bovine enamel and then pulled along their long axes with an Instron universal testing machine. Wire surface treatments included placing a right-angle bend in the wire, microetching the wire, and treating the wire with adhesion promoters; combinations of treatments were also examined. The results demonstrated a 24-fold increase in the wire-composite bond strength of wire that was microetched (sandblasted), compared with that of untreated straight wire. The difference between the amount of force required to break the bond produced by microetching alone (246.1 +/- 46.0 MPa) and that required for the bonds produced by the retentive bend (87.8 +/- 16.3 MPa), the adhesion promoters (silane, 11.0 +/- 3.1 MPa; Metal Primer, 28.5 +/- 15.8 MPa), or for any combination of surface treatments, was statistically significant. Microetching a stainless steel wire produced a higher wire-composite bond strength than that obtained from a coaxial wire (113.5 +/- 27.5 MPa). The results of this study indicate that microetching or sandblasting a stainless steel wire significantly increases the strength of the wire-composite bond.

  1. The stability of large oscillating bubbles

    Science.gov (United States)

    Blake, John; Pearson, Antony

    2002-11-01

    In a most remarkable paper, in October 1942, Penney & Price developed a theory for the stability of large oscillating bubbles; in their case they were interested in underwater explosions. Much of our current understanding on the stability of oscillating bubbles can be traced to the theoretical and experimental insight shown in this paper. While interest in this particular area continues with regard ship survivability to underwater explosions, other newer areas include the oscillatory behaviour of of seismic airgun generated bubbles. Apart from large volume oscillations with a characteristic period, the other dominant parameter is associated with buoyancy. An appropriate parameter is chosen that provides a measure of the distance of migration of a bubble over one period. An analytical and computational analysis of this class of problem reveals that this pressure gradient driven instability, normally observed in the form of a high speed liquid jet threading the bubble, is the most dominant surface instability, a characteristic feature borne out in most experimental and practical applications due to the presence of an incipient pressure gradient associated with hydrostatics, dynamics or boundaries

  2. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.

    2013-04-29

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting on a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, article 264506). These dynamics mainly occur within 50 -s after the first contact, requiring imaging at 1 million f.p.s. For a water drop impacting on a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Reynolds number Re above -12 000, up to 10 partial bubble rings have been observed at the base of the ejecta, starting when the contact is -20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into micro-bubbles. The different refractive index in the pool liquid reveals the destabilization of the vortices and the formation of streamwise vortices and intricate vortex tangles. Fine-scale axisymmetry is thereby destroyed. We show also that the shape of the drop has a strong influence on these dynamics. 2013 Cambridge University Press.

  3. Argonne Bubble Experiment Thermal Model Development III

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-11

    This report describes the continuation of the work reported in “Argonne Bubble Experiment Thermal Model Development” and “Argonne Bubble Experiment Thermal Model Development II”. The experiment was performed at Argonne National Laboratory (ANL) in 2014. A rastered 35 MeV electron beam deposited power in a solution of uranyl sulfate, generating heat and radiolytic gas bubbles. Irradiations were performed at beam power levels between 6 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was recorded. The previous report2 described the Monte-Carlo N-Particle (MCNP) calculations and Computational Fluid Dynamics (CFD) analysis performed on the as-built solution vessel geometry. The CFD simulations in the current analysis were performed using Ansys Fluent, Ver. 17.2. The same power profiles determined from MCNP calculations in earlier work were used for the 12 and 15 kW simulations. The primary goal of the current work is to calculate the temperature profiles for the 12 and 15 kW cases using reasonable estimates for the gas generation rate, based on images of the bubbles recorded during the irradiations. Temperature profiles resulting from the CFD calculations are compared to experimental measurements.

  4. Inflation and bubbles in general relativity

    Science.gov (United States)

    Laguna-Castillo, Pablo; Matzner, Richard A.

    1986-11-01

    Following Israel's study of singular hypersurfaces and thin shells in general relativity, the complete set of Einstein's field equations in the presence of a bubble boundary SIGMA is reviewed for all spherically symmetric embedding four-geometries M+/-. The mapping that identifies points between the boundaries Σ+ and Σ- is obtained explicitly when the regions M+ and M- are described by a de Sitter and a Minkowski metric, respectively. In addition, the evolution of a bubble with vanishing surface energy density is studied in a spatially flat Robertson-Walker space-time, for region M- radiation dominated with a vanishing cosmological constant, and an energy equation in M+ determined by the matching. It is found that this type of bubble leads to a ``worm-hole'' matching; that is, an infinite extent exterior of a sphere is joined across the wall to another infinite extent exterior of a sphere. Interior-interior matches are also possible. Under this model, solutions for a bubble following a Hubble law are analyzed. Numerical solutions for bubbles with constant tension are also obtained.

  5. Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum.

    Science.gov (United States)

    Singh, Sudarshan; Bothara, Sunil B

    2014-01-01

    Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm(-1) (-OH), 1660 cm(-1) (Alkenyl C-H & C=C Stretch), 1632 cm(-1) (-COO-), 1414 cm(-1) (-COO-), and 1219 cm(-1) (-CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose.

  6. Put Your Cable Wiring to the Test.

    Science.gov (United States)

    Day, C. William

    2001-01-01

    Discusses why schools and universities should use testing procedures in any wire bid specification for cable wiring and also know how experienced the installers are in testing and installing structured cabling systems. Key cabling terms are included. (GR)

  7. Vegetation status and socio-economic importance of gum and resin ...

    African Journals Online (AJOL)

    Ethiopian Journal of Biological Sciences ... Abstract. Study on population status, socio-economic importance and threats of gum- and resin-producing plant species was made in Borena, South Wollo, (Ethiopia). ... A total of 14 gum- and resin-bearing plant species representing seven families were recorded. Five of them ...

  8. Analysis of a gum from the exudates of Dichrostachys cinerea (L ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... This study was aimed to investigate the rheological properties, and the moisture and ash contents of the isolated gum resins ... These also play a collateral role to raise cost on health service. One solution to this ... The demulcent properties of Gum Arabic are employed in various cough, diarrhoea and throat ...

  9. Adverse Reaction to Nicotine Gum in Malay Female Smoker: A Case Report

    Science.gov (United States)

    Noorzurani, Md Haris Robson; Bond, Alyson; Wolff, Kim

    2008-01-01

    Nicotine replacement therapies (NRT) are prescribed in smoking cessation programmes to help smokers stop smoking. The ideal dosage of NRT should control cravings and withdrawal symptoms but avoid adverse reactions. This report describes a case of adverse reaction to nicotine gum in a female Malay smoker. Assays taken 2 h after the gum, showed that…

  10. Economic analysis of deforestation : the case of the gum Arabic belt in Sudan

    NARCIS (Netherlands)

    Rahim, A.

    2006-01-01

    Keywords: Gum Arabic; Deforestation; Entry and Exit; Real options Drought; Socio-economic, Oligopoly; Interdependent markets; Stackelberg.The gum arabic belt inSudanoffered in the past an

  11. Effect of chewing gum use on oral hygiene and volatile sulphur ...

    African Journals Online (AJOL)

    Chewing of gum has been favoured by many people because of its beneficial effects. The objective of this study was therefore to determine the difference between the oral hygiene status, organoleptic assessment, self perception of malodour as well as the mouth- air volatile sulphur compound concentration of chewing gum ...

  12. Unveiling the Sources of Chromium in Pictorialist Photographs: Gum-Dichromate Process or Paper Sizing?

    DEFF Research Database (Denmark)

    Vila, Anna; Centeno, Silvia A; Kennedy, Nora W

    2015-01-01

    For this issue of Hand Papermaking devoted to paper sizing, we offer a review and extension of pertinent results obtained in our investigations of the gum-dichromate photographic process, commonly known as the gum-bichromate process.1 We have published three articles to date on our findings; this...

  13. Protein-free cress seed (Lepidium sativum) gum: Physicochemical characterization and rheological properties

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Razavi, Seyed Mohammad Ali; Mohammadifar, Mohammad Amin

    2016-01-01

    Protein-free cress seed gum (PFCSG) was obtained by precipitation of crude cress seed gum (CSG) withethanol followed by treatment with protease. Molecular weight, moisture, ash and uronic acids contentdecreased after elimination of protein. Elimination of protein improved significantly rheologica...

  14. In situ effect of CPP-ACP chewing gum upon erosive enamel loss

    Directory of Open Access Journals (Sweden)

    Catarina Ribeiro Barros de ALENCAR

    Full Text Available Abstract Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPP-ACP on dental erosion. Objective This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase per group of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI – Sugar free chewing gum with CPP-ACP; GII – Conventional sugar free chewing gum; and GIII – No chewing gum (control. Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day. After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (µm. Data were analyzed by Repeated-Measures ANOVA and Tukey’s test (p0.05. Conclusion The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.

  15. A systematic review of the efficacy of gum chewing for the amelioration of postoperative ileus

    NARCIS (Netherlands)

    de Castro, S. M. M.; van den Esschert, J. W.; van Heek, N. T.; Dalhuisen, S.; Koelemay, M. J. W.; Busch, O. R. C.; Gouma, D. J.

    2008-01-01

    BACKGROUND: Recent trials have shown promising results for the efficacy of gum chewing for the amelioration of postoperative ileus. This finding could have a major clinical impact since gum chewing is relatively harmless and cheap while postoperative ileus has a significant impact on healthcare.

  16. Intra-species variation of the properties of gum exudates from Acacia ...

    African Journals Online (AJOL)

    Gum exudates from Acacia senegal var. senegal and Acacia seyal var. fistula from Tanzania have been analyzed and their inter- and intra-species variation of their properties evaluated. The results show that significant inter-species variation of the properties of the gum exudates from the two species exist, whereas only ...

  17. Investigation of the effect of zinc oxide-modified gum Arabic on polar ...

    African Journals Online (AJOL)

    Gum Arabic solution, a water-based adhesive, was modified with zinc oxide filler and the formulation was applied on wood, ceramic, glass and textile substrates. A strip of paper was used as a common adherent to all the substrates. Zinc oxide increased the viscosity of 30wt% gum Arabic solution and increased bond ...

  18. intra-species variation of the properties of gum exudates from acacia ...

    African Journals Online (AJOL)

    a

    senegal e.g. A senegal var. leiorhachis which may also find their way into commercial gum arabic shipments may have solution properties which vary significantly from the main species. This paper presents the intra-species variation of the properties of gum exudates from Acacia senegal var. senegal and A. seyal var. fistula ...

  19. Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets

    DEFF Research Database (Denmark)

    Christrup, Lona Louring; Angelo, H.R.; Bonde, J.

    1990-01-01

    Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum...

  20. Gas chromatographic-mass spectrometric characterisation of plant gums in samples from painted works of art.

    Science.gov (United States)

    Bonaduce, Ilaria; Brecoulaki, Hariclia; Colombini, Maria Perla; Lluveras, Anna; Restivo, Vincenzo; Ribechini, Erika

    2007-12-21

    This paper presents an analytical GC-MS procedure to study the chemical composition of plant gums, determining aldoses and uronic acids in one step. The procedure is based on the silylation of aldoses and uronic acids, released from plant gums by microwave assisted hydrolysis, and previously converted into the corresponding diethyl-dithioacetals and diethyl-dithioacetal lactones. Using this method only one peak for each compound is obtained, thus providing simple and highly reproducible chromatograms. The analytical procedure was optimised using reference samples of raw plant gums (arabic, karaya, ghatti, guar, locust bean and tragacanth, cherry, plum and peach gums), commercial watercolours and paint layers prepared according to ancient recipes at the Opificio delle Pietre Dure of Florence (Italy). To identify gum media in samples of unknown composition, a decisional schema for the gum identification and the principal component analysis of the relative sugar percentage contents were employed. The procedure was used to study samples collected from wall paintings from Macedonian tombs (4th-3rd centuries bc) and from the Mycenaean "Palace of Nestor" (13th century bc) in Pylos, Greece. The presence of carbohydrates was ascertained and plant gum binders (fruit and a mixture of tragacanth and fruit tree gums) were identified in some of the samples.

  1. Market-driven production with transaction costs outlook: Gum arabic collection systems in Senegal

    NARCIS (Netherlands)

    Mujawamariya, G.; Burger, C.P.J.; Haese, D' M.F.C.

    2015-01-01

    Low returns from marketing of non-timber forest products such as gum arabic restrict the collection of these products. A hypothesis is tested that access to good markets motivates collectors to harvest and market gum arabic. Analyses of the choice of participation in group marketing, sale price,

  2. Effect of Guar Gum with Sorbitol Coating on the Properties and Oil Absorption of French Fries

    Directory of Open Access Journals (Sweden)

    Bo Jia

    2017-12-01

    Full Text Available This paper investigated the effects of guar gum with sorbitol coating on the oil absorption of French fries by combined dye oil methods, confocal laser scanning microscopy (CLSM and scanning electron microscopy (SEM. The results showed that pretreatment of blanching with calcium ions and coating with guar gum and sorbitol could significantly reduce the structural oil (STO and penetrated surface oil (PSO of French fries and have no negative effects on its texture and also effectively control the final moisture content (p < 0.05. Compared with control or samples coated with guar gum (blanching with or without calcium ions, the total oil (TO of French fries with guar gum and sorbitol reduced by 50.8%, 33.1% and 30.6%, respectively. CLSM photographs confirmed that STO significantly reduced after coating with guar gum and sorbitol, followed by PSO. In the process of frying, the coatings of guar gum or guar gum with sorbitol could effectively prevent oil from infiltrating the potato tissue, which can be seen in the SEM photographs. The barrier properties of French fries were enhanced by coating guar gum, and sorbitol was added to avoid pores and cracks. Blanching with calcium ion can significantly reduce the final moisture content of coating French fries.

  3. An assessment of the soil-conditioning capacity of gums exuded by ...

    African Journals Online (AJOL)

    This study assesses the soil conditioning capacity of tree gums based on the level of resistance to crumble posed by moulds of treated soils to the impacts of artificial raindrops. Gums exuded by trees viz., Acacia occidental and Parkia bicolor as well as a sample of poly(vinyl) alcohol (PVA) were used as soil conditioners.

  4. Gum bleeding as a symptom of disease: are Nigerian mothers aware?

    African Journals Online (AJOL)

    %) did not know the probable causes of gum bleeding and of the remaining 277, only 61(13.1%) and 42 (9.1%) ascribed the cause to poor oral hygiene and bacteria respectively. Majority of them had wrong perceptions about gum bleeding.

  5. Estimative of relative stiffness of the exudate gum polysaccharides

    International Nuclear Information System (INIS)

    Oliveira, Marilia A.; Paula, Regina C.M.

    2001-01-01

    The Smidsrod empirical stiffness parameter (B) of A. occidentale and A. lebbeck gum were determined using the correlation of intrinsic viscosity [η] with ionic strength. The B value of 0.204 and 0.193 found respectively for A. occidentale and A. lebbeck suggests a flexible the molecule. The ionic strength has a greater influence on the [η]. The decrease of [η] increase of I, from 0.01 M to 0.1 M of NaCl, is higher for A. lebbeck (89%) than for A. occidentale (19%). (author)

  6. The mechanism of strength and deformation in Gum Metal

    International Nuclear Information System (INIS)

    Furuta, T.; Kuramoto, S.; Morris, J.W.; Nagasako, N.; Withey, E.; Chrzan, D.C.

    2013-01-01

    Gum Metal” refers to β-Ti alloys that achieve exceptional elastic elongation and, with a specific alloy composition, appear to deform via a dislocation-free mechanism involving elastic instability at the limit of strength. This paper describes the current status of research on its strength, deformation mechanism and the possible role of stress-induced martensite. The theoretical basis for deformation at ideal strength is presented. The relevant experimental data is then discussed, including ex situ nanoindentation behavior and in situ pillar compression observed by transmission electron microscopy

  7. Wall slip of bubbles in foams

    Science.gov (United States)

    Saugey, A.; Drenckhan, W.; Weaire, D.

    2006-05-01

    We present a computational analysis of the flow of liquid foam along a smooth wall, as encountered in the transport of foams in vessels and pipes. We concentrate on the slip of the bubbles at the wall and present some novel finite element calculations of this motion for the case of fully mobile gas/liquid interfaces. Our two-dimensional simulations provide for the first time the bubble shapes and entire flow field, giving detailed insight into the distribution of stresses and dissipation in the system. In particular, we investigate the relationship between the drag force and the slip velocity of the bubble, which for small slip velocities obeys power laws, as predicted by previous semianalytical treatments.

  8. High energy neutrinos from the Fermi bubbles.

    Science.gov (United States)

    Lunardini, Cecilia; Razzaque, Soebur

    2012-06-01

    Recently the Fermi-LAT data have revealed two gamma-ray emitting bubble-shaped structures at the Galactic center. If the observed gamma rays have hadronic origin (collisions of accelerated protons), the bubbles must emit high energy neutrinos as well. This new, Galactic, neutrino flux should trace the gamma-ray emission in spectrum and spatial extent. Its highest energy part, above 20-50 TeV, is observable at a kilometer-scale detector in the northern hemisphere, such as the planned KM3NeT, while interesting constraints on it could be obtained by the IceCube Neutrino Observatory at the South Pole. The detection or exclusion of neutrinos from the Fermi bubbles will discriminate between hadronic and leptonic models, thus bringing unique information on the still mysterious origin of these objects and on the time scale of their formation.

  9. Bubbles, sparks, and the postwar laboratory

    International Nuclear Information System (INIS)

    Galison, P.

    1989-01-01

    The development and use of bubble chambers and spark chambers in the 1950s form the main thrust of this article, the bubble chamber as an example of ''image-producing'' instruments and the spark chamber as a ''logic'' device. Work on a cloud chamber by Glaser led to the development of the bubble chamber detector using liquid hydrogen, which was later linked to a computer for accurate automatic track analysis. It made possible demonstrations of the existence of a particle or interaction. Spark chambers were easier to build and so soon became common, various types being developed across the world. The development of spark chambers originated in the need for timing devices for the Manhattan Project, but work on their design occurred in a number of units worldwide. (UK)

  10. Fermi Bubbles: Formation Scenarios and Substructure

    Science.gov (United States)

    Finkbeiner, Douglas P.

    2013-04-01

    The Milky Way has gamma-ray lobes extending several kpc above and below the Galactic center, known as the "Fermi Bubbles." Although the Galactic center is quiet today, these bubbles are a hint of past AGN activity, a burst of star formation, or some other dramatic energy injection. In the three years since their discovery, they have been modeled analytically and numerically, and additional radio and x-ray data have been obtained, leading to a number of ideas about their origins. I will review the latest data and report on some possible formation scenarios. I will also give an update on our tentative claim last year of a linear jet-like structure within the bubbles (arXiv:1205.5852).

  11. Rational speculative bubbles: A critical view

    Directory of Open Access Journals (Sweden)

    Radonjić Ognjen

    2007-01-01

    Full Text Available According to the theory of rational bubbles, the bubble is present whenever asset prices progressively diverge from their fundamental value, which occurs because agents expect that asset prices will continue to grow exponentially (self-fulfilling prophecies far in the future and consistently, which promises the realization of ever larger capital gains. In our opinion, the basic shortcoming of this theory refers to the assumption that all market agents are perfectly informed and rational and, accordingly, form homogeneous expectations. The model does not explain decision-making processes or expectation formation, nor does it detect potential psychological and institutional factors that might significantly influence decision making processes and market participants’ reactions to news. Since assumptions of the model critically determine its validity, we conclude that comprehensiveness of the rational bubble model is, to put it mildly, limited.

  12. Bubbles, shocks and elementary technical trading strategies

    Science.gov (United States)

    Fry, John

    2014-01-01

    In this paper we provide a unifying framework for a set of seemingly disparate models for bubbles, shocks and elementary technical trading strategies in financial markets. Markets operate by balancing intrinsic levels of risk and return. This seemingly simple observation is commonly over-looked by academics and practitioners alike. Our model shares its origins in statistical physics with others. However, under our approach, changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. This structure leads to an improved physical and econometric model. We develop models for bubbles, shocks and elementary technical trading strategies. The list of empirical applications is both interesting and topical and includes real-estate bubbles and the on-going Eurozone crisis. We close by comparing the results of our model with purely qualitative findings from the finance literature.

  13. Experimental investigation of bubble plume structure instability

    Energy Technology Data Exchange (ETDEWEB)

    Marco Simiano; Robert Zboray; Francois de Cachard [Thermal-Hydraulics Laboratory, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Djamel Lakehal; George Yadigaroglu [Institute of Energy Technology, Swiss Federal Institute of Technology, ETH-Zentrum/CLT, 8092 Zurich (Switzerland)

    2005-07-01

    Full text of publication follows: The hydrodynamic properties of a 3D bubble plume in a large water pool are investigated experimentally. Bubble plumes are present in various industrial processes, including chemical plants, stirred reactors, and nuclear power plants, e.g. in BWR suppression pools. In these applications, the main issue is to predict the currents induced by the bubbles in the liquid phase, and to determine the consequent mixing. Bubble plumes, especially large and unconfined ones, present strong 3D effects and a superposition of different characteristic length scales. Thus, they represent relevant test cases for assessment and verification of 3D models in thermal-hydraulic codes. Bubble plumes are often unsteady, with fluctuations in size and shape of the bubble swarm, and global movements of the plume. In this case, local time-averaged data are not sufficient to characterize the flow. Additional information regarding changes in plume shape and position is required. The effect of scale on the 3D flow structure and stability being complex, there was a need to conduct studies in a fairly large facility, closer to industrial applications. Air bubble plumes, up to 30 cm in base diameter and 2 m in height were extensively studied in a 2 m diameter water pool. Homogeneously sized bubbles were obtained using a particular injector. The main hydrodynamic parameters. i.e., gas and liquid velocities, void fraction, bubble shape and size, plume shape and position, were determined experimentally. Photographic and image processing techniques were used to characterize the bubble shape, and double-tip optical probes to measure bubble size and void fraction. Electromagnetic probes measured the recirculation velocity in the pool. Simultaneous two-phase flow particle image velocimetry (STPFPIV) in a vertical plane containing the vessel axis provided instantaneous velocity fields for both phases and therefore the relative velocity field. Video recording using two CCD

  14. ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS

    International Nuclear Information System (INIS)

    Bradner, H.; Solmitz, F.

    1958-01-01

    Since its invention by Glaser in 1953, the bubble chamber has become a most valuable tool in high-energy physics. It combines a number of advantages of various older methods of particle detection: it offers high spatial resolution, rapid accumulation of data, some time resolution, and some choice of the nucleus whose interaction one wants to study (bubble chambers have been made to operate with a large number of different liquids, including H 2 , D 2 , He, Xe, and several hydrocarbons). In order to exploit the advantages of spatial resolution and rapid data accumulation, high-speed high-precision analysis procedures must be developed. In this article they discuss some of the problems posed by such analysis. The discussion is based largely on experience gained in performing hydrogen bubble chamber experiments with the University of California's Bevatron (6-Bev proton synchrotron)

  15. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  16. Clinical bending of nickel titanium wires

    OpenAIRE

    Stephen Chain; Priyank Seth; Namrata Rastogi; Kenneth Tan; Mayank Gupta; Richa Singh

    2015-01-01

    Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our invento...

  17. Towards Unconventional Applications of Wire Bonding

    OpenAIRE

    Schröder, Stephan

    2018-01-01

    This thesis presents novel heterogeneous integration approaches of wire materials to fabricated and package MEMS devices by exploring unconventional applications of wire bonding technology. Wire bonding, traditionally endemic in the realm of device packaging to establish electrical die-to-package interconnections, is an attractive back-end technology, offering promising features, such as high throughput, flexibility and placement accuracy. Exploiting the advantages of state-of-the-art wire bo...

  18. Different mechanical properties in Seldinger guide wires

    Directory of Open Access Journals (Sweden)

    Wolfram Schummer

    2015-01-01

    Full Text Available Background and Aims: Most central venous catheters are placed using Seldinger guide wires. EN ISO 11070 is the guideline for testing guide wire flexing performance and tensile strength, and we can safely assume that guide wires in use meet these requirements. Unfortunately, EN ISO 11070 guidelines do not reflect the clinical requirements and we continue to see mechanical failures and their associated complications. Material and Methods: This in vitro study was performed in an accredited laboratory. With regard to flexing, we: (1 Established the minimum flexing performance needed to meet clinical requirements, (2 developed flexing performance tests which mimic clinical requirement, and (3 evaluated the mechanical properties of various guide wires relative to these requirements. With regard to tensile strength, we used the testing method prescribed in ISO 11070, but did not end the test at 5 Newton (N. We continued until the guide wire was damaged, or we reached maximum tractive force. We then did a wire-to-wire comparison. We examined two basic wire constructions, monofil and core and coil. Results: Tensile strength: All wires tested, except one, met EN ISO 11070 requirements for 5 N tensile strength. The mean of the wire types tested ranged from 15.06 N to 257.76 N. Flexing performance: None of the wires kinked. The monofil had no evidence of bending. Two core/coil wires displayed minor bending (angle 1.5°. All other wires displayed bending angles between 22.5° and 43.0°. Conclusion: We recommend that: (1 Clinicians use guide wires with high-end mechanical properties, (2 EN ISO 11070 incorporate our flexing test into their testing method, raise the flexing requirement to kink-proof, (3 and raise the tensile strength requirement to a minimum of 30 N, and (3 all manufacturers and suppliers be required to display mechanical properties of all guide wire, and guide wire kits sold.

  19. submitter Comparison of microstructure, second phases and texture formation during melt processing of Bi-2212 mono- and multifilament wires

    CERN Document Server

    Kadar, J; Rikel, MO; Di Michiel, M; Huang, Y

    2016-01-01

    Based on simultaneous in situ high energy synchrotron micro-tomography and x-ray diffraction (XRD) measurements we compare the microstructural changes and the formation of second phases and texture during the processing of Bi-2212 round wires with 15 μm filament diameter (multifilament) and 650 μm filament diameter (monofilament) fabricated using identical Bi-2212 precursor. The monofilament tomograms show in unprecedented detail how the distributed porosity agglomerates well before Bi-2212 melting decomposition to form lenticular voids that completely interrupt the filament connectivity along the wire axis. When the Bi-2212 phase completely melts connectivity in the axial wire direction is established via the changes in the void morphology from the lenticular voids to bubbles that remain when Bi-2212 crystallises out of the melt. By measuring the attenuation of the monochromatic x-ray beam, the associated Bi-2212 mass density changes have been monitored during the entire heat cycle. The XRD results reveal ...

  20. Vocational Preparation Curriculum: Electrical Wiring.

    Science.gov (United States)

    Usoro, Hogan

    This document is a curriculum guide for instructors teaching vocational preparation for electrical wiring to special needs students. The purpose of the curriculum guide is to provide minimum skills for disadvantaged and handicapped students entering the mainstream; to supplement vocational skills of those students already in a regular training…

  1. Transparency in nanophotonic quantum wires

    International Nuclear Information System (INIS)

    Singh, Mahi R

    2009-01-01

    We have studied the quantum optics of a photonic quantum nanowire doped with an ensemble of three-level nanoparticles. The wire is made from two photonic crystals A and B. Crystal A is embedded within crystal B and acts as a photonic nanowire. It is considered that the conduction band of crystal A lies below that of crystal B. As a result, photons are confined in crystal A and are reflected from crystal B. The bound states of the confined photons are calculated using the transfer matrix method. It is found that the number of bound states in the wire depends on the size of the wire and the energy difference between the conduction band extrema of crystals A and B. The absorption coefficient of the system has also been calculated using the Schroedinger equation method. It is considered that the nanoparticles interact with the photonic bound states. Numerical simulations show that when one of the resonance energies lies near the bound state, the system becomes transparent. However, when the resonance energy lies away from the bound state the crystal reverts to an absorbing state. Similarly, when the radius of the dielectric spheres is changed the location of the transparency peak is shifted. This means that the present system can be switched between two states by changing the size of the wire and the transition energy. These findings can be used to make new types of optical devices.

  2. Health care's 100 most wired.

    Science.gov (United States)

    Solovy, A; Serb, C

    1999-02-01

    They're wired all right, and America's 100 most techno-savvy hospitals and health systems share one more thing: a commitment to using technology to link with employees, patients, suppliers, and insurers. "We want to be a health care travel agency for our community," says one chief information officer. "And we see Internet technology as a key."

  3. Potential benefits of chewing gum for the delivery of oral therapeutics and its possible role in oral healthcare

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Maitra, Amarnath; Dodds, Michael W. J.; Busscher, Henk J.

    2016-01-01

    Introduction: Over the years, chewing gum has developed from a candy towards an oral health-promoting nutraceutical. This review summarizes evidence for the oral health benefits of chewing gum, emphasizing identification of active ingredients in gum that facilitate prevention and removal of oral

  4. Acoustical bubble trapper applied to hemodialysis.

    Science.gov (United States)

    Palanchon, P; Birmelé, B; Tranquart, F

    2008-04-01

    Gaseous microemboli can arise in extracorporeal lines and devices such as dialysis machines. They are associated with severe pulmonary side effects in patients undergoing chronic hemodialysis sessions. The goal of this study was to develop a gaseous emboli trapper using ultrasound waves to remove any air bubble from the tubing system before they reach the patient. A homemade bubble trapper, developed in the laboratory, consists of a Perspex block containing a main channel connected to the tubing of a hemodialysis machine and a second subchannel positioned perpendicularly to the main one, used to trap the air microemboli. The microemboli flowing in the main channel were insonified through an acoustic window with an ultrasound wave, at a frequency of 500 kHz and with a maximal acoustic pressure of 500 kPa, generated by a single-element transducer positioned 3 cm away from the main flow. The radiation force induced by the ultrasound beam acts directly on the flowing air emboli, by pushing them into the subchannel. Two Doppler probes operating both at 2 MHz, connected to a DWL Doppler machine were placed before and after the bubble trapper to count sequentially the number of embolic events. The flow of the machine was varied between 200 mL/min and 500 mL/min. Depending on the flow velocity, the number of microembolic signals (MES) detected by the Doppler probes before and after the trapping system was identical and ranged from 5 to 150 MES/min in absence of the ultrasound irradiation. When the air bubble trapper was activated, a reduction of the number of MES, up to 70%, was achieved. Doppler recordings suggest that the circulating bubbles were either fragmented into smaller bubble fragments or directly got pushed into the second subchannel where they were collected. This simple approach using an ultrasound-based trapping system was shown to operate adequately with the current settings and can be used to filter air microemboli.

  5. The management of xerostomia in patients on haemodialysis: comparison of artificial saliva and chewing gum.

    Science.gov (United States)

    Bots, Casper P; Brand, Henk S; Veerman, Enno C I; Valentijn-Benz, Marianne; Van Amerongen, Barbara M; Nieuw Amerongen, Arie V; Valentijn, Robert M; Vos, Pieter F; Bijlsma, Joost A; Bezemer, Pieter D; ter Wee, Piet M

    2005-04-01

    Many patients on haemodialysis (HD) therapy suffer from a dry mouth and xerostomia. This can be relieved by mechanical and gustatory stimulation or palliative care. The aim of this crossover study was to investigate the effect and preferences of a sugar-free chewing gum (Freedent White) and a xanthan gum-based artificial saliva (Xialine) in the management of xerostomia in chronic HD patients. Sixty-five HD patients participated in a 6-week crossover trial. The artificial saliva was rated significantly lower than the chewing gum for effectiveness, taste and a global assessment. No preference differences were found for gender and age, although older subjects rated the artificial saliva with a higher mark. Thirty-nine subjects (60%) preferred chewing gum, 15% (n=10) preferred the artificial saliva. Therefore, both chewing gum and artificial saliva could play an important role in the palliative care of xerostomia in HD patients.

  6. Synthesis, physico-chemical and biomedical applications of sulfated Aegle marmelos gum: Green chemistry approach

    Directory of Open Access Journals (Sweden)

    Manish Jindal

    2017-05-01

    Full Text Available The present investigation was aimed at obtaining a sulfated derivative of gum obtained from partially ripe fruits of Aegle marmelos employing the ultrasonication technique. Elemental analysis and FTIR-ATR studies confirmed successful sulfation. The molarity of sulfuric acid exerted maximum influence on the degree of substitution followed by reaction temperature and reaction time. The sulfated derivative showed higher swelling in both acidic and alkaline pH as compared to the unmodified gum. It also possessed higher negative zeta potential, higher viscosity, work of shear, firmness, consistency, cohesiveness and index of viscosity as compared to both unmodified gum as well as sodium alginate. Sulfated derivative was superior to unmodified gum and sodium alginate in terms of antimicrobial and anticoagulant activities. The sulfated sample appears to be a potential substitute over the unmodified gum sample and sodium alginate for modulating the physicochemical properties of food and drug release dosage forms.

  7. Purification of cress seed (Lepidium sativum) gum: Physicochemical characterization and functional properties

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Mohammadifar, Mohammad Amin; Razavi, Seyed Mohammad Ali

    2016-01-01

    The aim of the present study was to investigate the effects of different purification methods (ethanol, isopropanol and ethanol-isopropanol) on the physicochemical and functional characteristics of cress seed gum. Sugar composition and molecular weight of the samples varied significantly. All...... the purification methods reduced ash and protein content and molecular weight of cress seed gum. The main decomposition of the purified samples started above 200º C and initial decomposition temperature of the crude gum was 190.21º C. DSC thermograms of the purified gums showed two exothermic events at 257.......81-261.95 ºC and 302.46-311.57 ºC. Crude gum displayed an exothermic peak at 259.42º C. Sample I (purified using isopropanol) imparted the best surface activity among the purified samples as it had the highest protein and uronic acid contents and the lowest Mw. All the purification methods could improve...

  8. Purification of cress seed (Lepidium sativum) gum: A comprehensive rheological study

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Razavi, Seyed Mohammad Ali; Mohammadifar, Mohammad Amin

    2016-01-01

    In this paper, the effects of different purification methods (ethanol (sample E), isopropanol (sample I) and ethanol-isopropanol (sample EI)) on intrinsic viscosity, steady and dynamic rheological properties of cress seed gum were investigated. The gum dispersions exhibited viscoelastic properties......, the storage modulus (G′) was higher than the loss modulus (G″), and mechanical spectra of the crude and purified cress seed gums were classified as weak gels. The purified samples had stronger and more elastic network structure than the crude gum (CSG) and the gel network got stronger along the series of I......, EI and E. All the gum dispersions indicated shear-thinning behavior and the viscosity of the samples followed the order of E > EI > I > CSG. Herschel-Bulkley model was the best model to describe steady shear flow behavior and Arrhenius-type model was also applied to describe the effect of temperature...

  9. Multi-anode wire straw tube tracker

    International Nuclear Information System (INIS)

    Oh, S.H.; Ebenstein, W.L.; Wang, C.W.

    2011-01-01

    We report on a test of a straw tube detector design having several anode (sense) wires inside a straw tube. The anode wires form a circle inside the tube and are read out independently. This design could solve several shortcomings of the traditional single wire straw tube design such as double hit capability and stereo configuration.

  10. Home and School Technology: Wired versus Wireless.

    Science.gov (United States)

    Van Horn, Royal

    2001-01-01

    Presents results of informal research on smart homes and appliances, structured home wiring, whole-house audio/video distribution, hybrid cable, and wireless networks. Computer network wiring is tricky to install unless all-in-one jacketed cable is used. Wireless phones help installers avoid pre-wiring problems in homes and schools. (MLH)

  11. On the preparation of superconducting wires

    International Nuclear Information System (INIS)

    Topare, R.J.; Chinchure, A.D.; Shah, S.S.; Hadole, G.B.

    1993-01-01

    The different methods of preparation of superconducting wires have been discussed. The powder-in-tube technique is followed for the preparation of YBCO and BISCCO superconducting wires. The results are discussed. The present status of the industries in preparing the superconducting wires having the maximum J c values is discussed. (author). 30 refs., 6 figs., 2 tabs

  12. Pre-wired systems prove their worth.

    Science.gov (United States)

    2012-03-01

    The 'new generation' of modular wiring systems from Apex Wiring Solutions have been specified for two of the world's foremost teaching hospitals - the Royal London and St Bartholomew's Hospital, as part of a pounds sterling 1 billion redevelopment project, to cut electrical installation times, reduce on-site waste, and provide a pre-wired, factory-tested, power and lighting system. HEJ reports.

  13. 75 FR 4584 - Wire Decking From China

    Science.gov (United States)

    2010-01-28

    ... COMMISSION Wire Decking From China AGENCY: United States International Trade Commission. ACTION: Scheduling... retarded, by reason of subsidized and less-than-fair-value imports from China of wire decking, provided for..., producers, or exporters in China of wire decking, and that such ] products are being sold in the United...

  14. Bubble dynamics in a superheated liquid

    International Nuclear Information System (INIS)

    Sha, W.T.; Shah, V.L.

    1977-09-01

    The report presents an extensive literature survey on bubble dynamics. Growth of a single spherical bubble moving in a uniformly superheated liquid is considered. Equations of motion and energy are presented in the forms that take into consideration the interaction between the motion and the growth. The fourth-order Runge-Kutta method is used to obtain a simultaneous solution of equations of motion and growth rate, and the solution is compared with available experimental results. Results for liquid sodium are presented for a range of pressures and Jakob numbers

  15. Partial coalescence from bubbles to drops

    KAUST Repository

    Zhang, F. H.

    2015-10-07

    The coalescence of drops is a fundamental process in the coarsening of emulsions. However, counter-intuitively, this coalescence process can produce a satellite, approximately half the size of the original drop, which is detrimental to the overall coarsening. This also occurs during the coalescence of bubbles, while the resulting satellite is much smaller, approximately 10 %. To understand this difference, we have conducted a set of coalescence experiments using xenon bubbles inside a pressure chamber, where we can continuously raise the pressure from 1 up to 85 atm and thereby vary the density ratio between the inner and outer fluid, from 0.005 up to unity. Using high-speed video imaging, we observe a continuous increase in satellite size as the inner density is varied from the bubble to emulsion-droplet conditions, with the most rapid changes occurring as the bubble density grows up to 15 % of that of the surrounding liquid. We propose a model that successfully relates the satellite size to the capillary wave mode responsible for its pinch-off and the overall deformations from the drainage. The wavelength of the primary wave changes during its travel to the apex, with the instantaneous speed adjusting to the local wavelength. By estimating the travel time of this wave mode on the bubble surface, we also show that the model is consistent with the experiments. This wavenumber is determined by both the global drainage as well as the interface shapes during the rapid coalescence in the neck connecting the two drops or bubbles. The rate of drainage is shown to scale with the density of the inner fluid. Empirically, we find that the pinch-off occurs when 60 % of the bubble fluid has drained from it. Numerical simulations using the volume-of-fluid method with dynamic adaptive grid refinement can reproduce these dynamics, as well as show the associated vortical structure and stirring of the coalescing fluid masses. Enhanced stirring is observed for cases with second

  16. A large bubble around the Crab Nebula

    Science.gov (United States)

    Romani, Roger W.; Reach, William T.; Koo, Bon Chul; Heiles, Carl

    1990-01-01

    IRAS and 21 cm observations of the interstellar medium around the Crab nebula show evidence of a large bubble surrounded by a partial shell. If located at the canonical 2 kpc distance of the Crab pulsar, the shell is estimated to have a radius of about 90 pc and to contain about 50,000 solar masses of swept-up gas. The way in which interior conditions of this bubble can have important implications for observations of the Crab are described, and the fashion in which presupernova evolution of the pulsar progenitor has affected its local environment is described.

  17. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is of real particle tracks taken from the CERN 2 m liquid hydrogen bubble chamber and shows the production and decay of a negative omega particle. A negative kaon enters the chamber which decays into many particles, including a negative omega that travels a short distance before decaying into more particles. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  18. Stochastic modelling for financial bubbles and policy

    Directory of Open Access Journals (Sweden)

    John Fry

    2015-12-01

    Full Text Available In this paper, we draw upon the close relationship between statistical physics and mathematical finance to develop a suite of models for financial bubbles and crashes. By modifying previous approaches, we are able to derive novel analytical formulae for evaluation problems and for the expected timing of future change points. In particular, we help to explain why previous approaches have systematically overstated the timing of changes in market regime. The list of potential empirical applications is deep and wide ranging, and includes contemporary housing bubbles, the Eurozone crisis and the Crash of 2008.

  19. Antinociceptive activity of Astragalus gummifer gum (gum tragacanth through the adrenergic system: A in vivo study in mice

    Directory of Open Access Journals (Sweden)

    Seyyed Majid Bagheri

    2015-01-01

    Full Text Available Background: In Iranian traditional medicine, gum obtained from Astragalus gummifer and some other species of Astragalus was used as analgesic agent. Objective: In this study, we investigated the antinociceptive effect of several concentrations (125, 250, and 500 μg/kg body weight of Astragalus gummifer gum (AGG on thermal and acetic acid induced pain in mice. Materials and Methods: AGG was dissolved in distillated water and injected i.p to male mice 15 minute before the onset of experiment. Writhing and hot-plate tests were applied to study the analgesic effect of AGG and compared with that of diclofenac sodium (30 mg/kg, i.p. or morphine (8 mg/kg, i.p. To investigate the mechanisms involved in antinociception, yohimbine, naloxone, glibenclamide, and theophylline were used in writhing test. These drugs were injected intraperitoneally 15 min before the administration of AGG. The number of writhes were counted in 30 minutes and analyzed. Results: AGG exhibited a significant antinociceptive effect and the most effective dose of AGG was 500 μg/kg. The most maximum possible effect (%MPE was observed (117.4% 15 min after drug administration. The %inhibition of acetic acid-induced writhing in AGG 125, 250 and 500 was 47%, 50% and 54% vs %15 of control and 66.3% of diclofenac sodium group. The antinociceptive effect induced by this gum in the writhing test was reversed by the systemic administration of yohimbine (α2 -adrenergic antagonist, but naloxone, glibenclamide, and theophylline did not reverse this effect. Conclusions: The findings of this study indicated that AGG induced its antinociceptive through the adrenergic system.

  20. Simulations of Bubble Motion in an Oscillating Liquid

    Science.gov (United States)

    Kraynik, A. M.; Romero, L. A.; Torczynski, J. R.

    2010-11-01

    Finite-element simulations are used to investigate the motion of a gas bubble in a liquid undergoing vertical vibration. The effect of bubble compressibility is studied by comparing "compressible" bubbles that obey the ideal gas law with "incompressible" bubbles that are taken to have constant volume. Compressible bubbles exhibit a net downward motion away from the free surface that does not exist for incompressible bubbles. Net (rectified) velocities are extracted from the simulations and compared with theoretical predictions. The dependence of the rectified velocity on ambient gas pressure, bubble diameter, and bubble depth are in agreement with the theory. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. A note on effects of rational bubble on portfolios

    Science.gov (United States)

    Wang, Chan; Nie, Pu-yan

    2018-02-01

    In general, demand increases in wealth and decreases in price in microeconomics. We thereby propose a completely different perspective. By establishing expected utility function of investors, this article introduces one rational bubble asset and one bubble free asset in portfolios and focuses on the effects of bubble on investment portfolios from wealth and price perspectives. All conclusions are obtained by theoretical analysis with microeconomics theory. We argue that inferior goods and Giffen behavior can occur for the bubble free asset in microeconomic fields. The results can help investors to recognize bubble assets and bubble free assets more scientifically. Both bubble and bubble free assets can be inferior goods under some conditions, so we cannot to say which asset better than the other one absolutely.

  2. Effect of Different Types of Toothpaste on the Frictional Resistance Between Orthodontic Stainless Steel Brackets and Wires

    Science.gov (United States)

    Hosseinzadeh Nik, Tahereh; Hooshmand, Tabassom

    2017-01-01

    Objectives: The purpose of this study was to investigate the effect of different types of toothpaste on the frictional resistance between stainless steel brackets and archwires. Materials and Methods: Ninety stainless steel orthodontic brackets with stainless steel wires were bonded to bovine teeth and were divided into 6 groups for application of the following toothpastes: Colgate® Total® Advanced Whitening, Colgate® Total® Pro Gum Health, Colgate® Anticavity, Ortho.Kin®, and Sunstar GUM® Ortho toothpastes. No toothpaste was applied in the control group. Each group was brushed by a brushing machine with the use of the designated solution for 4.5 minutes. The frictional force was measured in a universal testing machine with a crosshead speed of 10 mm/minute over a 5-mm archwire. Data were analyzed using one-way analysis of variance (ANOVA) at the 0.05 significance level. Results: The frictional resistance values of Ortho.Kin® and GUM® Ortho toothpastes and the control group were not significantly different (P>0.05). However, there were significant differences between the frictional resistance values of Colgate® Total® Pro Gum Health and Colgate® Anticavity toothpastes with that of the control group (Porthodontic toothpastes did not increase the frictional resistance between the orthodontic stainless steel brackets and wires. PMID:29296113

  3. Contact Lens Wear at Altitude: Subcontact Lens Bubble Formation

    Science.gov (United States)

    1987-11-01

    incidence of (PMMA) lenses . Reported here are the results of contact lens subcontact lens bubble formation under scleral lenses at bubble studies with soft...vision from formation of large bubbles greater than 6,096 m (20,000 It). With soft contact lenses , bubble under their contact lenses . They also found...always located at the limbus and were without sequela to vision or corneal epithelial integrity. scleral lenses used by Jaeckle were permeable to gases

  4. Magnetic field induced motion behavior of gas bubbles in liquid

    OpenAIRE

    Keliang Wang; Pucheng Pei; Yu Pei; Ze Ma; Huachi Xu; Dongfang Chen

    2016-01-01

    The oxygen evolution reaction generally exists in electrochemical reactions. It is a ubiquitous problem about how to control the motion of oxygen bubbles released by the reaction. Here we show that oxygen bubbles during oxygen evolution reaction exhibit a variety of movement patterns in the magnetic field, including directional migration and rotational motion of oxygen bubbles when the magnet in parallel with the electrode, and exclusion movement of oxygen bubbles when the magnet perpendicula...

  5. Boundary curvature effects on gas bubble oscillations in underwater explosion

    OpenAIRE

    Matsumoto, Kazuhiro

    1996-01-01

    The oscillation of a gas bubble produced as a result of underwater explosion could cause the severe whipping damage on nearby marine vehicle. The effects of rigid boundary curvatures to explosive gas bubble oscillation behavior in underwater were investigated. The analyses were conducted using a multimaterial Lagrangian-Eulerian finite element code, MSC/DYTRAN. The incident shock wave pressure, bubble pulse pressure, gas bubble radius and period were calculated for the case of detonation of a...

  6. Franšīzes līgums

    OpenAIRE

    Bērziņš, Artūrs

    2011-01-01

    Bakalaura darba "Franšīzes līgums" mērķis ir jaunā nacionālā tiesiskā regulējuma izpēte, tā atbilstības starptautiskajam regulējumam konstatēšana. Bakalaura darbs sastāv no četrām nodaļām, kurās tiek aplūkots franšīzes līgums un tā būtība, tā atšķirība no citiem civiltieskiem līgumiem, franšīzes attīstība Latvijā un tiesiskā regulējuma pilnveidošana Eiropas Savienības tiesiskā regulējuma ietvaros, kā arī problēmjautājumi un to risinājums. Darba autors nonāk pie secinājuma, ka nolūkā past...

  7. Effect of Different Types of Toothpaste on the Frictional Resistance between Orthodontic Stainless Steel Brackets and Wires

    Directory of Open Access Journals (Sweden)

    Tahereh Hosseinzadeh Nik

    2017-12-01

    Full Text Available Objectives: The purpose of this study was to investigate the effect of different types of toothpaste on the frictional resistance between stainless steel brackets and archwires.Materials and Methods: Ninety stainless steel orthodontic brackets with stainless steel wires were bonded to bovine teeth and were divided into 6 groups for application of the following toothpastes: Colgate® Total® Advanced Whitening, Colgate® Total® Pro Gum Health, Colgate® Anticavity, Ortho.Kin®, and Sunstar GUM® Ortho toothpastes. No toothpaste was applied in the control group. Each group was brushed by a brushing machine with the use of the designated solution for 4.5 minutes. The frictional force was measured in a universal testing machine with a crosshead speed of 10 mm/minute over a 5-mm archwire. Data were analyzed using one-way analysis of variance (ANOVA at the 0.05 significance level.Results: The frictional resistance values of Ortho.Kin® and GUM® Ortho toothpastes and the control group were not significantly different (P>0.05. However, there were significant differences between the frictional resistance values of Colgate® Total® Pro Gum Health and Colgate® Anticavity toothpastes with that of the control group (P<0.05. The highest and lowest frictional resistance values were related to Colgate® Total® Pro Gum Health toothpaste and the control group, respectively.Conclusions: Among the evaluated toothpastes, the orthodontic toothpastes did not increase the frictional resistance between the orthodontic stainless steel brackets and wires.

  8. Study of chemical and physical properties of irradiated Guar Gum

    International Nuclear Information System (INIS)

    Hussein, H. A. S.

    2012-07-01

    This study was carried out to evaluate the effect of different gamma radiation doses to decontamination of micro-organisms present in Guar Gum powder. As well as to study the effect of radiation on the chemical and physical properties of the carbohydrate components of the Gum's material. Two types of samples were used in this study (powder and liquid). All samples were collected from commercially available Guar Gum (G G), which were obtained from the company (Sudanese Guar Gum ltd). Samples putted in polyethylene tightly closed container, then irradiated by applying different doses (2.5, 5, 7.5, 10, 20,30,40,and 50 kGy) from Co-60 source at room temperature in air. And take zero kGy as control. Irradiated powder samples of (2.5, 5, 7.5, 10 kGy) were investigated for contamination by using growth media agar and the result showed that 2.5 kGy is appropriate dose to remove the contamination of the samples. And then analyzed using fourier transform infrared (FTTR) x-ray fluorescence (X RF) and spectroscopy. The FTIR spectroscopy results suggested that there were no major chemical functional group transformation during irradiation. No change occurs by using low dose as 2.5 kGy. Also evaluation impact of radiation on liquid Samples (Aqueous solutions prepared in tow concentration of 1% and 5% wv that is by exposing the samples to the same dose of gamma rays) the effect of irradiation on it were investigated by using ultra violet spectroscopy ( UV.Vis), results showed that low dose has steeply effect in solutions specially in low concentration, it was more pronoun than that in high concentration, high dose has made change similar to that it made in powder. Also for both concentrations of liquid samples and for solutions made of irradiated powder pH measured and viscosity which used in investigations of molecular weight of liquid and powder, comparing the results of impact in the form of powder with the results of effects in the solutions found that the effects of

  9. The emission of sound by statistically homogeneous bubble layers

    NARCIS (Netherlands)

    van Wijngaarden, L.; van Wijngaarden, L.; Buist, J.

    1992-01-01

    This paper is concerned with the flow of a bubbly fluid along a wavy wall, which is one Fourier component of a linearized hydrofoil. The bubbles are dispersed, not throughout the whole of the liquid, but only over a certain distance from the wall, as occurs in practice with cavitation bubbles.

  10. Adhesion of solid particles to gas bubbles. Part 2: Experimental

    NARCIS (Netherlands)

    Omota, Florin; Dimian, Alexandre C.; Bliek, A.

    2006-01-01

    In slurry bubble columns, the adhesion of solid catalyst particles to bubbles may significantly affect the G–L mass transfer and bubble size distribution. This feature may be exploited in design by modifying the hydrophilic or hydrophobic nature of the particles used. Previously we have proposed a

  11. Rhetoric, Risk, and Markets: The Dot-Com Bubble

    Science.gov (United States)

    Goodnight, G. Thomas; Green, Sandy Edward, Jr.

    2010-01-01

    Post-conventional economic theories are assembled to inquire into the contingent, mimetic, symbolic, and material spirals unfolding the dot-com bubble, 1992-2002. The new technologies bubble is reconstructed as a rhetorical movement across the practices of the hybrid market-industry risk culture of communications. The legacies of the bubble task…

  12. Stability of a bubble expanding and translating through an inviscid ...

    Indian Academy of Sciences (India)

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

    Department of Mathematics, Delhi University, Delhi 110 007, India. MS received 27 August 2001; revised 2 February 2002. Abstract. A bubble expands adiabatically and translates in an incompressible and inviscid liquid. We investigate the number of equilibrium points of the bubble and the nature of stability of the bubble at ...

  13. Clinical bending of nickel titanium wires

    Directory of Open Access Journals (Sweden)

    Stephen Chain

    2015-01-01

    Full Text Available Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our inventory but also customized the wire according to the treatment.

  14. Emittance growth due to Tevatron flying wires

    Energy Technology Data Exchange (ETDEWEB)

    Syphers, M; Eddy, Nathan

    2004-06-01

    During Tevatron injection, Flying Wires have been used to measure the transverse beam size after each transfer from the Main Injector in order to deduce the transverse emittances of the proton and antiproton beams. This amounts to 36 + 9 = 45 flies of each of 3 wire systems, with an individual wire passing through each beam bunch twice during a single ''fly''. below they estimate the emittance growth induced by the interaction of the wires with the particles during these measurements. Changes of emittance from Flying Wire measurements conducted during three recent stores are compared with the estimations.

  15. Pneumatic artificial rubber muscle using shape-memory polymer sheet with embedded electrical heating wire

    International Nuclear Information System (INIS)

    Takashima, Kazuto; Sugitani, Kazuhiro; Morimoto, Naohiro; Sakaguchi, Seiya; Noritsugu, Toshiro; Mukai, Toshiharu

    2014-01-01

    Shape-memory polymer (SMP) can be deformed by applying a small load above its glass transition temperature (T g ). Shape-memory polymer maintains its shape after it has cooled below T g and returns to a predefined shape when subsequently heated above T g . The reversible change in the elastic modulus between the glassy and rubbery states of an SMP can be on the order of several hundred times. Based on the change in stiffness of the SMP in relation to the change in temperature, the present study attempts to evaluate the application of the SMP to soft actuators of a robot. In order to control the temperature of the SMP, we developed an SMP sheet with an embedded electrical heating wire. We formed a uniform, thin SMP sheet without air bubbles using a heat press. The SMP sheet with a heating wire can be heated quickly and can be maintained at a constant temperature. Moreover, the effects of the embedded wire on the mechanical properties in bending and tensile tests were small. Then, we applied the SMP sheet with the embedded electrical heating wire to a pneumatic artificial rubber muscle. The enhanced versatility of SMP sheet applications is demonstrated through a series of experiments conducted using a prototype. The initial shape and bending displacement of the pneumatic artificial rubber muscle can be changed by controlling the temperature of the SMP sheet. (paper)

  16. Pneumatic artificial rubber muscle using shape-memory polymer sheet with embedded electrical heating wire

    Science.gov (United States)

    Takashima, Kazuto; Sugitani, Kazuhiro; Morimoto, Naohiro; Sakaguchi, Seiya; Noritsugu, Toshiro; Mukai, Toshiharu

    2014-12-01

    Shape-memory polymer (SMP) can be deformed by applying a small load above its glass transition temperature (Tg). Shape-memory polymer maintains its shape after it has cooled below Tg and returns to a predefined shape when subsequently heated above Tg. The reversible change in the elastic modulus between the glassy and rubbery states of an SMP can be on the order of several hundred times. Based on the change in stiffness of the SMP in relation to the change in temperature, the present study attempts to evaluate the application of the SMP to soft actuators of a robot. In order to control the temperature of the SMP, we developed an SMP sheet with an embedded electrical heating wire. We formed a uniform, thin SMP sheet without air bubbles using a heat press. The SMP sheet with a heating wire can be heated quickly and can be maintained at a constant temperature. Moreover, the effects of the embedded wire on the mechanical properties in bending and tensile tests were small. Then, we applied the SMP sheet with the embedded electrical heating wire to a pneumatic artificial rubber muscle. The enhanced versatility of SMP sheet applications is demonstrated through a series of experiments conducted using a prototype. The initial shape and bending displacement of the pneumatic artificial rubber muscle can be changed by controlling the temperature of the SMP sheet.

  17. Is there a Housing Bubble in Turkey?

    Directory of Open Access Journals (Sweden)

    Coskun Yener

    2017-03-01

    Full Text Available There was a notable housing price inflation in aggregate/local levels in Turkey during the last few years. Although the country’s economic fundamentals remain strong, the probability of a housing bubble is a heated debate among market participants. This timely investigation brings greater clarity to whether the Turkish housing market is in a bubble. The study uses a multi-strand approach to dissect the bubble over the period of Jan. 2010 - Dec. 2014. First, monthly/annual price-to-income and monthly price-to-rent ratios are examined for the national Turkish as well as regional Istanbul, Izmir and Ankara housing markets. Second, an extended CASE and SHILLER (2003 model is applied assessing the interdependence between housing prices and a series of explanatory variables. Lastly, the Right Tail Augmented Dickey-Fuller (Rtadf test is performed to support the overall analysis. This study finds that neither affordability ratios nor regression estimates support the existence of the bubble in Turkey.

  18. The bubble distribution in glass refining channels

    Czech Academy of Sciences Publication Activity Database

    Němec, Lubomír; Cincibusová, P.

    2005-01-01

    Roč. 49, č. 4 (2005), s. 269-277 ISSN 0862-5468 Institutional research plan: CEZ:AV0Z40320502 Keywords : glass fining * bubble distribution s models * horizontal channel Subject RIV: CA - Inorganic Chemistry Impact factor: 0.463, year: 2005

  19. The charged bubble oscillator: Dynamics and thresholds

    Indian Academy of Sciences (India)

    of day-to-day medical devices and techniques using ultrasound ... When a pressure wave is incident on the bubble in the liquid .... Dependence of the expansion-compression ratio on the driving pressure amplitude Ps. we will merely cite the result here. We find the critical. Blake radius and the critical liquid pressure to be.

  20. Characterization of polymers by bubble inflation

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Rasmussen, Henrik K.; Kjær, Erik Michael

    1999-01-01

    In order to characterise materials using a simple and relative inexpensive method, the bubble inflation technique was modified. A polymer plate is clamped between a Teflon coated heating plate and a heated cylinder. By applying air through the heating plate the polymer membrane deforms...