WorldWideScience

Sample records for monitors drop shorts

  1. Monitoring Volcanoes by Use of Air-Dropped Sensor Packages

    Science.gov (United States)

    Kedar, Sharon; Rivellini, Tommaso; Webb, Frank; Blaes, Brent; Bracho, Caroline; Lockhart, Andrew; McGee, Ken

    2003-01-01

    Sensor packages that would be dropped from airplanes have been proposed for pre-eruption monitoring of physical conditions on the flanks of awakening volcanoes. The purpose of such monitoring is to gather data that could contribute to understanding and prediction of the evolution of volcanic systems. Each sensor package, denoted a volcano monitoring system (VMS), would include a housing with a parachute attached at its upper end and a crushable foam impact absorber at its lower end (see figure). The housing would contain survivable low-power instrumentation that would include a Global Positioning System (GPS) receiver, an inclinometer, a seismometer, a barometer, a thermometer, and CO2 and SO2 analyzers. The housing would also contain battery power, control, data-logging, and telecommunication subsystems. The proposal for the development of the VMS calls for the use of commercially available sensor, power, and telecommunication equipment, so that efforts could be focused on integrating all of the equipment into a system that could survive impact and operate thereafter for 30 days, transmitting data on the pre-eruptive state of a target volcano to a monitoring center. In a typical scenario, VMSs would be dropped at strategically chosen locations on the flanks of a volcano once the volcano had been identified as posing a hazard from any of a variety of observations that could include eyewitness reports, scientific observations from positions on the ground, synthetic-aperture-radar scans from aircraft, and/or remote sensing from aboard spacecraft. Once dropped, the VMSs would be operated as a network of in situ sensors that would transmit data to a local monitoring center. This network would provide observations as part of an integrated volcano-hazard assessment strategy that would involve both remote sensing and timely observations from the in situ sensors. A similar strategy that involves the use of portable sensors (but not dropping of sensors from aircraft) is

  2. Potential drop technique for monitoring stress corrosion cracking growth

    International Nuclear Information System (INIS)

    Neves, Celia F.C.; Schvartzman, Monica M.A.M.; Moreira, Pedro A.L.D.P.L.P.

    2002-01-01

    Stress corrosion cracking is one of most severe damage mechanisms influencing the lifetime of components in the operation of nuclear power plants. To assess the initiation stages and kinetics of crack growth as the main parameters coming to residual lifetime determination, the testing facility should allow active loading of specimens in the environment which is close to the real operation conditions of assessed component. Under cooperation of CDTN/CNEN and International Atomic Energy Agency a testing system has been developed by Nuclear Research Institute, Czech Republic, that will be used for the environmentally assisted cracking testing at CDTN/CNEN. The facility allows high temperature autoclave corrosion mechanical testing in well-defined LWR water chemistry using constant load, slow strain rate and rising displacement techniques. The facility consists of autoclave and refreshing water loop enabling testing at temperatures up to 330 deg C. Active loading system allows the maximum load on a specimen as high as 60 kN. The potential drop measurement is used to determine the instant crack length and its growth rate. The paper presents the facility and describes the potential drop technique, that is one of the most used techniques to monitor crack growth in specimens under corrosive environments. (author)

  3. In-Situ Creep Monitoring Using the Potential Drop Method

    Science.gov (United States)

    Madhi, E.; Sposito, G.; Davies, C. M.; Cawley, P.; Nagy, P. B.

    2011-06-01

    A directional low-frequency Alternating Current Potential Drop (ACPD) sensor was developed for in-situ monitoring of creep in metals. The sensor relies on a modified ACPD technique that measures simultaneously both values of resistance in the axial and lateral directions using a square electrode configuration. As compared to the more commonly used in-line electrode configuration, the square arrangement used in this sensor is much more directional and thus allows the detection of creep-induced anisotropy and texture. The technique monitors the variation in the ratio of the measured axial and lateral resistances, therefore can efficiently separate the mostly isotropic common part of the resistivity variation caused by reversible temperature variations from the mostly anisotropic differential part caused by direct geometrical and indirect material effects of creep. Initially, this ratio is roughly proportional to the axial creep strain, while at later stages, the resistance ratio increases even faster with creep strain because of the formation of directional discontinuities such as preferentially oriented grain boundary cavities and multiple-site microcracks in the material.

  4. Continuous monitoring of back-wall stress corrosion cracking propagation by means of potential drop techniques

    International Nuclear Information System (INIS)

    Sato, Yasumoto; Atsumi, Takeo; Shoji, Tetsuo

    2006-01-01

    In order to investigate the applicability of the potential drop techniques to the continuous monitoring of stress corrosion cracking (SCC) propagation, SCC tests were performed in a sodium thiosulfate solution at room temperature using plate specimens with weldments. The SCC propagation was monitored using the techniques of direct current potential drop (DCPD), alternating current potential drop (ACPD) and modified induced current potential drop (MICPD) on the reverse side that on which the SCC existed and effectiveness of each technique for the continuous monitoring from the reverse side of SCC was compared from the viewpoints of sensitivity to the crack propagation and measurement stability. The MICPD and DCPD techniques permit continuous monitoring of the back-wall SCC propagation, which initiates from a fatigue pre-crack at a depth of about 4 mm, from which it propagates through more than 80% of the specimen thickness. The MICPD technique can decrease the effect of the current flowing in the direction of the crack length by focusing the induced current into the local area of measurement using induction coils, so that the sensitivity of the continuous monitoring of the back wall SCC propagation is higher than that of the DCPD and ACPD techniques. (author)

  5. Monitoring method of short-emitters

    International Nuclear Information System (INIS)

    Gasanov, R.A.

    2013-01-01

    Radioprospecting is the initial stage of radioelectronic warfare and its main purpose is destination of the radio signal, determination of its parameters, to detect the content of broadcasts, as well as detection the locating of devices emitting radio signal. In all cases, the probability of signal interception is basically determined by the specified parameters of signals intelligence. The increase in speed is accompanied by a decrease in resolution and vice versa. This paper discusses the method of monitoring the short-term radio emissions, which adapts to the electromagnetic environment

  6. Potential drop crack growth monitoring in high temperature biaxial fatigue tests

    International Nuclear Information System (INIS)

    Fitzgerald, B.P.; Krempl, E.

    1993-01-01

    The present work describes a procedure for monitoring crack growth in high temperature, biaxial, low cycle fatigue tests. The reversing DC potential drop equipment monitors smooth, tubular type 304 stainless steel specimens during fatigue testing. Electrical interference from an induction heater is filtered out by an analog filter and by using a long integration time. A Fourier smoothing algorithm and two spline interpolations process the large data set. The experimentally determined electrical potential drop is compared with the theoretical electrostatic potential that is found by solving Laplace's equation for an elliptical crack in a semi-infinite conducting medium. Since agreement between theory and experiment is good, the method can be used to measure crack growth to failure from the threshold of detectability

  7. Characterization of new eye drops with choline salicylate and assessment of their irritancy by in vitro short time exposure tests.

    Science.gov (United States)

    Wroblewska, Katarzyna; Kucinska, Małgorzata; Murias, Marek; Lulek, Janina

    2015-09-01

    The aim of our study was to examine the irritation potential of new eye drops containing 2% choline salicylate (CS) as an active pharmaceutical ingredient (API) and various polymers increasing eye drop viscosity (hydroxyethylcellulose, hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, polyvinylpyrrolidone). The standard method for assessing the potential of irritating substances has been the Draize rabbit eye test. However the European Centre for Validation of Alternative Methods and the Coordinating Committee for Validation of Alternative Methods recommend, short time exposure (STE) in vitro tests as an alternative method for assessing eye irritation. The eye irritation potential was determined using cytotoxicity test methods for rabbit corneal cell line (SIRC) after 5 min exposure. The viability of cells was determined using two cytotoxicity assays: MTT and Neutral Red Uptake. According to the irritation rankings for the short time exposure test, all tested eye drops are classified as non-irritating (cell viability >70%).

  8. An improved potential drop method for measuring and monitoring defects in metallic structures

    International Nuclear Information System (INIS)

    Oppermann, W.; Keller, H.P.

    1993-01-01

    In the developed form described the direct current potential drop method is a reliable and relatively accurate procedure for the measuring and surveillance of surface cracks in metallic materials. There are also significant possibilities in practice of surveying cracks on the inaccessible side of the structure. The basis for the improvement in accuracy, in particular for short cracks, is firstly an improved measuring technique and secondly calibration curves determined using an electrolytic tank. Practical experience gained in conventional plants is to date positive. The opportunity exists of benefitting from the advantages that would be brought about by an increased use of the potential drop method in plant surveillance. In nuclear plants specifically this would achieve a reduction in the testing personnel's exposure to radiation. (orig.)

  9. Efficacy and safety of short-term application of pranoprofen eye drops for senile patients with dry eyes

    Directory of Open Access Journals (Sweden)

    Yu-Chan Li

    2018-06-01

    Full Text Available AIM:To investigate the efficacy and safety of short-term application of pranoprofen eye drops in the treatment of dry eyes in senile patients. METHODS: Totally 100 elderly patients with dry eyes treated in our hospital from June 2016 to May 2017 were randomly divided into 2 groups. All cases were bilateral onset, and the right eyes were marked as the observation eyes. The 50 eyes in the observation group were treated with 1g/L pranoprofen eye drops combined with 1g/L sodium hyaluronate eye drops, while 50 in the control group were treated with 1g/L sodium hyaluronate eye drops. The results of Schirmer Ⅰ, ocular surface disease index(OSDI, break-up time(BUT, ocular surface staining(OSS, human leukocyte antigen-DR(HLA-DRand CD11b in conjunctival epithelial cells before and at 2wk after treatment, and adverse reactions in 2 groups were observed. RESULTS: Before treatment, results of Schirmer I, OSDI, BUT, OSS, HLA-DR and CD11b in the two groups were similar, there were no statistically significant differences(P>0.05. After treatment, OSDI, OSS, HLA-DR, CD11b significantly decreased, BUT significantly increased in both groups, the differences were statistically significant(PPPCONCLUSION: Short term application of pranoprofen eye drops can effectively enhance the efficacy in treating elderly patients with dry eyes, release clinical symptoms, and the therapeutic mechanism may be related to the inhibitory effect on HLA-DR.

  10. Online monitoring method using Equipotential Switching Direct Current potential drop for piping wall loss by flow accelerated corrosion

    International Nuclear Information System (INIS)

    Ryu, Kyung Ha; Lee, Tae Hyun; Kim, Ji Hak; Hwang, Il Soon; Lee, Na Young; Kim, Ji Hyun; Park, Jin Ho; Sohn, Chang Ho

    2010-01-01

    The flow accelerated corrosion (FAC) phenomenon persistently impacts plant reliability and personnel safety. We have shown that Equipotential Switching Direct Current Potential Drop (ES-DCPD) can be employed to detect piping wall loss induced by FAC. It has been demonstrated to have sufficient sensitivity to cover both long and short lengths of piping. Based on this, new FAC screening and inspection approaches have been developed. For example, resolution of ES-DCPD can be adjusted according to its monitoring purpose. The developed method shows good integrity during long test periods. It also shows good reproducibility. The Seoul National University FAC Accelerated Simulation Loop (SFASL) has been constructed for ES-DCPD demonstration purposes. During one demonstration, the piping wall was thinned by 23.7% through FAC for a 13,000 min test period. In addition to the ES-DCPD method, ultrasonic technique (UT) has been applied to SFASL for verification while water chemistry was continually monitored and controlled using electrochemical sensors. Developed electrochemical sensors showed accurate and stable water conditions in the SFASL during the test period. The ES-DCPD results were also theoretically predicted by the Sanchez-Caldera's model. The UT, however, failed to detect thinning because of its localized characteristics. Online UT that covers only local areas cannot assure the detection of wall loss.

  11. An improved potential drop method for measuring and monitoring defects in structures

    International Nuclear Information System (INIS)

    Oppermann, W.; Keller, H.P.

    1991-01-01

    In its advanced form, the direct-current potential probe measuring technique is a reliable and relatively exact procedure for measuring and monitoring surface defects. In addition, there is the possibility - important for practical purposes - of measuring cracks at the inaccessible side of a component part. The improved accuracy, in particular with regard to short defects, is based on advanced measuring techniques and calibration curves determined at the electrolytical tank. (orig./DG) [de

  12. Monitoring Agent for Detecting Malicious Packet Drops for Wireless Sensor Networks in the Microgrid and Grid-Enabled Vehicles

    Directory of Open Access Journals (Sweden)

    Jongbin Ko

    2012-05-01

    Full Text Available Of the range of wireless communication technologies, wireless sensor networks (WSN will be one of the most appropriate technologies for the Microgrid and Grid-enabled Vehicles in the Smartgrid. To ensure the security of WSN, the detection of attacks is more efficient than their prevention because of the lack of computing power. Malicious packet drops are the easiest means of attacking WSNs. Thus, the sensors used for constructing a WSN require a packet drop monitoring agent, such as Watchdog. However, Watchdog has a partial drop problem such that an attacker can manipulate the packet dropping rate below the minimum misbehaviour monitoring threshold. Furthermore, Watchdog does not consider real traffic situations, such as congestion and collision, and so it has no way of recognizing whether a packet drop is due to a real attack or network congestion. In this paper, we propose a malicious packet drop monitoring agent, which considers traffic conditions. We used the actual traffic volume on neighbouring nodes and the drop rate while monitoring a sending node for specific period. It is more effective in real network scenarios because unlike Watchdog it considers the actual traffic, which only uses the Pathrater. Moreover, our proposed method does not require authentication, packet encryption or detection packets. Thus, there is a lower likelihood of detection failure due to packet spoofing, Man-In-the Middle attacks or Wormhole attacks. To test the suitability of our proposed concept for a series of network scenarios, we divided the simulations into three types: one attack node, more than one attack nodes and no attack nodes. The results of the simulations meet our expectations.

  13. Development of a piping thickness monitoring system using equipotential switching direct current potential drop method

    International Nuclear Information System (INIS)

    Kyung Ha, Ryu; Na Young, Lee; Il Soon, Hwang

    2007-01-01

    As nuclear power plants age, low alloy steel piping undergoes wall thickness reduction due to Flow Accelerated Corrosion (FAC). Persisting pipe rupture accidents prompted thinned pipe management programs. As a consequence extensive inspection activities are made based on the Ultrasonic Technique (UT). As the inspection points increase, time is needed to cover required inspection areas. In this paper, we present the Wide Range Monitoring (WiRM) concept with Equipotential Switching Direct Current Potential Drop (ES-DCPD) method by which FAC-active areas can be screened for detailed UT inspections. To apply ES-DCPD, we developed an electric resistance network model and electric field model based on Finite Element Analysis (FEA) to verify its feasibility. Experimentally we measured DCPD of the pipe elbow and confirmed the validity using UT inspections. For a more realistic validation test, we designed a high temperature flow test loop with environmental parameters turned for FAC simulation in the laboratory. Using electrochemical monitoring of water chemistry and local flow velocity prediction by computational fluid dynamic model, FAC rate is estimated. Based on the FAC prediction model and the simulation loop test, we plan to demonstrate the applicability of ES-DCPD in the PWR secondary environment. (authors)

  14. Continuous monitoring of back wall stress corrosion cracking growth in sensitized type 304 stainless steel weldment by means of potential drop techniques

    OpenAIRE

    SATO, Y; ATSUMI, T; SHOJI, T

    2007-01-01

    Stress corrosion cracking (SCC) tests on welded specimens of sensitized type 304SS with a thickness of 20 mm were performed in sodium thiosulphate solution at room temperature, with continuous monitoring of the SCC growth, using the techniques of modified induced current potential drop (MICPD), alternating current potential drop (ACPD) and direct current potential drop (DCPD). The MICPD and DCPD techniques permit continuous monitoring of the back wall SCC, which initiates from a fatigue pre-c...

  15. Effects of diquafosol sodium eye drops on tear film stability in short BUT type of dry eye.

    Science.gov (United States)

    Shimazaki-Den, Seika; Iseda, Hiroyuki; Dogru, Murat; Shimazaki, Jun

    2013-08-01

    To investigate the effects of diquafosol sodium (DQS) eye drops, a purinergic P2Y2 receptor agonist, on tear film stability in patients with unstable tear film (UTF). Two prospective studies were conducted. One was an exploratory nonrandomized trial on 39 eyes with dry eye symptoms and short tear film break-up time (BUT), but without epithelial damage. Changes in symptoms, BUT, Schirmer value, and ocular surface fluorescein staining (FS) scores were studied for 3 months. The other was a randomized clinical trial of DQS and artificial tears (AT) in 17 eyes with short BUT. Eyes with decreased Schirmer values (≤ 5 mm) were excluded. Changes in symptoms, BUT, FS scores, and tear film stability using continuous corneal topographic analysis were studied for 4 weeks. In the exploratory study, while Schirmer values were not significantly increased, significant improvements in symptoms and BUT were noted at both 1 and 3 months. In the randomized clinical trial, significant improvements in symptoms were noted in the DQS group, but not in the AT group, at 2 weeks. BUT was significantly prolonged in the DQS group at 4 weeks but not in the AT group. No significant changes were noted in FS scores or tear film stability. DQS improved subjective symptoms and prolonged BUT in eyes with UTF not associated with low tear secretion and ocular surface epithelial damage. Because many patients who have UTF are refractory to conventional treatments, DQS may offer benefits in the treatment of dry eyes.

  16. Miniaturized Air Dropped Sensors for Environmental Monitoring of Heavy Metals in Water, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA SBIR program would develop air-dropped wireless networked sensors using miniaturized chemical field effect transistors (ChemFET) for the detection and...

  17. Monitoring markers of muscle damage during a 3 week periodized drop-jump exercise programme

    DEFF Research Database (Denmark)

    Kamandulis, Sigitas; Skurvydas, Albertas; Snieckus, Audrius

    2011-01-01

    a progressive increase in load impact with respect to the number of jumps performed, drop (platform) height, squat depth amplitude, and addition of weights. Maximal concentric and isometric knee extensor strength were assessed immediately before and 10 min after each training session. Voluntary and 100 Hz...

  18. Characterization of new eye drops with choline salicylate and assessment of their irritancy by in vitro short time exposure tests

    OpenAIRE

    Wroblewska, Katarzyna; Kucinska, Małgorzata; Murias, Marek; Lulek, Janina

    2015-01-01

    The aim of our study was to examine the irritation potential of new eye drops containing 2% choline salicylate (CS) as an active pharmaceutical ingredient (API) and various polymers increasing eye drop viscosity (hydroxyethylcellulose, hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, polyvinylpyrrolidone). The standard method for assessing the potential of irritating substances has been the Draize rabbit eye test. However the European Centre for Validation of Alternative Met...

  19. Drop Tower Physics

    Science.gov (United States)

    Dittrich, William A.

    2014-01-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

  20. Foraging of the Indian Short-nosed Fruit Bat Cynopterus sphinx on banana in shops and on the pieces dropped by monkeys at a temple

    Directory of Open Access Journals (Sweden)

    A. Rathinakumar

    2016-11-01

    Full Text Available The Indian Short-nosed Fruit Bat Cynopterus sphinx fed on the pieces of banana fruit that were dropped by monkeys on the tower of a temple and in nearby shops.  The monkeys obtained fruits from devotees and shop owners.  The peak number of bat visits occurred during pre- and post- midnight hours at the tower and shops, respectively, coinciding with the lights off situation and reduced human disturbance.  The bats landed on bunches of ripe bananas hanging in the front of shops.  The number of bat landings on the tower was greater than that in the shops.  The overall number of bat visits were higher during October when compared to other periods of the year.  This may be due to the occurrence of more festivals during October.  Our study is an example of opportunistic feeding, in which banana pieces dropped while monkeys were feeding on them were eaten by the bats.

  1. On-Line Monitoring of Environment-Assisted Cracking in Nuclear Piping Using Array Probe Direct Current Potential Drop

    OpenAIRE

    Kim, Y.; Choi, S.; Yoon, J. Y.; Nam, W. C.; Hwang, I. S.; Bromberg, Leslie; Stahle, Peter W; Ballinger, Ronald G

    2015-01-01

    A direct current potential drop method utilizing array probes with measurement ends maintaining an equalized potential designated as equi-potential switching array probe direct current potential drop (ESAP-DCPD) technique has been developed earlier at Seoul National University. This paper validates ESAP-DCPD technique by showing consistency among experimental measurements, analytical solution and numerical predictions using finite element analysis (FEA) of electric field changes with crack gr...

  2. The pressure drop factor - a powerful monitoring tool for hydrotreaters; Der Druckverlustfaktor - ein leistungsstarkes Monitoringwerzeug fuer Entschwefelungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Riebel, A.; Kuczera, M. [MiRO Mineraloelraffinerie Oberrhein GmbH und Co. KG, Karlsruhe (Germany); Skyum, L. [Haldor Topsoe, Lyngby (Denmark)

    2004-08-01

    In order to reduce traffic air pollution the sulphur content in gasoline and diesel of 50 ppm was appointed Europe-wide for 2005 according to the auto oil programme (aop.) The Mineraloelraffinerie Oberrhein (MiRO-refinery) in Karlsruhe delivers gasoline and diesel with sulphur content below 10 ppm since the 1{sup st} of November 2001. For the deep desulphurisation process temperatures in the reactors had to be raised. Because the catalyst volume was partly considerably increased in order to compensate the thereby caused higher deactivation, now the maximum allowable pressure drop in fixed bed reactors limits the run time for hydrotreaters. Because the pressure drop increases as a first approximation with the squared volume flow, it is hard to distinguish between pressure drop caused by blockades of coke, polymerisation and corrosion products in the catalyst bed and the influence of changing volume flow due to different process conditions. However this necessary to predict the development of pressure drop in the future in order take the right action. The aim of this work is to calculate the loss of void space in the catalyst bed caused due to particulate matter by adequate pressure drop calculation in order to give recommendation and prepare counteractive measures. Using the existing works a model for calculating the pressure drop in hydro treating reactors was developed, which can determine the reduction of void space caused by coke, polymers or corrosion products. In order to verify the validity of the equations from pure gas phase to the trickle bed reactor a gasoline hydrotreater (100% gas phase), a hydrotreater for kerosene (98% gas phase) and a vacuum gas oil hydrotreater (83% gas phase) were regarded. Measured and calculated data match satisfyingly. The presented pressure drop factor takes into account the grown importance of pressure drop in hydrotreaters. The effects of operational changes or feed impurities can be identified in good time and counteractive

  3. A short history and critical review of individual monitoring

    International Nuclear Information System (INIS)

    Wernli, Christian

    2016-01-01

    Soon after the discovery of X-rays and the radioactive element radium harmful radiation effects occurred, mainly in the medical field. Consequently, the radiologists, a new profession at that time, called for a limitation of radiation exposures. First proposals were to limit the exposure rate to prevent the incidence of skin erythema. It took more than two decades and there were many victims of severe radiation effects until a sound basis for radiation protection and individual monitoring was established. For external dosimetry, the film dosemeter was invented in the 1920's. This device, often combined with an ion chamber-based pencil dosemeter, dominated the systems used in personnel dosimetry until the end of the twentieth century. For internal exposure, the concept of limiting the 'body burden' was commonly used, and only in the late 1970's, the new concept of the 'effective dose equivalent' published in ICRP publication 26 allowed for a unified interpretation and, therefore, addition of the dosimetric quantities for external and internal exposures. By the end of the last century, individual monitoring had to survive an inflation of proposals for new quantities, but fortunately, it was also the time of vast developments of new technologies, methods and procedures. Later on, much room was given to highly sophisticated regulations, requirements, metrological concepts and administrative procedures. In this complex environment, the original task of individual monitoring became more and more hidden behind secondary loads. Now, like about hundred years ago, however with different motivation, once again the ultimate goal of the professional work has to be thought about by asking: Do people always know why they do what they do? Or simply: Why individual monitoring? (authors)

  4. A new method to predict the epidemiology of fungal keratitis by monitoring the sales distribution of antifungal eye drops in Brazil.

    Directory of Open Access Journals (Sweden)

    Marlon Moraes Ibrahim

    Full Text Available PURPOSE: Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. METHODS: Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. RESULTS: A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01. A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01. CONCLUSIONS: Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier, when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.

  5. A new method to predict the epidemiology of fungal keratitis by monitoring the sales distribution of antifungal eye drops in Brazil.

    Science.gov (United States)

    Ibrahim, Marlon Moraes; de Angelis, Rafael; Lima, Acacio Souza; Viana de Carvalho, Glauco Dreyer; Ibrahim, Fuad Moraes; Malki, Leonardo Tannus; de Paula Bichuete, Marina; de Paula Martins, Wellington; Rocha, Eduardo Melani

    2012-01-01

    Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (phumidity and antifungal drug sales (R2 = 0.17,p<0.01). Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.

  6. A New Method to Predict the Epidemiology of Fungal Keratitis by Monitoring the Sales Distribution of Antifungal Eye Drops in Brazil

    Science.gov (United States)

    Ibrahim, Marlon Moraes; de Angelis, Rafael; Lima, Acacio Souza; Viana de Carvalho, Glauco Dreyer; Ibrahim, Fuad Moraes; Malki, Leonardo Tannus; de Paula Bichuete, Marina; de Paula Martins, Wellington; Rocha, Eduardo Melani

    2012-01-01

    Purpose Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. Methods Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. Results A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01). Conclusions Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects. PMID:22457787

  7. Verification of the Viability of Equipotential Switching Direct Current Potential Drop Method for Piping Wall Loss Monitoring with Signal Sensitivity Analysis

    International Nuclear Information System (INIS)

    Ryu, Kyung Ha; Hwang, Il Soon; Kim, Ji Hyun

    2008-01-01

    Flow accelerated corrosion (FAC) phenomenon of low alloy carbon steels in nuclear power plant has been known as one of major degradation mechanisms. It has a potential to cause nuclear pipe rupture accident which may directly impact on the plant reliability and safety. Recently, the equipotential switching direct current potential drop (ES-DCPD) method has been developed, by the present authors, as a method to monitor wall loss in a piping. This method can rapidly monitor the thinning of piping, utilizing either the wide range monitoring (WiRM) or the narrow range monitoring (NaRM) technique. WiRM is a method to monitor wide range of straight piping, whereas NaRM focuses significantly on a narrow range such as an elbow. WiRM and NaRM can improve the reliability of the current FAC screening method that is based on computer modeling on fluid flow conditions. In this paper, the measurements by ES-DCPD are performed with signal sensitivity analyses in the laboratory environment for extended period and showed the viability of ES-DCPD for real plant applications.

  8. Key technologies of the server monitor and control system based on GSM short messages

    International Nuclear Information System (INIS)

    Chen Taiwei; Zhou Zhenliu; Liu Baoxu

    2007-01-01

    The network management based on SNMP protocol cannot effectively monitor and control application-system states and key-process states on the computer server. Furthermore, it needs the administrator's longtime surveillance. When the administrator leaves the computer, he can't receive the malfunction message in time. In this paper we present a server monitor and control system based on monitor agents and GSM short messages, introduce the key technology to realize it, and implement a model system in the real network environment. (authors)

  9. Drop trampoline

    Science.gov (United States)

    Chantelot, Pierre; Coux, Martin; Clanet, Christophe; Quere, David

    2017-11-01

    Superhydrophobic substrates inspired from the lotus leaf have the ability to reflect impacting water drops. They do so very efficiently and contact lasts typically 10 ms for millimetric droplets. Yet unlike a lotus leaf most synthetic substrates are rigid. Focusing on the interplay between substrate flexibility and liquid repellency might allow us to understand the dynamic properties of natural surfaces. We perform liquid marbles impacts at velocity V onto thin ( 0.01 mm) stretched circular PDMS membranes. We obtain contact time reductions of up to 70%. The bouncing mechanism is drastically modified compared to that on a rigid substrate: the marble leaves the substrate while it is still spread in a disk shape as it is kicked upwards by the membrane. We show that the bouncing is controlled by an interplay between the dynamics of the drop and the membrane.

  10. Dropped Ceiling

    OpenAIRE

    Tabet, Rayyane

    2012-01-01

    On December 2nd 1950 the first drop of Saudi oil arrived to Lebanon via the newly constructed Trans-Arabian Pipeline, the world's longest pipeline and the largest American private investment in a foreign land. The 30inch wide structure which spanned 1213 kilometers passing through Saudi Arabia, Jordan, and Syria to end in Lebanon had required 3 years of planning and surveying, 2 years of installation, the fabrication of 256,000 tons of steel tubes, the employment of 30,000 workers, the ratifi...

  11. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  12. Short-term memory predictions across the lifespan: monitoring span before and after conducting a task.

    Science.gov (United States)

    Bertrand, Julie Marilyne; Moulin, Chris John Anthony; Souchay, Céline

    2017-05-01

    Our objective was to explore metamemory in short-term memory across the lifespan. Five age groups participated in this study: 3 groups of children (4-13 years old), and younger and older adults. We used a three-phase task: prediction-span-postdiction. For prediction and postdiction phases, participants reported with a Yes/No response if they could recall in order a series of images. For the span task, they had to actually recall such series. From 4 years old, children have some ability to monitor their short-term memory and are able to adjust their prediction after experiencing the task. However, accuracy still improves significantly until adolescence. Although the older adults had a lower span, they were as accurate as young adults in their evaluation, suggesting that metamemory is unimpaired for short-term memory tasks in older adults. •We investigate metamemory for short-term memory tasks across the lifespan. •We find younger children cannot accurately predict their span length. •Older adults are accurate in predicting their span length. •People's metamemory accuracy was related to their short-term memory span.

  13. The Development of a Proper Laser Displacement Monitoring System for Medium and Short Span Bridges

    Directory of Open Access Journals (Sweden)

    Hao Tian

    2014-09-01

    Full Text Available The Health Monitoring System (HMS for a Medium and Short Span (MSS bridge is different to one for a long span bridge, because of factors such assize, scale and importance. Therefore a proper HMS needs to be developed to meet the economic and applicability requirements of the large number of MSS bridges. Approximately 90 % of existing bridges in China are categorized as MSS bridges and most are beginning to deteriorate. Furthermore, there is not a suitable HMS that can assess the condition of the bridge in accordance with a growth market where traffic volumes are likely to increase. Indeed, the artificial patrolling system currently in use is unable to monitor bridges in the long-term and highlight problems within a sufficient time scale. Having discussed the necessity of a HMS for MSS bridges, this paper proposes a suitable system that uses displacement monitoring in addition to the necessary precision. Displacement was chosen as the main monitoring indicator for intuitive, convenient and direct viewing, as its critical characteristic is that it is both economical and straightforward to use. Specific details regarding the laser displacement sensor and the development of a wireless data acquisition and transmission system are also provided. The reliability of the displacement monitoring sensor and data processing system is confirmed through different stages of an installation test.

  14. Ambulatory blood pressure monitoring-derived short-term blood pressure variability in primary hyperparathyroidism.

    Science.gov (United States)

    Concistrè, A; Grillo, A; La Torre, G; Carretta, R; Fabris, B; Petramala, L; Marinelli, C; Rebellato, A; Fallo, F; Letizia, C

    2018-04-01

    Primary hyperparathyroidism is associated with a cluster of cardiovascular manifestations, including hypertension, leading to increased cardiovascular risk. The aim of our study was to investigate the ambulatory blood pressure monitoring-derived short-term blood pressure variability in patients with primary hyperparathyroidism, in comparison with patients with essential hypertension and normotensive controls. Twenty-five patients with primary hyperparathyroidism (7 normotensive,18 hypertensive) underwent ambulatory blood pressure monitoring at diagnosis, and fifteen out of them were re-evaluated after parathyroidectomy. Short-term-blood pressure variability was derived from ambulatory blood pressure monitoring and calculated as the following: 1) Standard Deviation of 24-h, day-time and night-time-BP; 2) the average of day-time and night-time-Standard Deviation, weighted for the duration of the day and night periods (24-h "weighted" Standard Deviation of BP); 3) average real variability, i.e., the average of the absolute differences between all consecutive BP measurements. Baseline data of normotensive and essential hypertension patients were matched for age, sex, BMI and 24-h ambulatory blood pressure monitoring values with normotensive and hypertensive-primary hyperparathyroidism patients, respectively. Normotensive-primary hyperparathyroidism patients showed a 24-h weighted Standard Deviation (P blood pressure higher than that of 12 normotensive controls. 24-h average real variability of systolic BP, as well as serum calcium and parathyroid hormone levels, were reduced in operated patients (P blood pressure variability is increased in normotensive patients with primary hyperparathyroidism and is reduced by parathyroidectomy, and may potentially represent an additional cardiovascular risk factor in this disease.

  15. Validation of the NPAQ-short - a brief questionnaire to monitor physical activity and compliance with the WHO recommendations

    DEFF Research Database (Denmark)

    Danquah, Ida Høgstedt; Petersen, Christina Bjørk; Skov, Sofie Smedegaard

    2018-01-01

    BACKGROUND: Using self-reported surveys to monitor physical activity levels in the population require short items covering both time and intensity. The present study aims to 1) develop the Nordic Physical Activity Questionnaire-short from the original version of the NPAQ, 2) assess test...... when using both open and closed-ended questions. However, using open-ended questions seems to be a better answering mode for self-reported surveys monitoring WHO's physical activity recommendations.......-retest reliability and criterion validity of the NPAQ-short, and 3) test the NPAQ-short's ability to monitor compliance with the WHO recommendations on physical activity. In addition, we aimed to compare open and closed-ended answering modes for the NPAQ-short. METHODS: A sample of 122 participants were included...

  16. Use long short-term memory to enhance Internet of Things for combined sewer overflow monitoring

    Science.gov (United States)

    Zhang, Duo; Lindholm, Geir; Ratnaweera, Harsha

    2018-01-01

    Combined sewer overflow causes severe water pollution, urban flooding and reduced treatment plant efficiency. Understanding the behavior of CSO structures is vital for urban flooding prevention and overflow control. Neural networks have been extensively applied in water resource related fields. In this study, we collect data from an Internet of Things monitoring CSO structure and build different neural network models for simulating and predicting the water level of the CSO structure. Through a comparison of four different neural networks, namely multilayer perceptron (MLP), wavelet neural network (WNN), long short-term memory (LSTM) and gated recurrent unit (GRU), the LSTM and GRU present superior capabilities for multi-step-ahead time series prediction. Furthermore, GRU achieves prediction performances similar to LSTM with a quicker learning curve.

  17. Establishment and monitoring of large scale trials of short rotation coppice for energy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.; Stevens, E.A.; Watters, M.P.

    1998-09-01

    The overall objective of the trials was to obtain information on costs, logistics, productivity and biology of short rotation coppice crops in order to evaluate their potential for producing wood for fuel. More specifically, the objectives of the final and most recent phase of the research work were: the continuing management and monitoring of the coppice trial sites established during phases 1 and 2 of the project; to provide technical and economic data on the management and maintenance of the continuing coppice trail sites; to identify appropriate methods for stool removal and land reclamation and provide technical and economic data on those operations; and to undertake yield assessment at the remaining sites using appropriate methods of yield estimation. (author)

  18. Emitted short wavelength infrared radiation for detection and monitoring of volcanic activity

    Science.gov (United States)

    Rothery, D. A.; Francis, P. W.; Wood, C. A.

    1988-01-01

    Thematic Mapper images from LANDSAT were used to monitor volcanoes. Achievements include: (1) the discovery of a magmatic precursor to the 16 Sept. 1986 eruption of Lascar, northern Chile, on images from Mar. and July 1985 and of continuing fumarolic activity after the eruption; (2) the detection of unreported major changes in the distribution of lava lakes on Erta'Ale, Ethiopia; and (3) the mapping of a halo of still-hot spatter surrounding a vent on Mount Erebus, Antarctica, on an image acquired 5 min after a minor eruption otherwise known only from seismic records. A spaceborne short wavelength infrared sensor for observing hot phenomena of volcanoes is proposed. A polar orbit is suggested.

  19. Air-drop blood supply in the French Army.

    Science.gov (United States)

    Javaudin, Olivier; Baillon, A; Varin, N; Martinaud, C; Pouget, T; Civadier, C; Clavier, B; Sailliol, A

    2018-02-12

    Haemorrhagic shock remains the leading cause of preventable death in overseas and austere settings. Transfusion of blood components is critical in the management of this kind of injury. For French naval and ground military units, this supply often takes too long considering the short shelf-life of red blood cell concentrates (RBCs) and the limited duration of transport in cooling containers (five to six days). Air-drop supply could be an alternative to overcome these difficulties on the condition that air-drop does not cause damage to blood units. After a period of study and technical development of packaging, four air-drops at medium and high altitudes were performed with an aircraft of the French Air Force. After this, one air-drop was carried out at medium altitude with 10 RBCs and 10 French lyophilised plasma (FLYP). A second air-drop was performed with a soldier carrying one FLYP unit at 12 000 feet. For these air-drops real blood products were used, and quality control testing and temperature monitoring were performed. The temperatures inside the containers were within the normal ranges. Visual inspection indicated that transfusion packaging and dumped products did not undergo deterioration. The quality control data on RBCs and FLYP, including haemostasis, suggested no difference before and after air-drop. The operational implementation of the air-drop of blood products seems to be one of the solutions for the supply of blood products in military austere settings or far forward on battlefield, allowing safe and early transfusion. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Monitoring the progress of NFFO-3 projects: short rotation willow coppice - agronomy and economics

    International Nuclear Information System (INIS)

    Twemlow, R.K.M.

    1997-01-01

    The involvement of Sidney C. Banks p.l.c., and the subsidiary company Banks Agriculture, in fuel supply for biofuelled power stations started some 4 years ago. When identifying possible opportunities and crops it was apparent that, with the third tranche of Non-Fossil Fuel Obligations (NFFO3) coming up, there were companies looking at developing biofuelled power stations, using Short Rotation Coppice (SRC) and for this they needed to link with potential fuel suppliers. Sidney C. Banks p.l.c. linked with South Western Power (SWP) (a subsidiary of South Western Electricity p.l.c. (SWEB)) to act as their sole fuel supplier on projected biofuel wood power stations. Subsequently two wood fuelled power stations were awarded to SWP and Sidney C. Banks p.l.c. in the 3rd Tranche from NFFO, in December 1994. The objectives of this project were to: establish a network of SRC growers to produce fuel for a NFFO project; monitor the success of the enterprise; implement a programme of constant improvement to optimise the fuel supply strategy; and provide valuable information as to the performance of the SRC crop in large scale commercial production. (author)

  1. Monitoring of processes with gamma-rays of neutron capture and short-living radionuclides

    International Nuclear Information System (INIS)

    Aripov, G.A.; Kurbanov, B.I.; Allamuratova, G.

    2004-01-01

    Element content is a fundamental parameter of a substance, on which all its properties, and also character of physical, chemical, biological, technological and ecological processes depend. Therefore monitoring of element content (in the course of technological process - on line; in natural conditions - in site; or in living organisms - in vivo) becomes necessary for investigation of aforementioned processes. This problem can be successfully solved by using the methods of prompt gamma activation analysis (PGAA) and instrumental neutron activation analysis (INAA) on short-living radionuclides. These methods don't depend on type of substance (biological, geological, technological etc.), since the content is determined by gamma radiation of nuclei, and allows to meet such a serious requirement like the necessity of achieving minimal irradiation of the object and its minimal residual activity. In this work minimal determinable concentrations of various elements are estimated (based on experimental data) by the method of PGAA using radionuclide 252 Cf - source of neutrons with the yield of the oil of 10 8 neutron/sec on the experimental device with preliminary focusing of neutrons /1/, and also data of determination of elements by their isotopes with maximum time efficiency /2,3/ by the method of INAA. (author)

  2. Monitoring stress among internal medicine residents: an experience-driven, practical and short measure.

    Science.gov (United States)

    Myszkowski, Nils; Villoing, Barbara; Zenasni, Franck; Jaury, Philippe; Boujut, Emilie

    2017-07-01

    Residents experience severely high levels of stress, depression and burnout, leading to perceived medical errors, as well as to symptoms of impairment, such as chronic anger, cognitive impairment, suicidal behavior and substance abuse. Because research has not yet provided a psychometrically robust population-specific tool to measure the level of stress of medicine residents, we aimed at building and validating such a measure. Using an inductive scale development approach, a short, pragmatic measure was built, based on the interviews of 17 medicine residents. The Internal Medicine Residency Stress Scale (IMRSS) was then administered in a sample of 259 internal medicine residents (199 females, 60 males, M Age  = 25.6) along with the Hospital Anxiety and Depression Scale, Maslach Burnout Inventory, Satisfaction With Life Scale and Ways of Coping Checklist. The IMRSS showed satisfactory internal reliability (Cronbach's α = .86), adequate structural validity - studied through Confirmatory Factor Analysis (χ 2 /df = 2.51, CFI = .94; SRMR = .037, RMSEA = .076) - and good criterion validity - the IMRSS was notably strongly correlated with emotional exhaustion (r = .64; p is recommended to quickly and frequently assess and monitor stress among internal medicine residents.

  3. Long-term and short-term action-effect links and their impact on effect monitoring.

    Science.gov (United States)

    Wirth, Robert; Steinhauser, Robert; Janczyk, Markus; Steinhauser, Marco; Kunde, Wilfried

    2018-04-23

    People aim to produce effects in the environment, and according to ideomotor theory, actions are selected and executed via anticipations of their effects. Further, to ensure that an action has been successful and an effect has been realized, we must be able to monitor the consequences of our actions. However, action-effect links might vary between situations, some might apply for a majority of situations, while others might only apply to special occasions. With a combination of behavioral and electrophysiological markers, we show that monitoring of self-produced action effects interferes with other tasks, and that the length of effect monitoring is determined by both, long-term action-effect links that hold for most situations, and short-term action-effect links that emerge from a current setting. Effect monitoring is fast and frugal when these action-effect links allow for valid anticipation of action effects, but otherwise effect monitoring takes longer and delays a subsequent task. Specific influences of long-term and short-term links on the P1/N1 and P3a further allow to dissect the temporal dynamics of when these links interact for the purpose of effect monitoring. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  4. Dynamics of deforming drops

    OpenAIRE

    Bouwhuis, W.

    2015-01-01

    Liquid drops play a dominant role in numerous industrial applications, such as spray coating, spray painting, inkjet printing, lithography processes, and spraying/sprinkling in agriculture or gardening. In all of these examples, the generation, flight, impact, and spreading of drops are separate stages of the corresponding industrial processes, which are all thoroughly studied for many years. This thesis focuses on drop dynamics, impact phenomena, Leidenfrost drops, and pouring flows. Based o...

  5. 8A.03: CONTINUOUS MONITORING OF HEMODYNAMICS IN THE SHORT ARM HUMAN CENTRIFUGE: A FEASIBILITY STUDY.

    Science.gov (United States)

    Londono, F; Uytterhaegen, B; Kassel, R; Vanraemdonck, R; Beck, A; Comet, B; Runge, A; Segers, P

    2015-06-01

    The aim was to test the technical feasibility of a set up combining tonometry and ultrasound, designated as Continuous Physiological and Medical Monitoring (CPMM), for cardiovascular assessment on humans and to evaluate the ability to assess physiological changes induced by artificial gravity in the short arm human centrifuge (SAHC, Verhaert, Belgium) for detecting and preventing potential disorders induced by weightlessness. The project was developed under an European Space Agency (ESA) contract (4000101988/10/NL/EM) and with its support, by the company Verhaert in consortium with the Institute for Space Medicine and Physiology (MEDES) and Ghent University. Measurements were performed at MEDES facilities in 4 young (presumably) healthy volunteers (3 males). For two volunteers, the protocol was divided in three periods: acceleration, steady rotation velocity and deceleration, obtaining carotid pulsed wave (PW)-Mode ultrasound sequences. For another volunteer (female), carotid PW-Mode ultrasound images and brachial and radial tonometry signals were acquired at baseline and during steady rotation. For the fourth volunteer, carotid and femoral PW-Mode ultrasound images and brachial, radial and carotid tonometry signals were acquired at baseline and during an initial (velocity1) and a following faster (velocity2) rotation velocity (see figure on the following page). Carotid PW-Mode ultrasound imaging was obtained in all 4 volunteers during different steps of the protocol. Femoral ultrasound imaging presented more difficulties related mainly to the placement of the probe after baseline, even if in one case results were feasible. Tonometry was, generally, a bigger challenge due to the intrinsic sensitivity of the method. Overall, radial artery tonometry provided the best results, while brachial artery results were acceptable only in one occasion. Carotid tonometry was measured only for one subject with suitable results for processing. Tonometry measurements were feasible

  6. ARBRE monitoring - ecology of short rotation coppice. Four year study involving wildlife monitoring of commercial SCR plantations planted on arable land and arable control plots

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, M.D.; Bishop, J.D.; McKay, H.V.; Sage, R.B.

    2004-07-01

    This report summarises the findings of the UK Department of Trade and Industry (DTI) funded project monitoring wildlife within and around a number of commercially managed Short Rotation Coppice (SRC) plantations aimed at using the information gathered to assess the ecological impact of SRC plantations on the wildlife in the area. The background to the study is traced, and details are given of the monitoring programme examining the distribution of flora and fauna within the plantations, and the monitoring of birds, plants, insects and butterflies. The greater diversity of wildlife and plants in the SRC plots, the higher densities of birds, and the increasing number of butterfly species are discussed along with the increased mean number of invertebrate orders with subsequent growth of willow coppices, and the habitats at the edges of the plots and at headlands designed for access to machinery within the plots.

  7. Short and long range gain monitoring of photomultipliers by means of a light pulser and an optical fibers bunch

    International Nuclear Information System (INIS)

    Besson, P.

    1989-01-01

    The gain monitoring of 8 XP3462 photomultipliers has been studied during a period of 3 months with a spark gap as a light pulser, an optical fibres bunch and 3 reference detectors. One of the reference PM is monitored thanks to a cristal of NaI irradiated by an 241 Am radioactive source, whereas the photodiode and its associated electronic is monitored thanks to a 57 Co source directly coupled to the junction. Two experimental methods have been tested. First the short term method consists in estimating several means of charge distributions and supposes the stability of different optical parameters like quantum efficiency or photoelectrons collection efficiency. The long term method consists in estimating several variances of charge distributions and supposes the validity, at first order, of photomultipliers' equations. In spite of unpropitious experimental conditions (tension switch off, no climatisation..), our results indicate that the short term method provides a precision of about 0.5% for the relative gain value but only during a short period which has been of 20 days. The long term method provides a precision of about 1.5% but is remained available during the 3 months of our experiment. This study has been developed for the new Neutrino oscillation program taking place near the Bugey nuclear plant and using 600 photomultipliers. The conclusions mentioned above are nevertheless valid for any particle detectors using photomultipliers [fr

  8. Telemetric implantable pressure sensor for short- and long-term monitoring of intracranial pressure.

    Science.gov (United States)

    Frischholz, M; Sarmento, L; Wenzel, M; Aquilina, K; Edwards, R; Coakham, H B

    2007-01-01

    Patients with hydrocephalus, idiopathic intracranial hypertension and head injury frequently require monitoring of intracranial pressure (ICP) and may need repeated episodes of monitoring months or years apart. The gold standard for measurement of ICP remains the external ventricular catheter. This is a fluid-filled catheter transducer system that allows regular recalibration and correction of zero drift by its position relative to a fixed anatomical reference. It also allows drainage of cerebrospinal fluid (CSF), providing a means of lowering the ICP. Several catheter tip transducer systems are currently in clinical use, including using strain gauges or fiber-optical pressure sensing techniques. In these devices, zero drift and calibration cannot be checked in vivo. All the ICP monitoring devices in current clinical use require a physical connection between the brain and the external environment. This is a source of infection and limits the duration of monitoring. A number of telemetric monitoring devices, in which data is in some way transmitted transcutaneously, have been developed over the last twenty years, but significant technical problems have precluded their use in routine clinical practice. All current ICP monitors are temporary percutaneous implanted devices. Placement of these devices carries significant morbidity, particularly infection. Patients undergoing repeated monitoring require multiple surgical procedures. Apart from decreasing the risk of infection in patients with severe head injury, the clinical value of an accurate telemetric ICP monitoring system which maintains its reliability over a long period of implantation is high.

  9. Scanning drop sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John

    2017-05-09

    Electrochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  10. Scanning drop sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Shinde, Aniketa A.; Guevarra, Dan W.; Jones, Ryan J.; Marcin, Martin R.; Mitrovic, Slobodan

    2017-05-09

    Electrochemical or electrochemical and photochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  11. Short- and long-term effects of real-time medication monitoring with short message service (SMS) reminders for missed doses on the refill adherence of people with Type 2 diabetes: evidence from a randomised controlled trial.

    NARCIS (Netherlands)

    Vervloet, M.; Dijk, L. van; Bakker, D.H. de; Souverein, P.C.; Santen-Reestman, J.; Vlijmen, B. van; Aarle, M.C.W. van; Hoek, L.S. van der; Bouvy, M.L.

    2014-01-01

    Aims: To investigate short- and long-term effects of real-time monitoring medication use combined with short message service (SMS) reminders for missed doses on refill adherence to oral anti-diabetic medication. Methods: A randomized controlled trial with two intervention groups and one control

  12. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  13. Axisymmetric Liquid Hanging Drops

    Science.gov (United States)

    Meister, Erich C.; Latychevskaia, Tatiana Yu

    2006-01-01

    The geometry of drops hanging on a circular capillary can be determined by numerically solving a dimensionless differential equation that is independent on any material properties, which enables one to follow the change of the height, surface area, and contact angle of drops hanging on a particular capillary. The results show that the application…

  14. 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

  15. Dynamics of deforming drops

    NARCIS (Netherlands)

    Bouwhuis, W.

    2015-01-01

    Liquid drops play a dominant role in numerous industrial applications, such as spray coating, spray painting, inkjet printing, lithography processes, and spraying/sprinkling in agriculture or gardening. In all of these examples, the generation, flight, impact, and spreading of drops are separate

  16. Monitor: a short-cut approach to remote-handling at LAMPF

    International Nuclear Information System (INIS)

    Horne, R.A.; Ekberg, E.L.

    1975-01-01

    The monitor, constructed from relatively cheap commercial components, is a straightforward, totally remotely operated handling system intended to work on components in the LAMPF external beam line or elsewhere. It can be towed or lifted into position, then hard-wire controlled from a distance by using television. (auth)

  17. Titration of High Frequency Percussive Ventilation by means of real-time monitoring of the viscoelastic respiratory system properties and endotracheal tubes pressure drop.

    OpenAIRE

    Lucangelo, Umberto

    2014-01-01

    2012/2013 The use of High Frequency Percussive Ventilation (HFPV) is still debated although this type of non-conventional ventilation has proven effective and safe in patients with acute respiratory failure. In the clinical practice, HFPV is not an intuitive ventilatory modality and the absence of real-time delivered volume monitoring produces disaffection among the physicians. Avoiding the "volutrauma" is the cornerstone of the "protective ventilation strategy", which assumes a cons...

  18. Strengthening capacity for monitoring and evaluation through short course training in Kenya

    Directory of Open Access Journals (Sweden)

    Hesborn Wao

    2017-04-01

    Conclusions: This study provides preliminary evidence of potential of the use of short course training as an approach to strengthening capacity in M&E in less-developed countries such as Kenya. It underscores the importance of participants’ self-stated objective(s as an element to be considered in the enhancement of knowledge, attitudes and skills needed for acceptable capacity building in M&E.

  19. Short-term diffusive sampler for nitrogen dioxide monitoring in epidemiology

    International Nuclear Information System (INIS)

    Michaud, J.P.; Quackenboss, J.

    1991-01-01

    An automated timed exposure diffusive sampler (TEDS) for sampling nitrogen dioxide (NO 2 ) was developed for use in epidemiological studies. The TEDS sequentially exposes four passive sampling devices (PSD) by microprocessor controlled valves while a pump and air flow guide prevent sampler starvation. Two TEDS units and two portable, real-time NO 2 monitors were tested for accuracy, precision, sensitivity, and linearity of response. The accuracy of the TEDS was within 10 percent of the means of the measured values. The TEDS sensitivity was 20 to 30 ppb-hour for NO 2 . Co-location of the TEDS with a chemiluminescent NO x monitor (EPA reference method) showed a similar responses to ambient NO 2 . TEDS allows better time resolution than traditional diffusive samplers (i.e., Palmes tube) while sharing their ability to sample a variety of gases

  20. Short-term and long-term Vadose zone monitoring: Current technologies, development, and applications

    International Nuclear Information System (INIS)

    Faybishenko, Boris

    1999-01-01

    At Hanford, Savannah River, Oak Ridge, Idaho National Engineering and Environmental Laboratory (INEEL), and other DOE sites, field vadose zone observations have shown complex water seepage and mass transport behavior in a highly heterogeneous, thick vadose zone on a variety of scales. Recent investigation showed that severe contamination of soils and groundwater by organic contaminant and nuclear waste occurred because of water seepage and contaminant transport along localized, preferential, fast flow within the heterogeneous vadose zone. However, most of the existing characterization and monitoring methods are not able to locate these localized and persistent preferential pathways associated with specific heterogeneous geologic features, such as clastic dikes, caliche layers, or fractures. In addition, changes in the chemical composition of moving and indigenous solutes, particularly sodium concentration, redox conditions, biological transformation of organic materials, and high temperature, may significantly alter water, chemicals, and bio-transformation exchange between the zones of fast flow and the rest of the media. In this paper, using the data from Hanford and INEEL sites, we will (1) present evidence that central problems of the vadose zone investigations are associated with preferential, fast flow phenomena and accelerated migration of organic and radioactive elements, (2) identify gaps in current characterization and monitoring technologies, and (3) recommend actions for the development of advanced vadose zone characterization and monitoring methods using a combination of hydrologic, geochemical, and geophysical techniques

  1. ARBRE monitoring - ecology of short rotation coppice plantations. Interim report 2000

    Energy Technology Data Exchange (ETDEWEB)

    Rich, T.J.; Sage, R.; Moore, N.; Robertson, P.; Aegerter, J.; Bishop, J.

    2001-07-01

    Short Rotation willow coppice (SRC) is a potential habitat for wildlife in the British countryside according to research reported in the late 1990s, but so far the trials have been on small plantations without reference to the land use it would supersede. This interim report, on a 4-year study which began in January 2000, discusses the commercial availability of SRC plantations and assesses what might be achievable by changing land usage. Work so far, conducted on indicator species (songbirds, ground flora, butterflies, insects), suggests that there are likely to be marked environmental benefits to be gained through SRC.

  2. Study on Turn-to-turn Short Circuit On一line Monitoring System for Dry一type Ai r一core Reactor

    Directory of Open Access Journals (Sweden)

    GAO Zi-wei

    2017-04-01

    Full Text Available The change of current value caused by turn-to-turn short circuit of dry-type air-core reactor is so little that failure detection is difficult to be carried out. In order to solve this problem,a new on-line monitoring system based on impedance variation of turn-to-turn short circuit is proposed. The numerical method is applied to analyze the variation of equivalent resistance and equivalent reactance when dry-type air-core reactor winding short circuit happens in different places,and the monitoring method based on harmonic analysis method and quasi- synchronization sampling method is analyzed by theory. The hardware system,which takes single-chip microcomputer as the core of data processing and logic control,completes data acquisition of voltage signal and current signal of the reactor. In the respect of software design,the impedance variation will be uploaded to the PC after it has been calculated by using the above monitoring method,and then monitoring of turn-to-turn short circuit fault will be realized. Finally,the design of on-line monitoring system is studied by testing. The research result shows that,the equivalent resistance increases and the equivalent reactance decreases when turn-to-turn short circuit occurs,and the variation of equivalent resistance is more obvious than equivalent reactance. The experiment results prove that this monitoring method is true and the on-line monitoring system is feasible.

  3. Yolk coelomitis in a white-throated monitor lizard (Varanus albigularis : short communication

    Directory of Open Access Journals (Sweden)

    B.R. Gardner

    2010-05-01

    Full Text Available Yolk coelomitis as a result of pre-ovulatory follicular stasis is a common disorder in captive reptiles, especially in captive lizards of various genera. The clinical signs are generally fairly non-specific and diagnosis is based on clinical signs together with most of the common diagnostic modalities. The condition is most likely a husbandry and environment-related reproductive disorder. It has not been reported in wild free-living specimens. This report describes the clinical presentation and post mortem lesions in a white-throated monitor lizard that died during treatment for non-specific clinical signs related to a severe yolk coelomitis.

  4. Multiparameter monitoring of short-term earthquake precursors and its physical basis. Implementation in the Kamchatka region

    Directory of Open Access Journals (Sweden)

    Pulinets Sergey

    2016-01-01

    Full Text Available We apply experimental approach of the multiparameter monitoring of short-term earthquake precursors which reliability was confirmed by the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC model created recently [1]. A key element of the model is the process of Ion induced Nucleation (IIN and formation of cluster ions occurring as a result of the ionization of near surface air layer by radon emanating from the Earth's crust within the earthquake preparation zone. This process is similar to the formation of droplet’s embryos for cloud formation under action of galactic cosmic rays. The consequence of this process is the generation of a number of precursors that can be divided into two groups: a thermal and meteorological, and b electromagnetic and ionospheric. We demonstrate elements of prospective monitoring of some strong earthquakes in Kamchatka region and statistical results for the Chemical potential correction parameter for more than 10 years of observations for earthquakes with M≥6. As some experimental attempt, the data of Kamchatka volcanoes monitoring will be demonstrated.

  5. Short communication: Monitoring the presence of perfluoroalkyl substances in Italian cow milk.

    Science.gov (United States)

    Barbarossa, Andrea; Gazzotti, Teresa; Zironi, Elisa; Serraino, Andrea; Pagliuca, Giampiero

    2014-01-01

    Perfluoroalkyl substances (PFAS) are fully fluorinated compounds widely used during the last 60 yr in the production of multiple industrial and consumer applications, such as food packaging, nonstick cookware, cleaning agents, and many more. These emerging contaminants have recently become of concern for human health because of their potential negative effects. The risk of exposure to PFAS for humans is mainly related to diet, and the increasing interest in food safety has led the European Commission to call Member States to monitor these contaminants in food matrices. The purpose of the present work was to perform the first monitoring on the presence of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the 2 main and most widely investigated molecules of this family, in cow milk commercially available in Italy. We used an analytical protocol consisting of liquid-liquid extraction followed by 2 purification steps through solid-phase extraction cartridges and injection on an ultra-performance liquid chromatography-tandem mass spectroscopy system. The analysis of 67 samples of different types of cow milk from Italy demonstrated that contamination by PFOS was often present, although at relatively low concentrations (up to 97 ng/L), whereas PFOA was rarely found. On the basis of these results and data reported in the literature on this matrix, milk does not seem to be a major source of PFAS compared with other food categories such as fish and seafood. However, variability among different types of milk must be taken into account, and surveys of milk-derived products would be helpful to better define the risk for consumers. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  7. Application of short-range photogrammetry for monitoring seepage erosion of riverbank by laboratory experiments

    Science.gov (United States)

    Masoodi, A.; Noorzad, A.; Majdzadeh Tabatabai, M. R.; Samadi, A.

    2018-03-01

    Temporal and spatial monitoring play a significant role in evaluating and examining the riverbank morphology and its spatiotemporal changes. Unlike the terrestrial laser scanners, other previously used methods such as satellite images, total station surveying, and erosion pins have limited application to quantify the small-scale bank variations due to the lack of rapid survey and resolution in data acquisition. High cost, lack of availability, specialized equipment and hard movement of laser scanners make it necessary to develop new accurate, economical and easily available methods. The present study aims to test the Kinect photogrametric technology for measuring and assessing riverbank variations in laboratory environment. For this purpose, three models of layered soil blocks for three different levels of groundwater (i.e. 24, 34 and 44 cm) were designed to investigate the seepage erosion behavior experimentally. The results indicate the high accuracy of Kinect in measuring the bank erosion cavity dimensions (i.e., 0.5% error) with high spatial resolution data (i.e. 300,000 points per frame). The high speed of Kinect in riverbank scanning enables the analysis of time variations of mechanisms such as seepage erosion which occurs rather rapidly. The results confirmed that there is a power relationship between the seepage gradient and the time of the bank failure with a determination coefficient of 0.97. Moreover, an increase in the level of groundwater on the riverbank increases the rate of undercutting retreat that caused more rapid failure of the riverbank.

  8. An interferometric radar sensor for monitoring the vibrations of structures at short ranges

    Directory of Open Access Journals (Sweden)

    Luzi Guido

    2018-01-01

    Full Text Available The Real-Aperture-Radar (RAR interferometry technique consolidated in the last decade as an operational tool for the monitoring of large civil engineering structures as bridges, towers, and buildings. In literature, experimental campaigns collected through a well-known commercial equipment have been widely documented, while the cases where different types of sensors have been tested are a few. On the bases of some experimental tests, a new sensor working at high frequency, providing some improved performances, is here discussed. The core of the proposed system is an off-the-shelf, linear frequency modulated continuous wave device. The development of this apparatus is aimed at achieving a proof-of-concept, tackling operative aspects related to the development of a low cost and reliable system. The capability to detect the natural frequencies of a lightpole has been verified; comparing the results of the proposed sensor with those ones obtained through a commercial system based on the same technique, a more detailed description of the vibrating structure has been achieved. The results of this investigation confirmed that the development of sensors working at higher frequencies, although deserving deeper studies, is very promising and could open new applications demanding higher spatial resolutions at close ranges.

  9. A New Approach to Detection of Systematic Errors in Secondary Substation Monitoring Equipment Based on Short Term Load Forecasting

    Directory of Open Access Journals (Sweden)

    Javier Moriano

    2016-01-01

    Full Text Available In recent years, Secondary Substations (SSs are being provided with equipment that allows their full management. This is particularly useful not only for monitoring and planning purposes but also for detecting erroneous measurements, which could negatively affect the performance of the SS. On the other hand, load forecasting is extremely important since they help electricity companies to make crucial decisions regarding purchasing and generating electric power, load switching, and infrastructure development. In this regard, Short Term Load Forecasting (STLF allows the electric power load to be predicted over an interval ranging from one hour to one week. However, important issues concerning error detection by employing STLF has not been specifically addressed until now. This paper proposes a novel STLF-based approach to the detection of gain and offset errors introduced by the measurement equipment. The implemented system has been tested against real power load data provided by electricity suppliers. Different gain and offset error levels are successfully detected.

  10. Impact of granular drops

    KAUST Repository

    Marston, J. O.

    2013-07-15

    We investigate the spreading and splashing of granular drops during impact with a solid target. The granular drops are formed from roughly spherical balls of sand mixed with water, which is used as a binder to hold the ball together during free-fall. We measure the instantaneous spread diameter for different impact speeds and find that the normalized spread diameter d/D grows as (tV/D)1/2. The speeds of the grains ejected during the “splash” are measured and they rarely exceed twice that of the impact speed.

  11. Impact of granular drops

    KAUST Repository

    Marston, J. O.; Mansoor, Mohammad M.; Thoroddsen, Sigurdur T

    2013-01-01

    We investigate the spreading and splashing of granular drops during impact with a solid target. The granular drops are formed from roughly spherical balls of sand mixed with water, which is used as a binder to hold the ball together during free-fall. We measure the instantaneous spread diameter for different impact speeds and find that the normalized spread diameter d/D grows as (tV/D)1/2. The speeds of the grains ejected during the “splash” are measured and they rarely exceed twice that of the impact speed.

  12. Ambulatory blood pressure monitoring-derived short-term blood pressure variability is increased in Cushing's syndrome.

    Science.gov (United States)

    Rebellato, Andrea; Grillo, Andrea; Dassie, Francesca; Sonino, Nicoletta; Maffei, Pietro; Martini, Chiara; Paoletta, Agostino; Fabris, Bruno; Carretta, Renzo; Fallo, Francesco

    2014-11-01

    Cushing's syndrome is associated with high cardiovascular morbility and mortality. Blood pressure (BP) variability within a 24-h period is increasingly recognized as an independent predictor of cardiovascular risk. The aim of our study was to investigate the short-term BP variability indices in Cushing's syndrome. Twenty-five patients with Cushing's syndrome (mean age 49 ± 13 years, 4 males; 21 Cushing's disease and 4 adrenal adenoma patients) underwent 24-h ambulatory BP monitoring (ABPM) and evaluation of cardiovascular risk factors. Cushing patients were divided into 8 normotensive (NOR-CUSH) and 17 hypertensive (HYP-CUSH) patients and were compared with 20 normotensive (NOR-CTR) and 20 hypertensive (HYP-CTR) age-, sex-, and BMI-matched control subjects. Short-term BP variability was derived from ABPM and calculated as the following: (1) standard deviation (SD) of 24-h, daytime, and nighttime BP; (2) 24-h weighted SD of BP; and (3) average real variability (ARV), i.e., the average of the absolute differences between consecutive BP measurements over 24 h. In comparison with controls, patients with Cushing's syndrome, either normotensive or hypertensive, had higher 24-h and daytime SD of BP, as well as higher 24-h weighted SD and ARV of BP (P = 0.03 to P CUSH or between HYP-CTR and HYP-CUSH subgroups. ABPM-derived short-term BP variability is increased in Cushing's syndrome, independent of BP elevation. It may represent an additional cardiovascular risk factor in this disease. The role of excess cortisol in BP variability has to be further clarified.

  13. Predicting Students Drop Out: A Case Study

    Science.gov (United States)

    Dekker, Gerben W.; Pechenizkiy, Mykola; Vleeshouwers, Jan M.

    2009-01-01

    The monitoring and support of university freshmen is considered very important at many educational institutions. In this paper we describe the results of the educational data mining case study aimed at predicting the Electrical Engineering (EE) students drop out after the first semester of their studies or even before they enter the study program…

  14. Predicting students drop out : a case study

    NARCIS (Netherlands)

    Dekker, G.W.; Pechenizkiy, M.; Vleeshouwers, J.M.; Barnes, T.; Desmarais, M.; Romero, C.; Ventura, S.

    2009-01-01

    The monitoring and support of university freshmen is considered very important at many educational institutions. In this paper we describe the results of the educational data mining case study aimed at predicting the Electrical Engineering (EE) students drop out after the first semester of their

  15. Potential drop sensors for sodium loops

    International Nuclear Information System (INIS)

    Selvaraj, R.

    1978-11-01

    Potential drop sensors to detect the presence or the absence of sodium in pipe lines are described. These are very handy during loop charging and dumping operations. Their suitability to detect level surges and to monitor continuous level of liquid metals in certain applications is discussed. (author)

  16. Assessment of the biomass related indoor air pollution in Kwale district in Kenya using short term monitoring.

    Science.gov (United States)

    Majdan, Marek; Svaro, Miroslav; Bodo, Jan; Taylor, Mark; Muendo, Redempta Malinda

    2015-09-01

    Indoor air pollution remains an important health problem in some countries. Although research data on this issue is available, routine monitoring in affected areas is limited. The aims of this study were to quantify exposure to biomass-related indoor air pollution; assess the respiratory health of subjects; and explore the feasibility of routine monitoring in Kwale district, Kenya. We sampled 125 rural houses using short-term monitoring for levels of CO, CO2 and TSP. Additional exposure information was obtained using a checklist. Respiratory health was also assessed using a questionnaire, and electronic spirometer in 172 inhabitants. The overall median levels of CO in the sampled houses on all study sites ranged from 5.9 (IQR 3-14.5) to 10 (5.5-21.2) mg/m3, levels of CO2 ranged from 774 (IQR 724-846) to 839 (IQR 749-961) mg/m3) and the levels of TSP ranged from 295 (IQR 79-853 to 1384 (IQR 557-3110) µg/m(3) which indicates that safe levels recommended by WHO and USEPA could be exceeded. Relatively high incidences of respiratory illness or symptoms were reported and the spirometry readings suggested impaired lung function in over 80% of respondents. Our results quantify that the use of biomass fuel can give rise to high levels of indoor air pollution. Given that poor lung function contributes to public health problems in rural regions of East Africa, such as Kwale in Kenya, our findings create grounds for more detailed investigations of the problem and may provide motivation for community based interventions.

  17. Two secondary drops

    Indian Academy of Sciences (India)

    Figure shows formation of two secondary drops of unequal size and their merger. The process is same as the earlier process until t= 0.039 Tc with necking occurring at two places, one at the bottom of the column and the other at the middle. The necking at the middle of the liquid column is due to Raleigh instability.

  18. Lambda-dropping

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1997-01-01

    Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

  19. Drop dynamics on a stretched viscoelastic filament: An experimental study

    Science.gov (United States)

    Peixinho, Jorge; Renoult, Marie-Charlotte; Crumeyrolle, Olivier; Mutabazi, Innocent

    2016-11-01

    Capillary pressure can destabilize a thin liquid filament during breakup into a succession of drops. Besides, the addition of a linear, high molecular weight, flexible and soluble polymer is enough to modify the morphology of this instability. In the time period preceding the breakup, the development of beads-on-a-string structures where drops are connected by thin threads is monitored. The drops dynamics involve drop formation, drop migration and drop coalescence. Experiments using a high-speed camera on stretched bridges of viscoelastic polymeric solutions were conducted for a range of viscosities and polymer concentrations. The rheological properties of the solutions are also quantified through conventional shear rheology and normal stress difference. The overall goal of this experimental investigation is to gain more insight into the formation and time evolution of the drops. The project BIOENGINE is co-financed by the European Union with the European regional development fund and by the Normandie Regional Council.

  20. A Distributed Web-based Solution for Ionospheric Model Real-time Management, Monitoring, and Short-term Prediction

    Science.gov (United States)

    Kulchitsky, A.; Maurits, S.; Watkins, B.

    2006-12-01

    provide inputs for the next ionospheic model time step and then stored in a MySQL database as the first part of the time-specific record. The RMM then performs synchronization of the input times with the current model time, prepares a decision on initialization for the next model time step, and monitors its execution. Then, as soon as the model completes computations for the next time step, RMM visualizes the current model output into various short-term (about 1-2 hours) forecasting products and compares prior results with available ionospheric measurements. The RMM places prepared images into the MySQL database, which can be located on a different computer node, and then proceeds to the next time interval continuing the time-loop. The upper-level interface of this real-time system is the a PHP-based Web site (http://www.arsc.edu/SpaceWeather/new). This site provides general information about the Earth polar and adjacent mid-latitude ionosphere, allows for monitoring of the current developments and short-term forecasts, and facilitates access to the comparisons archive stored in the database.

  1. Time-lapse ERT and DTS for seasonal and short-term monitoring of an alpine river hyporheic zone

    Science.gov (United States)

    Boaga, Jacopo; Laura, Busato; Mariateresa, Perri; Giorgio, Cassiani

    2016-04-01

    The hyporheic zone (HZ) is the area located beneath and adjacent to rivers and streams, where the interactions between surface water and groundwater take place. This complex physical domain allows the transport of several substances from a stream to the unconfined aquifer below, and vice versa, thus playing a fundamental role in the river ecosystem. The importance of the hyporheic zone makes its characterization a goal shared by several disciplines, which range from applied geophysics to biogeochemistry, from hydraulics to ecology. The frontier field of HZ characterization stays in applied non-invasive methodologies as Electrical Resistivity Tomography - ERT - and Distributed Temperature Sensing - DTS. ERT is commonly applied in cross-well configuration or with a superficial electrodes deployment while DTS is used in hydro-geophysics in the last decade, revealing a wide applicability to the typical issues of this field of study. DTS for hydro-geophysics studies is based on Raman scattering and employs heat as tracer and uses a fiber-optic cable to acquire temperature values. We applied both techniques for an alpine river case studies located in Val di Sole, TN, Italy. The collected measurements allow high-resolution characterization of the hyporheic zone, overcoming the critical problem of invasive measurements under riverbeds. In this work, we present the preliminary results regarding the characterization of the hyporheic zone of the alpine river obtained combining ERT and DTS time-lapse measurements. The data collection benefits from an innovative instrumentation deployment, which consists of both an ERT multicore cable and a DTS fiber-optic located in two separated boreholes drilled 5m under the watercourse and perpendicular to it. In particular we present the first year monitoring results and a short time-lapse monitoring experiment conducted during summer 2015. The site and the results here described are part of the EU FP7 CLIMB (Climate Induced Changes on the

  2. Dropping out of school

    Directory of Open Access Journals (Sweden)

    M. Teneva

    2017-09-01

    Full Text Available The modern technological society needs educated people who, through their high professionalism, are called upon to create its progress. In this aspect, a serious problem stands out – the dropout from school of a large number of children, adolescents and young people. The object of the research is the premature interruption of training for a large number of Bulgarian students. The subject of the study is the causes that provoke the students’ dropping out of school. The aim is to differentiate the negative factors leading to dropping out of school, and to identify the motivating factors that encourage the individual to return to the educational environment. In order to realize the so set target, a specially designed test-questionnaire has been used. The survey was conducted among students attending evening courses who have left their education for various reasons and are currently back to the school institution. The contingent of the study includes 120 students from the evening schools. The results indicate that the reasons which prompted the students to leave school early differentiate into four groups: family, social, economic, educational, personal. The motivation to return to school has been dictated in the highest degree by the need for realization of the person on the labor market, followed by the possibility for full social functioning.

  3. Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping

    NARCIS (Netherlands)

    Bobbert, M F; Huijing, P A; van Ingen Schenau, G J

    In the literature, athletes preparing for explosive activities are recommended to include drop jumping in their training programs. For the execution of drop jumps, different techniques and different dropping heights can be used. This study was designed to investigate for the performance of bounce

  4. Controlling charge on levitating drops.

    Science.gov (United States)

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation.

  5. First drop dissimilarity in drop-on-demand inkjet devices

    International Nuclear Information System (INIS)

    Famili, Amin; Palkar, Saurabh A.; Baldy, William J. Jr.

    2011-01-01

    As inkjet printing technology is increasingly applied in a broader array of applications, careful characterization of its method of use is critical due to its inherent sensitivity. A common operational mode in inkjet technology known as drop-on-demand ejection is used as a way to deliver a controlled quantity of material to a precise location on a target. This method of operation allows ejection of individual or a sequence (burst) of drops based on a timed trigger event. This work presents an examination of sequences of drops as they are ejected, indicating a number of phenomena that must be considered when designing a drop-on-demand inkjet system. These phenomena appear to be driven by differences between the first ejected drop in a burst and those that follow it and result in a break-down of the linear relationship expected between driving amplitude and drop mass. This first drop, as quantified by high-speed videography and subsequent image analysis, can be different in morphology, trajectory, velocity, and volume from subsequent drops within a burst. These findings were confirmed orthogonally by both volume and mass measurement techniques which allowed quantitation down to single drops.

  6. Studying the field induced breakup of acoustically levitated drops

    Science.gov (United States)

    Warschat, C.; Riedel, J.

    2017-10-01

    Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of

  7. Acute Short-Term Sleep Deprivation Does Not Affect Metacognitive Monitoring Captured by Confidence Ratings: A Systematic Literature Review

    Science.gov (United States)

    Jackson, Simon A.; Martin, Gregory D.; Aidman, Eugene; Kleitman, Sabina

    2018-01-01

    This article presents the results of a systematic review of the literature surrounding the effects that acute sleep deprivation has on metacognitive monitoring. Metacognitive monitoring refers to the ability to accurately assess one's own performance and state of knowledge. The mechanism behind this assessment is captured by subjective feelings of…

  8. Antroduodenal manometry: 24-hour ambulatory monitoring versus short-term stationary manometry in patients with functional dyspepsia

    NARCIS (Netherlands)

    Jebbink, R. J.; vanBerge-Henegouwen, G. P.; Akkermans, L. M.; Smout, A. J.

    1995-01-01

    OBJECTIVES: To examine the interdigestive and postprandial antroduodenal motility patterns of patients with functional dyspepsia using prolonged ambulatory antroduodenal manometry and to compare these findings with conventional stationary manometry. METHODS: Prolonged ambulatory and short-term

  9. Hanging drop crystal growth apparatus

    Science.gov (United States)

    Naumann, Robert J. (Inventor); Witherow, William K. (Inventor); Carter, Daniel C. (Inventor); Bugg, Charles E. (Inventor); Suddath, Fred L. (Inventor)

    1990-01-01

    This invention relates generally to control systems for controlling crystal growth, and more particularly to such a system which uses a beam of light refracted by the fluid in which crystals are growing to detect concentration of solutes in the liquid. In a hanging drop apparatus, a laser beam is directed onto drop which refracts the laser light into primary and secondary bows, respectively, which in turn fall upon linear diode detector arrays. As concentration of solutes in drop increases due to solvent removal, these bows move farther apart on the arrays, with the relative separation being detected by arrays and used by a computer to adjust solvent vapor transport from the drop. A forward scattering detector is used to detect crystal nucleation in drop, and a humidity detector is used, in one embodiment, to detect relative humidity in the enclosure wherein drop is suspended. The novelty of this invention lies in utilizing angular variance of light refracted from drop to infer, by a computer algorithm, concentration of solutes therein. Additional novelty is believed to lie in using a forward scattering detector to detect nucleating crystallites in drop.

  10. 45-FOOT HIGH DROP TOWER

    Data.gov (United States)

    Federal Laboratory Consortium — The Drop Tower is used to simulate and measure the impact shocks that are exerted on parachute loads when they hit the ground. It is also used for HSL static lift to...

  11. Short-term biological variation of clinical chemical values in dumeril's monitors (Varanus dumerili)

    DEFF Research Database (Denmark)

    Bertelsen, Mads Frost; Kjelgaard-Hansen, Mads Jens; Howell, Jennifer R.

    2007-01-01

    Plasma biochemical values are routinely used in the medical management of ill reptiles, and for monitoring the health of clinically normal animals. Laboratory tests, including clinical biochemical values, are subject to biological and analytical variation, the magnitude of which determines the ut...

  12. Fault clearance in medium-voltage networks using remote-monitored short-circuit alarms; Stoerungsbeseitigung im MS-Netz mit fernueberwachten Kurzschlussmeldern

    Energy Technology Data Exchange (ETDEWEB)

    Beran, B. [Reginalzentrum Neckar-Franken der EnBW Regional AG, Oehringen (Germany). Bereich Netzfuehrung; Deiss, R. [RBS Genius GmbH, Stuttgart (Germany). Bereich Korrosionsschutz und Gaslecksuche; Stibbe, T. [Phoenix Contact GmbH und Co KG, Blomberg (Lippe) (Germany). Vertrieb Deutschland

    2006-04-15

    In March 2005, a pilot project on remote monitoring of short-circuit alarms using GSM was started. In cooperation with RBS Genius GmbH (100 percent subsidiary of EnBW Regional AG) who already use a similar technology for controlling cathodic corrosion protection systems, and the EnBW-Regionalzentrum Neckar-Franken, the functionalities were specified. After only five months of development and assembly time, the first 15 units were installed in exposed and difficult-to-access sites. All sites were located along very long power lines in which localisation of the defect would be very time-consuming. (orig.)

  13. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    Energy Technology Data Exchange (ETDEWEB)

    Bigu, J [Department of Energy, Mines and Resources, Elliot Lake, Ontario (Canada). Elliot Lake Lab.; Raz, R; Golden, K; Dominguez, P [Alpha-NUCLEAR, Toronto, Ontario (Canada)

    1984-08-15

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operation with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross ..cap alpha..-count methods and ..cap alpha..-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of ..cap alpha..-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software.

  14. Design and development of a computer-based continuous monitor for the determination of the short-lived decay products of radon and thoron

    International Nuclear Information System (INIS)

    Bigu, J.

    1984-01-01

    A portable, rugged, monitor has been designed and built for measuring the short-lived decay products of radon and thoron. The monitor is computer-based and employs a continuous filter strip which can be advanced at programmable time intervals to allow unattended continuous operatin with automatic sampling, analysis and recording of radiation levels. Radionuclide analysis is carried out by two silicon diffused-junction alpha-detectors and electronic circuitry with multichannel spectral analysis capabilities. Standard gross α-count methods and α-spectroscopy methods can easily be implemented. The built-in computer performs a variety of operations via a specially designed interface module, including control and data recording functions, and computations, program storage and display functions. Programs and data are stored in the built-in casette tape drive and the computer integrated CRT display and keyboard allow simple, prompted menu-type operation of standard software. Graphical presentation of α-spectra can be shown on the computer CRT and printed when required on the computer built-in thermal printer. In addition, to implementing the specially developed radionuclide analysis software, the operator can interact and modify existing software, and program new ones, through BASIC language programming, or employ the computer in a totally unrelated, general purpose model. Although the monitor is ideally suited for environmental radon (thoron) daughter monitoring, it could also be used in the determination of other airborne radionuclides provided adequate analytical procedures are developed or included in the already existing computer software. (orig.)

  15. Liquid drops attract or repel by the inverted Cheerios effect.

    Science.gov (United States)

    Karpitschka, Stefan; Pandey, Anupam; Lubbers, Luuk A; Weijs, Joost H; Botto, Lorenzo; Das, Siddhartha; Andreotti, Bruno; Snoeijer, Jacco H

    2016-07-05

    Solid particles floating at a liquid interface exhibit a long-ranged attraction mediated by surface tension. In the absence of bulk elasticity, this is the dominant lateral interaction of mechanical origin. Here, we show that an analogous long-range interaction occurs between adjacent droplets on solid substrates, which crucially relies on a combination of capillarity and bulk elasticity. We experimentally observe the interaction between droplets on soft gels and provide a theoretical framework that quantitatively predicts the interaction force between the droplets. Remarkably, we find that, although on thick substrates the interaction is purely attractive and leads to drop-drop coalescence, for relatively thin substrates a short-range repulsion occurs, which prevents the two drops from coming into direct contact. This versatile interaction is the liquid-on-solid analog of the "Cheerios effect." The effect will strongly influence the condensation and coarsening of drops on soft polymer films, and has potential implications for colloidal assembly and mechanobiology.

  16. Short communication. Platform for bee-hives monitoring based on sound analysis. A perpetual warehouse for swarms daily activity

    Energy Technology Data Exchange (ETDEWEB)

    Atauri Mezquida, D.; Llorente Martinez, J.

    2009-07-01

    Bees and beekeeping are suffering a global crisis. Constant information on swarms conditions would be a key to study new diseases like colony collapse disorder and to develop new beekeeping tools to improve the hive management and make it more efficient. A platform for beehives monitoring is presented. It is based on the analysis of the colonies buzz which is registered by a bunch of sensors sending the data to a common database. Data obtained through sound processing shows plenty of patterns and tendency lines related to colonies activities and their conditions. It shows the potential of the sound as a swarm activity gauge. The goal of the platform is the possibility to store information about the swarms activity. The objective is to build a global net of monitored hives covering apiaries with different climates, razes and managements. (Author) 21 refs.

  17. Drop Spreading with Random Viscosity

    Science.gov (United States)

    Xu, Feng; Jensen, Oliver

    2016-11-01

    Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

  18. Thermocapillary reorientation of Janus drops

    Science.gov (United States)

    Rosales, Rodolfo; Saenz, Pedro

    2017-11-01

    Janus drops, named after the Ancient Roman two-faced god, are liquid drops formed from two immiscible fluids. Experimental observations indicate that a Janus drop may re-orientate in response to an applied external thermal gradient due to the Marangoni effect. Depending on the angle between the interior interface and the direction of the temperature gradient, disparities in the physical properties of the constituent liquids may lead to asymmetries in the thermocapillary flow. As a result, the drop will move along a curved path until a torque-free configuration is achieved, point after which it will continue on a straight trajectory. Here, we present the results of a theoretical investigation of this realignment phenomenon in the Stokes regime and in the limit of non-deformable interfaces. A 3D semi-analytical method in terms of polar spherical harmonics is developed to characterize and rationalize the hydrodynamic response (forces and torques), flow (velocity and temperature distribution) and trajectory of a Janus drop moving during the temperature-driven reorientation process. Furthermore, we discuss how this phenomenon may be exploited to develop dynamically reconfigurable micro-lenses. This work was partially supported by the US National Science Foundation through Grants DMS-1614043 and DMS-1719637.

  19. Deep ECGNet: An Optimal Deep Learning Framework for Monitoring Mental Stress Using Ultra Short-Term ECG Signals.

    Science.gov (United States)

    Hwang, Bosun; You, Jiwoo; Vaessen, Thomas; Myin-Germeys, Inez; Park, Cheolsoo; Zhang, Byoung-Tak

    2018-02-08

    Stress recognition using electrocardiogram (ECG) signals requires the intractable long-term heart rate variability (HRV) parameter extraction process. This study proposes a novel deep learning framework to recognize the stressful states, the Deep ECGNet, using ultra short-term raw ECG signals without any feature engineering methods. The Deep ECGNet was developed through various experiments and analysis of ECG waveforms. We proposed the optimal recurrent and convolutional neural networks architecture, and also the optimal convolution filter length (related to the P, Q, R, S, and T wave durations of ECG) and pooling length (related to the heart beat period) based on the optimization experiments and analysis on the waveform characteristics of ECG signals. The experiments were also conducted with conventional methods using HRV parameters and frequency features as a benchmark test. The data used in this study were obtained from Kwangwoon University in Korea (13 subjects, Case 1) and KU Leuven University in Belgium (9 subjects, Case 2). Experiments were designed according to various experimental protocols to elicit stressful conditions. The proposed framework to recognize stress conditions, the Deep ECGNet, outperformed the conventional approaches with the highest accuracy of 87.39% for Case 1 and 73.96% for Case 2, respectively, that is, 16.22% and 10.98% improvements compared with those of the conventional HRV method. We proposed an optimal deep learning architecture and its parameters for stress recognition, and the theoretical consideration on how to design the deep learning structure based on the periodic patterns of the raw ECG data. Experimental results in this study have proved that the proposed deep learning model, the Deep ECGNet, is an optimal structure to recognize the stress conditions using ultra short-term ECG data.

  20. Data summary report on short-term turbidity monitoring of pipeline river crossings in the Moyie River, Boundary County, Idaho: PGT-PG&E Pipeline Expansion Project

    Energy Technology Data Exchange (ETDEWEB)

    Gowdy, M.J.; Smits, M.P.; Wilkey, P.L.; Miller, S.F.

    1994-03-01

    A water-quality monitoring program was implemented for Bechtel Corporation to measure the short-term increases in turbidity in the Moyie River caused by construction activities of the Pacific Gas Transmission-Pacific Gas & Electric Pipeline Expansion Project. Construction of the buried, 42-in.-diameter, steel pipeline, during the summer of 1992, involved eight wet crossings of the Moyie River along the 13-mi section of pipeline immediately south of the Canadian-United States border in Boundary County, Idaho. This report summarizes the sampling and analysis protocol used and gives the results and observations for each of the eight crossings. The data obtained from this monitoring program, in addition to satisfying regulatory requirements for the Pipeline Expansion Project, will contribute to an ongoing long-term study of the Moyie River crossings being performed for the Gas Research Institute by Argonne National Laboratory. The purpose of this document is strictly limited to reporting the results of the monitoring program. Interpretation of the data is not within the scope of this report.

  1. Interfacial Instabilities in Evaporating Drops

    Science.gov (United States)

    Moffat, Ross; Sefiane, Khellil; Matar, Omar

    2007-11-01

    We study the effect of substrate thermal properties on the evaporation of sessile drops of various liquids. An infra-red imaging technique was used to record the interfacial temperature. This technique illustrates the non-uniformity in interfacial temperature distribution that characterises the evaporation process. Our results also demonstrate that the evaporation of methanol droplets is accompanied by the formation of wave-trains in the interfacial temperature field; similar patterns, however, were not observed in the case of water droplets. More complex patterns are observed for FC-72 refrigerant drops. The effect of substrate thermal conductivity on the structure of the complex pattern formation is also elucidated.

  2. Short-eared Owl (Asio flammeus surveys in the North American Intermountain West: utilizing citizen scientists to conduct monitoring across a broad geographic scale

    Directory of Open Access Journals (Sweden)

    Robert A. Miller

    2016-06-01

    Full Text Available The Short-eared Owl (Asio flammeus is an open-country species breeding in the northern United States and Canada, and has likely experienced a long-term, range-wide, and substantial decline. However, the cause and magnitude of the decline is not well understood. We set forth to address the first two of six previously proposed conservation priorities to be addressed for this species: (1 better define habitat use and (2 improve population monitoring. We recruited 131 volunteers to survey over 6.2 million ha within the state of Idaho for Short-eared Owls during the 2015 breeding season. We surveyed 75 transects, 71 of which were surveyed twice, and detected Short-eared Owls on 27 transects. We performed multiscale occupancy modeling to identify habitat associations, and performed multiscale abundance modeling to generate a state-wide population estimate. Our results suggest that within the state of Idaho, Short-eared Owls are more often found in areas with marshland or riparian habitat or areas with greater amounts of sagebrush habitat at the 1750 ha transect scale. At the 50 ha point scale, Short-eared Owls tend to associate positively with fallow and bare dirt agricultural land and negatively with grassland. Cropland was not chosen at the broader transect scale suggesting that Short-eared Owls may prefer more heterogeneous landscapes. On the surface our results may seem contradictory to the presumed land use by a "grassland" species; however, the grasslands of the Intermountain West, consisting largely of invasive cheatgrass (Bromus tectorum, lack the complex structure shown to be preferred by these owls. We suggest the local adaptation to agriculture represents the next best habitat to their historical native habitat preferences. Regardless, we have confirmed regional differences that should be considered in conservation planning for this species. Last, our results demonstrate the feasibility, efficiency, and effectiveness of utilizing public

  3. Fluid flow in drying drops

    NARCIS (Netherlands)

    Gelderblom, Hanneke

    2013-01-01

    When a suspension drop evaporates, it leaves behind a drying stain. Examples of these drying stains encountered in daily life are coffee or tea stains on a table top, mineral rings on glassware that comes out of the dishwasher, or the salt deposits on the streets in winter. Drying stains are also

  4. Pressure drop in contraction flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find...

  5. HBA1C AND MEAN GLUCOSE DERIVED FROM SHORT-TERM CONTINUOUS GLUCOSE MONITORING ASSESSMENT DO NOT CORRELATE IN PATIENTS WITH HBA1C >8.

    Science.gov (United States)

    Yamada, Eijiro; Okada, Shuichi; Nakajima, Yasuyo; Bastie, Claire C; Vatish, Manu; Tagaya, Yuko; Osaki, Aya; Shimoda, Yoko; Shibusawa, Ryo; Saito, Tsugumichi; Okamura, Takashi; Ozawa, Atsushi; Yamada, Masanobu

    2017-01-01

    Optimum therapy for patients with diabetes depends on both acute and long-term changes in plasma glucose, generally assessed by glycated hemoglobin (HbA1c) levels. However, the correlation between HbA1c and circulating glucose has not been fully determined. Therefore, we carefully examined this correlation when glucose levels were assessed by continuous glucose monitoring (CGM). Fifty-one patients (70% female, 30% male) were examined; among them were 28 with type 1 diabetes and 23 with type 2 diabetes. Clinically determined HbA1c levels were compared with blood glucose determined by CGM during a short time period. Changes in HbA1c levels up to 8.0% showed a clear and statistically strong correlation (R = 0.6713; PHbA1c and CGM-assessed glucose levels in our patient population when HbA1c was >8.0%. Short-term CGM appears to be a good clinical indicator of long-term glucose control (HbA1c levels); however, cautions should be taken while interpreting CGM data from patients with HbA1c levels >8.0%. Over- or underestimation of the actual mean glucose from CGM data could potentially increase the risks of inappropriate treatment. As such, our results indicate that a more accurate analysis of CGM data might be useful to adequately tailor clinical treatments. ADAG = A1c-Derived Average Glucose CGM = continuous glucose monitoring %CV = percent coefficient of variation HbA1c = glycated hemoglobin.

  6. Crack formation and prevention in colloidal drops

    Science.gov (United States)

    Kim, Jin Young; Cho, Kun; Ryu, Seul-A.; Kim, So Youn; Weon, Byung Mook

    2015-08-01

    Crack formation is a frequent result of residual stress release from colloidal films made by the evaporation of colloidal droplets containing nanoparticles. Crack prevention is a significant task in industrial applications such as painting and inkjet printing with colloidal nanoparticles. Here, we illustrate how colloidal drops evaporate and how crack generation is dependent on the particle size and initial volume fraction, through direct visualization of the individual colloids with confocal laser microscopy. To prevent crack formation, we suggest use of a versatile method to control the colloid-polymer interactions by mixing a nonadsorbing polymer with the colloidal suspension, which is known to drive gelation of the particles with short-range attraction. Gelation-driven crack prevention is a feasible and simple method to obtain crack-free, uniform coatings through drying-mediated assembly of colloidal nanoparticles.

  7. DO THE FERMI GAMMA-RAY BURST MONITOR AND SWIFT BURST ALERT TELESCOPE SEE THE SAME SHORT GAMMA-RAY BURSTS?

    International Nuclear Information System (INIS)

    Burns, Eric; Briggs, Michael S.; Connaughton, Valerie; Zhang, Bin-Bin; Lien, Amy; Goldstein, Adam; Pelassa, Veronique; Troja, Eleonora

    2016-01-01

    Compact binary system mergers are expected to generate gravitational radiation detectable by ground-based interferometers. A subset of these, the merger of a neutron star with another neutron star or a black hole, are also the most popular model for the production of short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs (SGRBs) at rates that reflect their relative sky exposures, with the BAT detecting 10 per year compared to about 45 for GBM. We examine the SGRB populations detected by Swift BAT and Fermi GBM. We find that the Swift BAT triggers on weaker SGRBs than Fermi GBM, providing they occur close to the center of the BAT field of view, and that the Fermi GBM SGRB detection threshold remains flatter across its field of view. Overall, these effects combine to give the instruments the same average sensitivity, and account for the SGRBs that trigger one instrument but not the other. We do not find any evidence that the BAT and GBM are detecting significantly different populations of SGRBs. Both instruments can detect untriggered SGRBs using ground searches seeded with time and position. The detection of SGRBs below the on-board triggering sensitivities of Swift BAT and Fermi GBM increases the possibility of detecting and localizing the electromagnetic counterparts of gravitational wave (GW) events seen by the new generation of GW detectors

  8. DO THE FERMI GAMMA-RAY BURST MONITOR AND SWIFT BURST ALERT TELESCOPE SEE THE SAME SHORT GAMMA-RAY BURSTS?

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Eric; Briggs, Michael S. [University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Connaughton, Valerie [Universities Space Research Association, Science and Technology Institute, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Zhang, Bin-Bin [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Lien, Amy [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Goldstein, Adam [NASA Postdoctoral Program, Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pelassa, Veronique [Smithsonian Astrophysical Observatory, P.O. Box 97, Amado, AZ 85645 (United States); Troja, Eleonora, E-mail: eb0016@uah.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-20

    Compact binary system mergers are expected to generate gravitational radiation detectable by ground-based interferometers. A subset of these, the merger of a neutron star with another neutron star or a black hole, are also the most popular model for the production of short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs (SGRBs) at rates that reflect their relative sky exposures, with the BAT detecting 10 per year compared to about 45 for GBM. We examine the SGRB populations detected by Swift BAT and Fermi GBM. We find that the Swift BAT triggers on weaker SGRBs than Fermi GBM, providing they occur close to the center of the BAT field of view, and that the Fermi GBM SGRB detection threshold remains flatter across its field of view. Overall, these effects combine to give the instruments the same average sensitivity, and account for the SGRBs that trigger one instrument but not the other. We do not find any evidence that the BAT and GBM are detecting significantly different populations of SGRBs. Both instruments can detect untriggered SGRBs using ground searches seeded with time and position. The detection of SGRBs below the on-board triggering sensitivities of Swift BAT and Fermi GBM increases the possibility of detecting and localizing the electromagnetic counterparts of gravitational wave (GW) events seen by the new generation of GW detectors.

  9. Short-term effects of benzalkonium chloride and atrazine on Elodea canadensis using a miniaturised microbioreactor system for an online monitoring of physiologic parameters.

    Science.gov (United States)

    Vervliet-Scheebaum, Marco; Ritzenthaler, Raphael; Normann, Johannes; Wagner, Edgar

    2008-02-01

    The study evaluated the effects of benzalkonium chloride (BAC) and atrazine on the macrophyte Elodea canadensis (Michaux) using a miniaturised monitoring test system consisting of a microbioreactor of reduced volume and integrated sensors for the online measurement of physiologic parameters, like oxygen production and different parameters of fluorescence. Different concentrations of both chemicals were applied to leaves of E. canadensis and the physiologic endpoints evaluated after 1h. A concentration-dependent reduction of the oxygen production and of the effective quantum yield of energy conversion was recorded. The mini-PAM technique implemented in the presented system allowed for a clear monitoring of the kinetic of BAC and atrazine, showing their distinct mode of action. No observable adverse effects were recorded up to concentrations of 2.5 mg/L and 10 microg/L, for BAC and atrazine, respectively. These values are in accordance with available results in the literature, hence indicating that the microbioreactor test system might be suitable, on the one hand, for the laboratory screening of potential short-term toxicity of contaminants on aquatic plants, and on the other hand, serve as an in situ field biomonitoring system for the rapid detection of pollutants in water.

  10. Capturing the sensitivity of land-use regression models to short-term mobile monitoring campaigns using air pollution micro-sensors.

    Science.gov (United States)

    Minet, L; Gehr, R; Hatzopoulou, M

    2017-11-01

    The development of reliable measures of exposure to traffic-related air pollution is crucial for the evaluation of the health effects of transportation. Land-use regression (LUR) techniques have been widely used for the development of exposure surfaces, however these surfaces are often highly sensitive to the data collected. With the rise of inexpensive air pollution sensors paired with GPS devices, we witness the emergence of mobile data collection protocols. For the same urban area, can we achieve a 'universal' model irrespective of the number of locations and sampling visits? Can we trade the temporal representation of fixed-point sampling for a larger spatial extent afforded by mobile monitoring? This study highlights the challenges of short-term mobile sampling campaigns in terms of the resulting exposure surfaces. A mobile monitoring campaign was conducted in 2015 in Montreal; nitrogen dioxide (NO 2 ) levels at 1395 road segments were measured under repeated visits. We developed LUR models based on sub-segments, categorized in terms of the number of visits per road segment. We observe that LUR models were highly sensitive to the number of road segments and to the number of visits per road segment. The associated exposure surfaces were also highly dissimilar. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Short-term use of continuous glucose monitoring system adds to glycemic control in young type 1 diabetes mellitus patients in the long run: A clinical trial

    Directory of Open Access Journals (Sweden)

    Bukara-Radujković Gordana

    2011-01-01

    Full Text Available Background/Aim. Balancing strict glycemic control with setting realistic goals for each individual child and family can optimize growth, ensure normal pubertal development and emotional maturation, and control long term complications in children with type 1 diabetes (T1DM. The aim of this study was to evaluate the efficacy of short-term continuous glucose monitoring system (CGMS application in improvement of glycemic control in pediatric type 1 diabetes mellitus (T1DM patients. Methods. A total of 80 pediatric T1DM patients were randomly assigned into the experimental and the control group. The experimental group wore CGMS sensor for 72 hours at the beginning of the study. Self-monitored blood glucose (SMBG levels and hemoglobin A1c (HbA1c levels were obtained for both groups at baseline, and at 3 and 6 months. Results. There was a significant improvement in HbA1c (p < 0.001, in both the experimental and the control group, without a significant difference between the groups. Nevertheless, after 6 months the improvement of mean glycemia was noticed only in the experimental group. This finding was accompanied with a decrease in the number of hyperglycemic events and no increase in the number of hypoglycemic events in the experimental group. Conclusions. The results suggest that the CGMS can be considered as a valuable tool in treating pediatric T1DM patients, however further research is needed to more accurately estimate to what extent, if any, it outperforms intensive self-monitoring of blood glucose.

  12. Short-term trajectories of use of a caloric-monitoring mobile phone app among patients with type 2 diabetes mellitus in a primary care setting.

    Science.gov (United States)

    Goh, Glenn; Tan, Ngiap Chuan; Malhotra, Rahul; Padmanabhan, Uma; Barbier, Sylvaine; Allen, John Carson; Østbye, Truls

    2015-02-03

    Self-management plays an important role in maintaining good control of diabetes mellitus, and mobile phone interventions have been shown to improve such self-management. The Health Promotion Board of Singapore has created a caloric-monitoring mobile health app, the "interactive Diet and Activity Tracker" (iDAT). The objective was to identify and describe short-term (8-week) trajectories of use of the iDAT app among patients with type 2 diabetes mellitus in a primary care setting in Singapore, and identify patient characteristics associated with each trajectory. A total of 84 patients with type 2 diabetes mellitus from a public primary care clinic in Singapore who had not previously used the iDAT app were enrolled. The app was demonstrated and patients' weekly use of the app was monitored over 8 weeks. Weekly use was defined as any record in terms of food entry or exercise workout entry in that week. Information on demographics, diet and exercise motivation, diabetes self-efficacy (Diabetes Empowerment Scale-Short Form), and clinical variables (body mass index, blood pressure, and glycosylated hemoglobin/HbA1c) were collected at baseline. iDAT app use trajectories were delineated using latent-class growth modeling (LCGM). Association of patient characteristics with the trajectories was ascertained using logistic regression analysis. Three iDAT app use trajectories were observed: Minimal Users (66 out of 84 patients, 78.6%, with either no iDAT use at all or use only in the first 2 weeks), Intermittent-Waning Users (10 out of 84 patients, 11.9%, with occasional weekly use mainly in the first 4 weeks), and Consistent Users (8 out of 84 patients, 9.5%, with weekly use throughout all or most of the 8 weeks). The adjusted odds ratio of being a Consistent User, relative to a Minimal User, was significantly higher for females (OR 19.55, 95% CI 1.78-215.42) and for those with higher exercise motivation scores at baseline (OR 4.89, 95% CI 1.80-13.28). The adjusted odds ratio

  13. Remote monitoring of inhaled bronchodilator use and weekly feedback about asthma management: an open-group, short-term pilot study of the impact on asthma control.

    Directory of Open Access Journals (Sweden)

    David Van Sickle

    Full Text Available OBJECTIVE: Adequate symptom control is a problem for many people with asthma. We asked whether weekly email reports on monitored use of inhaled, short-acting bronchodilators might improve scores on composite asthma-control measures. METHODS: Through an investigational electronic medication sensor attached to each participant's inhaler, we monitored 4 months' use of inhaled, short-acting bronchodilators. Participants completed surveys, including the Asthma Control Test(TM (ACT, to assess asthma control at entry and monthly thereafter. After the first month, participants received weekly email reports for 3 months. The reports summarized inhaled bronchodilator use during the preceding week and provided suggestions derived from National Asthma Education and Prevention Program (NAEPP guidelines. Paired t-tests and random-effects mixed models were implemented to assess changes in primary asthma endpoints. RESULTS: Thirty individuals participated in the 4-month study; 29 provided complete asthma control information. Mean age was 36.8 years (range: 19-74 years; 52% of respondents were female. Mean ACT scores were 17.6 (Standard Deviation [SD]  = 3.35 at entry and 18.4 (SD = 3.60 at completion of the first month. No significant difference appeared between ACT values at entry and completion of the first month (p = 0.66; however, after participants began receiving email reports and online information about their inhaler use, mean ACT scores increased 1.40 points (95% CI: 0.61, 2.18 for each subsequent study month. Significant decreases occurred in 2-week histories of daytime symptoms (β = -1.35, 95% CI: -2.65, -0.04 and nighttime symptoms (β = -0.84, 95% CI: -1.25, -0.44; no significant change in activity limitation (β = -0.21, 95% CI: -0.69, 0.26 was observed. Participants reported increased awareness and understanding of asthma patterns, level of control, bronchodilator use (timing, location and triggers, and improved

  14. From nuclei to liquid drops

    Energy Technology Data Exchange (ETDEWEB)

    Menchaca-Rocha, A.; Huidobro, F.; Michaelian, K.; Perez, A.; Rodriguez, V. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Carjan, N. [Bordeaux-1 Univ., 33 - Gradignan (France). Centre d`Etudes Nucleaires

    1995-12-31

    Collisions of symmetric mercury-drop pairs have been studied experimentally as a function of impact parameter, in a relative-velocity range going from a coalescence-dominated region to interactions yielding several residues. The experiments are compared with predictions of a dynamical model used in nuclear physics. The time evolution of the shapes is well reproduced by the simulation. (authors). 8 refs., 3 figs.

  15. The dynamics of Leidenfrost drops

    OpenAIRE

    van Limbeek, Michiel Antonius Jacobus

    2017-01-01

    Temperature control is omnipresent in today’s life: from keeping your fridge cold, maintaining a room at a pleasant temperature or preventing your computer from overheating. Efficient ways of heat transfer are often based on phase change, making use of the high latent heat of evaporation. In the context of spray cooling, liquid drops are impacting a hot plate to ensure a rapid cooling. At some temperature however, no contact occurs between the liquid and the plate, and the heat transfer rate ...

  16. Device for making liquid drops

    International Nuclear Information System (INIS)

    Yamada, Masao; Fukuda, Fumito; Nishikawa, Masana; Ishii, Takeshi.

    1976-01-01

    Object: To provide a device for producing liquid drops in the form of liquefied gases indispensable to make deuterium and tritium ice pellets used as a fusion fuel in a tokamak type fusion reactor. Structure: First, pressure P 1 at the upper surface of liquefied gas in a container and outlet pressure P 2 of a nozzle disposed at the lower part of the container are adjusted into the state of P 1 >= P 2 , and it is preset so that even under such conditions, the liquefied gas from the nozzle is not naturally flown out. Next, a vibration plate disposed within the container is rapidly downwardly advanced toward the nozzle through a predetermined distance. As a result, pressure of the liquefied gas within a depression under the vibration plate rises instantaneously or in a pulse fashion to dissatisfy the aforesaid set condition whereby the liquefied gas may be flown out from the nozzle in the form of liquid drops. In accordance with the present device, it is possible to produce a suitable number of drops at a suitable point. (Yoshihara, H.)

  17. Toward 2D Seismic Wavefield Monitoring: Seismic Gradiometry for Long-Period Seismogram and Short-Period Seismogram Envelope applied to the Hi-net Array

    Science.gov (United States)

    Maeda, T.; Nishida, K.; Takagi, R.; Obara, K.

    2015-12-01

    The high-sensitive seismograph network Japan (Hi-net) operated by National Research Institute for Earth Science and Disaster Prevention (NIED) has about 800 stations with average separation of 20 km. We can observe long-period seismic wave propagation as a 2D wavefield with station separations shorter than wavelength. In contrast, short-period waves are quite incoherent at stations, however, their envelope shapes resemble at neighbor stations. Therefore, we may be able to extract seismic wave energy propagation by seismogram envelope analysis. We attempted to characterize seismic waveform at long-period and its envelope at short-period as 2D wavefield by applying seismic gradiometry. We applied the seismic gradiometry to a synthetic long-period (20-50s) dataset prepared by numerical simulation in realistic 3D medium at the Hi-net station layout. Wave amplitude and its spatial derivatives are estimated by using data at nearby stations. The slowness vector, the radiation pattern and the geometrical spreading are extracted from estimated velocity, displacement and its spatial derivatives. For short-periods at shorter than 1 s, seismogram envelope shows temporal and spatial broadening through scattering by medium heterogeneity. It is expected that envelope shape may be coherent among nearby stations. Based on this idea, we applied the same method to the time-integration of seismogram envelope to estimate its spatial derivatives. Together with seismogram envelope, we succeeded in estimating the slowness vector from the seismogram envelope as well as long-period waveforms by synthetic test, without using phase information. Our preliminarily results show that the seismic gradiometry suits the Hi-net to extract wave propagation characteristics both at long and short periods. This method is appealing that it can estimate waves at homogeneous grid to monitor seismic wave as a wavefield. It is promising to obtain phase velocity variation from direct waves, and to grasp wave

  18. Vortex flow in acoustically levitated drops

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Z.L.; Xie, W.J. [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China); Wei, B., E-mail: bbwei@nwpu.edu.cn [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2011-08-29

    The internal flow of acoustically levitated water drops is investigated experimentally. This study reveals a kind of vortex flow which rotates in the meridional plane of the levitated drop. The magnitude of fluid velocity is nearly vanishing at the drop center, whereas it increases toward the free surface of a levitated drop until the maximum value of about 80 mm/s. A transition of streamline shapes from concentric circles to ellipses takes place at the distance of about 1.2 mm from the drop center. The fluid velocity distribution is plotted as a function of polar angle for seven characteristic streamlines. -- Highlights: → We experimentally observe the internal flow of acoustically levitated water drops. → We present a fascinating structure of vortex flow inside the levitated water drop. → This vortex flow rotates around the drop center in the meridional plane. → Velocity distribution information of this vortex flow is quantitatively analyzed.

  19. Vortex flow in acoustically levitated drops

    International Nuclear Information System (INIS)

    Yan, Z.L.; Xie, W.J.; Wei, B.

    2011-01-01

    The internal flow of acoustically levitated water drops is investigated experimentally. This study reveals a kind of vortex flow which rotates in the meridional plane of the levitated drop. The magnitude of fluid velocity is nearly vanishing at the drop center, whereas it increases toward the free surface of a levitated drop until the maximum value of about 80 mm/s. A transition of streamline shapes from concentric circles to ellipses takes place at the distance of about 1.2 mm from the drop center. The fluid velocity distribution is plotted as a function of polar angle for seven characteristic streamlines. -- Highlights: → We experimentally observe the internal flow of acoustically levitated water drops. → We present a fascinating structure of vortex flow inside the levitated water drop. → This vortex flow rotates around the drop center in the meridional plane. → Velocity distribution information of this vortex flow is quantitatively analyzed.

  20. A systematic search of sudden pressure drops on Gale crater during two Martian years derived from MSL/REMS data

    Science.gov (United States)

    Ordonez-Etxeberria, Iñaki; Hueso, Ricardo; Sánchez-Lavega, Agustín

    2018-01-01

    The Mars Science Laboratory (MSL) rover carries a suite of meteorological detectors that constitute the Rover Environmental Monitoring Station (REMS) instrument. REMS investigates the meteorological conditions at Gale crater by obtaining high-frequency data of pressure, air and ground temperature, relative humidity, UV flux at the surface and wind intensity and direction with some limitations in the wind data. We have run a search of atmospheric pressure drops of short duration (pressure data during its first 1417 sols (more than two Martian years). The identified daytime pressure drops could be caused by the close passages of warm vortices and dust devils. Previous systematic searches of warm vortices from REMS pressure data (Kahanpää et al., 2016; Steakley and Murphy, 2016) cover about one Martian year. We show that sudden pressure drops are twice more abundant in the second Martian year [sols 671-1339] than in the first one analyzed in previous works. The higher number of detections could be linked to a combination of different topography, higher altitudes (120 m above the landing site) and true inter-annual meteorological variability. We found 1129 events with a pressure drop larger than 0.5 Pa. Of these, 635 occurred during the local daytime (∼56%) and 494 were nocturnal. The most intense pressure drop (4.2 Pa) occurred at daytime on sol 1417 (areocentric solar longitude Ls = 195°) and was accompanied by a simultaneous decrease in the UV signal of 7.1%, pointing to a true dust devil. We also discuss similar but less intense simultaneous pressure and UV radiation drops that constitute 0.7% of all daytime events. Most of the intense daytime pressure drops with variations larger than 1.0 Pa occur when the difference between air and ground temperature is larger than 15 K. Statistically, the frequency of daytime pressure drops peaks close to noon (12:00-13:00 Local True Solar Time or LTST) with more events in spring and summer (Ls from 180° to 360°). The

  1. Radiation monitoring system in medical facilities

    International Nuclear Information System (INIS)

    Matsuno, Kiyoshi

    1981-01-01

    (1) RI selective liquid effluent monitor is, in many cases, used at medical facilities to obtain data for density of radioactivity of six radionuclides. In comparison with the conventional gross measuring systems, over-evaluation is less, and the monitor is more practical. (2) Preventive monitor for loss of radium needle is a system which prevents missing of radium needle at a flush-toilet in radium treatment wards, and this monitor is capable of sensing a drop-off of radium needle of 0.5 mCi (minimum). (3) Short-lived positron gas measuring device belongs to a BABY CYCLOTRON installed in a hospital, and this device is used to measure density of radioactivity, radioactive impurity and chemical impurity of produced radioactive gas. (author)

  2. Naturally Occurring Egg Drop Syndrome Infection in Turkeys

    Directory of Open Access Journals (Sweden)

    Z. Biđin

    2007-01-01

    Full Text Available A decrease in the egg quality, production, fertility and hatchability without serious clinical signs of illness was recorded in turkey fl ocks in Croatia at the beginning of 2002. It was assumed that the egg drop syndrome virus might be one of the etiological agents responsible for the abnormalities in the egg production. The systematic serological monitoring, using a haemagglutination inhibition test, showed that the antibodies to the egg drop syndrome virus existed in 94.4 and 55.1% of the sera analysed in 2002 and 2003, respectively. The haemagglutination inhibition titres ranged from 16 to 128. The sera samples were randomly collected from 11 - to 46-week-old hens from the affected fl ocks. The serological evidence of the egg drop syndrome virus infection was confirmed by detection of the presence of the virus genome in the turkey sera by the polymerase chain reaction. Vaccination of the 18- and 25-week-old turkey hens against the egg drop syndrome virus started in March 2003. After this period, the presence of antibodies to the egg drop syndrome virus (the haemagglutination inhibition titres between 16 and 256 was found in 96.7% of the analysed sera, while the egg production reached normal or higher values for the Nicholas hybrid line of turkeys.

  3. Drag and drop display & builder

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, Timofei B.; Petrov, Andrey D.; /Fermilab

    2007-12-01

    The Drag and Drop (DnD) Display & Builder is a component-oriented system that allows users to create visual representations of data received from data acquisition systems. It is an upgrade of a Synoptic Display mechanism used at Fermilab since 2002. Components can be graphically arranged and logically interconnected in the web-startable Project Builder. Projects can be either lightweight AJAX- and SVG-based web pages, or they can be started as Java applications. The new version was initiated as a response to discussions between the LHC Controls Group and Fermilab.

  4. CANFLEX fuel bundle junction pressure drop

    International Nuclear Information System (INIS)

    Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

    1996-11-01

    This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs

  5. CANFLEX fuel bundle junction pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

    1996-11-01

    This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs.

  6. 49 CFR 178.603 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... used for the hydrostatic pressure or stacking test. Exceptions for the number of steel and aluminum..., non-resilient, flat and horizontal surface. (e) Drop height. Drop heights, measured as the vertical... than flat drops, the center of gravity of the test packaging must be vertically over the point of...

  7. Electrohydrodynamics of a viscous drop with inertia.

    Science.gov (United States)

    Nganguia, H; Young, Y-N; Layton, A T; Lai, M-C; Hu, W-F

    2016-05-01

    Most of the existing numerical and theoretical investigations on the electrohydrodynamics of a viscous drop have focused on the creeping Stokes flow regime, where nonlinear inertia effects are neglected. In this work we study the inertia effects on the electrodeformation of a viscous drop under a DC electric field using a novel second-order immersed interface method. The inertia effects are quantified by the Ohnesorge number Oh, and the electric field is characterized by an electric capillary number Ca_{E}. Below the critical Ca_{E}, small to moderate electric field strength gives rise to steady equilibrium drop shapes. We found that, at a fixed Ca_{E}, inertia effects induce larger deformation for an oblate drop than a prolate drop, consistent with previous results in the literature. Moreover, our simulations results indicate that inertia effects on the equilibrium drop deformation are dictated by the direction of normal electric stress on the drop interface: Larger drop deformation is found when the normal electric stress points outward, and smaller drop deformation is found otherwise. To our knowledge, such inertia effects on the equilibrium drop deformation has not been reported in the literature. Above the critical Ca_{E}, no steady equilibrium drop deformation can be found, and often the drop breaks up into a number of daughter droplets. In particular, our Navier-Stokes simulations show that, for the parameters we use, (1) daughter droplets are larger in the presence of inertia, (2) the drop deformation evolves more rapidly compared to creeping flow, and (3) complex distribution of electric stresses for drops with inertia effects. Our results suggest that normal electric pressure may be a useful tool in predicting drop pinch-off in oblate deformations.

  8. Implementation and Operational Research: CD4 Count Monitoring Frequency and Risk of CD4 Count Dropping Below 200 Cells Per Cubic Millimeter Among Stable HIV-Infected Patients in New York City, 2007-2013.

    Science.gov (United States)

    Myers, Julie E; Xia, Qiang; Torian, Lucia V; Irvine, Mary; Harriman, Graham; Sepkowitz, Kent A; Shepard, Colin W

    2016-03-01

    The evidence has begun to mount for diminishing the frequency of CD4 count testing. To determine whether these observations were applicable to an urban US population, we used New York City (NYC) surveillance data to explore CD4 testing among stable patients in NYC, 2007-2013. We constructed a population-based retrospective open cohort analysis of NYC HIV surveillance data. HIV+ patients aged ≥ 13 years with stable viral suppression (≥ 1 viral load the previous year; all per milliliter) and immune status (≥ 1 CD4 the previous year; all ≥ 200 cells per cubic millimeter) entered the cohort the following year beginning January 1, 2007. Each subsequent year, eligible patients not previously included entered the cohort on January 1. Outcomes were annual frequency of CD4 monitoring and probability of maintaining CD4 ≥ 200 cells per cubic millimeter. A multivariable Cox model identified factors associated with maintaining CD4 ≥ 200 cells per cubic millimeter. During 1.9 years of observation (median), 62,039 patients entered the cohort. The mean annual number of CD4 measurements among stable patients was 2.8 and varied little by year or characteristic. Two years after entering, 93.4% and 97.8% of those with initial CD4 350-499 and CD4 ≥ 500 cells per cubic millimeter, respectively, maintained CD4 ≥ 200 cells per cubic millimeter. Compared to those with initial CD4 ≥ 500 cells per cubic millimeter, those with CD4 200-349 cells per cubic millimeter and CD4 350-499 cells per cubic millimeter were more likely to have a CD4 per cubic millimeter, controlling for sex, race, age, HIV risk group, and diagnosis year. In a population-based US cohort with well-controlled HIV, the probability of maintaining CD4 ≥ 200 cells per cubic millimeter for ≥ 2 years was >90% among those with initial CD4 ≥ 350 cells per cubic millimeter, suggesting that limited CD4 monitoring in these patients is appropriate.

  9. Impacts of Insufficient Observations on the Monitoring of Short- and Long-Term Suspended Solids Variations in Highly Dynamic Waters, and Implications for an Optimal Observation Strategy

    Directory of Open Access Journals (Sweden)

    Qu Zhou

    2018-02-01

    Full Text Available Coastal water regions represent some of the most fragile ecosystems, exposed to both climate change and human activities. While remote sensing provides unprecedented amounts of data for water quality monitoring on regional to global scales, the performance of satellite observations is frequently impeded by revisiting intervals and unfavorable conditions, such as cloud coverage and sun glint. Therefore, it is crucial to evaluate the impacts of varied sampling strategies (time and frequency and insufficient observations on the monitoring of short-term and long-term tendencies of water quality parameters, such as suspended solids (SS, in highly dynamic coastal waters. Taking advantage of the first high-frequency in situ SS dataset (at 30 min sampling intervals from 2007 to 2008, collected in Deep Bay, China, this paper presents a quantitative analysis of the influences of sampling strategies on the monitoring of SS, in terms of sampling frequency and time of day. Dramatic variations of SS were observed, with standard deviation coefficients of 48.9% and 54.1%, at two fixed stations; in addition, significant uncertainties were revealed, with the average absolute percent difference of approximately 13%, related to sampling frequency and time, using nonlinear optimization and random simulation methods. For a sampling frequency of less than two observations per day, the relative error of SS was higher than 50%, and stabilized at approximately 10%, when at least four or five samplings were conducted per day. The optimal recommended sampling times for SS were at around 9:00, 12:00, 14:00, and 16:00 in Deep Bay. The “pseudo” MODIS SS dataset was obtained from high-frequency in situ SS measurements at 10:30 and 14:00, masked by the temporal gap distribution of MODIS coverage to avoid uncertainties propagated from atmospheric correction and SS models. Noteworthy uncertainties of daily observations from the Terra/Aqua MODIS were found, with mean relative

  10. Capillary Thinning of Particle-laden Drops

    Science.gov (United States)

    Wagoner, Brayden; Thete, Sumeet; Jahns, Matt; Doshi, Pankaj; Basaran, Osman

    2015-11-01

    Drop formation is central in many applications such as ink-jet printing, microfluidic devices, and atomization. During drop formation, a thinning filament is created between the about-to-form drop and the fluid hanging from the nozzle. Therefore, the physics of capillary thinning of filaments is key to understanding drop formation and has been thoroughly studied for pure Newtonian fluids. The thinning dynamics is, however, altered completely when the fluid contains particles, the physics of which is not well understood. In this work, we explore the impact of solid particles on filament thinning and drop formation by using a combination of experiments and numerical simulations.

  11. Vibration-Induced Climbing of Drops

    Science.gov (United States)

    Brunet, P.; Eggers, J.; Deegan, R. D.

    2007-10-01

    We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

  12. Who is dropping your course?

    Science.gov (United States)

    Storrs, Alex; Ghent, C.; Labattaglia, R.

    2011-01-01

    We present an analysis of pre and post instruction instruments in a basic astronomy course. This analysis is built on the Light and Spectroscopy Concept Inventory (LSCI, Bardar et al. 2007). In addition to assessing our student's gain in knowledge of this fundamental topic, we have added some demographic questions. While the primary purpose is to compare the gain in knowledge during a semester of instruction to changes in instruction, we also look at the demographics of students who take the pretest but not the posttest. These students are usually excluded from this type of analysis. We look for trends in the demographic information among students who drop the course, and suggest ways to make the course more palatable. References: Bardar et al., 2007: "Development and Validation of the Light and Spectroscopy Concept Inventory", Astr. Ed. Rev. 5(2), 103-113

  13. Magnetically focused liquid drop radiator

    Science.gov (United States)

    Botts, Thomas E.; Powell, James R.; Lenard, Roger

    1986-01-01

    A magnetically focused liquid drop radiator for application in rejecting rgy from a spacecraft, characterized by a magnetizable liquid or slurry disposed in operative relationship within the liquid droplet generator and its fluid delivery system, in combination with magnetic means disposed in operative relationship around a liquid droplet collector of the LDR. The magnetic means are effective to focus streams of droplets directed from the generator toward the collector, thereby to assure that essentially all of the droplets are directed into the collector, even though some of the streams may be misdirected as they leave the generator. The magnetic focusing means is also effective to suppress splashing of liquid when the droplets impinge on the collector.

  14. DropBot: An open-source digital microfluidic control system with precise control of electrostatic driving force and instantaneous drop velocity measurement

    International Nuclear Information System (INIS)

    Fobel, Ryan; Fobel, Christian; Wheeler, Aaron R.

    2013-01-01

    We introduce DropBot: an open-source instrument for digital microfluidics (http://microfluidics.utoronto.ca/dropbot). DropBot features two key functionalities for digital microfluidics: (1) real-time monitoring of instantaneous drop velocity (which we propose is a proxy for resistive forces), and (2) application of constant electrostatic driving forces through compensation for amplifier-loading and device capacitance. We anticipate that this system will enhance insight into failure modes and lead to new strategies for improved device reliability, and will be useful for the growing number of users who are adopting digital microfluidics for automated, miniaturized laboratory operation.

  15. Total sleep time severely drops during adolescence.

    Directory of Open Access Journals (Sweden)

    Damien Leger

    Full Text Available UNLABELLED: Restricted sleep duration among young adults and adolescents has been shown to increase the risk of morbidities such as obesity, diabetes or accidents. However there are few epidemiological studies on normal total sleep time (TST in representative groups of teen-agers which allow to get normative data. PURPOSE: To explore perceived total sleep time on schooldays (TSTS and non schooldays (TSTN and the prevalence of sleep initiating insomnia among a nationally representative sample of teenagers. METHODS: Data from 9,251 children aged 11 to 15 years-old, 50.7% of which were boys, as part of the cross-national study 2011 HBSC were analyzed. Self-completion questionnaires were administered in classrooms. An estimate of TSTS and TSTN (week-ends and vacations was calculated based on specifically designed sleep habits report. Sleep deprivation was estimated by a TSTN - TSTS difference >2 hours. Sleep initiating nsomnia was assessed according to International classification of sleep disorders (ICSD 2. Children who reported sleeping 7 hours or less per night were considered as short sleepers. RESULTS: A serious drop of TST was observed between 11 yo and 15 yo, both during the schooldays (9 hours 26 minutes vs. 7 h 55 min.; p<0.001 and at a lesser extent during week-ends (10 h 17 min. vs. 9 h 44 min.; p<0.001. Sleep deprivation concerned 16.0% of chidren aged of 11 yo vs. 40.5% of those of 15 yo (p<0.001. Too short sleep was reported by 2.6% of the 11 yo vs. 24.6% of the 15 yo (p<0.001. CONCLUSION: Despite the obvious need for sleep in adolescence, TST drastically decreases with age among children from 11 to 15 yo which creates significant sleep debt increasing with age.

  16. [Dropped head syndrome as first manifestation of primary hyperparathyroid myopathy].

    Science.gov (United States)

    Ota, Kiyobumi; Koseki, Sayo; Ikegami, Kenji; Onishi, Iichiroh; Tomimitsu, Hiyoryuki; Shintani, Shuzo

    2018-03-28

    75 years old woman presented with 6-month history of progressive dropped head syndrome. Neurological examination revealed moderate weakness of flexor and extensor of neck and mild weakness of proximal appendicular muscles with normal deep tendon reflexes. The needle electromyography showed short duration and low amplitude motor unit potential. No fibrillation potentials or positive sharp waves were seen. Biopsy of deltoid muscle was normal. Laboratory studies showed elevated levels of serum calcium (11.8 mg/dl, upper limit of normal 10.1) and intact parathyroid hormone (104 pg/ml, upper limit of normal 65), and decreased level of serum phosphorus (2.3 mg/dl, lower limit of normal 2.7). Ultrasonography and enhanced computed tomography revealed a parathyroid tumor. The tumor was removed surgically. Pathological examination proved tumor to be parathyroid adenoma. Dropped head and weakness of muscles were dramatically improved within a week after the operation. Although hyperparathyroidism is a rare cause of dropped head syndrome, neurologists must recognize hyperparathyroidism as a treatable cause of dropped head syndrome.

  17. Sepsis from dropped clips at laparoscopic cholecystectomy

    International Nuclear Information System (INIS)

    Hussain, Sarwat

    2001-01-01

    We report seven patients in whom five dropped surgical clips and two gallstones were visualized in the peritoneal cavity, on radiological studies. In two, subphrenic abscesses and empyemas developed as a result of dropped clips into the peritoneal cavity during or following laparoscopic cholecystectomy. In one of these two, a clip was removed surgically from the site of an abscess. In two other patients dropped gallstones, and in three, dropped clips led to no complications. These were seen incidentally on studies done for other indications. Abdominal abscess secondary to dropped gallstones is a well-recognized complication of laparoscopic cholecystectomy (LC). We conclude that even though dropped surgical clips usually do not cause problems, they should be considered as a risk additional to other well-known causes of post-LC abdominal sepsis

  18. Hydrothermal waves in evaporating sessile drops

    OpenAIRE

    Brutin, D.; Rigollet, F.; Niliot, C. Le

    2009-01-01

    Drop evaporation is a simple phenomena but still unclear concerning the mechanisms of evaporation. A common agreement of the scientific community based on experimental and numerical work evidences that most of the evaporation occurs at the triple line. However, the rate of evaporation is still empirically predicted due to the lack of knowledge on the convection cells which develop inside the drop under evaporation. The evaporation of sessile drop is more complicated than it appears due to the...

  19. Effect of drop jump technique on the reactive strength index

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-09-01

    Full Text Available The basic drill of plyometric training aimed at improving lower limb power and jump height is a drop jump. This exercise can be performed using different techniques, which substantially affects jump variables. Therefore, the aim of this study was to compare the values of the reactive strength index (RSI for countermovement drop jumps (CDJs and bounce drop jumps (BDJs. The study was carried out in a group of 8 male youth basketball players. The tests were conducted using the AMTI BP600900 force plate to measure ground reaction forces and the Noraxon MyoMotion system to record kinematic data. Each player performed two CDJs and two BDJs from the height of 15, 30, 45 and 60 cm. The RSI was calculated as a ratio of jump height and contact time. Moreover, the RSI was determined for the amortization and take-off phases separately. Significant differences (p < 0.05 between RSI values for CDJs and BDJs were recorded for jumps from 30, 45 and 60 cm. Differences in RSI values for jumps from 15 cm were not significant. Furthermore, CDJ height values were significantly higher (p < 0.05 than the values recorded for BDJs. Times of contact, amortization and take-off during BDJs were significantly shorter (p < 0.05 than the respective values obtained for CDJs. Therefore, the use of the RSI to monitor plyometric training should be based on the drop jump technique that is commonly performed by basketball players.

  20. Parametric resonance in acoustically levitated water drops

    International Nuclear Information System (INIS)

    Shen, C.L.; Xie, W.J.; Wei, B.

    2010-01-01

    Liquid drops can be suspended in air with acoustic levitation method. When the sound pressure is periodically modulated, the levitated drop is usually forced into an axisymmetric oscillation. However, a transition from axisymmetric oscillation into sectorial oscillation occurs when the modulation frequency approaches some specific values. The frequency of the sectorial oscillation is almost exactly half of the modulation frequency. It is demonstrated that this transition is induced by the parametric resonance of levitated drop. The natural frequency of sectorial oscillation is found to decrease with the increase of drop distortion extent.

  1. Parametric resonance in acoustically levitated water drops

    Energy Technology Data Exchange (ETDEWEB)

    Shen, C.L.; Xie, W.J. [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China); Wei, B., E-mail: bbwei@nwpu.edu.c [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2010-05-10

    Liquid drops can be suspended in air with acoustic levitation method. When the sound pressure is periodically modulated, the levitated drop is usually forced into an axisymmetric oscillation. However, a transition from axisymmetric oscillation into sectorial oscillation occurs when the modulation frequency approaches some specific values. The frequency of the sectorial oscillation is almost exactly half of the modulation frequency. It is demonstrated that this transition is induced by the parametric resonance of levitated drop. The natural frequency of sectorial oscillation is found to decrease with the increase of drop distortion extent.

  2. Nonlinear oscillations of inviscid free drops

    Science.gov (United States)

    Patzek, T. W.; Benner, R. E., Jr.; Basaran, O. A.; Scriven, L. E.

    1991-01-01

    The present analysis of free liquid drops' inviscid oscillations proceeds through solution of Bernoulli's equation to obtain the free surface shape and of Laplace's equation for the velocity potential field. Results thus obtained encompass drop-shape sequences, pressure distributions, particle paths, and the temporal evolution of kinetic and surface energies; accuracy is verified by the near-constant drop volume and total energy, as well as the diminutiveness of mass and momentum fluxes across drop surfaces. Further insight into the nature of oscillations is provided by Fourier power spectrum analyses of mode interactions and frequency shifts.

  3. Drop "impact" on an airfoil surface.

    Science.gov (United States)

    Wu, Zhenlong

    2018-05-17

    Drop impact on an airfoil surface takes place in drop-laden two-phase flow conditions such as rain and icing, which are encountered by wind turbines or airplanes. This phenomenon is characterized by complex nonlinear interactions that manifest rich flow physics and pose unique modeling challenges. In this article, the state of the art of the research about drop impact on airfoil surface in the natural drop-laden two-phase flow environment is presented. The potential flow physics, hazards, characteristic parameters, droplet trajectory calculation, drop impact dynamics and effects are discussed. The most key points in establishing the governing equations for a drop-laden flow lie in the modeling of raindrop splash and water film. The various factors affecting the drop impact dynamics and the effects of drop impact on airfoil aerodynamic performance are summarized. Finally, the principle challenges and future research directions in the field as well as some promising measures to deal with the adverse effects of drop-laden flows on airfoil performance are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Soft drop jet mass measurement

    CERN Document Server

    Roloff, Jennifer Kathryn; The ATLAS collaboration

    2018-01-01

    Calculations of jet substructure observables that are accurate beyond leading-logarithm accuracy have recently become available. Such observables are significant not only for probing the collinear regime of QCD that is largely unexplored at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider. This poster documents a measurement of the first jet substructure quantity at a hadron collider to be calculated at next-to-next-to-leading-logarithm accuracy. The normalized, differential cross-section is measured as a function of log( ρ^2), where ρ is the ratio of the soft-drop mass to the ungroomed jet transverse momentum. This quantity is measured in dijet events from 32.9 ifb of sqrt(s) = 13 TeV proton-proton collisions recorded by the ATLAS detector. The data are unfolded to correct for detector effects and compared to precise QCD calculations and leading-logarithm particle-level Monte Carlo simulations.

  5. Combining spray nozzle simulators with meshes: characterization of rainfall intensity and drop properties

    Science.gov (United States)

    Carvalho, Sílvia C. P.; de Lima, João L. M. P.; de Lima, M. Isabel P.

    2013-04-01

    Rainfall simulators can be a powerful tool to increase our understanding of hydrological and geomorphological processes. Nevertheless, rainfall simulators' design and operation might be rather demanding, for achieving specific rainfall intensity distributions and drop characteristics. The pressurized simulators have some advantages over the non-pressurized simulators: drops do not rely on gravity to reach terminal velocity, but are sprayed out under pressure; pressurized simulators also yield a broad range of drop sizes in comparison with drop-formers simulators. The main purpose of this study was to explore in the laboratory the potential of combining spray nozzle simulators with meshes in order to change rainfall characteristics (rainfall intensity and diameters and fall speed of drops). Different types of spray nozzles were tested, such as single full-cone and multiple full-cone nozzles. The impact of the meshes on the simulated rain was studied by testing different materials (i.e. plastic and steel meshes), square apertures and wire thicknesses, and different vertical distances between the nozzle and the meshes underneath. The diameter and fall speed of the rain drops were measured using a Laser Precipitation Monitor (Thies Clima). The rainfall intensity range and coefficients of uniformity of the sprays and the drop size distribution, fall speed and kinetic energy were analysed. Results show that when meshes intercept drop trajectories the spatial distribution of rainfall intensity and the drop size distribution are affected. As the spray nozzles generate typically small drop sizes and narrow drop size distributions, meshes can be used to promote the formation of bigger drops and random their landing positions.

  6. The effects of the bologna process on college enrollment and drop-out rates

    OpenAIRE

    Horstschräer, Julia; Sprietsma, Maresa

    2010-01-01

    This paper estimates the short-term effects of the introduction of the Bachelor degree in the framework of the Bologna Process on college enrollment and drop-out rates. We use variation in the timing of the Bachelor implementation at the department level to identify the effect of the reform based on longitudinal administrative student data from Germany. We find no significant effects on college enrollment or drop-out rates for most subjects.

  7. Drop Impact Dynamics with Sessile Drops and Geometries: Spreading, Jetting, and Fragmentation

    Science.gov (United States)

    Tilger, Christopher F.

    The tendency of surface tension to cause small parcels of fluid to form into drops allows convenient packaging, transport, dispersal of liquid phase matter. Liquid drop impacts with solids, liquids, and other drops have realized and additional future applications in biological, manufacturing, heat transfer, and combustion systems. Experiments were conducted to investigate the dynamics of multiple drop collisions, rather than the most-studied phenomenon of single drop impacts. Additional drop impacts were performed on rigid hemispheres representing sessile drops, angled substrates, and into the vertex of two tilted surfaces arranged into a vee shape. A qualitative inspection of drop-sessile drop impacts shows distinct post-impact shapes depending on the offset distance between the drops. At intermediate offset distances, distinct jets issue from the overlap region between the two drops projected areas. These jets are observed to reach their maximum extent at a critical offset distance ratio, epsilon epsilon ˜ 0.75-0.80, with substrate contact angle and W e having a lesser effect. Capillary waves that traverse the sessile drop after collision cause a lower aspect ratio liquid column to emanate from the sessile drop opposite the impact. In order to better understand the jetting phenomenon seen in the offset drop-sessile drop impacts, simpler solid geometries are investigated that elicit a similar behavior. Solid hemispheres do not show the singular jetting observed in the fluidic case, however, a simple vee formed by two intersection planar substrates do jet in a similar fashion to the fluidic case. A geometric model with partnered experiments is developed to describe the bisymmetric spread of an impacting drop on an angled substrate. This geometric model is used to guide a time of arrival based model for various features of the drop impact, which is used to predict jetting in various vee channel experiments.

  8. Many Drops Make a Lake

    Directory of Open Access Journals (Sweden)

    Chaitanya S. Mudgal

    2014-03-01

    greater knowledge, better skills and disseminate this knowledge through this journal to influence as many physicians and their patients as possible. They have taken the knowledge of their teachers, recognized their giants and are now poised to see further than ever before. My grandmother often used to quote to me a proverb from India, which when translated literally means “Many drops make a lake”. I cannot help but be amazed by the striking similarities between the words of Newton and this Indian saying. Therefore, while it may seem intuitive, I think it must be stated that it is vital for the betterment of all our patients that we recognize our own personal lakes to put our drops of knowledge into. More important is that we recognize that it is incumbent upon each and every one of us to contribute to our collective lakes of knowledge such as ABJS. And finally and perhaps most importantly we need to be utterly cognizant of never letting such lakes of knowledge run dry.... ever.

  9. Monitoring crack growth by a potential drop method

    International Nuclear Information System (INIS)

    Tomlinson, J.R.

    1978-01-01

    A theoretical model has been developed for the surface current flow and potential distribution around a surface breaking crack. This model's predictions have been confirmed in the laboratory and the method applied on site. It proved possible by careful design and rigorous testing to overcome the problems of interference in an electrically noisy environment. The principal weaknesses of the technique are that it is only capable of detecting cracks that break the accessible surface of the component, and that there may be problems with conductive bridging across the crack. On the other hand, the lack of any sophisticated probe in contact with the component makes the method suitable for high temperature use, and, being an electrical method, it is capable of continuous use. The use of a.c., as opposed to d.c., enables lower currents to be used. Given good access to the crack tip, a high sensitivity can be obtained, which enables noise rejection to be achieved with the use of a high threshold. (orig.) [de

  10. Drop test facility available to private industry

    International Nuclear Information System (INIS)

    Shappert, L.B.; Box, W.D.

    1983-01-01

    In 1978, a virtually unyielding drop test impact pad was constructed at Oak Ridge National Laboratory's (ORNL's) Tower Shielding Facility (TSF) for the testing of heavy shipping containers designed for transporting radioactive materials. Because of the facility's unique capability for drop-testing large, massive shipping packages, it has been identified as a facility which can be made available for non-DOE users

  11. University Drop-Out: An Italian Experience

    Science.gov (United States)

    Belloc, Filippo; Maruotti, Antonello; Petrella, Lea

    2010-01-01

    University students' drop-out is a crucial issue for the universities' efficiency evaluation and funding. In this paper, we analyze the drop-out rate of the Economics and Business faculty of Sapienza University of Rome. We use administrative data on 9,725 undergraduates students enrolled in three-years bachelor programs from 2001 to 2007 and…

  12. Total Site Heat Integration Considering Pressure Drops

    Directory of Open Access Journals (Sweden)

    Kew Hong Chew

    2015-02-01

    Full Text Available Pressure drop is an important consideration in Total Site Heat Integration (TSHI. This is due to the typically large distances between the different plants and the flow across plant elevations and equipment, including heat exchangers. Failure to consider pressure drop during utility targeting and heat exchanger network (HEN synthesis may, at best, lead to optimistic energy targets, and at worst, an inoperable system if the pumps or compressors cannot overcome the actual pressure drop. Most studies have addressed the pressure drop factor in terms of pumping cost, forbidden matches or allowable pressure drop constraints in the optimisation of HEN. This study looks at the implication of pressure drop in the context of a Total Site. The graphical Pinch-based TSHI methodology is extended to consider the pressure drop factor during the minimum energy requirement (MER targeting stage. The improved methodology provides a more realistic estimation of the MER targets and valuable insights for the implementation of the TSHI design. In the case study, when pressure drop in the steam distribution networks is considered, the heating and cooling duties increase by 14.5% and 4.5%.

  13. Why Do Students Drop Advanced Mathematics?

    Science.gov (United States)

    Horn, Ilana

    2004-01-01

    Students, especially black, Latino and Native American youth and students of low socio-economic status drop out of advanced mathematics. Teachers must coordinate their expectations, their knowledge of students and their teaching practices in order to stop struggling students from dropping out of advanced math classes.

  14. CPAS Preflight Drop Test Analysis Process

    Science.gov (United States)

    Englert, Megan E.; Bledsoe, Kristin J.; Romero, Leah M.

    2015-01-01

    Throughout the Capsule Parachute Assembly System (CPAS) drop test program, the CPAS Analysis Team has developed a simulation and analysis process to support drop test planning and execution. This process includes multiple phases focused on developing test simulations and communicating results to all groups involved in the drop test. CPAS Engineering Development Unit (EDU) series drop test planning begins with the development of a basic operational concept for each test. Trajectory simulation tools include the Flight Analysis and Simulation Tool (FAST) for single bodies, and the Automatic Dynamic Analysis of Mechanical Systems (ADAMS) simulation for the mated vehicle. Results are communicated to the team at the Test Configuration Review (TCR) and Test Readiness Review (TRR), as well as at Analysis Integrated Product Team (IPT) meetings in earlier and intermediate phases of the pre-test planning. The ability to plan and communicate efficiently with rapidly changing objectives and tight schedule constraints is a necessity for safe and successful drop tests.

  15. Pressure drop in ET-RR-1

    International Nuclear Information System (INIS)

    Khattab, M.; Mina, A.R.

    1990-01-01

    Measurements of pressure drop through a bundle comprising 16 rods and their lower arrangement grid as well as orifices similar to those of ET-RR-1 core have been done. Experiments are carried out under adiabatic turbulent flow conditions at about 35 degree C. Bundle Reynolds number range is 4 x 10 -2 x 10. Orifices of diameters 4.5, 3.25 or 2.5 cm. are mounted underneath the bundle. The bundle and lower grid pressure drop coefficients are 3.75 and 1.8 respectively. Orifices pressure drop coefficients are 2.65, 19.67 and 53.55 respectively. The ratio of bundle pressure drop to that of 4.5 cm. Orifice diameter is 1.415. The pressure drop coefficients are utilizer to calculate flow through bundles. The flow rate per bundle is 39.1, 20.4 or 13.1 m 3 /hr. Depending on orifice diameter

  16. Thermal interaction for molten tin dropped into water

    Energy Technology Data Exchange (ETDEWEB)

    Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

    1978-03-01

    Multiflash photography with extremely short duration exposure times per flash was used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapor explosions. It was also found that the thermal constraints required to produce vapor explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapor explosion was reduced from about 500 to 343/sup 0/C.

  17. Thermal interaction for molten tin dropped into water

    International Nuclear Information System (INIS)

    Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

    1978-01-01

    Multiflash photography with extremely short duration exposure times per flash has been used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapour explosions. It was also found that the thermal constraints required to produce vapour explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapour explosion was reduced from about 500 to 343 0 C. (author)

  18. Drop impact splashing and air entrapment

    KAUST Repository

    Thoraval, Marie-Jean

    2013-03-01

    Drop impact is a canonical problem in fluid mechanics, with numerous applications in industrial as well as natural phenomena. The extremely simple initial configuration of the experiment can produce a very large variety of fast and complex dynamics. Scientific progress was made in parallel with major improvements in imaging and computational technologies. Most recently, high-speed imaging video cameras have opened the exploration of new phenomena occurring at the micro-second scale, and parallel computing allowed realistic direct numerical simulations of drop impacts. We combine these tools to bring a new understanding of two fundamental aspects of drop impacts: splashing and air entrapment. The early dynamics of a drop impacting on a liquid pool at high velocity produces an ejecta sheet, emerging horizontally in the neck between the drop and the pool. We show how the interaction of this thin liquid sheet with the air, the drop or the pool, can produce micro-droplets and bubble rings. Then we detail how the breakup of the air film stretched between the drop and the pool for lower impact velocities can produce a myriad of micro-bubbles.

  19. Drop size measurements in Venturi scrubbers

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Alonso, D.; Azzopardi, B.J. [Nottingham Univ. (United Kingdom). Dept. of Chemical Engineering; Goncalves, J.A.S.; Coury, J.R. [Universidade Federal de Sao Carlos (Brazil). Departamento de Engenharia Quimica

    2001-07-01

    Venturi scrubbers are high efficiency gas cleaners in which suspended particles are removed from gas streams by drops formed by liquid atomisation, usually in the Venturi throat. The size of the drops formed are of fundamental importance to the performance of the equipment, both in terms of pressure drop and dust removal efficiency. In this study, drop sizes in a cylindrical laboratory-scale Venturi scrubber were measured using a laser diffraction technique. Gas velocity and liquid to gas ratios varied from 50 to 90 m/s and 0.5 to 2.0 1/m{sup 3}, respectively. Water was injected using two different arrangements: either as jets in the throat or as a film just upstream of the convergence. Drop size measurements were performed at three positions in the case of jet injection: two located along the throat, and the last one at the end of the diffuser. The present data shows that the Sauter mean diameter of the spray can be well correlated by the equation of Boll et al. (J. Air Pollut. Control Assoc. 24 (1974) 932). Drop size distributions are satisfactorily represented by a Rosin-Rammler function. This paper also provides a simple method for calculating the parameters of the Rosin-Rammler function. As a result of this work, drop sizes in Venturi scrubbers can be estimated with much higher accuracy. (Author)

  20. "Self-Shaping" of Multicomponent Drops.

    Science.gov (United States)

    Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

    2017-06-13

    In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

  1. Thyrotoxicosis Presenting as Unilateral Drop Foot.

    Science.gov (United States)

    Hara, Kenju; Miyata, Hajime; Motegi, Takahide; Shibano, Ken; Ishiguro, Hideaki

    2017-01-01

    Neuromuscular disorders associated with hyperthyroidism have several variations in their clinical phenotype, such as ophthalmopathy, periodic paralysis, and thyrotoxic myopathy. We herein report an unusual case of thyrotoxic myopathy presenting as unilateral drop foot. Histopathological examinations of the left tibialis anterior muscle showed marked variation in the fiber size, mild inflammatory cell infiltration, and necrotic and regenerated muscle fibers with predominantly type 1 fiber atrophy. Medical treatment with propylthiouracil resulted in complete improvement of the left drop foot. This case expands the phenotype of thyrotoxicosis and suggests that thyrotoxicosis be considered as a possible cause of unilateral drop foot.

  2. Preparation and characterisation of superheated drop detectors

    International Nuclear Information System (INIS)

    Krishnamoorthy, P.

    1989-01-01

    Basic mechanism of bubble nucleation in superheated drops with respect to minimum energy of radiation and temperature is discussed. Experimental details and techniques for the preparation of Superheated Drop Detectors (SDDs) is explained. For the sample preparation, homogeneous composition of polymer (Morarfloc) and glycerine was used as the host medium and three different refrigerants Mafron-21, Mafron-12 and Mafron-11/12 (50:50) were chosen as the sensitive liquids. A pressure reactor developed at Health and Safety Laboratory is used for dispersing the sensitive liquid drops in the homogeneous composition under pressure. Some of the imporatant detector characteristics were studied. (author). 26 refs., 9 figs., 1 tab

  3. Enhanced conflict monitoring via a short-duration, video-assisted deep breathing in healthy young adults: an event-related potential approach through the Go/NoGo paradigm

    Directory of Open Access Journals (Sweden)

    Kok Suen Cheng

    2017-10-01

    Full Text Available Objectives Practitioners of mindfulness are reported to have greater cognitive control especially in conflict monitoring, response inhibition and sustained attention. However, due to the various existing methods in each mindfulness practices and also, the high commitment factor, a barrier still exists for an individual to pick up the practices. Therefore, the effect of short duration deep breathing on the cognitive control is investigated here. Methods Short duration guided deep breathing videos consisting of 5, 7 and 9 min respectively were created and used on subjects training. The effect on cognitive control was assessed using a Go/NoGo task along with event-related potential (ERP measurements at Fz, Cz, and Pz. Results From the study, the significant outcome showed at the follow-up session in which participants engaged for 5 min deep breathing group showed a profound NoGo N2 amplitude increment as compared to the control group, indicating an enhanced conflict monitoring ability. An inverse relationship between the NoGo N2 amplitude and the breathing duration is observed as well at the follow-up session. Conclusion These results indicated the possibility of performing short duration deep breathing guided by a video to achieve an enhanced conflict monitoring as an alternative to other mindfulness practices and 5 min is found to be the optimum practice duration. Significant This study is the first to establish a relationship between deep breathing and conflict monitoring through ERP. The study population of young adults taken from the same environment reduces the variance in ERP results due to age and environment. Limitation A larger sample size would provide a greater statistical power. A longer duration of deep breathing should be investigated to further clarify the relationship between the practice duration and the NoGo N2 amplitude. The result can be split by gender and analyzed separately due to the different brain structure of males

  4. Chemical analysis of acoustically levitated drops by Raman spectroscopy.

    Science.gov (United States)

    Tuckermann, Rudolf; Puskar, Ljiljana; Zavabeti, Mahta; Sekine, Ryo; McNaughton, Don

    2009-07-01

    An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS), is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation. After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid-base reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension.

  5. Imaging in short stature

    OpenAIRE

    Vikas Chaudhary; Shahina Bano

    2012-01-01

    Short stature can be a sign of disease, disability, and social stigma causing psychological stress. It is important to have an early diagnosis and treatment. Short stature may result from skeletal dysplasias, endocrine disorders, may be familial, or may be the result of malnutrition and chronic illnesses. A team effort of the healthcare professionals like pediatricians, endocrinologists, radiologists, and pathologists is required to diagnose, treat and monitor various pathological conditions ...

  6. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T; Takehara, Kohsei; Etoh, Takeharugoji

    2012-01-01

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  7. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-07-18

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  8. Calcium-Phosphate-Osteopontin Particles Reduce Biofilm Formation and pH Drops in in situ Grown Dental Biofilms.

    Science.gov (United States)

    Schlafer, Sebastian; Ibsen, Casper J S; Birkedal, Henrik; Nyvad, Bente

    2017-01-01

    This 2-period crossover study investigated the effect of calcium-phosphate-osteopontin particles on biofilm formation and pH in 48-h biofilms grown in situ. Bovine milk osteopontin is a highly phosphorylated glycoprotein that has been shown to interfere with bacterial adhesion to salivary-coated surfaces. Calcium-phosphate-osteopontin particles have been shown to reduce biofilm formation and pH drops in a 5-species laboratory model of dental biofilm without affecting bacterial viability. Here, smooth surface biofilms from 10 individuals were treated ex vivo 6 times/day for 30 min with either calcium-phosphate-osteopontin particles or sterile saline. After growth, the amount of biofilm formed was determined by confocal microscopy, and pH drops upon exposure to glucose were monitored using confocal-microscopy-based pH ratiometry. A total of 160 biofilms were analysed. No adverse effects of repeated ex vivo treatment with calcium-phosphate-osteopontin particles were observed. Particle treatment resulted in a 32% lower amount of biofilm formed (p Biofilm pH was significantly higher upon particle treatment, both shortly after the addition of glucose and after 30 min of incubation with glucose (p biofilms as well as the remineralizing potential of the particles. © 2016 S. Karger AG, Basel.

  9. Blood drop patterns: Formation and applications.

    Science.gov (United States)

    Chen, Ruoyang; Zhang, Liyuan; Zang, Duyang; Shen, Wei

    2016-05-01

    The drying of a drop of blood or plasma on a solid substrate leads to the formation of interesting and complex patterns. Inter- and intra-cellular and macromolecular interactions in the drying plasma or blood drop are responsible for the final morphologies of the dried patterns. Changes in these cellular and macromolecular components in blood caused by diseases have been suspected to cause changes in the dried drop patterns of plasma and whole blood, which could be used as simple diagnostic tools to identify the health of humans and livestock. However, complex physicochemical driving forces involved in the pattern formation are not fully understood. This review focuses on the scientific development in microscopic observations and pattern interpretation of dried plasma and whole blood samples, as well as the diagnostic applications of pattern analysis. Dried drop patterns of plasma consist of intricate visible cracks in the outer region and fine structures in the central region, which are mainly influenced by the presence and concentration of inorganic salts and proteins during drying. The shrinkage of macromolecular gel and its adhesion to the substrate surface have been thought to be responsible for the formation of the cracks. Dried drop patterns of whole blood have three characteristic zones; their formation as functions of drying time has been reported in the literature. Some research works have applied engineering treatment to the evaporation process of whole blood samples. The sensitivities of the resultant patterns to the relative humidity of the environment, the wettability of the substrates, and the size of the drop have been reported. These research works shed light on the mechanisms of spreading, evaporation, gelation, and crack formation of the blood drops on solid substrates, as well as on the potential applications of dried drop patterns of plasma and whole blood in diagnosis. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  10. Pressure drop in flashing flow through obstructions

    International Nuclear Information System (INIS)

    Weinle, M.E.; Johnston, B.S.

    1985-01-01

    An experiment was designed to investigate the pressure drop for flashing flow across obstructions of different geometries at various flow rates. Tests were run using two different orifices to determine if the two-phase pressure drop could be characterized by the single phase loss coefficient and the general behavior of the two-phase multiplier. For the geometries studied, it was possible to correlate the multiplier in a geometry-independent fashion

  11. Pressure drop in T's in concentric ducts

    International Nuclear Information System (INIS)

    Shock, R.A.W.

    1983-02-01

    A set of experiments has been carried out to measure the pressure drop characteristics of single-phase flow in dividing and joining right-angled T's in a concentric ducting system. These have been compared with measured pressure drops in a simple round tube system. In most tests with the concentric system the number of velocity heads lost is either similar to, or more than, the value for the round tubes. (author)

  12. Hanging drop crystal growth apparatus and method

    Science.gov (United States)

    Carter, Daniel C. (Inventor); Smith, Robbie E. (Inventor)

    1989-01-01

    An apparatus (10) is constructed having a cylindrical enclosure (16) within which a disc-shaped wicking element (18) is positioned. A well or recess (22) is cut into an upper side (24) of this wicking element, and a glass cover plate or slip (28) having a protein drop disposed thereon is sealably positioned on the wicking element (18), with drop (12) being positioned over well or recess (22). A flow of control fluid is generated by a programmable gradient former (16), with this control fluid having a vapor pressure that is selectively variable. This flow of control fluid is coupled to the wicking element (18) where control fluid vapor diffusing from walls (26) of the recess (22) is exposed to the drop (12), forming a vapor pressure gradient between the drop (12) and the control fluid vapor. Initially, this gradient is adjusted to draw solvent from the drop (12) at a relatively high rate, and as the critical supersaturation point is approached (the point at which crystal nucleation occurs), the gradient is reduced to more slowly draw solvent from the drop (12). This allows discrete protein molecules more time to orient themselves into an ordered crystalline lattice, producing protein crystals which, when processed by X-ray crystallography, possess a high degree of resolution.

  13. Free drop impact analysis of shipping cask

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.; Kennedy, J.M.

    1989-01-01

    The WHAMS-2D and WHAMS-3D codes were used to analyze the dynamic response of the RAS/TREAT shielded shipping cask subjected to transient leadings for the purpose of assessing potential damage to the various components that comprise the the cask. The paper describes how these codes can be used to provide and intermediate level of detail between full three-dimensional finite element calculations and hand calculations which are cost effective for design purposes. Three free drops were adressed: (1) a thirty foot axial drop on either end; (2) a thirty foot oblique angle drop with the cask having several different orientations from the vertical with impact on the cask corner; and (3) a thirty foot side drop with simultaneous impact on the lifting trunnion and the bottom end. Results are presented for two models of the side and oblique angle drops; one model includes only the mass of the lapped sleeves of depleted uranium (DU) while the other includes the mass and stiffness of the DU. The results of the end drop analyses are given for models with and without imperfections in the cask. Comparison of the analysis to hand calculations and simplified analyses are given. (orig.)

  14. Drop Performance Test of CRDMs for JRTR

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myoung-Hwan; Cho, Yeong-Garp; Chung, Jong-Ha [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jung-Hyun [POSCO Plandtec Co. Ltd, Ulsan (Korea, Republic of); Lee, Kwan-Hee [RIST, Pohang (Korea, Republic of)

    2015-10-15

    The drop test results of CRDMs with AC-type electromagnet show that the initial delay times are not satisfied with the requirement, 0.15 seconds. After the replacement of the electromagnet from AC-type to DCtype, the drop times of CARs and accelerations due to the impact of moving parts are satisfied with all requirements. As a result, it is found that four CRDMs to be installed at site have a good drop performance, and meet all performance requirements. A control rod drive mechanism (CRDM) is a device to control the position of a control absorber rod (CAR) in the core by using a stepping motor which is commanded by the reactor regulating system (RRS) to control the reactivity during the normal operation of the reactor. The top-mounted CRDM driven by the stepping motor for Jordan Research and Training Reactor (JRTR) has been developed in KAERI. The CRDM for JRTR has been optimized by the design improvement based on that of the HANARO. It is necessary to verify the performances such as the stepping, drop, endurance, vibration, seismic and structural integrity for active components. Especially, the CAR drop curves are important data for the safety analysis. This paper describes the test results to demonstrate the drop performances of a prototype and 4 CRDMs to be installed at site. The tests are carried out at a test rig simulating the actual reactor's conditions.

  15. Short philtrum

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003302.htm Short philtrum To use the sharing features on this page, please enable JavaScript. A short philtrum is a shorter than normal distance between ...

  16. Imaging in short stature.

    Science.gov (United States)

    Chaudhary, Vikas; Bano, Shahina

    2012-09-01

    Short stature can be a sign of disease, disability, and social stigma causing psychological stress. It is important to have an early diagnosis and treatment. Short stature may result from skeletal dysplasias, endocrine disorders, may be familial, or may be the result of malnutrition and chronic illnesses. A team effort of the healthcare professionals like pediatricians, endocrinologists, radiologists, and pathologists is required to diagnose, treat and monitor various pathological conditions associated with growth abnormality. In this review, we have discussed the role of imaging in diagnosing and characterizing various pathological conditions associated with short stature.

  17. Imaging in short stature

    Directory of Open Access Journals (Sweden)

    Vikas Chaudhary

    2012-01-01

    Full Text Available Short stature can be a sign of disease, disability, and social stigma causing psychological stress. It is important to have an early diagnosis and treatment. Short stature may result from skeletal dysplasias, endocrine disorders, may be familial, or may be the result of malnutrition and chronic illnesses. A team effort of the healthcare professionals like pediatricians, endocrinologists, radiologists, and pathologists is required to diagnose, treat and monitor various pathological conditions associated with growth abnormality. In this review, we have discussed the role of imaging in diagnosing and characterizing various pathological conditions associated with short stature.

  18. The evaporation of the charged and uncharged water drops

    Indian Academy of Sciences (India)

    Drop evaporation; ventilation coefficient; evaporation-effect of electrical forces. ... to study the effect of ventilation on the rate of evaporation of the millimeter sized ... a ventilated drop to reach its equilibrium temperature increases with the drop ...

  19. [Optimize dropping process of Ginkgo biloba dropping pills by using design space approach].

    Science.gov (United States)

    Shen, Ji-Chen; Wang, Qing-Qing; Chen, An; Pan, Fang-Lai; Gong, Xing-Chu; Qu, Hai-Bin

    2017-07-01

    In this paper, a design space approach was applied to optimize the dropping process of Ginkgo biloba dropping pills. Firstly, potential critical process parameters and potential process critical quality attributes were determined through literature research and pre-experiments. Secondly, experiments were carried out according to Box-Behnken design. Then the critical process parameters and critical quality attributes were determined based on the experimental results. Thirdly, second-order polynomial models were used to describe the quantitative relationships between critical process parameters and critical quality attributes. Finally, a probability-based design space was calculated and verified. The verification results showed that efficient production of Ginkgo biloba dropping pills can be guaranteed by operating within the design space parameters. The recommended operation ranges for the critical dropping process parameters of Ginkgo biloba dropping pills were as follows: dropping distance of 5.5-6.7 cm, and dropping speed of 59-60 drops per minute, providing a reference for industrial production of Ginkgo biloba dropping pills. Copyright© by the Chinese Pharmaceutical Association.

  20. Wireless system for location of permanent faults by short circuit current monitoring in electric power distribution network; Sistema wireless para localizacao de faltas permanentes atraves da monitoracao da corrente de curto-circuito em redes de distribuicao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.G.; Correa, A.C.; Machado, R.N. das M.; Ferreira, A.M.D.; Pinto, J.A.C. [Instituto Federal de Educacao, Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil)], E-mail: alcidesmachado000@yahoo.com.br; Barra Junior, W. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Tecnologia. Faculdade de Engenharia Eletrica], E-mail: walbarra@ufpa.br

    2009-07-01

    This paper presents the development of an automatic system for permanent short-circuits location in medium voltage (13.8 kV) electric power system distribution feeders, by indirect monitoring of the line current. When a permanent failure occurs, the developed system uses mobile telephony (GSM) text messages (SMS) to inform the power company operation center where the failure most likely took place. With this information in real time, the power company operation center may provide the network restoration in a faster and efficient way. (author)

  1. Analysis of preparation of Chinese traditional medicine based on the fiber fingerprint drop trace

    Science.gov (United States)

    Zhang, Zhilin; Wang, Jialu; Sun, Weimin; Yan, Qi

    2010-11-01

    The purpose of the fiber micro-drop analyzing technique is to measure the characteristics of liquids using optical methods. The fiber fingerprint drop trace (FFDT) is a curve of light intensity vs. time. This curve indicates the forming, growing and dripping processes of the liquid drops. A pair of fibers was used to monitor the dripping process. The FFDTs are acquired and analyzed by a computer. Different liquid samples of many kinds of preparation of Chinese traditional medicines were tested by using the fiber micro-drop sensor in the experiments. The FFDTs of preparation of Chinese traditional medicines with different concentrations were analyzed in different ways. Considering the characters of the FFDTs, a novel method is proposed to measure the different preparation of Chinese traditional medicines and its concentration based on the corresponding relationship of FFDTs and the physical and chemical parameters of the liquids.

  2. Bubble and Drop Nonlinear Dynamics (BDND)

    Science.gov (United States)

    Trinh, E. H.; Leal, L. Gary; Thomas, D. A.; Crouch, R. K.

    1998-01-01

    Free drops and bubbles are weakly nonlinear mechanical systems that are relatively simple to characterize experimentally in 1-G as well as in microgravity. The understanding of the details of their motion contributes to the fundamental study of nonlinear phenomena and to the measurement of the thermophysical properties of freely levitated melts. The goal of this Glovebox-based experimental investigation is the low-gravity assessment of the capabilities of a modular apparatus based on ultrasonic resonators and on the pseudo- extinction optical method. The required experimental task is the accurate measurements of the large-amplitude dynamics of free drops and bubbles in the absence of large biasing influences such as gravity and levitation fields. A single-axis levitator used for the positioning of drops in air, and an ultrasonic water-filled resonator for the trapping of air bubbles have been evaluated in low-gravity and in 1-G. The basic feasibility of drop positioning and shape oscillations measurements has been verified by using a laptop-interfaced automated data acquisition and the optical extinction technique. The major purpose of the investigation was to identify the salient technical issues associated with the development of a full-scale Microgravity experiment on single drop and bubble dynamics.

  3. Cavity optomechanics in a levitated helium drop

    Science.gov (United States)

    Childress, L.; Schmidt, M. P.; Kashkanova, A. D.; Brown, C. D.; Harris, G. I.; Aiello, A.; Marquardt, F.; Harris, J. G. E.

    2017-12-01

    We describe a proposal for a type of optomechanical system based on a drop of liquid helium that is magnetically levitated in vacuum. In the proposed device, the drop would serve three roles: its optical whispering-gallery modes would provide the optical cavity, its surface vibrations would constitute the mechanical element, and evaporation of He atoms from its surface would provide continuous refrigeration. We analyze the feasibility of such a system in light of previous experimental demonstrations of its essential components: magnetic levitation of mm-scale and cm-scale drops of liquid He , evaporative cooling of He droplets in vacuum, and coupling to high-quality optical whispering-gallery modes in a wide range of liquids. We find that the combination of these features could result in a device that approaches the single-photon strong-coupling regime, due to the high optical quality factors attainable at low temperatures. Moreover, the system offers a unique opportunity to use optical techniques to study the motion of a superfluid that is freely levitating in vacuum (in the case of 4He). Alternatively, for a normal fluid drop of 3He, we propose to exploit the coupling between the drop's rotations and vibrations to perform quantum nondemolition measurements of angular momentum.

  4. 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.

  5. Drop Testing Representative Multi-Canister Overpacks

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Spencer D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Morton, Dana K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    The objective of the work reported herein was to determine the ability of the Multi- Canister Overpack (MCO) canister design to maintain its containment boundary after an accidental drop event. Two test MCO canisters were assembled at Hanford, prepared for testing at the Idaho National Engineering and Environmental Laboratory (INEEL), drop tested at Sandia National Laboratories, and evaluated back at the INEEL. In addition to the actual testing efforts, finite element plastic analysis techniques were used to make both pre-test and post-test predictions of the test MCOs structural deformations. The completed effort has demonstrated that the canister design is capable of maintaining a 50 psig pressure boundary after drop testing. Based on helium leak testing methods, one test MCO was determined to have a leakage rate not greater than 1x10-5 std cc/sec (prior internal helium presence prevented a more rigorous test) and the remaining test MCO had a measured leakage rate less than 1x10-7 std cc/sec (i.e., a leaktight containment) after the drop test. The effort has also demonstrated the capability of finite element methods using plastic analysis techniques to accurately predict the structural deformations of canisters subjected to an accidental drop event.

  6. The role of national system of radiological survey in short, intermediate and long term monitoring the environment radioactivity and health status in uranium industry areas

    International Nuclear Information System (INIS)

    Dumitrescu, Alina; Milu, C.

    2000-01-01

    The environment radioactivity survey in Romania is performed by CNCAN (National Commission for Nuclear Activities Control) national network. The health status survey of population is carried out by national network of Health Ministry which comprises 23 laboratories. The tasks of the these networks are the following: assessment of natural and artificial irradiation of occupationally exposed personnel and population, as well as goods used by them; determination of population irradiation, survey of environment, food and human internal contamination; survey of health status of the population exposed to radiation, monitoring the medical checkups of the occupationally exposed personnel as well as their dosimetric monitoring; specific enactment, authorization and supervision of nuclear facilities, sanitary expertise and medical examinations; educational activities related to hygiene, radiotoxicology, radioecology and radiobiology. (authors)

  7. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Dipen N. (Los Alamos, NM)

    1998-01-01

    Ultrasonic characterization of single drops of liquids. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities.

  8. Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

    Science.gov (United States)

    Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

    2016-04-01

    Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.

  9. Short- and long-term monitoring of radon, thoron and carbon dioxide in soil-gas at Altos de pipe, Venezuela

    International Nuclear Information System (INIS)

    LaBrecque, J.J.; Cordoves, P.R.

    2004-01-01

    Radon and thoron activities in soil-gases have been measured since July 9, 1997 Cariaco earthquake (Mw=6.9) until the end of 2000. Carbon dioxide concentrations were also monitored between 1998-2000. The soil-gas was collected between 50-55 cm depths at two sampling points at Altos de pipe (Instituto Venezolano de Investigaciones Cientificas-IVIC) near Caracas, Venezuela. The radon and thoron measurements were performed daily employing radiation monitors with scintillation cells and the carbon dioxide was monitored with portable gas analyzers. Average weekly and monthly values were calculated and plotted for this three-four year period. In general, both the radon and carbon dioxide values showed sinusoidal trends due to seasonal changes. During the dry season the radon and carbon dioxide values decreased, while the radon activity was relative constant (flat) during the rainy season at one of the sampling points. Only two monthly radon values were seen to be anomalous in the graphs in respect to seven anomalous periods for the average weekly values. No anomalous periods were clearly seen for carbon dioxide. Finally, it was difficult to try to relate these radon anomalous periods with specific earthquakes due to the large number of minor earthquakes during these years, but it seem that the minor earthquake (Mb=5.9) of October 4, 2000 could be associated with the radon anomalous period in September, when there were no other minor earthquakes (Mb≥4.0). (author)

  10. Liquid toroidal drop under uniform electric field

    Science.gov (United States)

    Zabarankin, Michael

    2017-06-01

    The problem of a stationary liquid toroidal drop freely suspended in another fluid and subjected to an electric field uniform at infinity is addressed analytically. Taylor's discriminating function implies that, when the phases have equal viscosities and are assumed to be slightly conducting (leaky dielectrics), a spherical drop is stationary when Q=(2R2+3R+2)/(7R2), where R and Q are ratios of the phases' electric conductivities and dielectric constants, respectively. This condition holds for any electric capillary number, CaE, that defines the ratio of electric stress to surface tension. Pairam and Fernández-Nieves showed experimentally that, in the absence of external forces (CaE=0), a toroidal drop shrinks towards its centre, and, consequently, the drop can be stationary only for some CaE>0. This work finds Q and CaE such that, under the presence of an electric field and with equal viscosities of the phases, a toroidal drop having major radius ρ and volume 4π/3 is qualitatively stationary-the normal velocity of the drop's interface is minute and the interface coincides visually with a streamline. The found Q and CaE depend on R and ρ, and for large ρ, e.g. ρ≥3, they have simple approximations: Q˜(R2+R+1)/(3R2) and CaE∼3 √{3 π ρ / 2 } (6 ln ⁡ρ +2 ln ⁡[96 π ]-9 )/ (12 ln ⁡ρ +4 ln ⁡[96 π ]-17 ) (R+1 ) 2/ (R-1 ) 2.

  11. The new Drop Tower catapult system

    Science.gov (United States)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  12. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-01-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  13. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-12-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  14. Evaluation of the ability of rod drop tests to verify the stability margins in FTR

    International Nuclear Information System (INIS)

    Harris, R.A.; Sevenich, R.A.

    1976-01-01

    Predictions of the stability characteristics of FTR indicate that the reactor can be easily controlled even under the worst possible conditions. Nevertheless, experimental verification and monitoring of these characteristics will be performed during operation of the reactor. An initial evaluation of rod drop experiments which could possibly provide this verification is presented

  15. Liquid-metal pin-fin pressure drop by correlation in cross flow

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-01-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

  16. Acoustic forcing of a liquid drop

    Science.gov (United States)

    Lyell, M. J.

    1992-01-01

    The development of systems such as acoustic levitation chambers will allow for the positioning and manipulation of material samples (drops) in a microgravity environment. This provides the capability for fundamental studies in droplet dynamics as well as containerless processing work. Such systems use acoustic radiation pressure forces to position or to further manipulate (e.g., oscillate) the sample. The primary objective was to determine the effect of a viscous acoustic field/tangential radiation pressure forcing on drop oscillations. To this end, the viscous acoustic field is determined. Modified (forced) hydrodynamic field equations which result from a consistent perturbation expansion scheme are solved. This is done in the separate cases of an unmodulated and a modulated acoustic field. The effect of the tangential radiation stress on the hydrodynamic field (drop oscillations) is found to manifest as a correction to the velocity field in a sublayer region near the drop/host interface. Moreover, the forcing due to the radiation pressure vector at the interface is modified by inclusion of tangential stresses.

  17. 49 CFR 178.965 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... Large Packaging design types and performed periodically as specified in § 178.955(e) of this subpart. (b... § 178.960(d). (d) Test method. (1) Samples of all Large Packaging design types must be dropped onto a... be restored to the upright position for observation. (2) Large Packaging design types with a capacity...

  18. Modeling merging behavior at lane drops.

    Science.gov (United States)

    2015-02-01

    In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In : addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improvin...

  19. Pressure drops in low pressure local boiling

    International Nuclear Information System (INIS)

    Courtaud, Michel; Schleisiek, Karl

    1969-01-01

    For prediction of flow reduction in nuclear research reactors, it was necessary to establish a correlation giving the pressure drop in subcooled boiling for rectangular channels. Measurements of pressure drop on rectangular channel 60 and 90 cm long and with a coolant gap of 1,8 and 3,6 mm were performed in the following range of parameters. -) 3 < pressure at the outlet < 11 bars abs; -) 25 < inlet temperature < 70 deg. C; -) 200 < heat flux < 700 W/cm 2 . It appeared that the usual parameter, relative length in subcooled boiling, was not sufficient to correlate experimental pressure losses on the subcooled boiling length and that there was a supplementary influence of pressure, heat flux and subcooling. With an a dimensional parameter including these terms a correlation was established with an error band of ±10%. With a computer code it was possible to derive the relation giving the overall pressure drop along the channel and to determine the local gradients of pressure drop. These local gradients were then correlated with the above parameter calculated in local conditions. 95 % of the experimental points were computed with an accuracy of ±10% with this correlation of gradients which can be used for non-uniform heated channels. (authors) [fr

  20. The liquid drop nature of nucleoli.

    Science.gov (United States)

    Marko, John F

    2012-03-01

    Nucleoli are prominent subnuclear organelles, and are known to be hubs of ribosome synthesis. A recent study of Brangwynne et al. reports that the nucleoli of Xenopus oocytes display "liquid drop" behavior, suggesting that nucleolar structure may be driven by rather simple physical principles.

  1. Biomechanical analysis of drop and countermovement jumps

    NARCIS (Netherlands)

    Bobbert, M. F.; Mackay, M.T.; Schinkelshoek, D.; Huijing, P. A.; van Ingen Schenau, G. J.

    For 13 subjects the performance of drop jumps from a height of 40 cm (DJ) and of countermovement jumps (CMJ) was analysed and compared. From force plate and cine data biomechanical variables including forces, moments, power output and amount of work done were calculated for hip, knee and ankle

  2. The stability of cylindrical pendant drops

    CERN Document Server

    McCuan, John

    2018-01-01

    The author considers the stability of certain liquid drops in a gravity field satisfying a mixed boundary condition. He also considers as special cases portions of cylinders that model either the zero gravity case or soap films with the same kind of boundary behavior.

  3. Scaling the drop size in coflow experiments

    International Nuclear Information System (INIS)

    Castro-Hernandez, E; Gordillo, J M; Gundabala, V; Fernandez-Nieves, A

    2009-01-01

    We perform extensive experiments with coflowing liquids in microfluidic devices and provide a closed expression for the drop size as a function of measurable parameters in the jetting regime that accounts for the experimental observations; this expression works irrespective of how the jets are produced, providing a powerful design tool for this type of experiments.

  4. Scaling the drop size in coflow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Castro-Hernandez, E; Gordillo, J M [Area de Mecanica de Fluidos, Universidad de Sevilla, Avenida de los Descubrimientos s/n, 41092 Sevilla (Spain); Gundabala, V; Fernandez-Nieves, A [School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)], E-mail: jgordill@us.es

    2009-07-15

    We perform extensive experiments with coflowing liquids in microfluidic devices and provide a closed expression for the drop size as a function of measurable parameters in the jetting regime that accounts for the experimental observations; this expression works irrespective of how the jets are produced, providing a powerful design tool for this type of experiments.

  5. Goose droppings as food for reindeer

    NARCIS (Netherlands)

    van der Wal, R; Loonen, MJJE

    Feeding conditions for Svalbard reindeer, Rangifer tarandus platyrhynchus, on Spitsbergen are generally poor, owing to low availability of forage. We report on coprophagy: the use of goose faeces as an alternative food source for reindeer. Fresh droppings from Barnacle Geese, Branta leucopsis,

  6. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.; Takehara, K.; Etoh, T.G.; Thoroddsen, Sigurdur T

    2013-01-01

    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

  7. Idiopathic short stature

    Directory of Open Access Journals (Sweden)

    Vlaški Jovan

    2013-01-01

    Full Text Available Growth is a complex process and the basic characteristic of child- hood growth monitoring provides insight into the physiological and pathological events in the body. Statistically, the short stature means departure from the values of height for age and sex (in a particular environment, which is below -2 standard deviation score, or less than -2 standard deviation, i.e. below the third percentile. Advances in molecular genetics have contributed to the improvement of diagnostics in endocrinology. Analysis of patients’ genotypes should not be performed before taking a classical history, detailed clinical examination and appropriate tests. In patients with idiopathic short stature specific causes are excluded, such as growth hormone deficiency, Turner syndrome, short stature due to low birth weight, intrauterine growth retardation, small for gestational age, dysmorphology syndromes and chronic childhood diseases. The exclusion of abovementioned conditions leaves a large number of children with short stature whose etiology includes patients with genetic short stature or familial short stature and those who are low in relation to genetic potential, and who could also have some unrecognized endocrine defect. Idiopathic short stature represents a short stature of unknown cause of heterogeneous etiology, and is characterized by a normal response of growth hormone during stimulation tests (>10 ng/ml or 20 mJ/l, without other disorders, of normal body mass and length at birth. In idiopathic short stature standard deviation score rates <-2.25 (-2 to -3 or <1.2 percentile. These are also criteria for the initiation of growth hormone therapy. In children with short stature there is also the presence of psychological and social suffering. Goals of treatment with growth hormone involve achieving normal height and normal growth rate during childhood.

  8. Predictors of severe trunk postures among short-haul truck drivers during non-driving tasks: an exploratory investigation involving video-assessment and driver behavioural self-monitoring.

    Science.gov (United States)

    Olson, R; Hahn, D I; Buckert, A

    2009-06-01

    Short-haul truck (lorry) drivers are particularly vulnerable to back pain and injury due to exposure to whole body vibration, prolonged sitting and demanding material handling tasks. The current project reports the results of video-based assessments (711 stops) and driver behavioural self-monitoring (BSM) (385 stops) of injury hazards during non-driving work. Participants (n = 3) worked in a trailer fitted with a camera system during baseline and BSM phases. Descriptive analyses showed that challenging customer environments and non-standard ingress/egress were prevalent. Statistical modelling of video-assessment results showed that each instance of manual material handling increased the predicted mean for severe trunk postures by 7%, while customer use of a forklift, moving standard pallets and moving non-standard pallets decreased predicted means by 12%, 20% and 22% respectively. Video and BSM comparisons showed that drivers were accurate at self-monitoring frequent environmental conditions, but less accurate at monitoring trunk postures and rare work events. The current study identified four predictors of severe trunk postures that can be modified to reduce risk of injury among truck drivers and showed that workers can produce reliable self-assessment data with BSM methods for frequent and easily discriminated events environmental.

  9. Annual Occurrence of Meteorite-Dropping Fireballs

    Science.gov (United States)

    Konovalova, Natalia; Jopek, Tadeusz J.

    2016-07-01

    The event of Chelyabinsk meteorite has brought about change the earlier opinion about limits of the sizes of potentially dangerous asteroidal fragments that crossed the Earth's orbit and irrupted in the Earth's atmosphere making the brightest fireball. The observations of the fireballs by fireball networks allows to get the more precise data on atmospheric trajectories and coordinates of predicted landing place of the meteorite. For the reason to search the periods of fireball activity is built the annual distribution of the numbers of meteorites with the known fall dates and of the meteorite-dropping fireballs versus the solar longitude. The resulting profile of the annual activity of meteorites and meteorite-dropping fireballs shows several periods of increased activity in the course of the year. The analysis of the atmospheric trajectories and physical properties of sporadic meteorite-dropping fireballs observed in Tajikistan by instrumental methods in the summer‒autumn periods of increased fireballs activity has been made. As a result the structural strength, the bulk density and terminal mass of the studied fireballs that can survive in the Earth atmosphere and became meteorites was obtained. From the photographic IAU MDC_2003 meteor database and published sources based on the orbit proximity as determined by D-criterion of Southworth and Hawkins the fireballs that could be the members of group of meteorite-dropping fireballs, was found. Among the near Earth's objects (NEOs) the searching for parent bodies for meteorite-dropping fireballs was made and the evolution of orbits of these objects in the past on a long interval of time was investigated.

  10. CYCLAM - Recycling by a Laser-driven Drop Jet from Waste that Feeds AM

    Science.gov (United States)

    Kaplan, Alexander F. H.; Samarjy, Ramiz S. M.

    Additive manufacturing of metal parts is supplied by powder or wire. Manufacturing of this raw material causes additional costs and environmental impact. A new technique is proposed where the feeding directly originates from a metal sheet, which can even be waste. When cutting is done by laser-induced boiling, melt is continuously ejected downwards underneath the sheet. The ejected melt is deposited as a track on a substrate, enabling additive manufacturing by substrate movement along a desired path. The melt first flows downwards as a column and after a few millimeters separates into drops, here about 500 micrometer in diameter, as observed by high speed imaging. The drops incorporate sequentially and calmly into a long melt pool on the substrate. While steel drops formed regular tracks on steel and aluminium substrates, on copper substrate periodic drops solidified instead. For this new technique, called CYCLAM, the laser beam acts indirectly while the drop jet becomes the main tool. From imaging, properties like the width or fluctuations of the drop jet can be statistically evaluated. Despite oscillation of the liquid column, the divergence of the drop jet remained small, improving the precision and robustness. The melt leaves the cut sheet as a liquid column, 1 to 4 mm in length, which periodically separates drops that are transferred as a liquid jet to the substrate. For very short distance of 2 to 3 mm between the two sheets this liquid column can transfer the melt continuously as a liquid bridge. This phenomenon was observed, as a variant of the technique, but the duration of the bridge was limited by fluid mechanic instabilities.

  11. Measurement of short bunches

    International Nuclear Information System (INIS)

    Wang, D.X.

    1996-01-01

    In recent years, there has been increasing interest in short electron bunches for different applications such as short wavelength FELs, linear colliders, and advanced accelerators such as laser or plasma wakefield accelerators. One would like to meet various requirements such as high peak current, low momentum spread, high luminosity, small ratio of bunch length to plasma wavelength, and accurate timing. Meanwhile, recent development and advances in RF photoinjectors and various bunching schemes make it possible to generate very short electron bunches. Measuring the longitudinal profile and monitoring bunch length are critical to understand the bunching process and longitudinal beam dynamics, and to commission and operate such short bunch machines. In this paper, several commonly used measurement techniques for subpicosecond bunches and their relative advantages and disadvantages are discussed. As examples, bunch length related measurements at Jefferson Lab are presented. At Jefferson Lab, bunch lengths as short as 84 fs have been systematically measured using a zero-phasing technique. A highly sensitive Coherent Synchrotron Radiation (CSR) detector has been developed to noninvasively monitor bunch length for low charge bunches. Phase transfer function measurements provide a means of correcting RF phase drifts and reproducing RF phases to within a couple of tenths of a degree. The measurement results are in excellent agreement with simulations. A comprehensive bunch length control scheme is presented. (author)

  12. Measurement of short bunches

    International Nuclear Information System (INIS)

    Wang, D.X.

    1996-01-01

    In recent years, there has been increasing interest in short electron bunches for different applications such as short wavelength FELs, linear colliders, and advanced accelerators such as laser or plasma wakefield accelerators. One would like to meet various requirements such as high peak current, low momentum spread, high luminosity, small ratio of bunch length to plasma wavelength, and accurate timing. Meanwhile, recent development and advances in RF photoinjectors and various bunching schemes make it possible to generate very short electron bunches. Measuring the longitudinal profile and monitoring bunch length are critical to understand the bunching process and longitudinal beam dynamics, and to commission and operate such short bunch machines. In this paper, several commonly used measurement techniques for subpicosecond bunches and their relative advantages and disadvantages are discussed. As examples, bunch length related measurements at Jefferson lab are presented. At Jefferson Lab, bunch lengths s short as 84 fs have been systematically measured using a zero-phasing technique. A highly sensitive Coherent Synchrotron Radiation (CSR) detector has been developed to noninvasively monitor bunch length for low charge bunches. Phase transfer function measurements provide a means of correcting RF phase drifts and reproducing RF phases to within a couple of tenths of a degree. The measurement results are in excellent agreement with simulations. A comprehensive bunch length control scheme is presented

  13. Electronic compliance monitoring of topical treatment after ophthalmic surgery.

    Science.gov (United States)

    Hermann, Manuel Marcel; Ustündag, Can; Diestelhorst, Michael

    2010-08-01

    The success of many medical treatments is built on compliance. Electronic monitoring is the most accurate tool to quantify compliance by measuring adherence. In order to assess the efficiency of a recently introduced miniature monitoring device for eye drop application, we evaluated adherence in ophthalmic patients undergoing post-operative short-term topical treatment. This pilot study enrolled 30 outpatients (mean age 61.8 +/- 18.5 years) after cataract (n = 24) and glaucoma filtration surgery (n = 6) applying fixed-combination eye drops containing prednisolone and gentamicin five times daily for 2 weeks. Patients received eye drops in conventional bottles each equipped with a miniature monitoring device recording events of application. Two patients failed to bring back the monitoring device; therefore data collected from only 28 patients could be examined. Data showed highly variable results with a mean dose compliance of 50.2%. Dose compliance was below 25% in approximately one out of five patients. Four cataract patients, but no glaucoma patient, discontinued therapy prematurely. The observed mean dosage interval was calculated for each patient and ranged 4.6-19.7 h. Thirty percent of analysed dosage intervals exceeded 12.0 h. Different patterns of compliance behaviour-like early non-persistence, drug holiday and low treatment frequency could be identified and illustrated using electronic data. Age or gender did not significantly influence compliance rates. Our pilot study demonstrates successful electronic compliance monitoring using a technology capable of continuous data recording over weeks of treatment. The low compliance rate for a relevant part of the patients demonstrates the necessity to study and improve compliance in ophthalmology. In future, new application methods and electronic application devices may improve treatment response in eye care.

  14. Thermostatic tissue platform for intravital microscopy: 'the hanging drop' model.

    Science.gov (United States)

    Pavlovic, Dragan; Frieling, Helge; Lauer, Kai-Stephan; Bac, Vo Hoai; Richter, Joern; Wendt, Michael; Lehmann, Christian; Usichenko, Taras; Meissner, Konrad; Gruendling, Matthias

    2006-11-01

    Intravital microscopy imposes the particular problem of the combined control of the body temperature of the animal and the local temperature of the observed organ or tissues. We constructed and tested, in the rat ileum microcirculation preparation, a new organ-support platform. The platform consisted of an organ bath filled with physiological solution, and contained a suction tube, a superfusion tube, an intestine-support hand that was attached to a micromanipulator and a thermometer probe. To cover the intestine we used a cover glass plate with a plastic ring glued on its upper surface. After a routine procedure (anaesthesia, monitoring and surgery), the intestine segment (2-3 cm long) was gently exteriorized and placed on the 'hand' of the organ support. A small part of the intestine formed a small 'island' in the bath that was filled with physiological salt solution. The cover glass was secured in place. The physiological salt solution from the superfusion tube, which was pointed to the lower surface of the cover glass, formed a 'hanging drop'. The objective of the microscope was then immersed into distilled water that was formed by the cover glass plastic ring. The 'hanging drop' technique prevented any tissue quenching, ensured undisturbed microcirculation, provided for stable temperature and humidity, and permitted a clear visual field.

  15. Short communication

    African Journals Online (AJOL)

    abp

    2017-09-04

    Sep 4, 2017 ... Face-to-face interviews were conducted using a standardized ... Short communication. Open Access ... clinic during the time of the study and were invited to participate in the study. .... consume them. This is another ...

  16. SHORT COMMUNICATION

    African Journals Online (AJOL)

    PROF P.T. KAYE

    . SHORT COMMUNICATION. Formation and Structural Analysis of Novel Dibornyl Ethers. Perry T. Kaye*, Andrew R. Duggan, Joseph M. Matjila, Warner E. Molema, and. Swarnam S. Ravindran. Department of Chemistry, Rhodes University, Grahamstown, ...

  17. Coalescence collision of liquid drops I: Off-center collisions of equal-size drops

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2011-09-01

    Full Text Available The Smoothed Particle Hydrodynamics method (SPH is used here to model off-center collisions of equal-size liquid drops in a three-dimensional space. In this study the Weber number is calculated for several conditions of the droplets dynamics and the velocity vector fields formed inside the drops during the collision process are shown. For the permanent coalescence the evolution of the kinetic and internal energy is shown and also the approaching to equilibrium of the resulting drop. Depending of the Weber number three possible outcomes for the collision of droplets is obtained: permanent coalescence, flocculation and fragmentation. The fragmentation phenomena are modeled and the formation of small satellite drops can be seen. The ligament that is formed follows the “end pinching” mechanism and it is transformed into a flat structure.

  18. Design of Dataflow Monitoring and Searches for B to omega gamma, B to phi gamma and B to phi K-short gamma at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Swain, J

    2004-03-16

    In May 2003 PEP-II achieved instantaneous luminosities in excess of 6 x 10{sup 33} cm{sup -2}s{sup -1}, twice the design luminosity. To permit BABAR to operate in this challenging environment, development work on the data acquisition system continued after detector commissioning. A vital part of this process is understanding the performance of the data acquisition system. Considerable effort was invested in the design and implementation of an application capable of collecting performance statistics from hundreds of CPUs in the data acquisition system during data collection. The monitoring application and some examples of its operation are presented in this thesis. Also presented here are the searches for the exclusive radiative one-loop decays, B {yields} {omega}{gamma}, B {yields} {phi}{gamma} and B{sup 0} {yields} {phi}K{sub S}{sup 0}{gamma}, using a sample of 89 million B{bar B} events. No significant signal is seen in any of the channels. Upper limits on the branching ratios, {Beta}, were found to be {Beta}(B {yields} {omega}{gamma}) < 3.0 x 10{sup -6}, {Beta}(B {yields} {phi}{gamma}) < 2.9 x 10{sup -6}, and {Beta}(B{sup 0} {yields} {phi}K{sub S}{sup 0}{gamma}) < 3.8 x 10{sup -6}, at the 90% confidence level.

  19. Continuous monitoring α-activity on aerosol filters by the pseudo-coincidence-technique. Explicitly taking into account the short lived Po-218 activity; Kontinuierliche Ueberwachung der α-Aktivitaet eines Aerosolfilters mit der Pseudokoinzidenzmesstechnik. Explizite Beruecksichtigung der kurzlebigen Po-218 Aktivitaetsbeitraaege

    Energy Technology Data Exchange (ETDEWEB)

    Kraut, W.; Schwarz, W. [Duale Hochschule Baden-Wuerttemberg (DHBW), Karlsruhe (Germany). Studiengang Sicherheitswesen; Kraut, B. [Berthold Technologies GmbH und Co.KG, Bad Wildbad (Germany)

    2015-07-01

    Pseudo-coincidence-technique is applied to continuous monitoring of α-activity on aerosolfilters by proportional counters. Filter activity can markedly increase or decrease by changing air conditions especially by the amount of short lived Po-218 activity. Conditions of constant proportions of activity concentrations for the short lived species for operating this technique are seldom fulfilled. The dynamic behavior of artificial (long lived) and natural (short lived) activity is mathematically modelled and the measured moving count rates are analyzed under this model by a multivariate regression analysis for activity concentrations of artificial resp. short lived activity. Results are compared to standard recommendations of DIN ISO 11929.

  20. Drop evaporation and triple line dynamics

    Science.gov (United States)

    Sobac, Benjamin; Brutin, David; Gavillet, Jerome; Université de Provence Team; Cea Liten Team

    2011-03-01

    Sessile drop evaporation is a phenomenon commonly came across in nature or in industry with cooling, paintings or DNA mapping. However, the evaporation of a drop deposited on a substrate is not completely understood due to the complexity of the problem. Here we investigate, with several nano-coating of the substrate (PTFE, SiOx, SiOc and CF), the influence of the dynamic of the triple line on the evaporation process. The experiment consists in analyzing simultaneously the motion of the triple line, the kinetics of evaporation, the internal thermal motion and the heat and mass transfer. Measurements of temperature, heat-flux and visualizations with visible and infrared cameras are performed. The dynamics of the evaporative heat flux appears clearly different depending of the motion of the triple line

  1. How drops start sliding over solid surfaces

    Science.gov (United States)

    Gao, Nan; Geyer, Florian; Pilat, Dominik W.; Wooh, Sanghyuk; Vollmer, Doris; Butt, Hans-Jürgen; Berger, Rüdiger

    2018-02-01

    It has been known for more than 200 years that the maximum static friction force between two solid surfaces is usually greater than the kinetic friction force--the force that is required to maintain the relative motion of the surfaces once the static force has been overcome. But the forces that impede the lateral motion of a drop of liquid on a solid surface are not as well characterized, and there is a lack of understanding about liquid-solid friction in general. Here, we report that the lateral adhesion force between a liquid drop and a solid can also be divided into a static and a kinetic regime. This striking analogy with solid-solid friction is a generic phenomenon that holds for liquids of different polarities and surface tensions on smooth, rough and structured surfaces.

  2. A pressure drop model for PWR grids

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dong Seok; In, Wang Ki; Bang, Je Geon; Jung, Youn Ho; Chun, Tae Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-12-31

    A pressure drop model for the PWR grids with and without mixing device is proposed at single phase based on the fluid mechanistic approach. Total pressure loss is expressed in additive way for form and frictional losses. The general friction factor correlations and form drag coefficients available in the open literatures are used to the model. As the results, the model shows better predictions than the existing ones for the non-mixing grids, and reasonable agreements with the available experimental data for mixing grids. Therefore it is concluded that the proposed model for pressure drop can provide sufficiently good approximation for grid optimization and design calculation in advanced grid development. 7 refs., 3 figs., 3 tabs. (Author)

  3. Coupling slots without shunt impedance drop

    International Nuclear Information System (INIS)

    Balleyguier, P.

    1996-01-01

    It is well known that coupling slots between adjacent cells in a π-mode structure reduce shunt impedance per unit length with respect to single cell cavities. To design optimized coupling slots, one has to answer the following question: for a given coupling factor, what shape, dimension, position and number of slots lead to the lowest shunt impedance drop? A numerical study using the 3D code MAFIA has been carried out. The aim was to design the 352 MHz cavities for the high intensity proton accelerator of the TRISPAL project. The result is an unexpected set of four 'petal' slots. Such slots should lead to a quasi-negligible drop in shunt impedance: about -1% on average, for particle velocity from 0.4 c to 0.8 c. (author)

  4. A pressure drop model for PWR grids

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dong Seok; In, Wang Ki; Bang, Je Geon; Jung, Youn Ho; Chun, Tae Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A pressure drop model for the PWR grids with and without mixing device is proposed at single phase based on the fluid mechanistic approach. Total pressure loss is expressed in additive way for form and frictional losses. The general friction factor correlations and form drag coefficients available in the open literatures are used to the model. As the results, the model shows better predictions than the existing ones for the non-mixing grids, and reasonable agreements with the available experimental data for mixing grids. Therefore it is concluded that the proposed model for pressure drop can provide sufficiently good approximation for grid optimization and design calculation in advanced grid development. 7 refs., 3 figs., 3 tabs. (Author)

  5. Hospital executive compensation act dropped from ballot

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2016-08-01

    Full Text Available The Hospital Executive Compensation Act did not qualify for the November 8, 2016 ballot in Arizona as a state statute (1. The Service Employees International Union (SEIU dropped the initiative just before arguments were to begin in a lawsuit that challenged the legality of signature gatherers who failed to register with the state. The measure would have limited total pay for executives, administrators and managers of healthcare facilities and entities to the annual salary of the President of the United States. A similar measure in California was also dropped by the SEIU in 2014. Supporters of the proposal said it would decrease escalating healthcare costs. Opponents of the measure, including the Arizona Chamber of Commerce who filed the suit challenging the proposition, alleged that it would lead to poorer healthcare. However, a survey conducted by the Southwest Journal of Pulmonary and Critical Care showed that most supported the measure and felt that it would not lead to poorer healthcare (2.

  6. Semisupervised Community Detection by Voltage Drops

    Directory of Open Access Journals (Sweden)

    Min Ji

    2016-01-01

    Full Text Available Many applications show that semisupervised community detection is one of the important topics and has attracted considerable attention in the study of complex network. In this paper, based on notion of voltage drops and discrete potential theory, a simple and fast semisupervised community detection algorithm is proposed. The label propagation through discrete potential transmission is accomplished by using voltage drops. The complexity of the proposal is OV+E for the sparse network with V vertices and E edges. The obtained voltage value of a vertex can be reflected clearly in the relationship between the vertex and community. The experimental results on four real networks and three benchmarks indicate that the proposed algorithm is effective and flexible. Furthermore, this algorithm is easily applied to graph-based machine learning methods.

  7. Sessile Drop Evaporation and Leidenfrost Phenomenon

    OpenAIRE

    A. K. Mozumder; M. R. Ullah; A. Hossain; M. A. Islam

    2010-01-01

    Problem statement: Quenching and cooling are important process in manufacturing industry for controlling the mechanical properties of materials, where evaporation is a vital mode of heat transfer. Approach: This study experimentally investigated the evaporation of sessile drop for four different heated surfaces of Aluminum, Brass, Copper and Mild steel with a combination of four different liquids as Methanol, Ethanol, Water and NaCl solution. The time of evaporation for the droplet on the hot...

  8. Liquid drop parameters for hot nuclei

    International Nuclear Information System (INIS)

    Guet, C.; Strumberger, E.; Brack, M.

    1988-01-01

    Using the semiclassical extended Thomas-FERMI (ETF) density variational method, we derived selfconsistently the liquid drop model (LDM) coefficients for the free energy of hot nuclear systems from a realistic effective interaction (Skyrme SkM*). We expand the temperature (T) dependence of these coefficients up to the second order in T and test their application to the calculation of the fission barriers of the nuclei 208 Pb and 240 Pu

  9. Impact of water drops on small targets

    Science.gov (United States)

    Rozhkov, A.; Prunet-Foch, B.; Vignes-Adler, M.

    2002-10-01

    The collision of water drops against small targets was studied experimentally by means of a high-speed photography technique. The drop impact velocity was about 3.5 m/s. Drop diameters were in the range of 2.8-4.0 mm. The target was a stainless steel disk of 3.9 mm diameter. The drop spread beyond the target like a central cap surrounded by a thin, slightly conical lamella bounded by a thicker rim. By mounting a small obstacle near the target, surface-tension driven Mach waves in the flowing lamella were generated, which are formally equivalent to the familiar compressibility driven Mach waves in gas dynamics. From the measurement of the Mach angle, the values of some flow parameters could be obtained as functions of time, which provided insight into the flow structure. The liquid flowed from the central cap to the liquid rim through the thin lamella at constant momentum flux. At a certain stage of the process, most of the liquid accumulated in the rim and the internal part of the lamella became metastable. In this situation, a rupture wave propagating through the metastable internal part of the lamella caused the rim to retract while forming outwardly directed secondary jets. The jets disintegrated into secondary droplets due to the Savart-Plateau-Rayleigh instability. Prior to the end of the retraction, an internal circular wave of rupture was formed. It originated at the target and then it propagated to meet the retracting rim. Their meeting resulted in a crown of tiny droplets. A theoretical analysis of the ejection process is proposed.

  10. The jet mass distribution after Soft Drop

    Science.gov (United States)

    Marzani, Simone; Schunk, Lais; Soyez, Gregory

    2018-02-01

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects.

  11. Sporadic frame dropping impact on quality perception

    Science.gov (United States)

    Pastrana-Vidal, Ricardo R.; Gicquel, Jean Charles; Colomes, Catherine; Cherifi, Hocine

    2004-06-01

    Over the past few years there has been an increasing interest in real time video services over packet networks. When considering quality, it is essential to quantify user perception of the received sequence. Severe motion discontinuities are one of the most common degradations in video streaming. The end-user perceives a jerky motion when the discontinuities are uniformly distributed over time and an instantaneous fluidity break is perceived when the motion loss is isolated or irregularly distributed. Bit rate adaptation techniques, transmission errors in the packet networks or restitution strategy could be the origin of this perceived jerkiness. In this paper we present a psychovisual experiment performed to quantify the effect of sporadically dropped pictures on the overall perceived quality. First, the perceptual detection thresholds of generated temporal discontinuities were measured. Then, the quality function was estimated in relation to a single frame dropping for different durations. Finally, a set of tests was performed to quantify the effect of several impairments distributed over time. We have found that the detection thresholds are content, duration and motion dependent. The assessment results show how quality is impaired by a single burst of dropped frames in a 10 sec sequence. The effect of several bursts of discarded frames, irregularly distributed over the time is also discussed.

  12. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.; Li, Erqiang; Thoroddsen, Sigurdur T

    2017-01-01

    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  13. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.

    2017-08-31

    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  14. Eye-Drops for Activation of DREADDs

    Directory of Open Access Journals (Sweden)

    William T. Keenan

    2017-11-01

    Full Text Available Designer Receptors Exclusively Activated by Designer Drugs (DREADDs are an important tool for modulating and understanding neural circuits. Depending on the DREADD system used, DREADD-targeted neurons can be activated or repressed in vivo following a dose of the DREADD agonist clozapine-N-oxide (CNO. Because DREADD experiments often involve behavioral assays, the method of CNO delivery is important. Currently, the most common delivery method is intraperitoneal (IP injection. IP injection is both a fast and reliable technique, but it is painful and stressful particularly when many injections are required. We sought an alternative CNO delivery paradigm, which would retain the speed and reliability of IP injections without being as invasive. Here, we show that CNO can be effectively delivered topically via eye-drops. Eye-drops robustly activated DREADD-expressing neurons in the brain and peripheral tissues and does so at the same dosages as IP injection. Eye-drops provide an easier, less invasive and less stressful method for activating DREADDs in vivo.

  15. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, D.N.

    1998-04-14

    Ultrasonic characterization of single drops of liquids is disclosed. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities. 5 figs.

  16. Quantitative analysis of UV-A shock and short term stress using iTRAQ, pseudo selective reaction monitoring (pSRM) and GC-MS based metabolite analysis of the cyanobacterium Nostoc punctiforme ATCC 29133.

    Science.gov (United States)

    Wase, Nishikant; Pham, Trong Khoa; Ow, Saw Yen; Wright, Phillip C

    2014-09-23

    A quantitative proteomics and metabolomics analysis was performed using iTRAQ, HPLC and GC-MS in the filamentous cyanobacterium Nostoc punctiforme ATCC 29133 to understand the effect of short and long term UV-A exposure. Changes in the proteome were measured for short-term stress (4-24h) using iTRAQ. Changes in the photosynthetic pigments and intracellular metabolites were observed at exposures of up to 7days (pigments) and up to 11days (intracellular metabolites). To assess iTRAQ measurement quality, pseudo selected reaction monitoring (pSRM) was used, with this confirming underestimation of protein abundance levels by iTRAQ. Our results suggest that short term UV-A radiation lowers the abundance of PS-I and PS-II proteins. We also observed an increase in abundance of intracellular redox homeostasis proteins and plastocyanin. Additionally, we observed statistically significant changes in scytonemin, Chlorophyll A, astaxanthin, zeaxanthin, and β-carotene. Assessment of intracellular metabolites showed significant changes in several, suggesting their potential role in the Nostoc's stress mitigation strategy. Cyanobacteria under UV-A radiation have reduced growth due to intensive damage to essential functions, but the organism shows a defense response by remodeling bioenergetics pathway, induction of the UV protection compound scytonemin and increased levels of proline and tyrosine as a mitigation response. The effect of UV-A radiation on the proteome and intracellular metabolites of N. punctiforme ATCC 29133 including photosynthetic pigments has been described. We also verify the expression of 13 iTRAQ quantified protein using LC-pSRM. Overall we observed that UV-A radiation has a drastic effect on the photosynthetic machinery, photosynthetic pigments and intracellular amino acids. As a mitigation strategy against UV-A radiation, proline, glycine, and tyrosine were accumulated. Copyright © 2014. Published by Elsevier B.V.

  17. Short Stature

    DEFF Research Database (Denmark)

    Christesen, Henrik Boye Thybo; Pedersen, Birgitte Tønnes; Pournara, Effie

    2016-01-01

    -scale, non-interventional, multinational study. The patient cohort consisted of 5996 short pediatric patients diagnosed with growth hormone deficiency (GHD), Turner syndrome (TS) or born small for gestational age (SGA). The proportions of children with baseline height standard deviation score (SDS) below......The use of appropriate growth standards/references is of significant clinical importance in assessing the height of children with short stature as it may determine eligibility for appropriate therapy. The aim of this study was to determine the impact of using World Health Organization (WHO) instead...... of national growth standards/references on height assessment in short children. Data were collected from routine clinical practice (1998-2014) from nine European countries that have available national growth references and were enrolled in NordiNet® International Outcome Study (IOS) (NCT00960128), a large...

  18. Short Review

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Rühli, Frank

    2015-01-01

    modality in ancient mummy research. The aim of this short review is to address the advantages and pitfalls of this particular technique for such unique samples. We recommend that when results of X-ray examination of mummies are presented, the specific recording data should be listed, and any given finds...

  19. Short fusion

    CERN Multimedia

    2002-01-01

    French and UK researchers are perfecting a particle accelerator technique that could aid the quest for fusion energy or make X-rays that are safer and produce higher-resolution images. Led by Dr Victor Malka from the Ecole Nationale Superieure des Techniques Avancees in Paris, the team has developed a better way of accelerating electrons over short distances (1 page).

  20. Short communication

    African Journals Online (AJOL)

    UPuser

    Short communication. Polymorphisms of the CAST gene in the Meishan and five other pig populations in China. Q.S. Wang. 1. , Y.C. Pan. 1#. , L.B. Sun. 2 and H. Meng. 1. 1 Department of Animal Science, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai. 201101, P.R. China. 2 Shanghai Institute of ...

  1. SHORT COMMUNICATION

    African Journals Online (AJOL)

    a

    ______. *Corresponding author. E-mail: vani_chem@yahoo.com. SHORT COMMUNICATION. OXIDATION OF L-CYSTINE BY CHROMIUM(VI) - A KINETIC STUDY. Kalyan Kumar Adari, Annapurna Nowduri and Vani Parvataneni*. Department of Inorganic and Analytical Chemistry, School of Chemistry, Andhra University,.

  2. Short communication

    NARCIS (Netherlands)

    Pantophlet, Andre J.; Gilbert, M.S.; Gerrits, W.J.J.; Vonk, R.J.

    2017-01-01

    Heavy veal calves (4-6 mo old) often develop problems with insulin sensitivity. This could lead to metabolic disorders and impaired animal growth performance. Studies in various animal species have shown that the supplementation of short-chain fructo-oligosaccharides (scFOS) can improve insulin

  3. Effect of bundle junction face and misalignment on the pressure drops across a randomly loaded and aligned 12 bundles in CANDU fuel channel

    Energy Technology Data Exchange (ETDEWEB)

    Suk, H. C.; Sim, K. S.; Chang, C. H.; Lee, Y. O. [Korea Atomic Energy Reaearch Institute, Taejon (Korea, Republic of)

    1996-06-01

    The pressure drop of twelve fuel bundle string in the CANDU-6 fuel channel is equal to the sum of the eleven junction pressure losses, the bundle string entrance and exit pressure losses, the skin friction pressure loss, and other appendage pressure losses, where the junction loss is dependent on the bundle and faces and angular alignments of the junctions. The results of the single junction pressure drop tests in a short rig show that the most probable pressure drop of the eleven junction was analytically equal to the eleven times of average pressure drop of all the possible single junction pressure drops, and also that the largest and smallest junction pressure drops across the eleven junctions probably occurred only with BA and BB type junctions, respectively, where A and B denote the bundle end sides with an end-plates on which a company monogram is stamped and unstamped, respectively. 5 refs., 7 figs., 1 tab. (author).

  4. Critical look at South Africa’s Green Drop Programme

    CSIR Research Space (South Africa)

    Ntombela, Cebile

    2016-10-01

    Full Text Available (WSAs) in the controversial wastewater services sector. In particular, we focus on DWS’s incentive-based mechanism, the National Green Drop Certification Programme (Green Drop Programme), and evaluate the achievements and challenges associated with its...

  5. Imaging transport phenomena during lysozyme protein crystal growth by the hanging drop technique

    Science.gov (United States)

    Sethia Gupta, Anamika; Gupta, Rajive; Panigrahi, P. K.; Muralidhar, K.

    2013-06-01

    The present study reports the transport process that occurs during the growth of lysozyme protein crystals by the hanging drop technique. A rainbow schlieren technique has been employed for imaging changes in salt concentration. A one dimensional color filter is used to record the deflection of the light beam. An optical microscope and an X-ray crystallography unit are used to characterize the size, tetragonal shape and Bravais lattice constants of the grown crystals. A parametric study on the effect of drop composition, drop size, reservoir height and number of drops on the crystal size and quality is reported. Changes in refractive index are not large enough to create a meaningful schlieren image in the air gap between the drop and the reservoir. However, condensation of fresh water over the reservoir solution creates large changes in the concentration of NaCl, giving rise to clear color patterns in the schlieren images. These have been analyzed to obtain salt concentration profiles near the free surface of the reservoir solution as a function of time. The diffusion of fresh water into the reservoir solution at the early stages of crystal growth followed by the mass flux of salt from the bulk solution towards the free surface has been recorded. The overall crystal growth process can be classified into two regimes, as demarcated by the changes in slope of salt concentration within the reservoir. The salt concentration in the reservoir equilibrates at long times when the crystallization process is complete. Thus, transport processes in the reservoir emerge as the route to monitor protein crystal growth in the hanging drop configuration. Results show that crystal growth rate is faster for a higher lysozyme concentration, smaller drops, and larger reservoir heights.

  6. The jet mass distribution after Soft Drop

    Energy Technology Data Exchange (ETDEWEB)

    Marzani, Simone [Universita di Genova, Dipartimento di Fisica, Genoa (Italy); INFN, Sezione di Genova (Italy); Schunk, Lais [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Soyez, Gregory [IPhT, CEA Saclay, CNRS UMR 3681, Gif-Sur-Yvette (France)

    2018-02-15

    We present a first-principle computation of the mass distribution of jets which have undergone the grooming procedure known as Soft Drop. This calculation includes the resummation of the large logarithms of the jet mass over its transverse momentum, up to next-to-logarithmic accuracy, matched to exact fixed-order results at next-to-leading order. We also include non-perturbative corrections obtained from Monte-Carlo simulations and discuss analytic expressions for hadronisation and Underlying Event effects. (orig.)

  7. Drop Calibration of Accelerometers for Shock Measurement

    Science.gov (United States)

    2011-08-01

    important that the screen is clear, the records displayed are crisp and values are easily read. The current DSO, used within the Division, in the...Capacitor ≤ ± 0.01% ξc Tolerance of capacitor Drop Mass Reading ≤ ± 0.083 %  dm 0.1g over 120g (typically) Reference Mass Reading ≤ ± 0.1 % rm...Therefore m has uncertainty components due to rm ,  dm and ξrme. The random component is  222 dmrmm  (6.8) and once again  dsodc

  8. Drops on hydrophobic surfaces & vibrated fluid surfaces

    DEFF Research Database (Denmark)

    Wind-Willassen, Øistein

    in the literature. Furthermore, we quantify the energy associated with center of mass translation and internal fluid motion. The model predicts trajectories for tracer particles deposited inside the drop, and satisfactorily describes the sliding motion of steadily accelerating droplets. The model can be used...... numerically, and the results are compared to experiments. We provide, again, the most detailed regime diagram of the possible orbits depending on the forcing and the rotation rate of the fluid bath. We highlight each class of orbit, and analyze in depth the wobbling state, precessing orbits, wobble...

  9. 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

  10. An Unusual Presentation of Right-Sided Sciatica with Foot Drop.

    Science.gov (United States)

    McCabe, Fergus J; McCabe, John P

    2016-01-01

    Rarely, sciatica is of extraspinal aetiology. By compressing the sciatic nerve, swelling of the short external rotators of the hip can cause sciatica. Uncommon anatomical relationships between the sciatic nerve and local muscles may potentiate this compressive effect. In this report, we describe the presentation of right sciatica and foot drop resulting from both extreme local constriction and unusual anatomical variation of the right sciatic nerve.

  11. Spent Nuclear Fuel (SNF) Bounding Drop Support Calculations

    International Nuclear Information System (INIS)

    CHENAULT, D.M.

    1999-01-01

    This report evaluates different drop heights, concrete and other impact media to which the transport package and/or the MCO is dropped. A prediction method is derived for estimating the resultant impact factor for determining the bounding drop case for the SNF Project

  12. Underwater sound produced by individual drop impacts and rainfall

    DEFF Research Database (Denmark)

    Pumphrey, Hugh C.; Crum, L. A.; Jensen, Leif Bjørnø

    1989-01-01

    An experimental study of the underwater sound produced by water drop impacts on the surface is described. It is found that sound may be produced in two ways: first when the drop strikes the surface and, second, when a bubble is created in the water. The first process occurs for every drop...

  13. Drop test of reinforced concrete slab onto storage cask

    International Nuclear Information System (INIS)

    Kato, Y.; Hattori, S.; Ito, C.; Sirai, K.; Ozaki, S.; Kato, O.

    1993-01-01

    In this research, drop tests onto full-scale casks considering the specifications of a falling object (weight, construction, drop height, etc.) demonstrate and evaluate the integrity of casks in case a heavy object drops into the storage facilities. (J.P.N.)

  14. Development status of the experimental and numerical load analysis of package units CASTOR registered under drop test conditions

    International Nuclear Information System (INIS)

    Voelzer, Walter; Schaefer, Marc; Rumanus, Erkan; Liedtke, Ralph; Brehmer, Frank

    2012-01-01

    The mechanical integrity of package units CASTOR registered for a 9-m drop test under accident conditions has to be demonstrated according the requirements of IAEA among others. For reduction of the loads the containers have to be equipped with shock absorbers on the bottom and top sides. The determination of loads under drop test conditions can be performed with experimental or numerical methods. Due to the complexity of the load state and the verification of results both methods are usually used for integrity demonstration. The numerical codes have to model the short-term dynamic behavior of the whole container for different drop orientations and temperatures, local stress states have to be quantifiable for assessment. One of the problems is the modeling of the material behavior of wood that is used in the shock absorbers. The so far used energetic calculation approach will be replaced by a dynamic approach, the numerical models will have to be verified by experimental drop tests.

  15. Short Communication

    African Journals Online (AJOL)

    huis

    Short Communication. QTL analysis of production traits on SSC3 in a Large White×Meishan pig resource family. B. Zuo. 1. , Y.Z. Xiong. 1#. , Y.H. Su. 2. , C.Y. Deng. 1. , M.G. Lei. 1. , F.E. Li. 1. , R. Zheng. 1 and S.W. Jiang. 1. 1 Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture & Key Lab of Agricultural ...

  16. Model of an Evaporating Drop Experiment

    Science.gov (United States)

    Rodriguez, Nicolas

    2017-11-01

    A computational model of an experimental procedure to measure vapor distributions surrounding sessile drops is developed to evaluate the uncertainty in the experimental results. Methanol, which is expected to have predominantly diffusive vapor transport, is chosen as a validation test for our model. The experimental process first uses a Fourier transform infrared spectrometer to measure the absorbance along lines passing through the vapor cloud. Since the measurement contains some errors, our model allows adding random noises to the computational integrated absorbance to mimic this. Then the resulting data are interpolated before passing through a computed tomography routine to generate the vapor distribution. Next, the gradients of the vapor distribution are computed along a given control volume surrounding the drop so that the diffusive flux can be evaluated as the net rate of diffusion out of the control volume. Our model of methanol evaporation shows that the accumulated errors of the whole experimental procedure affect the diffusive fluxes at different control volumes and are sensitive to how the noisy data of integrated absorbance are interpolated. This indicates the importance of investigating a variety of data fitting methods to choose which is best to present the data. Trinity University Mach Fellowship.

  17. Vlasov simulations of parallel potential drops

    Directory of Open Access Journals (Sweden)

    H. Gunell

    2013-07-01

    Full Text Available An auroral flux tube is modelled from the magnetospheric equator to the ionosphere using Vlasov simulations. Starting from an initial state, the evolution of the plasma on the flux tube is followed in time. It is found that when applying a voltage between the ends of the flux tube, about two thirds of the potential drop is concentrated in a thin double layer at approximately one Earth radius altitude. The remaining part is situated in an extended region 1–2 Earth radii above the double layer. Waves on the ion timescale develop above the double layer, and they move toward higher altitude at approximately the ion acoustic speed. These waves are seen both in the electric field and as perturbations of the ion and electron distributions, indicative of an instability. Electrons of magnetospheric origin become trapped between the magnetic mirror and the double layer during its formation. At low altitude, waves on electron timescales appear and are seen to be non-uniformly distributed in space. The temporal evolution of the potential profile and the total voltage affect the double layer altitude, which decreases with an increasing field aligned potential drop. A current–voltage relationship is found by running several simulations with different voltages over the system, and it agrees with the Knight relation reasonably well.

  18. 40 CFR 63.1657 - Monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ... practices that minimizes emissions per § 63.6(e)(1)(i) of subpart A. (b) Venturi scrubbers. (1) The owner or operator must monitor the pressure drop across the venturi at least every 5 minutes and record the average...

  19. Autologous serum eye drops for dry eye

    Science.gov (United States)

    Pan, Qing; Angelina, Adla; Marrone, Michael; Stark, Walter J; Akpek, Esen K

    2017-01-01

    Background Theoretically, autologous serum eye drops (AS) offer a potential advantage over traditional therapies on the assumption that AS not only serve as a lacrimal substitute to provide lubrication but contain other biochemical components that allow them to mimic natural tears more closely. Application of AS has gained popularity as second-line therapy for patients with dry eye. Published studies on this subject indicate that autologous serum could be an effective treatment for dry eye. Objectives We conducted this review to evaluate the efficacy and safety of AS given alone or in combination with artificial tears as compared with artificial tears alone, saline, placebo, or no treatment for adults with dry eye. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2016), Embase (January 1980 to July 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (December 2016) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 July 2016. Selection criteria We included randomized controlled trials (RCTs) that compared AS versus artificial tears for treatment of adults with dry eye. Data collection and analysis Two review authors independently screened all titles and abstracts and assessed full-text reports of potentially eligible trials. Two review authors extracted data and assessed risk of bias and characteristics of included

  20. Vertical vibration and shape oscillation of acoustically levitated water drops

    International Nuclear Information System (INIS)

    Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B.

    2014-01-01

    We present the vertical harmonic vibration of levitated water drops within ultrasound field. The restoring force to maintain such a vibration mode is provided by the resultant force of acoustic radiation force and drop gravity. Experiments reveal that the vibration frequency increases with the aspect ratio for drops with the same volume, which agrees with the theoretical prediction for those cases of nearly equiaxed drops. During the vertical vibration, the floating drops undergo the second order shape oscillation. The shape oscillation frequency is determined to be twice the vibration frequency.

  1. Vertical vibration and shape oscillation of acoustically levitated water drops

    Energy Technology Data Exchange (ETDEWEB)

    Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B., E-mail: bbwei@nwpu.edu.cn [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-09-08

    We present the vertical harmonic vibration of levitated water drops within ultrasound field. The restoring force to maintain such a vibration mode is provided by the resultant force of acoustic radiation force and drop gravity. Experiments reveal that the vibration frequency increases with the aspect ratio for drops with the same volume, which agrees with the theoretical prediction for those cases of nearly equiaxed drops. During the vertical vibration, the floating drops undergo the second order shape oscillation. The shape oscillation frequency is determined to be twice the vibration frequency.

  2. Deformed liquid marbles: Freezing drop oscillations with powders

    KAUST Repository

    Marston, Jeremy; Zhu, Y.; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

    2012-01-01

    In this work we show that when a liquid drop impacts onto a fine-grained hydrophobic powder, the final form of the drop can be very different from the spherical form with which it impacts. In all cases, the drop rebounds due to the hydrophobic nature of the powder. However, we find that above a critical impact speed, the drop undergoes a permanent deformation to a highly non-spherical shape with a near-complete coverage of powder, which then freezes the drop oscillations during rebound. © 2012 Elsevier B.V.

  3. Deformed liquid marbles: Freezing drop oscillations with powders

    KAUST Repository

    Marston, Jeremy

    2012-09-01

    In this work we show that when a liquid drop impacts onto a fine-grained hydrophobic powder, the final form of the drop can be very different from the spherical form with which it impacts. In all cases, the drop rebounds due to the hydrophobic nature of the powder. However, we find that above a critical impact speed, the drop undergoes a permanent deformation to a highly non-spherical shape with a near-complete coverage of powder, which then freezes the drop oscillations during rebound. © 2012 Elsevier B.V.

  4. Applicability of short-term accelerated biofouling studies to predict long-term biofouling accumulation in reverse osmosis membrane systems

    KAUST Repository

    Sanawar, Huma

    2018-02-02

    Biofouling studies addressing biofouling control are mostly executed in short-term studies. It is unclear whether data collected from these experiments are representative for long-term biofouling as occurring in full-scale membrane systems. This study investigated whether short-term biofouling studies accelerated by biodegradable nutrient dosage to feed water were predictive for long-term biofouling development without nutrient dosage. Since the presence of a feed spacer has an strong effect on the degree of biofouling, this study employed six geometrically different feed spacers. Membrane fouling simulators (MFSs) were operated with the same (i) membrane, (ii) feed flow and (iii) feed water, but with feed spacers varying in geometry. For the short-term experiment, biofilm formation was enhanced by nutrient dosage to the MFS feed water, whereas no nutrient dosage was applied in the long-term experiment. Pressure drop development was monitored to characterize the extent of biofouling, while the accumulated viable biomass content at the end of the experimental run was quantified by adenosine triphosphate (ATP) measurements. Impact of feed spacer geometry on biofouling was compared for the short-term and long-term biofouling study. The results of the study revealed that the feed spacers exhibited the same biofouling behavior for (i) the short-term (9-d) study with nutrient dosage and (ii) the long-term (96-d) study without nutrient dosage. For the six different feed spacers, the accumulated viable biomass content (pg ATP.cm) was roughly the same, but the biofouling impact in terms of pressure drop increase in time was significantly different. The biofouling impact ranking of the six feed spacers was the same for the short-term and long-term biofouling studies. Therefore, it can be concluded that short-term accelerated biofouling studies in MFSs are a representative and suitable approach for the prediction of biofouling in membrane filtration systems after long

  5. Liquid-gas mass transfer at drop structures

    DEFF Research Database (Denmark)

    Matias, Natércia; Nielsen, Asbjørn Haaning; Vollertsen, Jes

    2017-01-01

    -water mass transfer, little is known about hydrogen sulfide emission under highly turbulent conditions (e.g., drop structures, hydraulic jumps). In this study, experimental work was carried out to analyze the influence of characteristics of drops on reaeration. Physical models were built, mimicking typical...... sewer drop structures and allowing different types of drops, drop heights, tailwater depths and flow rates. In total, 125 tests were performed. Based on their results, empirical expressions translating the relationship between the mass transfer of oxygen and physical parameters of drop structures were...... established. Then, by applying the two-film theory with two-reference substances, the relation to hydrogen sulfide release was defined. The experiments confirmed that the choice of the type of drop structure is critical to determine the uptake/emission rates. By quantifying the air-water mass transfer rates...

  6. Calculation of drop course of control rod assembly in PWR

    International Nuclear Information System (INIS)

    Zhou Xiaojia; Mao Fei; Min Peng; Lin Shaoxuan

    2013-01-01

    The validation of control rod drop performance is an important part of safety analysis of nuclear power plant. Development of computer code for calculating control rod drop course will be useful for validating and improving the design of control rod drive line. Based on structural features of the drive line, the driving force on moving assembly was analyzed and decomposed, the transient value of each component of the driving force was calculated by choosing either theoretical method or numerical method, and the simulation code for calculating rod cluster control assembly (RCCA) drop course by time step increase was achieved. The analysis results of control rod assembly drop course calculated by theoretical model and numerical method were validated by comparing with RCCA drop test data of Qinshan Phase Ⅱ 600 MW PWR. It is shown that the developed RCCA drop course calculation code is suitable for RCCA in PWR and can correctly simulate the drop course and the stress of RCCA. (authors)

  7. Pendent_Drop: An ImageJ Plugin to Measure the Surface Tension from an Image of a Pendent Drop

    Directory of Open Access Journals (Sweden)

    Adrian Daerr

    2016-01-01

    Full Text Available The pendent drop method for surface tension measurement consists in analysing the shape of an axisymmetric drop hanging from a capillary tube. This software is an add-on for the public domain image processing software ImageJ which matches a theoretical profile to the contour of a pendent drop, either interactively or by automatically minimising the mismatch. It provides an estimate of the surface tension, drop volume and surface area from the best matching parameters. It can be used in a headless setup. It is hosted on http://fiji.sc/List_of_update_sites with the source code on https://github.com/adaerr/pendent-drop

  8. Bubble and Drop Nonlinear Dynamics experiment

    Science.gov (United States)

    2003-01-01

    The Bubble and Drop Nonlinear Dynamics (BDND) experiment was designed to improve understanding of how the shape and behavior of bubbles respond to ultrasound pressure. By understanding this behavior, it may be possible to counteract complications bubbles cause during materials processing on the ground. This 12-second sequence came from video downlinked from STS-94, July 5 1997, MET:3/19:15 (approximate). The BDND guest investigator was Gary Leal of the University of California, Santa Barbara. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced fluid dynamics experiments will be a part of investigations plarned for the International Space Station. (189KB JPEG, 1293 x 1460 pixels; downlinked video, higher quality not available) The MPG from which this composite was made is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300163.html.

  9. Load drop evaluation for TWRS FSAR

    Energy Technology Data Exchange (ETDEWEB)

    Julyk, L.J.; Ralston, G.L.

    1996-09-30

    Operational or remediation activities associated with existing underground high-level waste storage tank structures at the Hanford Site often require the installation/removal of various equipment items. To gain tank access for installation or removal of this equipment, large concrete cover blocks must be removed and reinstalled in existing concrete pits above the tanks. An accidental drop of the equipment or cover blocks while being moved over the tanks that results in the release of contaminants to the air poses a potential risk to onsite workers or to the offsite public. To minimize this potential risk, the use of critical lift hoisting and rigging procedures and restrictions on lift height are being considered during development of the new tank farm Basis for Interim Operation and Final Safety Analysis Report. The analysis contained herein provides information for selecting the appropriate lift height restrictions for these activities.

  10. Drop Impact on a Solid Surface

    KAUST Repository

    Josserand, C.

    2015-09-22

    © Copyright 2016 by Annual Reviews. All rights reserved. A drop hitting a solid surface can deposit, bounce, or splash. Splashing arises from the breakup of a fine liquid sheet that is ejected radially along the substrate. Bouncing and deposition depend crucially on the wetting properties of the substrate. In this review, we focus on recent experimental and theoretical studies, which aim at unraveling the underlying physics, characterized by the delicate interplay of not only liquid inertia, viscosity, and surface tension, but also the surrounding gas. The gas cushions the initial contact; it is entrapped in a central microbubble on the substrate; and it promotes the so-called corona splash, by lifting the lamella away from the solid. Particular attention is paid to the influence of surface roughness, natural or engineered to enhance repellency, relevant in many applications.

  11. Drop Impact on to Moving Liquid Pools

    Science.gov (United States)

    Muñoz-Sánchez, Beatriz Natividad; Castrejón-Pita, José Rafael; Castrejón-Pita, Alfonso Arturo; Hutchings, Ian M.

    2014-11-01

    The deposition of droplets on to moving liquid substrates is an omnipresent situation both in nature and industry. A diverse spectrum of phenomena emerges from this simple process. In this work we present a parametric experimental study that discerns the dynamics of the impact in terms of the physical properties of the fluid and the relative velocity between the impacting drop and the moving liquid pool. The behaviour ranges from smooth coalescence (characterized by little mixing) to violent splashing (generation of multiple satellite droplets and interfacial vorticity). In addition, transitional regimes such as bouncing and surfing are also found. We classify the system dynamics and show a parametric diagram for the conditions of each regime. This work was supported by the EPSRC (Grant EP/H018913/1), the Royal Society, Becas Santander Universidades and the International Relationships Office of the University of Extremadura.

  12. Effect of Bilineaster Drop on Neonatal Hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Zahra Ameli

    2017-01-01

    Full Text Available Background: Hyperbilirubinemia is considered one of the most prevalent problems in newborns. Phototherapy, exchange transfusion, and herbal medicine are common therapeutic approaches for preventing any neurologic damage in infants with neonatal jaundice. However, herbal medicine is less commonly used. Aim: This study aimed to investigate the effect of bilineaster drop on neonatal hyperbilirubinemia. Method: This study was a randomized clinical trial conducted on 98 term neonates (aged 2-14 days with neonatal jaundice admitted to Ghaem Hospital of Mashhad, Iran, during 2015. These newborns were randomly assigned into intervention (phototherapy and bilineaster drop and control (only phototherapy groups. Total and direct serum bilirubin levels were measured at the time of admission and then 12, 24, 36, and 48 h after treatment. Data were analyzed using independent t-test and repeated measures ANOVA through Stata software (Version 12. Results: The mean ages of the newborns at the time of admission were 6.2 ±2.5 and 6.04 ±2.4 days in the intervention and control groups, respectively. The intervention group showed higher reduction in mean duration of hospital stay, readmission rate, and bilirubin levels 12 and 24 h after the intervention, compared to the control group (P>0.001. However, the two groups demonstrated no statistically significant difference 36 h and 48 h after the intervention (P=0.06, P=0.22, respectively. Repeated measures ANOVA indicated that the intervention had no significant effect on the reduction trend of bilirubin levels (P=0.10 [total], P=0.06 [indirect] in both groups. Nonetheless, bilirubin levels significantly diminished in both groups over time (P

  13. Marangoni Flow Induced Evaporation Enhancement on Binary Sessile Drops.

    Science.gov (United States)

    Chen, Pin; Harmand, Souad; Ouenzerfi, Safouene; Schiffler, Jesse

    2017-06-15

    The evaporation processes of pure water, pure 1-butanol, and 5% 1-butanol aqueous solution drops on heated hydrophobic substrates are investigated to determine the effect of temperature on the drop evaporation behavior. The evolution of the parameters (contact angle, diameter, and volume) during evaporation measured using a drop shape analyzer and the infrared thermal mapping of the drop surface recorded by an infrared camera were used in investigating the evaporation process. The pure 1-butanol drop does not show any thermal instability at different substrate temperatures, while the convection cells created by the thermal Marangoni effect appear on the surface of the pure water drop from 50 °C. Because 1-butanol and water have different surface tensions, the infrared video of the 5% 1-butanol aqueous solution drop shows that the convection cells are generated by the solutal Marangoni effect at any substrate temperature. Furthermore, when the substrate temperature exceeds 50 °C, coexistence of the thermal and solutal Marangoni flows is observed. By analyzing the relation between the ratio of the evaporation rate of pure water and 1-butanol aqueous solution drops and the Marangoni number, a series of empirical equations for predicting the evaporation rates of pure water and 1-butanol aqueous solution drops at the initial time as well as the equations for the evaporation rate of 1-butanol aqueous solution drop before the depletion of alcohol are derived. The results of these equations correspond fairly well to the experimental data.

  14. Dynamic response of an electrostatically actuated microbeam to drop-table test

    International Nuclear Information System (INIS)

    Ouakad, Hassen M; Younis, Mohammad I; Alsaleem, Fadi

    2012-01-01

    In this paper, we present a theoretical and experimental investigation into the dynamic response of an electrostatically actuated microbeam when subjected to drop-table test. For the theoretical part, a reduced-order model based on an Euler–Bernoulli beam model is utilized. The model accounts for the electrostatic bias on the microbeam and the shock pulse of the drop-table test. Simulation results are presented showing the combined effect of electrostatic force and mechanical shock in triggering early pull-in instability of the cantilever microbeams. The analytical simulation results are validated by finite-element results for the static response. Dynamic pull-in threshold as a function of the mechanical shock amplitude is shown over a wide range of shock spanning hundreds of thousands of g up to zero g. For the experimental part, a micromachined cantilever beam made of gold of length 50 µm is subjected to drop-table tests while being biased by electrostatic loads. Several experimental data are shown demonstrating the phenomenon of collapse due to the combined shock and electrostatic forces. It is also demonstrated that by biasing short and too stiff microbeams with electrostatic voltages, their stiffness is weakened. This lowers their threshold of collapse considerably to the range of acceleration that enables testing them with in-house shock testing equipments, such as drop-table tests. (paper)

  15. Clinical outcomes of psychotherapy dropouts: does dropping out of psychotherapy necessarily mean failure?

    Directory of Open Access Journals (Sweden)

    Rodrigo T. Lopes

    2017-09-01

    Full Text Available Objective: A large proportion of psychotherapy patients remain untreated, mostly because they drop out. This study compares the short- and long-term outcomes of patients who dropped out of psychotherapy to those of therapy completers. Methods: The sample included 63 patients (23 dropouts and 40 completers from a controlled clinical trial, which compared narrative therapy vs. cognitive-behavioral therapy for major depressive disorder. Patients were assessed at the eighth session, post-treatment, and at 31-month follow-up. Results: Dropouts improved less than completers by the last session attended, but continued to improve significantly more than completers during the follow-up period. Some dropout patients improved with a small dose of therapy (17% achieved a clinically significant change before abandoning treatment, while others only achieved clinically significant change after a longer period (62% at 31-month follow-up. Conclusion: These results emphasize the importance of dealing effectively with patients at risk of dropping out of therapy.Patients who dropped out also reported improvement of depressive symptoms without therapy, but took much longer to improve than did patients who completed therapy. This might be attributable to natural remission of depression. Further research should use a larger patient database, ideally gathered by meta-analysis.

  16. DROpS: an object of learning in computer simulation of discrete events

    Directory of Open Access Journals (Sweden)

    Hugo Alves Silva Ribeiro

    2015-09-01

    Full Text Available This work presents the “Realistic Dynamics Of Simulated Operations” (DROpS, the name given to the dynamics using the “dropper” device as an object of teaching and learning. The objective is to present alternatives for professors teaching content related to simulation of discrete events to graduate students in production engineering. The aim is to enable students to develop skills related to data collection, modeling, statistical analysis, and interpretation of results. This dynamic has been developed and applied to the students by placing them in a situation analogous to a real industry, where various concepts related to computer simulation were discussed, allowing the students to put these concepts into practice in an interactive manner, thus facilitating learning

  17. Drop Test Results of CRDM under Seismic Loads

    International Nuclear Information System (INIS)

    Choi, Myoung-Hwan; Cho, Yeong-Garp; Kim, Gyeong-Ho; Sun, Jong-Oh; Huh, Hyung

    2016-01-01

    This paper describes the test results to demonstrate the drop performance of CRDM under seismic loads. The top-mounted CRDM driven by the stepping motor for Jordan Research and Training Reactor (JRTR) has been developed in KAERI. The CRDM for JRTR has been optimized by the design improvement based on that of the HANARO. It is necessary to verify the drop performance under seismic loads such as operating basis earthquake (OBE) and safe shutdown earthquake (SSE). Especially, the CAR drop times are important data for the safety analysis. confirm the drop performance under seismic loads. The delay of drop time at Rig no. 2 due to seismic loads is greater than that at Rig no. 3. The total pure drop times under seismic loads are estimated as 1.169 and 1.855, respectively

  18. Ballistic Jumping Drops on Superhydrophobic Surfaces via Electrostatic Manipulation.

    Science.gov (United States)

    Li, Ning; Wu, Lei; Yu, Cunlong; Dai, Haoyu; Wang, Ting; Dong, Zhichao; Jiang, Lei

    2018-02-01

    The ballistic ejection of liquid drops by electrostatic manipulating has both fundamental and practical implications, from raindrops in thunderclouds to self-cleaning, anti-icing, condensation, and heat transfer enhancements. In this paper, the ballistic jumping behavior of liquid drops from a superhydrophobic surface is investigated. Powered by the repulsion of the same kind of charges, water drops can jump from the surface. The electrostatic acting time for the jumping of a microliter supercooled drop only takes several milliseconds, even shorter than the time for icing. In addition, one can control the ballistic jumping direction precisely by the relative position above the electrostatic field. The approach offers a facile method that can be used to manipulate the ballistic drop jumping via an electrostatic field, opening the possibility of energy efficient drop detaching techniques in various applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Drop Impact on Textile Material: Effect of Fabric Properties

    Directory of Open Access Journals (Sweden)

    Romdhani Zouhaier

    2014-09-01

    Full Text Available This paper presents an experimental study of impact of water drop on a surface in a spreading regime with no splashing. Three surfaces were studied: virgin glass, coating film and woven cotton fabric at different construction parameters. All experiments were carried out using water drop with the same free fall high. Digidrop with high-resolution camera is used to measure the different parameters characterising this phenomenon. Results show an important effect of the height of the free fall on the drop profile and the spreading behaviour. An important drop deformation at the surface impact was observed. Then, fabric construction as the weft count deeply affects the drop impact. For plain weave, an increase of weft count causes a decrease in penetration and increase in the spreading rate. The same result was obtained for coated fabric. Therefore, the impact energy was modified and the drop shape was affected, which directly influenced the spreading rate.

  20. Drop Test Results of CRDM under Seismic Loads

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myoung-Hwan; Cho, Yeong-Garp; Kim, Gyeong-Ho; Sun, Jong-Oh; Huh, Hyung [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This paper describes the test results to demonstrate the drop performance of CRDM under seismic loads. The top-mounted CRDM driven by the stepping motor for Jordan Research and Training Reactor (JRTR) has been developed in KAERI. The CRDM for JRTR has been optimized by the design improvement based on that of the HANARO. It is necessary to verify the drop performance under seismic loads such as operating basis earthquake (OBE) and safe shutdown earthquake (SSE). Especially, the CAR drop times are important data for the safety analysis. confirm the drop performance under seismic loads. The delay of drop time at Rig no. 2 due to seismic loads is greater than that at Rig no. 3. The total pure drop times under seismic loads are estimated as 1.169 and 1.855, respectively.

  1. Experimental Setup For Study of Drop Deformation In Air Flow

    Directory of Open Access Journals (Sweden)

    Basalaev Sergey

    2017-01-01

    Full Text Available Experimental study for study of deformation of drops in air flow is considered. Experimental setup includes a module for obtaining the drops, an air flow system and measuring system. Module for formation of drops is in the form of vertically arranged dropper with capillary with the possibility of formation of fixed drops. Air flow supply system comprises an air pump coupled conduit through a regulating valve with a cylindrical pipe, installed coaxially with dropper. The measuring system includes the video camera located with possibility of visualization of drop and the Pitot gage for measurement of flow rate of air located in the output section of branch pipe. This experimental setup allows to provide reliable and informative results of the investigation of deformation of drops in the air flow.

  2. Levitation of a drop over a film flow

    Science.gov (United States)

    Sreenivas, K. R.; de, P. K.; Arakeri, Jaywant H.

    1999-02-01

    A vertical jet of water impinging on a horizontal surface produces a radial film flow followed by a circular hydraulic jump. We report a phenomenon where fairly large (1 ml) drops of liquid levitate just upstream of the jump on a thin air layer between the drop and the film flow. We explain the phenomenon using lubrication theory. Bearing action both in the air film and the water film seems to be necessary to support large drops. Horizontal support is given to the drop by the hydraulic jump. A variety of drop shapes is observed depending on the volume of the drop and liquid properties. We show that interaction of the forces due to gravity, surface tension, viscosity and inertia produces these various shapes.

  3. A study of fungi on droppings of certain birds

    Directory of Open Access Journals (Sweden)

    C. S. Singh

    2014-08-01

    Full Text Available Droppings of fowl, owl, parrot, pigeon and sparrow were asepticaly collected in sterilized bottles from different places at Gorakhpur, 54 fungi were isolated. The number of fungi was more in the pigeon showing considerable decrease in the fowl and the sparrow. In the parrot and the owl, however. the fungi were egual in number. The number of Phycomycetes was almost the same on droppings of all birds, from parrot only one species could be isolated. A larger number of Ascomyteces was recorded from fowl, less from pigeon and owl and the least (two each on sparrow and parrot droppings. The Basidiomycetes, represented by two species only, were recorded on owl and pigeon droppings. Pigeon droppings yielded the largest number of Deuteromycetes. They were egual in numbers on owl and parrot while on fowl and sparrow their number was comparatively less. Mycelia sterilia, though poor in their numbers, were recorded on all the bird droppings excepting owl.

  4. New methods for the voltage drop desensitization of frequency converters for asynchronous machines; De nouvelles methodes de desensibilisation aux creux de tension des convertisseurs de frequence pour machines asynchrones

    Energy Technology Data Exchange (ETDEWEB)

    David, A.

    1995-12-31

    In order to reduce the vulnerability of electronic speed variators to load transients and outages, and more especially to short ones (inferior to one second), which represent 95 pc of voltage drop and failures, Electricite de France (EDF) has developed (and patented) several insensitivity techniques: voltage drop compensation, free-wheel machine speed identification, automatic adjustment and synchronization of converter and machine during the drop. These techniques have been validated through experiments

  5. Impact of biofilm accumulation on transmembrane and feed channel pressure drop: Effects of crossflow velocity, feed spacer and biodegradable nutrient

    KAUST Repository

    Dreszer, C.; Flemming, H. C.; Zwijnenburg, A.; Kruithof, J. C.; Vrouwenvelder, Johannes S.

    2014-01-01

    . As biodegradable nutrient, acetate was dosed to the feed water (1.0 and 0.25mgL-1 carbon) to enhance biofilm accumulation in the monitors. The studies showed that biofilm formation caused an increased transmembrane resistance and feed channel pressure drop

  6. Evaporation of a sessile water drop and a drop of aqueous salt solution.

    Science.gov (United States)

    Misyura, S Y

    2017-11-07

    The influence of various factors on the evaporation of drops of water and aqueous salt solution has been experimentally studied. Typically, in the studies of drop evaporation, only the diffusive vapor transfer, radiation and the molecular heat conduction are taken into account. However, vapor-gas convection plays an important role at droplet evaporation. In the absence of droplet boiling, the influence of gas convection turns out to be the prevailing factor. At nucleate boiling, a prevailing role is played by bubbles generation and vapor jet discharge at a bubble collapse. The gas convection behavior for water and aqueous salt solution is substantially different. With a growth of salt concentration over time, the influence of the convective component first increases, reaches an extremum and then significantly decreases. At nucleate boiling in a salt solution it is incorrect to simulate the droplet evaporation and the heat transfer in quasi-stationary approximation. The evaporation at nucleate boiling in a liquid drop is divided into several characteristic time intervals. Each of these intervals is characterized by a noticeable change in both the evaporation rate and the convection role.

  7. Electromagnetic Drop Scale Scattering Modelling for Dynamic Statistical Rain Fields

    OpenAIRE

    Hipp, Susanne

    2015-01-01

    This work simulates the scattering of electromagnetic waves by a rain field. The calculations are performed for the individual drops and accumulate to a time signal dependent on the dynamic properties of the rain field. The simulations are based on the analytical Mie scattering model for spherical rain drops and the simulation software considers the rain characteristics drop size (including their distribution in rain), motion, and frequency and temperature dependent permittivity. The performe...

  8. Self-excited hydrothermal waves in evaporating sessile drops

    OpenAIRE

    Sefiane K.; Moffat J.R.; Matar O.K.; Craster R.V.

    2008-01-01

    Pattern formation driven by the spontaneous evaporation of sessile drops of methanol, ethanol, and FC-72 using infrared thermography is observed and, in certain cases, interpreted in terms of hydrothermal waves. Both methanol and ethanol drops exhibit thermal wave trains, whose wave number depends strongly on the liquid volatililty and substrate thermal conductivity. The FC- 72 drops develop cellular structures whose size is proportional to the local thickness. Prior to this work, hydrotherma...

  9. Drop-out from a psychodynamic group psychotherapy outpatient unit.

    Science.gov (United States)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2014-11-01

    BACKGROUND. Drop-out from psychotherapy is common and represents a considerable problem in clinical practice and research. Aim. To explore pre-treatment predictors of early and late drop-out from psychodynamic group therapy in a public outpatient unit for non-psychotic disorders in Denmark. Methods. Naturalistic design including 329 patients, the majority with mood, neurotic and personality disorders referred to 39-session group therapy. Predictors were socio-demographic and clinical variables, self-reported symptoms (Symptom Check List-90-Revised) and personality style (Millon Clinical Multiaxial Inventory-II). Drop-out was classified into early and late premature termination excluding patients who dropped out for external reasons. Results. Drop-out comprised 20.6% (68 patients) of the sample. Logistic regression revealed social functioning, vocational training, alcohol problems and antisocial behavior to be related to drop-out. However, early drop-outs had prominent agoraphobic symptoms, lower interpersonal sensitivity and compulsive personality features, and late drop-outs cognitive and somatic anxiety symptoms and antisocial personality features. Clinical and psychological variables accounted for the major part of variance in predictions of drop-out, which ranged from 15.6% to 19.5% (Nagelkerke Pseudo R-Square). Conclusion. Social functioning was consistently associated with drop-out, but personality characteristics and anxiety symptoms differentiated between early and late drop-out. Failure to discriminate between stages of premature termination may explain some of the inconsistencies in the drop-out literature. Clinical implications. Before selection of patients to time-limited psychodynamic groups, self-reported symptoms should be thoroughly considered. Patients with agoraphobic symptoms should be offered alternative treatment. Awareness of and motivation to work with interpersonal issues may be essential for compliance with group therapy.

  10. Analysis of DCI cask drop test onto reinforced concrete pad

    International Nuclear Information System (INIS)

    Ito, C.; Kato, Y.; Hattori, S.; Shirai, K.; Misumi, M.; Ozaki, S.

    1993-01-01

    In a cask-storage facility, a cask may be subjected to an impact load as a result of a free drop onto the floor because of cask mishandling. We performed drop tests of casks onto a reinforced concrete (RC) slab representing the floor of a facility as well as simulation analysis [Kato et al]. This paper describes the details of the FEM analysis and calculated results and compares them with the drop test results. (J.P.N.)

  11. Reducing Variability in Stress Drop with Root-Mean Acceleration

    Science.gov (United States)

    Crempien, J.; Archuleta, R. J.

    2012-12-01

    Stress drop is a fundamental property of the earthquake source. For a given tectonic region stress drop is assumed to be constant allowing for the scaling of earthquake spectra. However, the variability of the stress drop, either for worldwide catalogs or regional catalogs, is quite large. The variability around the median value is on the order of 1.5 in log10 units. One question that continues to pervade the analysis of stress drop is whether this variability is an inherent characteristic of the Earth or is an artifact of the determination of stress drop via the use of the spectral analysis. It is simple to see that the stress drop determined by seismic moment times corner frequency cubed that errors in the corner frequency will strongly influence the variability in the stress drop. To avoid this strong dependence on corner frequency cubed, we have examined the determination of stress drop based on the approach proposed by Hanks (1979), namely using the root-mean-square acceleration. The stress drop determined using rms acceleration may be advantageous because the stress drop is only affected by the square root of the corner frequency. To test this approach we have determined stress drops for the 2000 Tottori earthquake and its aftershocks. We use both the classic method of fitting to a spectrum as well as using rms acceleration. For a preliminary analysis of eight aftershocks and the mainshock we find that the variability in stress drop is reduced by about a factor of two. This approach needs more careful analysis of more events, which will be shown at the meeting.

  12. [Stability of physical state on compound hawthorn dropping pills].

    Science.gov (United States)

    Zhang, Wei; Chen, Hong-Yan; Jiang, Jian-Lan

    2008-11-01

    To evaluate the stability of physical state with accelerate test and dropping in process before and after on compound hawthorn dropping pills. Scanning electron microscope, TG-DTA, FT-IR and XRD were used. The active components presented amorphous, tiny crystal and molecular state in dropping pills, and it had no obvious reaction between PEG 4000 and active components. With time prolonging, a little of active components changed from amorphous state to tiny crystal or molecular state. Solid dispersion improved the stability and dissolution of compound hawthorn dropping pills.

  13. Theory of magnetostriction of electron-hole drops in Ge

    International Nuclear Information System (INIS)

    Markiewicz, R.S.

    1978-01-01

    A large mass of electron-hole liquid (γ drop) formed in a strain-induced potential well in Ge is known to distort its shape significantly in a magnetic field B > or approx. = 1 kG. It is shown in this paper that the shape change can be understood in detail as due to a ''recombination current'' of electron-hole pairs needed to replace those pairs which recombine in the drop volume. The Lorentz force deflects this current and produces a macroscopic dipole current loop inside the drop. The drop then changes shape to minimize its total energy, including magnetic, strain, and surface energies. While the drop usually flattens along the field direction, both para- and diamagnetic effects (elongated drops) are found to be possible, depending on excitation conditions, in accord with experiment. Similar effects are predicted to occur in small drops in unstrained Ge. This paper presents a magnetohydrodynamic theory of the magnetostriction which takes into account density variations which occur in the strain well and in high magnetic fields. A simpler theory is given for the special case in which the drop may be considered incompressible (small drops and moderate fields). Effects of carrier mass anisotropy and fluid viscosity are taken into consideration

  14. Ground Motion Prediction Equations Empowered by Stress Drop Measurement

    Science.gov (United States)

    Miyake, H.; Oth, A.

    2015-12-01

    Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.

  15. Allelic drop-out probabilities estimated by logistic regression

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Asplund, Maria

    2012-01-01

    We discuss the model for estimating drop-out probabilities presented by Tvedebrink et al. [7] and the concerns, that have been raised. The criticism of the model has demonstrated that the model is not perfect. However, the model is very useful for advanced forensic genetic work, where allelic drop-out...... is occurring. With this discussion, we hope to improve the drop-out model, so that it can be used for practical forensic genetics and stimulate further discussions. We discuss how to estimate drop-out probabilities when using a varying number of PCR cycles and other experimental conditions....

  16. Motion of a drop driven by substrate vibrations

    Science.gov (United States)

    Brunet, P.; Eggers, J.; Deegan, R. D.

    2009-01-01

    We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wet by the drop. Frequency of vibrations ranges from 30 to 200 Hz, and above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up/down symmetry-breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements.

  17. Career drop outs of young elite athletes

    Directory of Open Access Journals (Sweden)

    Petra Fišer

    2007-12-01

    Full Text Available The main problem of the study was to examine the characteristics of sports career drop outs of young elite sportswomen and their adaptation to the post-sport life. The sample included 20 ex-young elite sportswomen, who had brought their successful sport careers to an end before the age of 19. We used a modified interview about sports career termination (Cecić Erpič, 1998 for the investigation of the characteristics of their sports careers. To examine the caracteristics of sport careers we used frequency analysis and cluster analysis. The results showed that the participants mostly stated more than one reason for the termination of their career. The most common reasons for career termination were: lack of motivation, bad relations with trainers or co-competitors and dedication to school or education. After the end of a sports career most of the young sportswomen stayed actively in touch with sport, either as trainers, judges, or they remained engaged in sports for recreation.

  18. The viruses of wild pigeon droppings.

    Directory of Open Access Journals (Sweden)

    Tung Gia Phan

    Full Text Available Birds are frequent sources of emerging human infectious diseases. Viral particles were enriched from the feces of 51 wild urban pigeons (Columba livia from Hong Kong and Hungary, their nucleic acids randomly amplified and then sequenced. We identified sequences from known and novel species from the viral families Circoviridae, Parvoviridae, Picornaviridae, Reoviridae, Adenovirus, Astroviridae, and Caliciviridae (listed in decreasing number of reads, as well as plant and insect viruses likely originating from consumed food. The near full genome of a new species of a proposed parvovirus genus provisionally called Aviparvovirus contained an unusually long middle ORF showing weak similarity to an ORF of unknown function from a fowl adenovirus. Picornaviruses found in both Asia and Europe that are distantly related to the turkey megrivirus and contained a highly divergent 2A1 region were named mesiviruses. All eleven segments of a novel rotavirus subgroup related to a chicken rotavirus in group G were sequenced and phylogenetically analyzed. This study provides an initial assessment of the enteric virome in the droppings of pigeons, a feral urban species with frequent human contact.

  19. GENDER, DEBT, AND DROPPING OUT OF COLLEGE.

    Science.gov (United States)

    Dwyer, Rachel E; Hodson, Randy; McLoud, Laura

    2013-02-01

    For many young Americans, access to credit has become critical to completing a college education and embarking on a successful career path. Young people increasingly face the trade-off of taking on debt to complete college or foregoing college and taking their chances in the labor market without a college degree. These trade-offs are gendered by differences in college preparation and support and by the different labor market opportunities women and men face that affect the value of a college degree and future difficulties they may face in repaying college debt. We examine these new realities by studying gender differences in the role of debt in the pivotal event of graduating from college using the 1997 cohort of the national longitudinal Survey of youth. In this article, we find that women and men both experience slowing and even diminishing probabilities of graduating when carrying high levels of debt, but that men drop out at lower levels of debt than do women. We conclude by theorizing that high levels of debt are one of the mechanisms that sort women and men into different positions in the social stratification system.

  20. That's one small drop for Mankind...

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    In August, the members of an ISOLDE project called LOI88 successfully employed a new technique to study the interaction of metal ions in a liquid. It’s the first time that specific ions have been studied in a liquid medium - a technical achievement that opens promising doors for biochemistry.   In the heart of the LOI88 experiment: this is the point where the metal ions (from the left) enter the drop.  “More than half of the proteins in the human body contain metal ions such as magnesium, zinc and copper,” explains Monika Stachura, a biophysicist at the University of Copenhagen and the LOI88 project leader. “We know that these elements are crucial to a protein’s structure and function but their behaviour and interactions are not known in detail.” Detecting these ions directly in  a body-like environment is problematic as their closed atomic shells make them invisible to most spectroscopic techniques. However, using ...

  1. Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production.

    Science.gov (United States)

    Pirone-Davies, Cary; Prior, Natalie; von Aderkas, Patrick; Smith, Derek; Hardie, Darryl; Friedman, William E; Mathews, Sarah

    2016-05-01

    Many gymnosperms produce an ovular secretion, the pollination drop, during reproduction. The drops serve as a landing site for pollen, but also contain a suite of ions and organic compounds, including proteins, that suggests diverse roles for the drop during pollination. Proteins in the drops of species of Chamaecyparis, Juniperus, Taxus, Pseudotsuga, Ephedra and Welwitschia are thought to function in the conversion of sugars, defence against pathogens, and pollen growth and development. To better understand gymnosperm pollination biology, the pollination drop proteomes of pollination drops from two species of Cephalotaxus have been characterized and an ovular transcriptome for C. sinensis has been assembled. Mass spectrometry was used to identify proteins in the pollination drops of Cephalotaxus sinensis and C. koreana RNA-sequencing (RNA-Seq) was employed to assemble a transcriptome and identify transcripts present in the ovules of C. sinensis at the time of pollination drop production. About 30 proteins were detected in the pollination drops of both species. Many of these have been detected in the drops of other gymnosperms and probably function in defence, polysaccharide metabolism and pollen tube growth. Other proteins appear to be unique to Cephalotaxus, and their putative functions include starch and callose degradation, among others. Together, the proteins appear either to have been secreted into the drop or to occur there due to breakdown of ovular cells during drop production. Ovular transcripts represent a wide range of gene ontology categories, and some may be involved in drop formation, ovule development and pollen-ovule interactions. The proteome of Cephalotaxus pollination drops shares a number of components with those of other conifers and gnetophytes, including proteins for defence such as chitinases and for carbohydrate modification such as β-galactosidase. Proteins likely to be of intracellular origin, however, form a larger component of drops

  2. Rod cluster control assemblies and rod cluster control guide tubes: wear and drop time

    International Nuclear Information System (INIS)

    Zbinden, M.

    1997-01-01

    The wear of RCCAs and of RCC guide tubes is due to two quite different mechanisms and the remedies to apply for each case might lead to contradictory solutions: - the impact/sliding wear for the seldom moving RCCAs, namely the shutdown RCCAs, under flow-induced vibrations, - the axial sliding wear for the control rods subjected to the stepping movements ordered by the acting load. In this case the hydraulic sticking forces are those which produce an evolution of the surface states that may increase the drop time. The introduction, an historical survey of the encountered difficulties, is followed by short description of the components and then the paper presents contributions of EDF in the R and D field, which take place in two successive multi-annual projects. Lastly, some information is given about the recent evolutions and new problems as well for impact/sliding wear as for drop time under normal or seismic conditions. (author)

  3. A Novel Method for Short Distance Measurements

    International Nuclear Information System (INIS)

    Fernandez, M.G.; Ferrando, A.; Josa, M.I.; Molinero, A.; Oller, J.C.; Arce, P.; Calvo, E.; Figueroa, C.F.; Garcia, C.F.; Rodigrido, T.; Vila, I.; Virto, A.L.

    1998-01-01

    A new, accurate and un expensive device for measuring short distances, intended for monitoring in LHC experiments is presented. Data taken with a very simple prototype are shown and performance is extracted. (Author) 4 refs

  4. Evaluation of Sodium Sulphacetamide drops in the Treatment of ...

    African Journals Online (AJOL)

    Sodium sulphacetamide eye drops had been used successfully in the past in the treatment of ophthalmia neonatorium (ON) but its use has decreased remarkably in recent time. The efficacy of 10 percent sodium sulphacetamide eye drops in the treatment of ON was prospectively evaluated in 68 neonates seen in our ...

  5. Summary of Skoda JS rod drop measurements analysis

    International Nuclear Information System (INIS)

    Svarny, J.; Krysl, V.

    1999-01-01

    A summary is presented of the Skoda JS rod drop reactivity measurements analysis provided during last two years based on control rod worth measurements by the outer ion chambers. Standard analysis based on comparisons of dynamics macrocode MOBY-DICK-SK and experimental data is extended to the 8-th group delayed neutron structure and new features of rod drop process are investigated. (author)

  6. Fabrication and Operation of Microfluidic Hanging-Drop Networks.

    Science.gov (United States)

    Misun, Patrick M; Birchler, Axel K; Lang, Moritz; Hierlemann, Andreas; Frey, Olivier

    2018-01-01

    The hanging-drop network (HDN) is a technology platform based on a completely open microfluidic network at the bottom of an inverted, surface-patterned substrate. The platform is predominantly used for the formation, culturing, and interaction of self-assembled spherical microtissues (spheroids) under precisely controlled flow conditions. Here, we describe design, fabrication, and operation of microfluidic hanging-drop networks.

  7. Why Did They Not Drop Out? Narratives from Resilient Students

    Science.gov (United States)

    Lessard, Anne; Fortin, Laurier; Marcotte, Diane; Potvin, Pierre; Royer, Egide

    2009-01-01

    There is much to be learned from students who were at-risk for dropping out of school but persevered and graduated. The purpose of the study on which this article is based, was to describe how students who were at-risk for dropping out of school persevered and graduated. The voices of two students are introduced, highlighting the challenges they…

  8. Pressure Drop of Chamfer on Spacer Grid Strap

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Euijae; Kim, Kanghoon; Kim, Kyounghong; Nahm, Keeyil [KEPCO Nuclear Fuel Co., Daejeon (Korea, Republic of)

    2014-05-15

    A swirl flow and cross flow are generated by the spacer grid with mixing vane that enhances the thermal performance and critical heat flux (CHF). The additional pressure drop makes it difficult to meet acceptance criteria for overall pressure drop in fuel assembly depending upon the pump capacity. The chamfer on the end of spacer grid strap is one solution to reduce additional pressure drop without any adverse effect on flow fields. In this research, the pressure drop tests for spacer grid with and without chamfer were carried out at the hydraulic test facility. The result can be applied to develop high performance nuclear fuel assemblies for Pressurized Water Reactor (PWR) plants. The pressure drop tests for 5x5 spacer grid with and without chamfer as well as 6x6 spacer grid with and without chamfer were carried out at the INFINIT test facility. The Reynolds number ranged about from 16000 to 75000. The sweep-up and sweep-down test showed that the direction of sweep did not affect the pressure drop. The chamfer on spacer grid strap reduced the pressure drop due to the decreased in ratio of inlet area to outlet area. The pressure loss coefficient for spacer grid with chamfer was by up to 13.8 % lower than that for spacer grid without chamfer. Hence, the chamfer on spacer grid strap was one of effective ways to reduce the pressure drop.

  9. Delayed frost growth on jumping-drop superhydrophobic surfaces.

    Science.gov (United States)

    Boreyko, Jonathan B; Collier, C Patrick

    2013-02-26

    Self-propelled jumping drops are continuously removed from a condensing superhydrophobic surface to enable a micrometric steady-state drop size. Here, we report that subcooled condensate on a chilled superhydrophobic surface are able to repeatedly jump off the surface before heterogeneous ice nucleation occurs. Frost still forms on the superhydrophobic surface due to ice nucleation at neighboring edge defects, which eventually spreads over the entire surface via an interdrop frost wave. The growth of this interdrop frost front is shown to be up to 3 times slower on the superhydrophobic surface compared to a control hydrophobic surface, due to the jumping-drop effect dynamically minimizing the average drop size and surface coverage of the condensate. A simple scaling model is developed to relate the success and speed of interdrop ice bridging to the drop size distribution. While other reports of condensation frosting on superhydrophobic surfaces have focused exclusively on liquid-solid ice nucleation for isolated drops, these findings reveal that the growth of frost is an interdrop phenomenon that is strongly coupled to the wettability and drop size distribution of the surface. A jumping-drop superhydrophobic condenser minimized frost formation relative to a conventional dropwise condenser in two respects: preventing heterogeneous ice nucleation by continuously removing subcooled condensate, and delaying frost growth by limiting the success of interdrop ice bridge formation.

  10. From nuclear reactions to liquid-drop collisions

    International Nuclear Information System (INIS)

    Menchaca R, A.; Huidobro, F.; Martinez D, A.; Michaelian, K.; Perez, A.; Rodriguez, V.; Carjan, N.

    1997-01-01

    A review of the experimental and theoretical situation in coalescence and fragmentation studies of binary liquid-drop collisions is given, putting in perspective our own contributions, which include experiments with mercury and oil drops and the application of a nuclear reaction model, specifically modified by us for the macroscopic case. (Author)

  11. The origin of star-shaped oscillations of Leidenfrost drops

    Science.gov (United States)

    Ma, Xiaolei; Burton, Justin C.

    We experimentally investigate the oscillations of Leidenfrost drops of water, liquid nitrogen, ethanol, methanol, acetone and isopropyl alcohol. The drops levitate on a cushion of evaporated vapor over a hot, curved surface which keeps the drops stationary. We observe star-shaped modes along the periphery of the drop, with mode numbers n = 2 to 13. The number of observed modes is sensitive to the properties of the liquid. The pressure oscillation frequency in the vapor layer under the drop is approximately twice that of the drop frequency, which is consistent with a parametric forcing mechanism. However, the Rayleigh and thermal Marangoni numbers are of order 10,000, indicating that convection should play a dominating role as well. Surprisingly, we find that the wavelength and frequency of the oscillations only depend on the thickness of the liquid, which is twice the capillary length, and do not depend on the mode number, substrate temperature, or the substrate curvature. This robust behavior suggests that the wavelength for the oscillations is set by thermal convection inside the drop, and is less dependent on the flow in the vapor layer under the drop

  12. Student Drop-Out from German Higher Education Institutions

    Science.gov (United States)

    Heublein, Ulrich

    2014-01-01

    28% of students of any one year currently give up their studies in bachelor degree programmes at German higher education institutions. Drop-out is to be understood as the definite termination in the higher education system without obtaining an academic degree. The drop-out rate is thereby calculated with the help of statistical estimation…

  13. Fundamentals and applications of fast micro-drop impact

    NARCIS (Netherlands)

    Visser, C.W.

    2014-01-01

    3D-printing, biofabrication, diesel engines, and spray cleaning all depend on controlled drop impact. However, surprisingly, these drops have received scarce attention so far. This is mainly due to their small size and high impact velocity, which makes visualizing the impact a challenge. This thesis

  14. Drop shape visualization and contact angle measurement on curved surfaces.

    Science.gov (United States)

    Guilizzoni, Manfredo

    2011-12-01

    The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Generic versus brand-name North American topical glaucoma drops.

    Science.gov (United States)

    Mammo, Zaid N; Flanagan, John G; James, David F; Trope, Graham E

    2012-02-01

    To determine whether brand-name glaucoma drops differ from generic equivalents in bottle design, viscosity, surface tension, and volume in North America. Experimental study. We studied 5 bottles each of 11 kinds of glaucoma drops. Density-based calculations of drop volume were assessed using 0.1 mg analytic balance. Viscosity was measured using rotational rheometery. Bottle tip diameter was measured using 0.05 mm Vernier calipers. Surface tension was measured using a Fisher Scientific (Ottawa, ON) tensiometer. For the American brand-name Timoptic XE, the average drop volume was 38 ± 3.1 μL versus 24 ± 1.5 μL of Timolol GFS (p brand-name Timoptic XE, the average drop volume was 42 ± 4.0 μL versus 25 ± 2 μL of timolol maleate EX (p brand-name Timoptic drop volume was 28 ± 1.4 μL versus 35 ± 1.9 μL Apo-Timop (p brand-name Timoptic delivered significantly smaller drop volumes than generic Apo-Timop. Careful consideration should be given to drop viscosity and bottle design when generic ophthalmic products are evaluated for interchangeability and market entry. Copyright © 2012 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  16. Complex cooling water systems optimization with pressure drop consideration

    CSIR Research Space (South Africa)

    Gololo, KV

    2012-12-01

    Full Text Available Pressure drop consideration has shown to be an essential requirement for the synthesis of a cooling water network where reuse/recycle philosophy is employed. This is due to an increased network pressure drop associated with additional reuse...

  17. Prophylactic Vancomycin Drops Reduce the Severity of Early Bacterial Keratitis in Keratoprosthesis

    Science.gov (United States)

    Konstantopoulos, Aris; Tan, Xiao Wei; Goh, Gwendoline Tze Wei; Saraswathi, Padmanabhan; Chen, Liyan; Nyein, Chan Lwin; Zhou, Lei; Beuerman, Roger; Tan, Donald Tiang Hwee; Mehta, Jod

    2015-01-01

    prophylactic drops. Conclusions Prophylactic vancomycin drops provided short-term benefit, but did not prevent infection. Achieving MIC in the cornea was not sufficient to prevent Staphylococcus aureus keratitis. Patients should continue to be counselled regarding the risk of infection following keratoprosthesis. PMID:26460791

  18. Prophylactic Vancomycin Drops Reduce the Severity of Early Bacterial Keratitis in Keratoprosthesis.

    Directory of Open Access Journals (Sweden)

    Aris Konstantopoulos

    .Prophylactic vancomycin drops provided short-term benefit, but did not prevent infection. Achieving MIC in the cornea was not sufficient to prevent Staphylococcus aureus keratitis. Patients should continue to be counselled regarding the risk of infection following keratoprosthesis.

  19. Variation of rain intensity and drop size distribution with General Weather Patterns (GWL)

    Science.gov (United States)

    Ghada, Wael; Buras, Allan; Lüpke, Marvin; Menzel, Annette

    2017-04-01

    Short-duration rainfall extremes may cause flash floods in certain catchments (e.g. cities or fast responding watersheds) and pose a great risk to affected communities. In order to predict their occurrence under future climate change scenarios, their link to atmospheric circulation patterns needs to be well understood. We used a comprehensive data set of meteorological data (temperature, rain gauge precipitation) and precipitation spectra measured by a disdrometer (OTT PARSIVEL) between October 2008 and June 2010 at Freising, southern Germany. For the 21 months of the study period, we integrated the disdrometer spectra over intervals of 10 minutes to correspond to the temporal resolution of the weather station data and discarded measurements with air temperatures below 0°C. Daily General Weather Patterns ("Großwetterlagen", GWL) were downloaded from the website of the German Meteorological Service. Out of the 29 GWL, 14 were included in the analysis for which we had at least 12 rain events during our study period. For the definition of a rain event, we tested different lengths of minimum inter-event times and chose 30 min as a good compromise between number and length of resulting events; rain events started when more than 0.001 mm/h (sensitivity of the disdrometer) were recorded. The length of the rain events ranged between 10 min and 28 h (median 130 min) with the maximum rain intensity recorded being 134 mm/h on 24-07-2009. Seasonal differences were identified for rain event average intensities and maximum intensities per event. The influence of GWL on rain properties such as rain intensity and drop size distribution per time step and per event was investigated based on the above mentioned rain event definition. Pairwise Wilcoxon-tests revealed that higher rain intensity and larger drops were associated with the GWL "Low over the British Isles" (TB), whereas low rain intensities and less drops per interval were associated with the GWL "High over Central Europe

  20. Incore monitoring device

    International Nuclear Information System (INIS)

    Tai, Ichiro; Shirayama, Shin-pei; Nozaki, Shin-ichi.

    1978-01-01

    Purpose: To provide an incore monitoring device wherein both radiation monitoring and acoustic monitoring are carried out simultaneously by one detector, whereby installation of the device and signal pick-up are facilitated. Incore conditions are accurately grasped. Constitution: When a neutron is irradiated in a state where a DC voltage is applied between the electrode and the vessel in the device, an ionization current is occured by (n.γ) reaction of the transformed substance as in an ionization chamber, Accordingly, a voltage drop occurs at both ends of the resistor of the radiation signal processing system, as a result of which a neutron flux can be detected. Further, when a sound is generated in the reactor, the monitoring device bottom wall which formed by a piezoelectric element detects the sound-waves. This output signal is picked up by the acoustic signal processing system to judge the generation of sound. (Aizawa, K.)

  1. Factors associated with non-participation and drop-out in a lifestyle intervention for workers with an elevated risk of cardiovascular disease

    Directory of Open Access Journals (Sweden)

    van der Beek Allard J

    2009-12-01

    Full Text Available Abstract Background Non-response and drop-out are problems that are commonly encountered in health promotion trials. Understanding the health-related characteristics of non-participants and drop-outs and the reasons for non-participation and drop-out may be beneficial for future intervention trials. Methods Male construction workers with an elevated risk of cardiovascular disease (CVD were invited to participate in a lifestyle intervention study. In order to investigate the associations between participation and CVD risk factors, and drop-out and CVD risk factors, crude and multiple logistic regression analyses were performed. The reasons for non-participation and drop-out were assessed qualitatively. Results 20% of the workers who were invited decided to participate; 8.6% of the participants dropped out before the first follow-up measurement. The main reasons for non-participation were 'no interest', 'current (para-medical treatment', and 'feeling healthy', and for drop-out they were 'lack of motivation', 'current (para-medical treatment', and 'disappointment'. Participants were 4.2 years older, had a higher blood pressure, higher total cholesterol, and lower HDL cholesterol than non-participants, and were more likely to report 'tiredness and/or stress' and 'chest pain and/or shortness of breath'. After adjusting for age, most risk factors were not significantly associated with participation. Drop-outs were 4.6 years younger than those who completed the study. The prevalence of smoking was higher among non-participants and drop-outs. Conclusion Participants had a worse CVD risk profile than non-participants, mainly because of the difference in age. Non-participants and drop-outs were younger and more likely to be smokers. The main reasons for non-participation and drop-out were health-related. Investigators in the field of health promotion should be encouraged to share comparable information. Trial registration Current Controlled Trials ISRCTN

  2. Drop tests of the Three Mile Island knockout canister

    International Nuclear Information System (INIS)

    Box, W.D.; Aaron, W.S.; Shappert, L.B.; Childress, P.C.; Quinn, G.J.; Smith, J.V.

    1987-01-01

    A type of Three Mile Island Unit 2 (TMI-2) defueling canister, called a ''knockout'' canister, was subjected to a series of drop tests at the Oak Ridge National Laboratory's Drop Test Facility. These tests confirmed the structural integrity of internal fixed neutron poisons in support of a request for NRC licensing of this type of canister for the shipment of TMI-2 reactor fuel debris to the Idaho National Engineering Laboratory (INEL) for the Core Examination R and D Program. This report presents the data generated and the results obtained from a series of four drop tests that included two drops with the test assembly in the vertical position and two drops with the assembly in the horizontal position

  3. Building micro-soccer-balls with evaporating colloidal fakir drops

    Science.gov (United States)

    Gelderblom, Hanneke; Marín, Álvaro G.; Susarrey-Arce, Arturo; van Housselt, Arie; Lefferts, Leon; Gardeniers, Han; Lohse, Detlef; Snoeijer, Jacco H.

    2013-11-01

    Drop evaporation can be used to self-assemble particles into three-dimensional microstructures on a scale where direct manipulation is impossible. We present a unique method to create highly-ordered colloidal microstructures in which we can control the amount of particles and their packing fraction. To this end, we evaporate colloidal dispersion drops from a special type of superhydrophobic microstructured surface, on which the drop remains in Cassie-Baxter state during the entire evaporative process. The remainders of the drop consist of a massive spherical cluster of the microspheres, with diameters ranging from a few tens up to several hundreds of microns. We present scaling arguments to show how the final particle packing fraction of these balls depends on the drop evaporation dynamics, particle size, and number of particles in the system.

  4. Culturing muscle fibres in hanging drop: a novel approach to solve an old problem.

    Science.gov (United States)

    Archacka, Karolina; Pozzobon, Michela; Repele, Andrea; Rossi, Carlo Alberto; Campanella, Michelangelo; De Coppi, Paolo

    2014-02-01

    The satellite cells (SCs) associated with muscle fibres play a key role in postnatal growth and regeneration of skeletal muscle. Commonly used methods of isolation and in vitro culture of SCs lead to the mixture of their subpopulations that exist within muscle. To solve this problem, we used the well established technique, the hanging drop system, to culture SCs in a three-dimensional environment and thus, to monitor them in their original niche. Using hanging drop technique, we were able to culture SCs associated with the fibre at least for 9 days with one transfer of fibres to the fresh drops. In comparison, in the classical method of myofibres culture, that is, on the dishes coated with Matrigel, SCs leave the fibres within 3 days after the isolation. Cells cultured in both systems differed in expression of Pax7 and MyoD. While almost all cells cultured in adhesion system expressed MyoD before the fifth day of the culture, the majority of SCs cultured in hanging drop still maintained expression of Pax7 and were not characterised by the presence of MyoD. Among the cells cultured with single myofibre for up to 9 days, we identified two different subclones of SCs: low proliferative clone and high proliferative clone, which differed in proliferation rate and membrane potential. The hanging drop enables the myofibres to be kept in suspension for at least 9 days, and thus, allows SCs and their niche to interact each other for prolonged time. In a consequence, SCs cultured in hanging drop maintain expression of Pax7 while those cultured in a traditional adhesion culture, that is, devoid of signals from the original niche, activate and preferentially undergo differentiation as manifested by expression of MyoD. Thus, the innovative method of SCs culturing in the hanging drop system may serve as a useful tool to study the fate of different subpopulations of these cells in their anatomical location and to determine reciprocal interactions between them and their niche.

  5. Temperature Effect on Power Drop of Different Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Emad Talib Hahsim

    2016-05-01

    Full Text Available Solar module operating temperature is the second major factor affects the performance of solar photovoltaic panels after the amount of solar radiation. This paper presents a performance comparison of mono-crystalline Silicon (mc-Si, poly-crystalline Silicon (pc-Si, amorphous Silicon (a-Si and Cupper Indium Gallium di-selenide (CIGS photovoltaic technologies under Climate Conditions of Baghdad city. Temperature influence on the solar modules electric output parameters was investigated experimentally and their temperature coefficients was calculated. These temperature coefficients are important for all systems design and sizing. The experimental results revealed that the pc-Si module showed a decrease in open circuit voltage by -0.0912V/ºC while mc-Si and a-Si had nearly -0.07V/ºC and the CIGS has -0.0123V/ºC. The results showed a slightly increase in short circuit current with temperature increasing about 0.3mA/ºC ,4.4mA/ºC and 0.9mA/ºC for mc-Si , pc-Si and both a-Si and CIGS. The mc-Si had the largest drop in output power about -0.1353W/ºC while -0.0915, -0.0114 and -0.0276 W/ºC for pc-Si, a-Si and CIGS respectively. The amorphous silicon is the more suitable module for high operation temperature but it has the lowest conversion efficiency between the tested modules.

  6. Electrowetting-on-dielectrics for manipulation of oil drops and gas bubbles in aqueous-shell compound drops.

    Science.gov (United States)

    Li, Jiang; Wang, Yixuan; Chen, Haosheng; Wan, Jiandi

    2014-11-21

    We present the manipulation of oil, organic and gaseous chemicals by electrowetting-on-dielectric (EWOD) technology using aqueous-shell compound drops. We demonstrate that the transport and coalescence of viscous oil drops, the reaction of bromine with styrene in benzene solution, and the reaction of red blood cells with carbon monoxide bubbles can be accomplished using this method.

  7. Rhizosphere dynamics of two riparian plant species from the water fluctuation zone of Three Gorges Reservoir, P.R. China - pH, oxygen and LMWOA monitoring during short flooding events

    Science.gov (United States)

    Schreiber, Christina M.; Schurr, Ulrich; Zeng, Bo; Höltkemeier, Agnes; Kuhn, Arnd J.

    2010-05-01

    Since the construction of the Three Gorges Dam at the Yangtze River in China, the reservoir management created a new 30m water fluctuation zone 45-75m above the original water level. Only species well adapted to long-time flooding (up to several months) will be able to vegetate the river banks and replace the original vegetation. To investigate how common species of the riverbanks cope with submergence, Alternanthera philoxeroides Mart. and Arundinella anomala Steud., two flooding resistant riparian species, have been examined in a rhizotron environment. Short-time (2 days waterlogging, 2 days flooding, 2 days recovery) flooding cycles in the original substrate and long time (14 days waterlogging, flooding, recovery) flooding cycles, in original substrate and sterile glass bead substrate, have been simulated in floodable two-way access rhizotrons. Oxygen- and pH-sensitive foils (planar optodes, PreSens) automatically monitored root reaction in a confined space (2cm2 each) on the backside of the rhizotron, while soil solution samples were taken 2 times a day from the other side of the rhizotron at the corresponding area through filter and steel capillaries. The samples were analyzed by capillary electrophoresis for low molecular weight organic acids (LMWOA, i.e. oxalic, formic, succinic, malic, acetic, glyoxylic, lactic and citric acid). Results show diurnal rhythms of rhizospheric acidification for both species in high resolution, combined with oxygen entry into the root surrounding during waterlogged state. Flooding caused stronger acidification in the rhizosphere, that were however not accompanied by increased occurrence of LMWOA except for acetic and glyoxylic acid. First results from longer flooding periods show stable diurnal rhythms during waterlogging, but no strongly increased activity during the flooding event. Performance of the two species is not hampered by being waterlogged, and they follow a silencing strategy during a longer phase of anoxia without

  8. Effect of humidity on the filter pressure drop

    International Nuclear Information System (INIS)

    Vendel, J.; Letourneau, P.

    1995-01-01

    The effects of humidity on the filter pressure drop have been reported in some previous studies in which it is difficult to draw definite conclusions. These studies show contradictory effects of humidity on the pressure drop probably due to differences in the hygroscopicity of the test aerosols. The objective of this paper is to present experimental results on the evolution of the filter pressure drop versus mass loading, for different test aerosols and relative humidities. Present results are compared to those found in various publication. An experimental device has been designed to measure filter pressure drop as the function of the areal density for relative humidity varying in the range of 9 % to 85 %. Experiments have been conducted with hygroscopic: (CsOH) and nonhygroscopic aerosols (TiO 2 ). Cesium hydroxyde (CsOH) of size of 2 μ M AMMD has been generated by an ultrasonic generator and the 0.7 μm AMMD titanium oxyde has been dispersed by a open-quotes turn-tableclose quotes generator. As it is noted in the BISWAS'publication [3], present results show, in the case of nonhygroscopic aerosols, a linear relationship of pressure drop to mass loading. For hygroscopic aerosols two cases must be considered: for relative humidity below the deliquescent point of the aerosol, the relationship of pressure drop to mass loading remains linear; above the deliquescent point, the results show a sudden increase in the pressure drop and the mass capacity of the filter is drastically reduced

  9. Electric generation and ratcheted transport of contact-charged drops

    Science.gov (United States)

    Cartier, Charles A.; Graybill, Jason R.; Bishop, Kyle J. M.

    2017-10-01

    We describe a simple microfluidic system that enables the steady generation and efficient transport of aqueous drops using only a constant voltage input. Drop generation is achieved through an electrohydrodynamic dripping mechanism by which conductive drops grow and detach from a grounded nozzle in response to an electric field. The now-charged drops are transported down a ratcheted channel by contact charge electrophoresis powered by the same voltage input used for drop generation. We investigate how the drop size, generation frequency, and transport velocity depend on system parameters such as the liquid viscosity, interfacial tension, applied voltage, and channel dimensions. The observed trends are well explained by a series of scaling analyses that provide insight into the dominant physical mechanisms underlying drop generation and ratcheted transport. We identify the conditions necessary for achieving reliable operation and discuss the various modes of failure that can arise when these conditions are violated. Our results demonstrate that simple electric inputs can power increasingly complex droplet operations with potential opportunities for inexpensive and portable microfluidic systems.

  10. Measurement of an Evaporating Drop on a Reflective Substrate

    Science.gov (United States)

    Chao, David F.; Zhang, Nengli

    2004-01-01

    A figure depicts an apparatus that simultaneously records magnified ordinary top-view video images and laser shadowgraph video images of a sessile drop on a flat, horizontal substrate that can be opaque or translucent and is at least partially specularly reflective. The diameter, contact angle, and rate of evaporation of the drop as functions of time can be calculated from the apparent diameters of the drop in sequences of the images acquired at known time intervals, and the shadowgrams that contain flow patterns indicative of thermocapillary convection (if any) within the drop. These time-dependent parameters and flow patterns are important for understanding the physical processes involved in the spreading and evaporation of drops. The apparatus includes a source of white light and a laser (both omitted from the figure), which are used to form the ordinary image and the shadowgram, respectively. Charge-coupled-device (CCD) camera 1 (with zoom) acquires the ordinary video images, while CCD camera 2 acquires the shadowgrams. With respect to the portion of laser light specularly reflected from the substrate, the drop acts as a plano-convex lens, focusing the laser beam to a shadowgram on the projection screen in front of CCD camera 2. The equations for calculating the diameter, contact angle, and rate of evaporation of the drop are readily derived on the basis of Snell s law of refraction and the geometry of the optics.

  11. Inverse Leidenfrost effect: self-propelling drops on a bath

    Science.gov (United States)

    Gauthier, Anais; van der Meer, Devaraj; Lohse, Detlef; Physics of Fluids Team

    2017-11-01

    When deposited on very hot solid, volatile drops can levitate over a cushion of vapor, in the so-called Leidenfrost state. This phenomenon can also be observed on a hot bath and similarly to the solid case, drops are very mobile due to the absence of contact with the substrate that sustains them. We discuss here a situation of ``inverse Leidenfrost effect'' where room-temperature drops levitate on a liquid nitrogen pool - the vapor is generated here by the bath sustaining the relatively hot drop. We show that the drop's movement is not random: the liquid goes across the bath in straight lines, a pattern only disrupted by elastic bouncing on the edges. In addition, the drops are initially self-propelled; first at rest, they accelerate for a few seconds and reach velocities of the order of a few cm/s, before slowing down. We investigate experimentally the parameters that affect their successive acceleration and deceleration, such as the size and nature of the drops and we discuss the origin of this pattern.

  12. Effect of humidity on the filter pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Vendel, J.; Letourneau, P. [Institut de Protection et de Surete Nucleaire, Gif-sur-Yvette (France)

    1995-02-01

    The effects of humidity on the filter pressure drop have been reported in some previous studies in which it is difficult to draw definite conclusions. These studies show contradictory effects of humidity on the pressure drop probably due to differences in the hygroscopicity of the test aerosols. The objective of this paper is to present experimental results on the evolution of the filter pressure drop versus mass loading, for different test aerosols and relative humidities. Present results are compared to those found in various publication. An experimental device has been designed to measure filter pressure drop as the function of the areal density for relative humidity varying in the range of 9 % to 85 %. Experiments have been conducted with hygroscopic: (CsOH) and nonhygroscopic aerosols (TiO{sub 2}). Cesium hydroxyde (CsOH) of size of 2 {mu} M AMMD has been generated by an ultrasonic generator and the 0.7 {mu}m AMMD titanium oxyde has been dispersed by a {open_quotes}turn-table{close_quotes} generator. As it is noted in the BISWAS`publication [3], present results show, in the case of nonhygroscopic aerosols, a linear relationship of pressure drop to mass loading. For hygroscopic aerosols two cases must be considered: for relative humidity below the deliquescent point of the aerosol, the relationship of pressure drop to mass loading remains linear; above the deliquescent point, the results show a sudden increase in the pressure drop and the mass capacity of the filter is drastically reduced.

  13. Application of Proteomics to the Study of Pollination Drops

    Directory of Open Access Journals (Sweden)

    Natalie Prior

    2013-04-01

    Full Text Available Premise of the study: Pollination drops are a formative component in gymnosperm pollen-ovule interactions. Proteomics offers a direct method for the discovery of proteins associated with this early stage of sexual reproduction. Methods: Pollination drops were sampled from eight gymnosperm species: Chamaecyparis lawsoniana (Port Orford cedar, Ephedra monosperma, Ginkgo biloba, Juniperus oxycedrus (prickly juniper, Larix ×marschlinsii, Pseudotsuga menziesii (Douglas-fir, Taxus ×media, and Welwitschia mirabilis. Drops were collected by micropipette using techniques focused on preventing sample contamination. Drop proteins were separated using both gel and gel-free methods. Tandem mass spectrometric methods were used including a triple quadrupole and an Orbitrap. Results: Proteins are present in all pollination drops. Consistency in the protein complement over time was shown in L. ×marschlinsii. Representative mass spectra from W. mirabilis chitinase peptide and E. monosperma serine carboxypeptidase peptide demonstrated high quality results. We provide a summary of gymnosperm pollination drop proteins that have been discovered to date via proteomics. Discussion: Using proteomic methods, a dozen classes of proteins have been identified to date. Proteomics presents a way forward in deepening our understanding of the biological function of pollination drops.

  14. Effects of wind on the dynamics of the central jet during drop impact onto a deep-water surface

    Science.gov (United States)

    Liu, Xinan; Wang, An; Wang, Shuang; Dai, Dejun

    2018-05-01

    The cavity and central jet generated by the impact of a single water drop on a deep-water surface in a wind field are experimentally studied. Different experiments are performed by varying the impacting drop diameter and wind speed. The contour profile histories of the cavity (also called crater) and central jet (also called stalk) are measured in detail with a backlit cinematic shadowgraph technique. The results show that shortly after the drop hits the water surface an asymmetrical cavity appears along the wind direction, with a train of capillary waves on the cavity wall. This is followed by the formation of an inclined central jet at the location of the drop impact. It is found that the wind has little effect on the penetration depth of the cavity at the early stage of the cavity expansion, but markedly changes the capillary waves during the retraction of the cavity. The capillary waves in turn shift the position of the central jet formation leeward. The dynamics of the central jet are dominated by two mechanisms: (i) the oblique drop impact produced by the wind and (ii) the wind drag force directly acting on the jet. The maximum height of the central jet, called the stalk height, is drastically affected by the wind, and the nondimensional stalk height H /D decreases with increasing θ Re-1 , where D is the drop diameter, θ is the impingement angle of drop impact, and Re=ρaUwD /μa is the Reynolds number with air density ρa, wind speed Uw, and air viscosity μa.

  15. Preparation of magnesium hydroxide nanoflowers from boron mud via anti-drop precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xi [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China); Ma, Hongwen, E-mail: mahw@cugb.edu.cn [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Xiaoqian [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Zhouqing [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China)

    2014-08-15

    Highlights: • We use the anti-drop precipitation method for synthesis of magnesium hydroxide. • Boron mud which is solid waste from a borax factory is used as the magnesium source. • The magnesium hydroxide nanoflowers are prepared in a short time. • The as-prepared magnesium hydroxide can be used as an effective flame retardant. - Abstract: Using boron mud as the starting material, the flower-like magnesium hydroxide (MH) has been successfully prepared via anti-drop precipitation method. The effect of NH{sub 3}·H{sub 2}O concentration, aging time, and surfactant on the morphology of MH was investigated. The optimum precipitation conditions are dropping MgSO{sub 4} solution in 5% NH{sub 3}·H{sub 2}O solution, with 3% polyethylene glycol as surfactant, aging for 30 min. XRD, SEM, FI-IR, and TG/DTA have been employed to characterize the as-prepared samples. XRD reveals that MH with high purity has the brucite structure. SEM images show that the flower-like MH exists in the form of mono-disperse well uniform spherical aggregation with diameter of 3–5 μm. TG/DTA shows a total percentage of weight loss 33.6% with a well-defined endothermic peak near 381.3 °C corresponding to the decomposition of MH. Furthermore, it reports that the extremely fast primary nucleation is of significance for crystal growth of MH.

  16. An analysis of pipe degradation shape using potential drop method

    International Nuclear Information System (INIS)

    Jegal, S.; Lee, S. H.

    1999-01-01

    The Potential Drop (PD) method, one of NDE (Non-Destructive Evaluation) method is used to analyze the thickness distribution of pipes degraded by FAC (Flow Accelerated Corrosion). A DCPD (Direct Current Potential Drop) system which can measure PD for direct current was made, and the specimens with line defects and cylinder type defects have been used for experiments to prove the theory of Potential Drop method and to find out the effects of each factors. The experiment to find out defect distributions has been performed and it is found that PD method can analyze almost correct position of defects

  17. Ready-made allogeneic ABO-specific serum eye drops

    DEFF Research Database (Denmark)

    Harritshøj, Lene Holm; Nielsen, Connie; Ullum, Henrik

    2014-01-01

    serum treatment. CONCLUSION: Ready-made ABO-identical allogeneic serum eye drops were straightforwardly produced, quality-assured and registered as a safe standard blood product for the treatment of certain cases of severe dry eye disease. Therapeutic efficacy was comparable to previous reports......PURPOSE: To overcome problems and delays of the preparation of autologous serum eye drops, a production line of ABO-specific allogeneic serum eye drops from male blood donors was set up in a blood bank. Feasibility, clinical routine, safety and efficacy were evaluated in a cohort of patients...

  18. Controlling Vapor Pressure In Hanging-Drop Crystallization

    Science.gov (United States)

    Carter, Daniel C.; Smith, Robbie

    1988-01-01

    Rate of evaporation adjusted to produce larger crystals. Device helps to control vapor pressure of water and other solvents in vicinity of hanging drop of solution containing dissolved enzyme protein. Well of porous frit (sintered glass) holds solution in proximity to drop of solution containing protein or enzyme. Vapor from solution in frit controls evaporation of solvent from drop to control precipitation of protein or enzyme. With device, rate of nucleation limited to decrease number and increase size (and perhaps quality) of crystals - large crystals of higher quality needed for x-ray diffraction studies of macromolecules.

  19. Analysis of an Electrostatic MEMS Squeeze-film Drop Ejector

    Directory of Open Access Journals (Sweden)

    Edward P. Furlani

    2009-10-01

    Full Text Available We present an analysis of an electrostatic drop-on-demand MEMS fluid ejector. The ejector consists of a microfluidic chamber with a piston that is suspended a few microns beneath a nozzle plate. A drop is ejected when a voltage is applied between the orifice plate and the piston. This produces an electrostatic force that moves the piston towards the nozzle. The moving piston generates a squeeze-film pressure distribution that causes drop ejection. We discuss the operating physics of the ejector and present a lumped-element model for predicting its performance. We calibrate the model using coupled structural-fluidic CFD analysis.

  20. Internal flow of acoustically levitated drops undergoing sectorial oscillations

    International Nuclear Information System (INIS)

    Shen, C.L.; Xie, W.J.; Yan, Z.L.; Wei, B.

    2010-01-01

    We present the experimental observation and theoretical analysis of fluid flow in acoustically levitated water drop undergoing sectorial oscillations. The fluid always flows between the extended sections and the compressed sections. The magnitude of fluid velocity decreases from the equatorial fringe to the centre of levitated drop. The maximum fluid velocity is 60-160 mm/s and the Reynolds number of the oscillations is estimated to be 137-367. The internal flow of the drop is analyzed as potential flow, and the fluid velocity is found to be horizontal. In the equatorial plane, the calculated stream lines and velocity profiles agree well with the experimental observations.

  1. Ultrasonic defect sizing using decibel drop methods. III

    International Nuclear Information System (INIS)

    Mills, C.; Goszczynski, J.; Mitchell, A.B.

    1988-03-01

    An earlier study on the use of ultrasonic decibel drop sizing methods for determining the length and vertical extent of flaws in welded steel sections was based on the scanning of machined flaws and fabrication flaws. The present study utilized the techniques developed to perform a similar study of the type of flaws expected to develop during service (e.g. fatigue cracks). The general findings are that: a) the use of decibel drops of less than 14 dB generally undersize the length of fatigue cracks; and b) the use of decibel drop methods to determine vertical extent is questionable

  2. Association between portal vein pressure drop gradient after transjugular intrahepatic portosystemic shunt and clinical prognosis

    Directory of Open Access Journals (Sweden)

    XU Zhengguo

    2016-12-01

    Full Text Available ObjectiveTo investigate the association between portal vein pressure drop gradient in patients with cirrhotic portal hypertension treated by transjugular intrahepatic portosystemic shunt (TIPS and clinical prognosis, as well as the ideal range of portal vein pressure drop. MethodsA total of 58 patients who underwent TIPS in Xinqiao Hospital of Third Military Medical University from November 2013 to December 2015 were enrolled. All the patients underwent TIPS and embolization of the gastric coronary vein and the short gastric veins, and the change intervals of portal vein pressure gradient were monitored. The follow-up time ranged from 3 days to 2 years, and the association of portal vein pressure drop gradient with postoperative liver function, splenic function, rebleeding rate, hepatic encephalopathy, and portal hypertensive gastrointestinal diseases was analyzed. The paired t-test was used for comparison of parameters before and after treatment. ResultsThe patients had a significant reduction in liver function on day 3 after surgery. At 2 month after surgery, the levels of TBil was rised and had significant changes[(49.81±27.82μmol/L vs (31.64±17.67 μmol/L,t=5.372,P<0.001]. At 6 months after surgery, red blood cell count and platelet count had no significant changes,but,white blood cell count was reduced[(3.79±1.37)×109/L vs (4.57±2.24×109/L,t=2.835,P=0.006]. There was a 23% reduction in portal vein pressure after surgery (from 30.62±3.56 mmHg before surgery to 21.21±2.90 mmHg after surgery, t=23.318,P<0.001. All the patients had varying degrees of relief of gastrointestinal symptoms associated with portal vein hypertension, such as abdominal distension, poor appetite, and diarrhea. Of all patients, none experienced in-stent restenosis or occlusion and 13 experienced hepatic encephalopathy after surgery, which tended to occur at the time when postoperative portal vein pressure was reduced to 14.7-25.7 mmHg, i

  3. To monitor or not to monitor?: editorial

    International Nuclear Information System (INIS)

    Johns, T.F.

    1988-01-01

    After a brief discussion about results for occupational exposure in New Zealand and the UK, a short editorial raises a number of questions about personal dosimetry practice. These questions include whether the right people are being monitored and whether less attention should be paid to the monitoring of certain groups of workers who are occupationally exposed to external beta/gamma radiation, and more to the monitoring of workers or members of the general public who are exposed to higher doses from radon daughters, so as to focus attention on the areas where the largest savings in collective dose could be achieved. (U.K.)

  4. Non-isothermal spreading of liquid drops on horizontal plates

    International Nuclear Information System (INIS)

    Ehrhard, P.; Davis, S.H.

    1990-05-01

    A viscous-liquid drop spreads on a smooth horizontal surface, which is uniformly heated or cooled. Lubrication theory is used to study thin drops subject to capillary, thermocapillary and gravity forces, and a variety of contact-angle-versus-speed conditions. It is found for isothermal drops that gravity is very important at large times and determines the power law for unlimited spreading. Predictions compare well with the experimental data on isothermal spreading for both two-dimensional and axisymmetric configurations. It is found that heating (cooling) retards (augments) the spreading process. When the advancing contact angle is zero, heating will cause the drop to spread only finitely far. For positive advancing contact angles, sufficient cooling will cause unlimited spreading. Thus, the heat transfer serves as a sentitive control on the spreading. (orig.) [de

  5. Satellite Formation during Coalescence of Unequal Size Drops

    KAUST Repository

    Zhang, F. H.

    2009-03-12

    The coalescence of a drop with a flat liquid surface pinches off a satellite from its top, in the well-known coalescence cascade, whereas the coalescence of two equally sized drops does not appear to leave such a satellite. Herein we perform experiments to identify the critical diameter ratio of two drops, above which a satellite is produced during their coalescence. We find that the critical parent ratio is as small as 1.55, but grows monotonically with the Ohnesorge number. The daughter size is typically about 50% of the mother drop. However, we have identified novel pinch-off dynamics close to the critical size ratio, where the satellite does not fully separate, but rather goes directly into a second stage of the coalescence cascade, thus generating a much smaller satellite droplet.

  6. Modeling merging behavior at lane drops : [tech transfer summary].

    Science.gov (United States)

    2015-02-01

    A better understanding of the merging behavior of drivers will lead : to the development of better lane-drop traffic-control plans and : strategies, which will provide better guidance to drivers for safer : merging.

  7. Determination of the viscosity by spherical drop using nuclear tecniques

    International Nuclear Information System (INIS)

    Silva, F.V. da; Qassim, R.Y.; Souza, Roberto de; Rio de Janeiro Univ.

    1983-01-01

    The measurements of the drop limit velocity of a Sphere in a fluid using a radiotracer method are analyzed. The dynamic process involved was observed, identifying the density and viscosity of the fluid. (E.G.) [pt

  8. Drop performance test and evaluation for HANARO shutoff units

    International Nuclear Information System (INIS)

    Jung, Y. H.; Cho, Y. K.; Lee, J. H.; Choi, Y. S.; Woo, J. S.

    2004-01-01

    The function of the shutoff units of the HANARO is to rapidly insert the shutoff rod into the reactor core for safe shutdown of reactor. This paper describes drop performance test and evaluation for a shutoff unit for the technical verification of lifetime extension and localization of the HANARO shutoff units. We have performed preliminary drop performance tests for a shutoff unit at 1/2-core test loop and analyzed through the comparison with the test results performed during design verification test and the results of the periodic performance test in HANARO. It shows that the results of the local fabrication, installation and alignment for the shutoff unit meet the basic performance requirements, Furthermore, the performance evaluation method of the periodic drop test of the HANARO shutoff units is a conservative method comparing with the real drop time

  9. The effect of dropping impact on bruising pomegranate fruit

    Directory of Open Access Journals (Sweden)

    M Mohammad Shafie

    2016-04-01

    Full Text Available Introduction: The pomegranate journey from orchard to supermarket is very complex and pomegranates are subjected to the variety of static and dynamic loads that could result in this damage and bruise occurring. Bruise area and bruise volume are the most important parameters to evaluate fruit damage occurred in harvest and postharvest stages. The bruising is defined as damage to fruit flesh usually with no abrasion of the peel. The two different types of dynamic loading which can physically cause fruit bruising are impact and vibration. The impact and vibration loadings may occur during picking or sorting as the pomegranates are dropped into storage bins and during transportation. The focus of this work was on the impact loading as this appeared to be the most prevalent. In view of the limitations of conventional testing methods (ASTM D3332 Standard Test Methods for Mechanical Shock Fragility of Products, the method and procedure for determining dropping bruise boundary of fruit were also established by adapting free-fall dropping tests. Materials and Methods: After the ‘Malas-e-Saveh’ pomegranates had been selected, they were numbered, and the weight and dimension of each sample were measured and recorded. Firmness in cheek region of each fruit was also measured. Fruit firmness was determined by measuring the maximum force during perforating the sample to a depth of 10 mm at a velocity of 100 mm min-1 with an 8 mm diameter cylindrical penetrometer mounted onto a STM-5 Universal Testing Machine (SANTAM, Design CO. LTD., England. Free-fall dropping tests with a series of drop heights (6, 7, 10, 15, 30 and 60 cm were conducted on fresh ‘Malas-e-Saveh’ pomegranates. Three samples were used for each dropping height, and each sample was subjected to impact on two different positions. Before the test was started, it was necessary to control the sample's drop position. The cheek of sample was placed on the fruit holder. An aluminum plate mounted

  10. Self-excited hydrothermal waves in evaporating sessile drops

    Science.gov (United States)

    Sefiane, K.; Moffat, J. R.; Matar, O. K.; Craster, R. V.

    2008-08-01

    Pattern formation driven by the spontaneous evaporation of sessile drops of methanol, ethanol, and FC-72 using infrared thermography is observed and, in certain cases, interpreted in terms of hydrothermal waves. Both methanol and ethanol drops exhibit thermal wave trains, whose wave number depends strongly on the liquid volatililty and substrate thermal conductivity. The FC-72 drops develop cellular structures whose size is proportional to the local thickness. Prior to this work, hydrothermal waves have been observed in the absence of evaporation in shallow liquid layers subjected to an imposed temperature gradient. In contrast, here both the temperature gradients and the drop thickness vary spatially and temporally and are a natural consequence of the evaporation process.

  11. Electrostatic charging and levitation of helium II drops

    International Nuclear Information System (INIS)

    Niemela, J.J.

    1997-01-01

    Liquid Helium II drops, of diameter 1 mm or less, are charged with positive helium ions and subsequently levitated by static electric fields. Stable levitation was achieved for drops of order 100-150 micrometers in diameter. The suspended drops could be translated to arbitrary positions within the levitator using additional superimposed DC electric fields, and also could be made to oscillate stably about their average positions by means of an applied time-varying electric field. A weak corona discharge was used to produce the necessary ions for levitation. A novel superfluid film flow device, developed for the controlled deployment of large charged drops, is described. Also discussed is an adjustable electric fountain that requires only a field emission tip operating at modest potentials, and works in both Helium I and Helium II

  12. Origin and dynamics of vortex rings in drop splashing.

    Science.gov (United States)

    Lee, Ji San; Park, Su Ji; Lee, Jun Ho; Weon, Byung Mook; Fezzaa, Kamel; Je, Jung Ho

    2015-09-04

    A vortex is a flow phenomenon that is very commonly observed in nature. More than a century, a vortex ring that forms during drop splashing has caught the attention of many scientists due to its importance in understanding fluid mixing and mass transport processes. However, the origin of the vortices and their dynamics remain unclear, mostly due to the lack of appropriate visualization methods. Here, with ultrafast X-ray phase-contrast imaging, we show that the formation of vortex rings originates from the energy transfer by capillary waves generated at the moment of the drop impact. Interestingly, we find a row of vortex rings along the drop wall, as demonstrated by a phase diagram established here, with different power-law dependencies of the angular velocities on the Reynolds number. These results provide important insight that allows understanding and modelling any type of vortex rings in nature, beyond just vortex rings during drop splashing.

  13. Sludge pipe flow pressure drop prediction using composite power ...

    African Journals Online (AJOL)

    Sludge pipe flow pressure drop prediction using composite power-law friction ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue ... When predicting pressure gradients for the flow of sludges in pipes, the ...

  14. Dropped fuel damage prediction techniques and the DROPFU code

    International Nuclear Information System (INIS)

    Mottershead, K.J.; Beardsmore, D.W.; Money, G.

    1995-01-01

    During refuelling, and fuel handling, at UK Advanced Gas Cooled Reactor (AGR) stations it is recognised that the accidental dropping of fuel is a possibility. This can result in dropping individual fuel elements, a complete fuel stringer, or a whole assembly. The techniques for assessing potential damage have been developed over a number of years. This paper describes how damage prediction techniques have subsequently evolved to meet changing needs. These have been due to later fuel designs and the need to consider drops in facilities outside the reactor. The paper begins by briefly describing AGR fuel and possible dropped fuel scenarios. This is followed by a brief summary of the damage mechanisms and the assessment procedure as it was first developed. The paper then describes the additional test work carried out, followed by the detailed numerical modelling. Finally, the paper describes the extensions to the practical assessment methods. (author)

  15. Bird nesting and droppings control on highway structures.

    Science.gov (United States)

    2010-10-01

    This report provides a comprehensive literature survey of permanent and temporary deterrents to nesting and roosting, a : discussion of risks to human health and safety from exposure to bird nests and droppings and recommended protective measures, : ...

  16. Magnetohydrodynamic pressure drop in a quickly changing magnetic field

    International Nuclear Information System (INIS)

    Xu, Z.Y.; Chen, J.M.; Qian, J.P.; Jiang, W.H.; Pan, C.J.; Li, W.Z.

    1995-01-01

    The magnetohydrodynamic (MHD) pressure drop of 22 Na 78 K flow in a circular duct was measured under a quickly changing magnetic field. The MHD pressure drop reduced with time as the magnetic field strength decreased. However, the dimensionless pressure drop gradient varied with the interaction parameter and had a higher value in the middle of the range of values of the interaction parameter. Therefore, a quickly changing magnetic field is harmful to the structural material in a liquid metal self-cooled blanket of a fusion reactor, since the greater pressure drop gradient may cause a larger stress in the blanket. This is even more harmful if the magnetic field strength decreases very quickly or its distribution in space is greatly non-uniform. (orig.)

  17. Satellite Formation during Coalescence of Unequal Size Drops

    KAUST Repository

    Zhang, F. H.; Li, E. Q.; Thoroddsen, Sigurdur T

    2009-01-01

    The coalescence of a drop with a flat liquid surface pinches off a satellite from its top, in the well-known coalescence cascade, whereas the coalescence of two equally sized drops does not appear to leave such a satellite. Herein we perform experiments to identify the critical diameter ratio of two drops, above which a satellite is produced during their coalescence. We find that the critical parent ratio is as small as 1.55, but grows monotonically with the Ohnesorge number. The daughter size is typically about 50% of the mother drop. However, we have identified novel pinch-off dynamics close to the critical size ratio, where the satellite does not fully separate, but rather goes directly into a second stage of the coalescence cascade, thus generating a much smaller satellite droplet.

  18. Rotavirus and the Vaccine (Drops) to Prevent It

    Science.gov (United States)

    ... Resources Maternal Immunization Resources Related Links Vaccines & Immunizations Rotavirus and the Vaccine (Drops) to Prevent It Language: ... the vaccine. Why should my child get the rotavirus vaccine? The rotavirus vaccine: Protects your child from ...

  19. 24 hydrocarbon degradation in poultry droppings and cassava peels

    African Journals Online (AJOL)

    OLUWOLE AKINNAGBE

    2009-01-01

    Jan 1, 2009 ... This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels ... shift in the composition of bacterial community to ..... Oil and Gas Journal. pp. ... Prentice-Hall of India Private Ltd.

  20. Drop-out rate and drop-out reasons among promising Norwegian track and field athletes: a 25 year study

    OpenAIRE

    Enoksen, Eystein

    2011-01-01

    © Eystein Enoksen, 2011 The aim of the present study was to identify the total drop-out rate and drop-out reasons for a group of promising track and field athletes. 202 males and 98 females, aged 16 ±2 years, took part in this study. Questionnaires were administrated in 1975, 1983, and 1989. In-depth interviews were conducted in 1989 and in 2000. A chi-square test was administrated to test the difference between males and females dropping out and to test the most significant reasons influe...

  1. [Culture of pancreatic progenitor cells in hanging drop and on floating filter].

    Science.gov (United States)

    Ma, Feng-xia; Chen, Fang; Chi, Ying; Yang, Shao-guang; Lu, Shi-hong; Han, Zhong-chao

    2013-06-01

    To construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method. Murine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR). One day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose. In hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

  2. Impact of ultra-viscous drops: air-film gliding and extreme wetting

    KAUST Repository

    Langley, Kenneth; Li, Erqiang; Thoroddsen, Sigurdur T

    2017-01-01

    water drop, the viscous-dominated flow in the thin air layer counteracts the inertia of the drop liquid. For highly viscous drops the viscous stresses within the liquid also affect the interplay between the drop and the gas. Here the drop also forms a

  3. Analysis of the rod drop accident for Angra-1

    International Nuclear Information System (INIS)

    Veloso, M.A.; Atayde, P.A.

    1989-01-01

    The aim of this work is to present a rod drop accident analysis for the third cycle of the Angra-1 nuclear power plant operating in the automatic control mode. In this analysis all possible configurations for dropped rods caused by a single failure in the controller circuits have been considered. The dropped rod worths, power distributions and excore detector tilts were determined by using the Siemens/KWU neutronic code system, in particular the MEDIUM2, PINPOW and DETILT codes. The transient behaviour of the plant during the rod drop event was simulated with the SACI2/MOD0 code, developed at CDTN. Determinations related to the DNBR design limit were conducted by utilizing the CDTN PANTERA-1P subchannel code. The transient analysis indicated that for dropped rod worths greater than about 425 pcm reactor trip from negative neutron flux rate will take place independently of core conditions. In the range from 0 to 425 pcm large power overshoots may occur as a consequence of the automatic control system action. The magnitude of the maximum power peaking during the event increases with the dropped rod worth, as far as the control bank is able to compensate the initial reactivity decrease. Thermal-hydraulic evaluations carried out with the PANTERA-1P code show that for all the relevant dropped rod worths the minimum DNBR will remain above a limit value of 1.365. Even if this conservative limit is met, the calculated nuclear power peaking factors, F N AH , will be at least 6% higher than the allowable F N AH -values. Therefore, the DNBR design margin will be preserved at the event of rod drop. (author)

  4. Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard

    2002-01-01

    The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature.......The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

  5. Leidenfrost drops cooling surfaces: theory and interferometric measurement

    OpenAIRE

    Van Limbeek, Michiel A. J.; Klein Schaarsberg, Martin H.; Sobac, Benjamin; Rednikov, Alexey; Sun, Chao; Colinet, Pierre; Lohse, Detlef

    2017-01-01

    When a liquid drop is placed on a highly superheated surface, it can be levitated by its own vapour. This remarkable phenomenon is referred to as the Leidenfrost effect. The thermally insulating vapour film results in a severe reduction of the heat transfer rate compared to experiments at lower surface temperatures, where the drop is in direct contact with the solid surface. A commonly made assumption is that this solid surface is isothermal, which is at least questionable for materials of lo...

  6. Active structuring of colloidal armour on liquid drops

    OpenAIRE

    Dommersnes, Paul; Rozynek, Zbigniew; Mikkelsen, Alexander; Castberg, Rene; Kjerstad, Knut; Hersvik, Kjetil; Fossum, Jon Otto

    2013-01-01

    Adsorption and assembly of colloidal particles at the surface of liquid droplets are at the base of particle-stabilized emulsions and templating. Here we report that electrohydrodynamic and electro-rheological effects in leaky-dielectric liquid drops can be used to structure and dynamically control colloidal particle assemblies at drop surfaces, including electric-fieldassisted convective assembly of jammed colloidal ‘ribbons’, electro-rheological colloidal chains confined to a...

  7. Nectar and pollination drops: how different are they?

    Science.gov (United States)

    Nepi, Massimo; von Aderkas, Patrick; Wagner, Rebecca; Mugnaini, Serena; Coulter, Andrea; Pacini, Ettore

    2009-08-01

    Pollination drops and nectars (floral nectars) are secretions related to plant reproduction. The pollination drop is the landing site for the majority of gymnosperm pollen, whereas nectar of angiosperm flowers represents a common nutritional resource for a large variety of pollinators. Extrafloral nectars also are known from all vascular plants, although among the gymnosperms they are restricted to the Gnetales. Extrafloral nectars are not generally involved in reproduction but serve as 'reward' for ants defending plants against herbivores (indirect defence). Although very different in their task, nectars and pollination drops share some features, e.g. basic chemical composition and eventual consumption by animals. This has led some authors to call these secretions collectively nectar. Modern techniques that permit chemical analysis and protein characterization have very recently added important information about these sugary secretions that appear to be much more than a 'reward' for pollinating (floral nectar) and defending animals (extrafloral nectar) or a landing site for pollen (pollination drop). Nectar and pollination drops contain sugars as the main components, but the total concentration and the relative proportions are different. They also contain amino acids, of which proline is frequently the most abundant. Proteomic studies have revealed the presence of common functional classes of proteins such as invertases and defence-related proteins in nectar (floral and extrafloral) and pollination drops. Invertases allow for dynamic rearrangement of sugar composition following secretion. Defence-related proteins provide protection from invasion by fungi and bacteria. Currently, only few species have been studied in any depth. The chemical composition of the pollination drop must be investigated in a larger number of species if eventual phylogenetic relationships are to be revealed. Much more information can be provided from further proteomic studies of both

  8. An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process

    International Nuclear Information System (INIS)

    Liao, Y S; Chang, T Y; Chuang, T J

    2008-01-01

    A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed

  9. Drop detachment and motion on fuel cell electrode materials.

    Science.gov (United States)

    Gauthier, Eric; Hellstern, Thomas; Kevrekidis, Ioannis G; Benziger, Jay

    2012-02-01

    Liquid water is pushed through flow channels of fuel cells, where one surface is a porous carbon electrode made up of carbon fibers. Water drops grow on the fibrous carbon surface in the gas flow channel. The drops adhere to the superficial fiber surfaces but exhibit little penetration into the voids between the fibers. The fibrous surfaces are hydrophobic, but there is a substantial threshold force necessary to initiate water drop motion. Once the water drops begin to move, however, the adhesive force decreases and drops move with minimal friction, similar to motion on superhydrophobic materials. We report here studies of water wetting and water drop motion on typical porous carbon materials (carbon paper and carbon cloth) employed in fuel cells. The static coefficient of friction on these textured surfaces is comparable to that for smooth Teflon. But the dynamic coefficient of friction is several orders of magnitude smaller on the textured surfaces than on smooth Teflon. Carbon cloth displays a much smaller static contact angle hysteresis than carbon paper due to its two-scale roughness. The dynamic contact angle hysteresis for carbon paper is greatly reduced compared to the static contact angle hysteresis. Enhanced dynamic hydrophobicity is suggested to result from the extent to which a dynamic contact line can track topological heterogeneities of the liquid/solid interface.

  10. Drop tests of the Three Mile Island knockout canister

    International Nuclear Information System (INIS)

    Box, W.D.; Aaron, W.S.; Shappert, L.B.; Childress, P.C.; Quinn, G.J.; Smith, J.V.

    1986-09-01

    A type of Three Mile Island Unit 2 (TMI-2) defueling canister, called a ''knockout'' canister, was subjected to a series of drop tests at the Oak Ridge National Laboratory's Drop Test Facility. These tests were designed to confirm the structural integrity of internal fixed neutron poisons in support of a request for NRC licensing of this type of canister for the shipment of TMI-2 reactor fuel debris to the Idaho National Engineering Laboratory (INEL) for the Core Examination R and D Program. Work conducted at the Oak Ridge National Laboratory included (1) precise physical measurements of the internal poison rod configuration before assembly, (2) canister assembly and welding, (3) nondestructive examination (an initial hydrostatic pressure test and an x-ray profile of the internals before and after each drop test), (4) addition of a simulated fuel load, (5) instrumentation of the canister for each drop test, (6) fabrication of a cask simulation vessel with a developed and tested foam impact limiter, (7) use of refrigeration facilities to cool the canister to well below freezing prior to three of the drops, (8) recording the drop test with still, high-speed, and normal-speed photography, (9) recording the accelerometer measurements during impact, (10) disassembly and post-test examination with precise physical measurements, and (11) preparation of the final report

  11. Filter aids influence on pressure drop across a filtration system

    Science.gov (United States)

    Hajar, S.; Rashid, M.; Nurnadia, A.; Ammar, M. R.; Hasfalina, C. M.

    2017-06-01

    Filter aids is commonly used to reduce pressure drop across air filtration system as it helps to increase the efficiency of filtration of accumulated filter cake. Filtration velocity is one of the main parameters that affect the performance of filter aids material. In this study, a formulated filter aids consisting of PreKot™ and activated carbon mixture (designated as PrekotAC) was tested on PTFE filter media under various filtration velocities of 5, 6, and 8 m/min at a constant material loading of 0.2 mg/mm2. Results showed that pressure drop is highly influenced by filtration velocity where higher filtration velocity leads to a higher pressure drop across the filter cake. It was found that PrekotAC performed better in terms of reducing the pressure drop across the filter cake even at the highest filtration velocity. The diversity in different particle size distribution of non-uniform particle size in the formulated PrekotAC mixture presents a higher permeability causes a lower pressure drop across the accumulated filter cake. The finding suggests that PrekotAC is a promising filter aids material that helps reducing the pressure drop across fabric filtration system.

  12. Vortex-ring-induced large bubble entrainment during drop impact

    KAUST Repository

    Thoraval, Marie-Jean

    2016-03-29

    For a limited set of impact conditions, a drop impacting onto a pool can entrap an air bubble as large as its own size. The subsequent rise and rupture of this large bubble plays an important role in aerosol formation and gas transport at the air-sea interface. The large bubble is formed when the impact crater closes up near the pool surface and is known to occur only for drops that are prolate at impact. Herein we use experiments and numerical simulations to show that a concentrated vortex ring, produced in the neck between the drop and the pool, controls the crater deformations and pinchoff. However, it is not the strongest vortex rings that are responsible for the large bubbles, as they interact too strongly with the pool surface and self-destruct. Rather, it is somewhat weaker vortices that can deform the deeper craters, which manage to pinch off the large bubbles. These observations also explain why the strongest and most penetrating vortex rings emerging from drop impacts are not produced by oblate drops but by more prolate drop shapes, as had been observed in previous experiments.

  13. Drop formation of black liquor spraying; Mustalipeaen pisaroituminen

    Energy Technology Data Exchange (ETDEWEB)

    Fogelholm, C J; Kankkunen, A; Nieminen, K; Laine, J; Miikkulainen, P [Helsinki Univ. of Technology, Otaniemi (Finland): Lab. of Energy Technology and Environmental Protection

    1997-10-01

    Black liquor is a spent liquor of the pulp and paper industry. It is burned in kraft recovery boilers for chemical and energy recovery. The high dry solids content and viscosity of black liquor require a high spraying temperature. This affects the performance of the boiler. Kraft recovery boiler deposit formation, emissions and chemical recovery are strongly affected by the drop size and the velocity of the black liquor spray formed by a splashplate nozzle. The sheet breakup mechanism is studied with a system based on a video and image-analysis. The drop size of mill-scale nozzles was measured also with an image-analysis-system. Measurements were carried out in a spray test chamber. The sheet breakup mechanism and drop size tests were carried out both below and over the boiling point of black liquor. Special attention was paid to the effect of flashing on drop formation. Temperature increase normally decreases drop size. In the temperature where the wavy-sheet disintegration changes to perforated-sheet disintegration the drop size increases. Spray velocity rises when the temperature is increased above the boiling point. (orig.)

  14. Visualization study of film drops produced by bubble bursting

    International Nuclear Information System (INIS)

    Ma Chao; Bo Hanliang

    2012-01-01

    The phenomenon that bubble bursting results in drops production is common in the steam generator of the nuclear power plant, and the fine drops generated by this way is one of the most important source of the drop entrainment in the vapor stream. The visualization experiment about the film drops produced by the bursting bubbles at a free water surface was studied using a high-speed video camera. The results show that the bubble cap breaks up in a single point, within the limits of bubble size in the experiment at present. The whole process can be distinguished into four successive stages: A primary inertial drainage, the bubble cap puncture at the foot or on the top, the film rolls-up and the liquid ring appearing with the hole expanding, and fine film drops emission under the effect of destabilization of a Rayleigh-Taylor type. The expression about the bubble radius and the film drops number is obtain by fitting the experiment data at the bubble radius range from 3-25 mm. The result trend agrees well with the previous work. (authors)

  15. Afterlife of a Drop Impacting a Liquid Pool

    Science.gov (United States)

    Saha, Abhishek; Wei, Yanju; Tang, Xiaoyu; Law, Chung K.

    2017-11-01

    Drop impact on liquid pool is ubiquitous in industrial processes, such as inkjet printing and spray coating. While merging of drop with the impacted liquid surface is essential to facilitate the printing and coating processes, it is the afterlife of this merged drop and associated mixing which control the quality of the printed or coated surface. In this talk we will report an experimental study on the structural evolution of the merged droplet inside the liquid pool. First, we will analyze the depth of the crater created on the pool surface by the impacted drop for a range of impact inertia, and we will derive a scaling relation and the associated characteristic time-scale. Next, we will focus on the toroidal vortex formed by the moving drop inside the liquid pool and assess the characteristic time and length scales of the penetration process. The geometry of the vortex structure which qualitatively indicates the degree of mixedness will also be discussed. Finally, we will present the results from experiments with various viscosities to demonstrate the role of viscous dissipation on the geometry and structure formed by the drop. This work is supported by the Army Research Office and the Xerox Corporation.

  16. Ultrasonic defect-sizing using decibel drop methods. I

    International Nuclear Information System (INIS)

    Murphy, R.V.

    1987-03-01

    Results are reported of a study performed to investigate the accuracy and repeatability of various ultrasonic decibel (dB) drop sizing methods in determining the length, vertical extent and orientation of artificial and real weld flaws in thin steel sections. Seven artificial flaws and nine real weld flaws were examined; over 200 data plots were produced. The general findings are: a) length and vertical extent are assessed most accurately when using a 14 dB drop from the maximum indication amplitude; b) decibel drops less that 14 dB generally undersize flaws while decibel drops greater than 14 dB generally oversize flaws; c) flaws which are smaller than the width of the sound beam cannot be assessed accurately using dB drop methods; d) large flaws are assessed most accurately when the sound beam strikes the flaws at near normal incidence; e) the vertical extent and orientation of large flaws are plotted most accurately using the beam centre line method as opposed to the beam profile method; and, f) the limitations of dB-drop-sizing methods have considerable ramifications for CAN3-N285.4-M83 and ASME XI evaluation criteria

  17. Water Penetration through a Superhydrophobic Mesh During a Drop Impact

    Science.gov (United States)

    Ryu, Seunggeol; Sen, Prosenjit; Nam, Youngsuk; Lee, Choongyeop

    2017-01-01

    When a water drop impacts a mesh having submillimeter pores, a part of the drop penetrates through the mesh if the impact velocity is sufficiently large. Here we show that different surface wettability, i.e., hydrophobicity and superhydrophobicity, leads to different water penetration dynamics on a mesh during drop impact. We show, despite the water repellence of a superhydrophobic surface, that water can penetrate a superhydrophobic mesh more easily (i.e., at a lower impact velocity) over a hydrophobic mesh via a penetration mechanism unique to a superhydrophobic mesh. On a superhydrophobic mesh, the water penetration can occur during the drop recoil stage, which appears at a lower impact velocity than the critical impact velocity for water penetration right upon impact. We propose that this unique water penetration on a superhydrophobic mesh can be attributed to the combination of the hydrodynamic focusing and the momentum transfer from the water drop when it is about to bounce off the surface, at which point the water drop retrieves most of its kinetic energy due to the negligible friction on superhydrophobic surfaces.

  18. High-precision drop shape analysis on inclining flat surfaces: introduction and comparison of this special method with commercial contact angle analysis.

    Science.gov (United States)

    Schmitt, Michael; Heib, Florian

    2013-10-07

    Drop shape analysis is one of the most important and frequently used methods to characterise surfaces in the scientific and industrial communities. An especially large number of studies, which use contact angle measurements to analyse surfaces, are characterised by incorrect or misdirected conclusions such as the determination of surface energies from poorly performed contact angle determinations. In particular, the characterisation of surfaces, which leads to correlations between the contact angle and other effects, must be critically validated for some publications. A large number of works exist concerning the theoretical and thermodynamic aspects of two- and tri-phase boundaries. The linkage between theory and experiment is generally performed by an axisymmetric drop shape analysis, that is, simulations of the theoretical drop profiles by numerical integration onto a number of points of the drop meniscus (approximately 20). These methods work very well for axisymmetric profiles such as those obtained by pendant drop measurements, but in the case of a sessile drop onto real surfaces, additional unknown and misunderstood effects on the dependence of the surface must be considered. We present a special experimental and practical investigation as another way to transition from experiment to theory. This procedure was developed to be especially sensitive to small variations in the dependence of the dynamic contact angle on the surface; as a result, this procedure will allow the properties of the surface to be monitored with a higher precession and sensitivity. In this context, water drops onto a 111 silicon wafer are dynamically measured by video recording and by inclining the surface, which results in a sequence of non-axisymmetric drops. The drop profiles are analysed by commercial software and by the developed and presented high-precision drop shape analysis. In addition to the enhanced sensitivity for contact angle determination, this analysis technique, in

  19. Rain drop size densities over land and over sea

    Science.gov (United States)

    Bumke, Karl

    2010-05-01

    A detailed knowledge of rain drop size densities is an essential presumption with respect to remote sensing of precipitation. Since maritime and continental aerosol is significantly different yielding to differences in cloud drop size densities, maritime and continental rain drop size densities may be different, too. In fact only a little is known about differences in rain drop size densities between land and sea due to a lack of suitable data over the sea. To fill in this gap measurements were performed during the recent 10 years at different locations in Germany and on board of research vessels over the Baltic Sea, the North Sea, Atlantic, Indian, and Pacific Ocean. Measurements were done by using an optical disdrometer (ODM 470, Großklaus et al., 1998), which is designed especially to perform precipitation measurements on moving ships and under high wind speeds. Temporal resolution of measurements is generally 1 minute, total number of time series is about 220000. To investigate differences in drop size densities over land and over sea measurements have been divided into four classes on the basis of prevailing continental or maritime influence: land measurements, coastal measurements, measurements in areas of semi-enclosed seas, and open sea measurements. In general differences in drop size densities are small between different areas. A Kolmogoroff Smirnoff test does not give any significant difference between drop size densities over land, coastal areas, semi-enclosed, and open seas at an error rate of 5%. Thus, it can be concluded that there are no systematic differences between maritime and continental drop size densities. The best fit of drop size densities is an exponential decay curve, N(D ) = 6510m -3mm -1mm0.14h- 0.14×R-0.14×exp(- 4.4mm0.25h-0.25×R- 0.25×D mm -1), it is estimated by using the method of least squares. N(D) is the drop size density normalized by the resolution of the optical disdrometer, D the diameter of rain drops in mm, and R the

  20. Many Drops Interactions I: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2012-06-01

    Full Text Available Smoothed Particle Hydrodynamics (SPH is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. In this study, the SPH method is applied to simulate the hydrodynamics interaction of many drops, showing some settings for the coalescence, fragmentation and flocculation problem of equally sized liquid drops in three-dimensional spaces. For small velocities the drops interact only through their deformed surfaces and the flocculation of the droplets arises. This result is very different if the collision velocity is large enough for the fragmentation of droplets takes place. We observe that for velocities around 15 mm/ms the coalescence of droplets occurs. The velocity vector fields formed inside the drops during the collision process are shown.

  1. Pressure-Drop Considerations in the Characterization of Dew-Point Transfer Standards at High Temperatures

    Science.gov (United States)

    Mitter, H.; Böse, N.; Benyon, R.; Vicente, T.

    2012-09-01

    During calibration of precision optical dew-point hygrometers (DPHs), it is usually necessary to take into account the pressure drop induced by the gas flow between the "point of reference" and the "point of use" (mirror or measuring head of the DPH) either as a correction of the reference dew-point temperature or as part of the uncertainty estimation. At dew-point temperatures in the range of ambient temperature and below, it is sufficient to determine the pressure drop for the required gas flow, and to keep the volumetric flow constant during the measurements. In this case, it is feasible to keep the dry-gas flow into the dew-point generator constant or to measure the flow downstream the DPH at ambient temperature. In normal operation, at least one DPH in addition to the monitoring DPH are used, and this operation has to be applied to each instrument. The situation is different at high dew-point temperatures up to 95 °C, the currently achievable upper limit reported in this paper. With increasing dew-point temperatures, the reference gas contains increasing amounts of water vapour and a constant dry-gas flow will lead to a significant enhanced volume flow at the conditions at the point of use, and therefore, to a significantly varying pressure drop depending on the applied dew-point temperature. At dew-point temperatures above ambient temperature, it is also necessary to heat the reference gas and the mirror head of the DPH sufficiently to avoid condensation which will additionally increase the volume flow and the pressure drop. In this paper, a method is provided to calculate the dry-gas flow rate needed to maintain a known wet-gas flow rate through a chilled mirror for a range of temperature and pressures.

  2. Natural short sleeper

    Science.gov (United States)

    Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

  3. Acoustics short-term passive monitoring using sonobuoys in the Bering, Chukchi, and Western Beaufort Seas conducted by Alaska Fisheries Scientific Center, National Marine Mammal Laboratory from 2007-08-01 to 2015-09-28 (NCEI Accession 0138863)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory (NMML) has conducted passive acoustic monitoring in the Bering, Chukchi, and Western Beaufort Seas to determine spatio-temporal...

  4. X-38 Drop Model: Landing Sequence Collage from Cessna Drop Test

    Science.gov (United States)

    1995-01-01

    This sequence of photographs shows a 4-foot-long model of NASA's X-38 gliding to earth after being dropped from a Cessna aircraft in late 1995. The model was used to test the ram-air parafoil landing system, which could allow for accurate and controlled landings of an emergency Crew Return Vehicle spacecraft returning to earth. The X-38 Crew Return Vehicle (CRV) research project is designed to develop the technology for a prototype emergency crew return vehicle, or lifeboat, for the International Space Station. The project is also intended to develop a crew return vehicle design that could be modified for other uses, such as a joint U.S. and international human spacecraft that could be launched on the French Ariane-5 Booster. The X-38 project is using available technology and off-the-shelf equipment to significantly decrease development costs. Original estimates to develop a capsule-type crew return vehicle were estimated at more than $2 billion. X-38 project officials have estimated that development costs for the X-38 concept will be approximately one quarter of the original estimate. Off-the-shelf technology is not necessarily 'old' technology. Many of the technologies being used in the X-38 project have never before been applied to a human-flight spacecraft. For example, the X-38 flight computer is commercial equipment currently used in aircraft and the flight software operating system is a commercial system already in use in many aerospace applications. The video equipment for the X-38 is existing equipment, some of which has already flown on the space shuttle for previous NASA experiments. The X-38's primary navigational equipment, the Inertial Navigation System/Global Positioning System, is a unit already in use on Navy fighters. The X-38 electromechanical actuators come from previous joint NASA, U.S. Air Force, and U.S. Navy research and development projects. Finally, an existing special coating developed by NASA will be used on the X-38 thermal tiles to

  5. On-state voltage drop based power limit detection of IGBT inverters

    DEFF Research Database (Denmark)

    Trintis, Ionut; Ghimire, Pramod; Munk-Nielsen, Stig

    2015-01-01

    Power density is a key performance factor in order to reduce the cost and size of a power converter. Because of the unknown junction temperature, today’s design margins are relatively high to ensure safe and a reliable operation. In this paper, the on-state voltage drop is measured online for all...... insulated gate bipolar transistors (IGBTs) in the inverter, using advanced gate driver. The die temperature is estimated and monitored on each device during power converter operation. Based on the monitored temperature in real time, the maximum power capability is detected. The output power is increased...... until a safe operating temperature of power modules. This enable a power density is increased by 11.16 kW/litre to 19.13 kW/litre in a low voltage power stack which is typically used in wind power converters. Experiment results are shown for safe operation of converter at around 1.2 MW, which is built...

  6. Reactor power monitoring device

    International Nuclear Information System (INIS)

    Kono, Shigehiro.

    1990-01-01

    Among a plurality of power monitoring programs in a reactor power monitoring device, rapid response is required for a scram judging program for the power judging processing of scram signals. Therefore, the scram judging program is stored independently from other power monitoring programs, applied with a priority order, and executed in parallel with other programs, to output scram signals when the detected data exceeds a predetermined value. As a result, the capacity required for the scram judging program is reduced and the processing can be conducted in a short period of time. In addition, since high priority is applied to the scram judging program which is divided into a small capacity, it is executed at higher frequency than other programs when they are executed in parallel. That is, since the entire processings for the power monitoring program are repeated in a short cycle, the response speed of the scram signals required for high responsivity can be increased. (N.H.)

  7. Measurement of interfacial tension by use of pendant drop video techniques

    Science.gov (United States)

    Herd, Melvin D.; Thomas, Charles P.; Bala, Gregory A.; Lassahn, Gordon D.

    1993-09-01

    This report describes an instrument to measure the interfacial tension (IFT) of aqueous surfactant solutions and crude oil. The method involves injection of a drop of fluid (such as crude oil) into a second immiscible phase to determine the IFT between the two phases. The instrument is composed of an AT-class computer, optical cell, illumination, video camera and lens, video frame digitizer board, monitor, and software. The camera displays an image of the pendant drop on the monitor, which is then processed by the frame digitizer board and non-proprietary software to determine the IFT. Several binary and ternary phase systems were taken from the literature and used to measure the precision and accuracy of the instrument in determining IFT's. A copy of the software program is included in the report. A copy of the program on diskette can be obtained from the Energy Science and Technology Software Center, P.O. Box 1020, Oak Ridge, TN 37831-1020. The accuracy and precision of the technique and apparatus presented is very good for measurement of IFT's in the range from 72 to 10(exp -2) mN/m, which is adequate for many EOR applications. With modifications to the equipment and the numerical techniques, measurements of ultralow IFT's (less than 10(exp -3) mN/m) should be possible as well as measurements at reservoir temperature and pressure conditions. The instrument has been used at the Idaho National Engineering Laboratory to support the research program on microbial enhanced oil recovery. Measurements of IFT's for several bacterial supernatants and unfractionated acid precipitates of microbial cultures containing biosurfactants against medium to heavy crude oils are reported. These experiments demonstrate that the use of automated video imaging of pendant drops is a simple and fast method to reliably determine interfacial tension between two immiscible liquid phases, or between a gas and a liquid phase.

  8. Surfactant-Enhanced Benard Convection on an Evaporating Drop

    Science.gov (United States)

    Nguyen, Van X.; Stebe, Kathleen J.

    2001-11-01

    Surfactant effects on an evaporating drop are studied experimentally. Using a fluorescent probe, the distribution and surface phase of the surfactant is directly imaged throughout the evaporation process. From these experiments, we identify conditions in which surfactants promote surface tension-driven Benard instabilities in aqueous systems. The drops under study contain finely divided particles, which act as tracers in the flow, and form well-defined patterns after the drop evaporates. Two flow fields have been reported in this system. The first occurs because the contact line becomes pinned by solid particles at the contact line region. In order for the contact line to remain fixed, an outward flow toward the ring results, driving further accumulation at the contact ring. A ‘coffee ring’ of particles is left as residue after the drop evaporates[1]. The second flow is Benard convection, driven by surface tension gradients on the drop[2,3]. In our experiments, an insoluble monolayer of pentadecanoic acid is spread at the interface of a pendant drop. The surface tension is recorded, and the drop is deposited on a well-defined solid substrate. Fluorescent images of the surface phase of the surfactant are recorded as the drop evaporates. The surfactant monolayer assumes a variety of surface states as a function of the area per molecule at the interface: surface gaseous, surface liquid expanded, and surface liquid condensed phases[4]. Depending upon the surface state of the surfactant as the drop evaporates, transitions of residue patterns left by the particles occur, from the coffee ring pattern to Benard cells to irregular patterns, suggesting a strong resistance to outward flow are observed. The occurrence of Benard cells on a surfactant-rich interface occurs when the interface is in LE-LC coexistence. Prior research concerning surfactant effects on this instability predict that surfactants are strongly stabilizing[5]. The mechanisms for this change in behavior

  9. Calculation method for control rod dropping time in reactor

    International Nuclear Information System (INIS)

    Nogami, Takeki; Kato, Yoshifumi; Ishino, Jun-ichi; Doi, Isamu.

    1996-01-01

    If a control rod starts dropping, the dropping speed is rapidly increased, then settled substantially constant, rapidly decreased when it reaches a dash pot. A second detection signal generated by removing an AC component from a first detection signal is differentiated twice. The time when the maximum value among the twice differentiated values is generated is determined as a time when the control rods starts dropping. The time when minimum value among the twice differentiated values is generated is determined as a time when the control rod reaches the dash pot of the reactor. The measuring time within a range from the time when the control rod starts dropping to the time when the control rod reaches the dash pot of the reactor is determined. As a result, processing for the calculation of the dropping start time and dash pot reaching time of the control rod can be automatized. Further, it is suffice to conduct differentiation twice till the reaching time, which can facilitate the processing thereby enabling to determine a reliable time range. (N.H.)

  10. Electrohydrodynamics of suspension of liquid drops in AC fields

    Science.gov (United States)

    Abdul Halim, Md.; Esmaeeli, Asghar

    2012-11-01

    Manipulation of liquid drops by an externally applied electric field is currently the focus of increased attention because of its relevance in a broad range of industrial processes. The effect of a uniform DC electric field on a solitary drop is well studied; however, less is know about the impact of electric field on suspension of liquid drops, and very little information is available on the impact of AC field on a single or a suspension of drops. Here we report the results of Direct Numerical Simulations of electrohydrodynamics of suspension of liquid drops. The governing equations are solved using a front tracking/finite difference technique, in conjunction with Taylor's leaky dielectric model. The imposed electric potential comprises of two parts, a time-independent base and a time-dependent part. The goal is to explore the relative importance of these two components in setting the statistically steady state behavior of the suspension. To this end, we report the results of three sets of simulations, where (i) the time-dependent part act as a perturbation on the base potential, (ii) the two components are of the same order, and (iii) the time-dependent part is much larger than the base potential. The problem is studied as a function of the governing nondimensional parameters.

  11. 9 m side drop test of scale model

    International Nuclear Information System (INIS)

    Ku, Jeong-Hoe; Chung, Seong-Hwan; Lee, Ju-Chan; Seo, Ki-Seog

    1993-01-01

    A type B(U) shipping cask had been developed in KAERI for transporting PWR spent fuel. Since the cask is to transport spent PWR fuel, it must be designed to meet all of the structural requirements specified in domestic packaging regulations and IAEA safety series No.6. This paper describes the side drop testing of a one - third scale model cask. The crush and deformations of the shock absorbing covers directly control the deceleration experiences of the cask during the 9 m side drop impact. The shock absorbing covers greatly mitigated the inertia forces of the cask body due to the side drop impact. Compared with the side drop test and finite element analysis, it was verified that the 1/3 scale model cask maintain its structural integrity of the model cask under the side drop impact. The test and analysis results could be used as the basic data to evaluate the structural integrity of the real cask. (J.P.N.)

  12. Scaling during capillary thinning of particle-laden drops

    Science.gov (United States)

    Thete, Sumeet; Wagoner, Brayden; Basaran, Osman

    2017-11-01

    A fundamental understanding of drop formation is crucial in many applications such as ink-jet printing, microfluidic devices, and atomization. During drop formation, the about-to-form drop is connected to the fluid hanging from the nozzle via a thinning filament. Therefore, the physics of capillary thinning of filaments is key to understanding drop formation and has been thoroughly studied for pure Newtonian fluids using theory, simulations, and experiments. In some of the applications however, the forming drop and hence the thinning filament may contain solid particles. The thinning dynamics of such particle-laden filaments differs radically from that of particle-free filaments. Moreover, our understanding of filament thinning in the former case is poor compared to that in the latter case despite the growing interest in pinch-off of particle-laden filaments. In this work, we go beyond similar studies and experimentally explore the impact of solid particles on filament thinning by measuring both the radial and axial scalings in the neck region. The results are summarized in terms of a phase diagram of capillary thinning of particle-laden filaments.

  13. Electrohydrodynamics of drops in strong electric fields: Simulations and theory

    Science.gov (United States)

    Saintillan, David; Das, Debasish

    2016-11-01

    Weakly conducting dielectric liquid drops suspended in another dielectric liquid exhibit a wide range of dynamical behaviors when subject to an applied uniform electric field contingent on field strength and material properties. These phenomena are best described by the much celebrated Maylor-Taylor leaky dielectric model that hypothesizes charge accumulation on the drop-fluid interface and prescribes a balance between charge relaxation, the jump in Ohmic currents and charge convection by the interfacial fluid flow. Most previous numerical simulations based on this model have either neglected interfacial charge convection or restricted themselves to axisymmetric drops. In this work, we develop a three-dimensional boundary element method for the complete leaky dielectric model to systematically study the deformation and dynamics of liquid drops in electric fields. The inclusion of charge convection in our simulation permits us to investigate drops in the Quincke regime, in which experiments have demonstrated symmetry-breaking bifurcations leading to steady electrorotation. Our simulation results show excellent agreement with existing experimental data and small deformation theories. ACSPRF Grant 53240-ND9.

  14. A Novel Virus Causes Scale Drop Disease in Lates calcarifer.

    Directory of Open Access Journals (Sweden)

    Ad de Groof

    2015-08-01

    Full Text Available From 1992 onwards, outbreaks of a previously unknown illness have been reported in Asian seabass (Lates calcarifer kept in maricultures in Southeast Asia. The most striking symptom of this emerging disease is the loss of scales. It was referred to as scale drop syndrome, but the etiology remained enigmatic. By using a next-generation virus discovery technique, VIDISCA-454, sequences of an unknown virus were detected in serum of diseased fish. The near complete genome sequence of the virus was determined, which shows a unique genome organization, and low levels of identity to known members of the Iridoviridae. Based on homology of a series of putatively encoded proteins, the virus is a novel member of the Megalocytivirus genus of the Iridoviridae family. The virus was isolated and propagated in cell culture, where it caused a cytopathogenic effect in infected Asian seabass kidney and brain cells. Electron microscopy revealed icosahedral virions of about 140 nm, characteristic for the Iridoviridae. In vitro cultured virus induced scale drop syndrome in Asian seabass in vivo and the virus could be reisolated from these infected fish. These findings show that the virus is the causative agent for the scale drop syndrome, as each of Koch's postulates is fulfilled. We have named the virus Scale Drop Disease Virus. Vaccines prepared from BEI- and formalin inactivated virus, as well as from E. coli produced major capsid protein provide efficacious protection against scale drop disease.

  15. Drop splashing: the role of surface wettability and liquid viscosity

    Science.gov (United States)

    Almohammadi, Hamed; Amirfazli, Alidad; -Team

    2017-11-01

    There are seemingly contradictory results in the literature about the role of surface wettability and drop viscosity for the splashing behavior of a drop impacting onto a surface. Motivated by such issues, we conducted a systematic experimental study where splashing behavior for a wide range of the liquid viscosity (1-100 cSt) and surface wettability (hydrophilic to hydrophobic) are examined. The experiments were performed for the liquids with both low and high surface tensions ( 20 and 72 mN/m). We found that the wettability affects the splashing threshold at high or low contact angle values. At the same drop velocity, an increase of the viscosity (up to 4 cSt) promotes the splashing; while, beyond such value, any increase in viscosity shows the opposite effect. It is also found that at a particular combination of liquid surface tension and viscosity (e.g. silicone oil, 10 cSt), an increase in the drop velocity changes the splashing to spreading. We relate such behaviors to the thickness, shape, and the velocity of the drop's lamella. Finally, to predict the splashing, we developed an empirical correlation which covers all of the previous reported data, hence clarifying the ostensible existing contradictions.

  16. A PIV Study of Drop-interface Coalescence with Surfactants

    Science.gov (United States)

    Weheliye, Weheliye Hashi; Dong, Teng; Angeli, Panagiota

    2017-11-01

    In this work, the coalescence of a drop with an aqueous-organic interface was studied by Particle Image Velocimetry (PIV). The effect of surfactants on the drop surface evolution, the vorticity field and the kinetic energy distribution in the drop during coalescence were investigated. The coalescence took place in an acrylic rectangular box with 79% glycerol solution at the bottom and Exxsol D80 oil above. The glycerol solution drop was generated through a nozzle fixed at 2cm above the aqueous/oil interface and was seeded with Rhodamine particles. The whole process was captured by a high-speed camera. Different mass ratios of non-ionic surfactant Span80 to oil were studied. The increase of surfactant concentration promoted deformation of the interface before the rupture of the trapped oil film. At the early stages after film rupture, two counter-rotating vortices appeared at the bottom of the drop which then travelled to the upper part. The propagation rates, as well as the intensities of the vortices decreased at high surfactant concentrations. At early stages, the kinetic energy was mainly distributed near the bottom part of the droplet, while at later stages it was distributed near the upper part of the droplet. Programme Grant MEMPHIS, Chinese Scholarship Council (CSC).

  17. Research on combustion of black-liquor drops

    International Nuclear Information System (INIS)

    Macek, A.

    1999-01-01

    Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practised for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) re-examines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. (author)

  18. Expression patterns of cell wall-modifying genes from banana during fruit ripening and in relationship with finger drop

    Science.gov (United States)

    Mbéguié-A-Mbéguié, D.; Hubert, O.; Baurens, F. C.; Matsumoto, T.; Chillet, M.; Fils-Lycaon, B.; Sidibé-Bocs, S.

    2009-01-01

    Few molecular studies have been devoted to the finger drop process that occurs during banana fruit ripening. Recent studies revealed the involvement of changes in the properties of cell wall polysaccharides in the pedicel rupture area. In this study, the expression of cell-wall modifying genes was monitored in peel tissue during post-harvest ripening of Cavendish banana fruit, at median area (control zone) and compared with that in the pedicel rupture area (drop zone). To this end, three pectin methylesterase (PME) and seven xyloglucan endotransglycosylase/hydrolase (XTH) genes were isolated. The accumulation of their mRNAs and those of polygalaturonase, expansin, and pectate lyase genes already isolated from banana were examined. During post-harvest ripening, transcripts of all genes were detected in both zones, but accumulated differentially. MaPME1, MaPG1, and MaXTH4 mRNA levels did not change in either zone. Levels of MaPME3 and MaPG3 mRNAs increased greatly only in the control zone and at the late ripening stages. For other genes, the main molecular changes occurred 1–4 d after ripening induction. MaPME2, MaPEL1, MaPEL2, MaPG4, MaXTH6, MaXTH8, MaXTH9, MaEXP1, MaEXP4, and MaEXP5 accumulated highly in the drop zone, contrary to MaXTH3 and MaXTH5, and MaEXP2 throughout ripening. For MaPG2, MaXET1, and MaXET2 genes, high accumulation in the drop zone was transient. The transcriptional data obtained from all genes examined suggested that finger drop and peel softening involved similar mechanisms. These findings also led to the proposal of a sequence of molecular events leading to finger drop and to suggest some candidates. PMID:19357434

  19. Foamed emulsion drainage: flow and trapping of drops.

    Science.gov (United States)

    Schneider, Maxime; Zou, Ziqiang; Langevin, Dominique; Salonen, Anniina

    2017-06-07

    Foamed emulsions are ubiquitous in our daily life but the ageing of such systems is still poorly understood. In this study we investigate foam drainage and measure the evolution of the gas, liquid and oil volume fractions inside the foam. We evidence three regimes of ageing. During an initial period of fast drainage, both bubbles and drops are very mobile. As the foam stabilises drainage proceeds leading to a gradual decrease of the liquid fraction and slowing down of drainage. Clusters of oil drops are less sheared, their dynamic viscosity increases and drainage slows down even further, until the drops become blocked. At this point the oil fraction starts to increase in the continuous phase. The foam ageing leads to an increase of the capillary pressure until the oil acts as an antifoaming agent and the foam collapses.

  20. Steam explosion studies with single drops of molten refractory materials

    International Nuclear Information System (INIS)

    Nelson, L.S.

    1980-01-01

    Laser heating, levitation melting, and metal combustion were used to prepare individual drops of molten refractory materials which simulate LWR fuel melt products. Drop temperatures ranged from approx. = 1500 to > 3000K. These drops, several millimeters in diameter, were injected into water and subjected to pressure transients (approx. = 1MPa peak pressures) generated by a submerged exploding bridgewire. Molten oxides of Fe, Al and Zr could be induced to explode with bridgewire initiation. High speed films showed the explosions with exceptional clarity, and pressure transducer records could be correlated with individual frames in the films. Pressure spikes one or two MPa high were generated whenever an explosion occurred. Debris particles were mostly spheroidal, with diameters in the range 10 to 1000 μm

  1. Bacterial and fungal flora of seagull droppings in Jersey

    Science.gov (United States)

    Cragg, John; Clayton, Yvonne M.

    1971-01-01

    In Jersey 166 fresh and 122 dried seagull droppings were obtained and studied locally and in London for the presence of bacteria and fungi of potentially pathogenic nature. There were no salmonella or shigella bacteria isolated from the two groups but there was a high proportion of Candida albicans obtained from the fresh material (21·7%) and only 1·6% from the dry faeces. Cryptococcus neoformans and Histoplasma capsulatum were not found in either the dry or fresh droppings. The normal bacterial and fungal flora of the seagull was established and it is considered that the C. albicans in fresh gull droppings would not materially increase albicans infections in man. PMID:5104846

  2. A Partial Equilibrium Theory for Drops and Capillary Liquids

    International Nuclear Information System (INIS)

    Searcy, Alan W.; Beruto, Dario T.; Barberis, Fabrizio

    2006-01-01

    The two-century old theory of Young and Laplace retains a powerful influence on surface and interface studies because it quantitatively predicts the height of rise of capillary liquids from the contact angles of drops. But the classical theory does not acknowledge that equilibrium requires separate minimization of partial free energies of one-component liquids bonded to immiscible solids. We generalize a theorem of Gibbs and Curie to obtain a partial equilibrium (PE) theory that does so and that also predicts the height of capillary rise from contact angles of drops. Published observations and our own measurements of contact angles of water bonded to glass and Teflon surfaces support the conclusion of PE theory that contact angles of meniscuses and of drops are different dependent variables. PE theory provides thermodynamic and kinetic guidance to nanoscale processes that the classical theory obscures, as illustrated by examples in our concluding section

  3. Playing with water drops: from wetting to optics through electrostatics

    International Nuclear Information System (INIS)

    Domps, A; Roques-Carmes, T

    2011-01-01

    We present a consistent series of activities, including experiments and basic computational studies, investigating the shape and optical properties of water drops in connection with novel technological devices. Most of the work can be carried out with simple teaching equipment and is well suited to undergraduate students. Firstly, we show how the mass variations of a sessile drop can be used to control its curvature and hence to produce lenses with tunable focal distance. Alternatively, the shape of the drop can be varied using electrowetting on dielectric (EWOD). We propose a simple pedagogical approach to this phenomenon in connection with historical electrostatic apparatus. A detailed process for the preparation of an EWOD device is given, together with a focimetric method allowing the analysis of electrowetting effects in practical exercises. Finally, the manipulations of a commercialized variable focus lens illustrate that EWOD is at the heart of most recent technological developments, making practical work in optics more attractive than traditional exercises using conventional lenses.

  4. Emulsion Design. Analysis of Drop Deformations in Mixed Flows

    DEFF Research Database (Denmark)

    Egholm, Runi Ditlev

    2008-01-01

    . Furthermore wall effects are also investigated by varying the size of the computational domain which consists of a box with variable mesh size. In the center of the domain, where the drop resides, the mesh consists of a fine region whereas closer to the walls the elements gradually increase in size. Tests...... by the drop in the rotor-stator device is emulated in the computational box used for carrying out drop shape simulations. Comparison of simulated and experimentally obtained deformations show that in general the agreement is acceptable on a qualitative level. However, the simulations predict deformations...... there is a relaxation in the flow field. Furthermore we observe that for small viscosity ratios (A ~ 0.1) tip streaming is predominant while for larger viscosity ratios either binary or capillary break-up is predominant....

  5. Estimation of pressure drop in gasket plate heat exchangers

    Directory of Open Access Journals (Sweden)

    Neagu Anisoara Arleziana

    2016-06-01

    Full Text Available In this paper, we present comparatively different methods of pressure drop calculation in the gasket plate heat exchangers (PHEs, using correlations recommended in literature on industrial data collected from a vegetable oil refinery. The goal of this study was to compare the results obtained with these correlations, in order to choose one or two for practical purpose of pumping power calculations. We concluded that pressure drop values calculated with Mulley relationship and Buonopane & Troupe correlation were close and also Bond’s equation gave results pretty close to these but the pressure drop is slightly underestimated. Kumar correlation gave results far from all the others and its application will lead to oversize. In conclusion, for further calculations we will chose either the Mulley relationship or the Buonopane & Troupe correlation.

  6. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    Science.gov (United States)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-10-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  7. Superheated drop, open-quotes Bubbleclose quotes, dosimeters

    International Nuclear Information System (INIS)

    Harper, M.J.; Lindler, K.W.; Nelson, M.E.; Johnson, T.L.; Jones, C.R.; Rabovsky, J.L.; Rao, N.; Kerschner, H.F.; Reil, G.K.; Schwartz, R.B.

    1991-01-01

    Superheated Drop Dosimeters (SDD) offer a sensitive, immediate measure of the neutron dose equivalent, but their dynamic range is limited and their response varies with temperature, pressure, and vibration. They contain thousands of superheated liquid drops in a stabilizing matrix. High linear energy transfer (LET) radiation triggers vaporization of the drops into visible bubbles. If the matrix is a liquid, the bubbles slowly rise, and the number present indicates the dose rate. Dose may be measured by displacement of the matrix, or by counting the sounds of vaporization. If the matrix is a gel, the bubbles are fixed, and their number is proportional to the dose equivalent. Our research has focused on modeling and elimination of the environmental response, extension of the dynamic range, and tests and evaluations of prototype devices

  8. Potential drop crack measurement systems for CANDU components

    Energy Technology Data Exchange (ETDEWEB)

    Sahney, R [Carleton Univ., Ottawa, ON (Canada)

    1994-12-31

    A project to develop an automated crack measurement system for CANDU pressure tube burst testing is currently underway. The system will utilize either Direct Current Potential Drop (DCPD) or Alternating Current Potential Drop (ACPD) techniques for crack measurement. The preliminary stage of the project involves testing and comparison of both ACPD and DCPD methods on a Zr - 2.5% Nb alloy plate with saw cuts (used to simulate cracks). Preliminary results show that both ACPD and DCPD techniques are capable of detecting cracks; further testing is in progress to determine the ability of each of the two systems to make accurate crack depth measurements. This paper will describe the two potential drop techniques and will present test results from the experimental program. (author). 10 refs., 7 figs.

  9. MHD pressure drop in ducts with imperfectly insulating coatings

    International Nuclear Information System (INIS)

    Malang, S.; Buehler, L.

    1994-08-01

    Liquid metal cooled blankets in fusion tokamak's are feasible only with electrically insulating coatings at the coolant channel walls. The requirements of such coatings are investigated and a simple analytical model is developed to determine the influence of imperfections in the coatings on the magneto-hydrodynamic pressure drop. This model is compared with the results of a 3D-MHD code based on the core flow approach. Both methods are in good agreement as long as the imperfections do not increase the pressure drop by more than 20%. The analytical model over-estimates the pressure drop for values larger than 20%. The importance of self-healing of coatings in case of cracking or flaking is quantified and an equation for the equilibrium conditions between the generation of imperfection and the healing of such spots is provided

  10. Neuromuscular function during drop jumps in young and elderly males.

    Science.gov (United States)

    Piirainen, Jarmo M; Linnamo, Vesa; Sippola, Niina; Avela, Janne

    2012-12-01

    The Hoffman reflex (H-reflex), indicating alpha-motoneuron pool activity, has been shown to be task - and in resting conditions - age dependent. How aging affects H-reflex activity during explosive movements is not clear at present. The purpose of this study was to examine the effects of aging on H-reflexes during drop jumps, and its possible role in drop jump performance. Ten young (26.8 ± 2.7 years) and twenty elderly (64.2 ± 2.7 years) subjects participated in the study. Maximal drop jump performance and soleus H-reflex response (H/M jump) 20 ms after ground contact were measured in a sledge ergometer. Maximal H-reflex, maximal M-wave, Hmax/Mmax-ratio and H-reflex excitability curves were measured during standing rest. Although in young the H-reflex response (Hmax/Mmax) was 6.5% higher during relaxed standing and 19.7% higher during drop jumps (H jump/M jump) than in the elderly group, these differences were not statistically significant. In drop jumps, the elderly subjects had lower jumping height (30.4%, p push-off force (18.0%, p push-off time (31.0% p push-off force (r = 0.833, p push-off time (r = -0.857, p < 0.01) in young but not in the elderly. Correlations between H-reflex response and jumping parameters in young may indicate different jumping and activation strategies in drop jumps. However, it does not fully explain age related differences in jumping performance, since age related differences in H-reflex activity were non-significant. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Falling drops skating on a film of air

    Science.gov (United States)

    Rubinstein, Shmuel

    2012-02-01

    When a raindrop hits a window, the surface immediately becomes wet as the water spreads. Indeed, this common observation of a drop impacting a surface is ubiquitous in our everyday experience. I will show that the impact of a drop on a surface is a much richer, more complex phenomenon than our simple experience may suggests: To completely wet the surface the drop must first expel all the air beneath it; however, this does not happened instantaneously. Instead, a very thin film of air, only a few tens of nanometers thick, remains trapped between the falling drop and the surface as the fluid spreads. The thin film of air serves to lubricate the drop enabling the fluid to skate laterally outward at strikingly high velocities. Simultaneously, the wetting fluid spreads inward at a much slower velocity, trapping a bubble of air within the drop. However, these events occur at diminutive length scales and fleeting time scales; therefore, to visualize them we develop new imaging modalities that are sensitive to the behavior right at the surface and that have time resolution superior to even the very fastest cameras. These imaging techniques reveal that the ultimate wetting of the surface occurs through a completely new mechanism, the breakup of the thin film of air through a spinodal like dewetting process that breaks the cylindrical symmetry of the impact and drives an anomalously rapid spreading of a wetting front. These results are in accord with recent theoretical predictions and challenge the prevailing paradigm in which contact between the liquid and solid occurs immediately, and spreading is dominated by the dynamics of a single contact line.

  12. Stability and in vitro toxicity of an infliximab eye drop formulation.

    Science.gov (United States)

    Robert, Marie-Claude; Spurr-Michaud, Sandra; Frenette, Mathieu; Young, David; Gipson, Ilene K; Dohlman, Claes H

    2014-01-01

    The purpose of this study was to develop a novel 10-mg/mL infliximab eye drop, to characterize its physical and biological stability under recommended storage conditions, and to assess the formulation's toxicity to ocular surface epithelium in vitro. Infliximab (10 mg/mL) was reconstituted using equal volumes of sterile water and 1% carboxymethylcellulose artificial tears. Aliquots were stored in either a 4 degrees C refrigerator or -20 degrees C freezer for up to 45 days. Physical stability was assessed through monitoring the solution's appearance, pH, ultraviolet-visible-near infrared absorbance and scattering, as well as protein gel electrophoresis. Biological stability was assayed through binding to tumor necrosis factor-alpha using an enzyme-linked immunosorbent assay. In vitro cytotoxicity to human corneal-limbal epithelial cells was examined following a 4-hour exposure to the study drug. Refrigerated and frozen infliximab eye drops remained clear and colorless for the duration of study. The formulation's pH (7.0) was comparable to that of the artificial tear vehicle alone. Low levels of ultraviolet-visible-near infrared light absorbance and scattering established the lack of protein precipitate after refrigeration or freezing. Protein gel electrophoresis performed under reducing conditions revealed the presence of two main protein bands of approximately 50 kDa and 25 kDa, representing immunoglobulin G heavy and light chains. The migration pattern of the proteins did not change under the different storage conditions and between day 10 and 45 after formulation. Infliximab binding to tumor necrosis factor-alpha remained stable for up to 45 days, with conservation of 101% and 102% of its initial binding activity when refrigerated or frozen, respectively. In vitro human corneal-limbal epithelial cultures showed no increase in cytotoxicity with infliximab treatment when compared to vehicle and culture media controls (P > 0.05). Infliximab can be formulated as an

  13. Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

    Science.gov (United States)

    Shrivas, Kamlesh; Wu, Hui-Fen

    2007-11-02

    A simple and rapid sample cleanup and preconcentration method for the quantitative determination of caffeine in one drop of beverages and foods by gas chromatography/mass spectrometry (GC/MS) has been proposed using drop-to-drop solvent microextraction (DDSME). The best optimum experimental conditions for DDSME were: chloroform as the extraction solvent, 5 min extraction time, 0.5 microL exposure volume of the extraction phase and no salt addition at room temperature. The optimized methodology exhibited good linearity between 0.05 and 5.0 microg/mL with correlation coefficient of 0.980. The relative standard deviation (RSD) and limits of detection (LOD) of the DDSME/GC/MS method were 4.4% and 4.0 ng/mL, respectively. Relative recovery of caffeine in beverages and foods were found to be 96.6-101%, which showing good reliability of this method. This DDSME excludes the major disadvantages of conventional method of caffeine extraction, like large amount of organic solvent and sample consumption and long sample pre-treatment process. So, this approach proves that the DDSME/GC/MS technique can be applied as a simple, fast and feasible diagnosis tool for environmental, food and biological application for extremely small amount of real sample analysis.

  14. Drops and bubbles in contact with solid surfaces

    CERN Document Server

    Ferrari, Michele

    2012-01-01

    The third volume in a series dedicated to colloids and interfaces, Drops and Bubbles in Contact with Solid Surfaces presents an up-to-date overview of the fundamentals and applications of drops and bubbles and their interaction with solid surfaces. The chapters cover the theoretical and experimental aspects of wetting and wettability, liquid-solid interfacial properties, and spreading dynamics on different surfaces, including a special section on polymers. The book examines issues related to interpretation of contact angle from nano to macro systems. Expert contributors discuss interesting pec

  15. Hanging colloidal drop: A new photonic crystal synthesis route

    Science.gov (United States)

    Sandu, Ion; Dumitru, Marius; Fleaca, Claudiu Teodor; Dumitrache, Florian

    2018-05-01

    High-quality photonic crystals (hundreds of micrometres in thickness) were grown by the free evaporation of a colloidal drop consisting of silica and polystyrene nanospheres with dimensions of 300 nm, 500 nm, and 1000 nm. The essence of experimental findings is that the drop has to hang on a pillar. This leads to the inhibition of the droplet spreading, the minimisation of the convective force, and the zeroing of the static frictional force between nanospheres and the liquid/air interface, where the first layer is formed. The theoretical essence is the continuous adjustment of nanospheres positions during the growth of photonic crystal, a key condition of the self-assembling phenomenon.

  16. Hanging drop cultures of human testis and testis cancer samples

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Young, J; Nielsen, J E

    2014-01-01

    cultured in 'hanging drops' and effects of activin A and follistatin treatment were investigated in seminoma cultures. RESULTS: Testis fragments with normal spermatogenesis or CIS cells were cultured for 14 days with sustained proliferation of germ cells and CIS cells and without increased apoptosis....... Seminoma cultures survived 7 days, with proliferating cells detectable during the first 5 days. Activin A treatment significantly reduced KIT transcript and protein levels in seminoma cultures, thereby demonstrating a specific treatment response. CONCLUSIONS: Hanging drop cultures of human testis...

  17. Bioconversion of poultry droppings for biogas and algal production

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevaswamy, M.; Venkataraman, L.V.

    1986-01-01

    An integrated system for the bioconversion of poultry droppings for biogas production and utilization of the effluent for the production of the blue-green alga Spirulina platensis was studied. Poultry droppings produced 0.54 cubic m of biogas per kilogran of Total Solids (TS). The 2% TS biogas plant effluent as sole nutrient medium for Spirulina yielded 7-8 g dry algae a day. The biomass was harvested by filtration. The sundried algal biomass has been used as a poultry feed component. In economic terms the system appears promising. 18 references.

  18. Neck extensor muscle weakness (Dropped head syndrome) following radiotherapy

    International Nuclear Information System (INIS)

    Bhatia, S.; Miller, R.C.; Lachance, D.L.

    2006-01-01

    Background. Dropped head syndrome is an unusual condition in which the head cannot be held upright in its normal anatomic position secondary to pronounced, isolated, neck extensor muscle weakness. Case report. A case of dropped head syndrome in a female with a history of radiotherapy for Hodgkin's lymphoma and a clinical history consistent with multiple sclerosis is presented, and potential etiologies are discussed. Conclusions. Muscular atrophy and lower motor neuron injury secondary to isolated anterior horn cell injury from radiotherapy emerge as the most likely etiology. (author)

  19. Efficacy of atropine and anisodamine eye drops for adolescent pseudomyopia

    OpenAIRE

    Hui-Jie Wang

    2017-01-01

    AIM:To investigate the effect and local influence of atropine and anisodamine eye drops on adolescent pseudomyopia. METHODS:Totally 110 cases of juvenile pseudomyopia were randomly divided into two groups, the control group was given 10g/L atropine sulfate eye gel, and the observation group was treated with 5g/L raceanisodamine eye drops. The efficacy of two methods, the changes of axial length and intraocular pressure before and after treatment, and the incidence of adverse reactions were co...

  20. Predicting pressure drop in venturi scrubbers with artificial neural networks.

    Science.gov (United States)

    Nasseh, S; Mohebbi, A; Jeirani, Z; Sarrafi, A

    2007-05-08

    In this study a new approach based on artificial neural networks (ANNs) has been used to predict pressure drop in venturi scrubbers. The main parameters affecting the pressure drop are mainly the gas velocity in the throat of venturi scrubber (V(g)(th)), liquid to gas flow rate ratio (L/G), and axial distance of the venturi scrubber (z). Three sets of experimental data from five different venturi scrubbers have been applied to design three independent ANNs. Comparing the results of these ANNs and the calculated results from available models shows that the results of ANNs have a better agreement with experimental data.

  1. Structure and Dynamics of Interfaces: Drops and Films

    Science.gov (United States)

    Mann, J. Adin, Jr.; Mann, Elizabeth K.; Meyer, William V.; Neumann, A. Wilhelm; Tavana, Hossein

    2015-01-01

    We aim to acquire measurements of the structure and dynamics of certain liquid-fluid interfaces using an ensemble of techniques in collaboration: (1) Total internal reflection (TIR) Surface light scattering spectroscopy (SLSS), (2) Brewster angle microscopy (BAM), and (3) Drop-shape analysis. SLSS and BAM can be done on a shared interfacial footprint. Results using a 50-50 mixture of pentane-isohexane, which extends the range of NASA's Confined Vapor Bubble (CVB) experiment, yield surface tension results that differ from the expected Langmuir Fit. These results were confirmed using both the SLSS and drop-shape analysis approaches.

  2. Medium carbon vanadium micro alloyed steels for drop forging

    International Nuclear Information System (INIS)

    Jeszensky, Gabor; Plaut, Ronald Lesley

    1992-01-01

    Growing competitiveness of alternative manufacturing routes requires cost minimization in the production of drop forged components. The authors analyse the potential of medium carbon, vanadium microalloyed steels for drop forging. Laboratory and industrial experiments have been carried out emphasizing deformation and temperature cycles, strain rates and dwell times showing a typical processing path, associated mechanical properties and corresponding microstructures. The steels the required levels of mechanical properties on cooling after forging, eliminating subsequent heat treatment. The machinability of V-microalloyed steels is also improved when compared with plain medium carbon steels. (author)

  3. Organizational Behavior: Short Changed

    OpenAIRE

    Etchells, Matthew James

    2016-01-01

    There is a growing voice from concerned teachers and education researchers that ‘one of the worrying facts for schools is the potentially high drop-out rate from university’, (Marland, 2003, p. 202). 75% of students who drop-out of university state reasons associated with the first year of study (Tinto, 1995, cited in Dalziel & Peat, 1998). Power, Robertson, and Baker, (1987) suggests universities should devote ‘much attention in the early part of the first year’. The method of data c...

  4. Characterization of polymorphic states in energetic samples of 1,3,5-trinitro-1,3,5-triazine (RDX) fabricated using drop-on-demand inkjet technology.

    Science.gov (United States)

    Emmons, Erik D; Farrell, Mikella E; Holthoff, Ellen L; Tripathi, Ashish; Green, Norman; Moon, Raphael P; Guicheteau, Jason A; Christesen, Steven D; Pellegrino, Paul M; Fountain, Augustus W

    2012-06-01

    The United States Army and the first responder community are evaluating optical detection systems for the trace detection of hazardous energetic materials. Fielded detection systems must be evaluated with the appropriate material concentrations to accurately identify the residue in theater. Trace levels of energetic materials have been observed in mutable polymorphic phases and, therefore, the systems being evaluated must be able to detect and accurately identify variant sample phases observed in spectral data. In this work, we report on the novel application of drop-on-demand technology for the fabrication of standardized trace 1,3,5-trinitro-1,3,5-triazine (RDX) samples. The drop-on-demand sample fabrication technique is compared both visually and spectrally to the more commonly used drop-and-dry technique. As the drop-on-demand technique allows for the fabrication of trace level hazard materials, concerted efforts focused on characterization of the polymorphic phase changes observed with low concentrations of RDX commonly used in drop-on-demand processing. This information is important when evaluating optical detection technologies using samples prepared with a drop-on-demand inkjet system, as the technology may be "trained" to detect the common bulk α phase of the explosive based on its spectral features but fall short in positively detecting a trace quantity of RDX (β-phase). We report the polymorphic shifts observed between α- and β-phases of this energetic material and discuss the conditions leading to the favoring of one phase over the other.

  5. Comparison of the lateral retention forces on sessile and pendant water drops on a solid surface

    Science.gov (United States)

    de la Madrid, Rafael; Whitehead, Taylor; Irwin, George M.

    2015-06-01

    We present a simple experiment that demonstrates how a water drop hanging from a Plexiglas surface (pendant drop) experiences a lateral retention force that is comparable to, and in some cases larger than, the lateral retention force on a drop resting on top of the surface (sessile drop). The experiment also affords a simple demonstration of the Coriolis effect in two dimensions.

  6. Structure Irregularity Impedes Drop Roll-Off at Superhydrophobic Surfaces

    DEFF Research Database (Denmark)

    Larsen, Simon Tylsgaard; Andersen, Nis Korsgaard; Søgaard, Emil

    2014-01-01

    -off angles is found to be caused by a decrease of the receding contact angle, which in turn is caused by an increase of the triple phase contact line of the drops for those more irregular surfaces. To understand the observation, we propose to treat the microdrops as rigid bodies and apply a torque balance...

  7. Air Entrapment and Drop Formation in Piezo Inkjet Printing

    NARCIS (Netherlands)

    van der Bos, J.A.

    2011-01-01

    Piezo drop-on-demand (DOD) inkjet printers are used in an increasing number of applications for their reliable deposition of droplets onto a substrate. Droplets of a few picoliters are ejected from an ink jet nozzle at a frequency of up to 50 kHz. However, entrapment of an air microbubble into the

  8. Monte Carlo studies of nuclei and quantum liquid drops

    International Nuclear Information System (INIS)

    Pandharipande, V.R.; Pieper, S.C.

    1989-01-01

    The progress in application of variational and Green's function Monte Carlo methods to nuclei is reviewed. The nature of single-particle orbitals in correlated quantum liquid drops is discussed, and it is suggested that the difference between quasi-particle and mean-field orbitals may be of importance in nuclear structure physics. 27 refs., 7 figs., 2 tabs

  9. A critical look at South Africa's Green Drop Programme

    African Journals Online (AJOL)

    direct regulation. The programme is based on DWS's realisation that rewarding positive behaviour may be more efficient and effective than sanctioning negative behaviour (Ntombela, 2013). The Green Drop Programme aims to sustainably improve the quality of wastewater management in South Africa by identifying.

  10. Predicting Drop-Out from Social Behaviour of Students

    Science.gov (United States)

    Bayer, Jaroslav; Bydzovska, Hana; Geryk, Jan; Obsivac, Tomas; Popelinsky, Lubomir

    2012-01-01

    This paper focuses on predicting drop-outs and school failures when student data has been enriched with data derived from students social behaviour. These data describe social dependencies gathered from e-mail and discussion board conversations, among other sources. We describe an extraction of new features from both student data and behaviour…

  11. Drop amalgam voltammetric study of lead complexation by natural ...

    African Journals Online (AJOL)

    A study of inorganic complexation of lead using drop amalgam voltammetry is described. The study has been carried out in simulated salt lake water and at ionic strength of 7.35 M, the predetermined ionic strength of Lake Katwe. The complexation of lead with the simple ligands (Cl-, CO32-) created anodic waves and the ...

  12. Drop Jumping as a Training Method for Jumping Ability

    NARCIS (Netherlands)

    Bobbert, Maarten F.

    1990-01-01

    Vertical jumping ability is of importance for good performance in sports such as basketball and volleyball. Coaches are in need of exercises that consume only little time and still help to improve their players’ jumping ability, without involving a high risk of injury. Drop jumping is assumed to

  13. Price drop and increasing competition; Sinkende Preise und mehr Wettbewerb

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Joachim

    2012-01-06

    Competition in the German PV sector is getting harder. German wholesale providers are dropping their prices, strengthening their marketing activities and expanding their range of services. This is the result of an enquiry made by SONNE WIND and WAeRME in November 2011.

  14. Effects of relative humidity on banana fruit drop

    NARCIS (Netherlands)

    Saengpook, C.; Ketsa, S.; Doorn, van W.G.

    2007-01-01

    Commercial ripening of banana fruit occurs at high relative humidity (RH), which prevents browning of damaged skin areas. In experiments with ripening at high RH (94 ± 1%) the individual fruit (fingers) of `Sucrier¿ (Musa acuminata, AA Group) banana exhibited a high rate of drop. The falling off of

  15. Analysis of the reflection of a micro drop fiber sensor

    Science.gov (United States)

    Sun, Weimin; Liu, Qiang; Zhao, Lei; Li, Yingjuan; Yuan, Libo

    2005-01-01

    Micro drop fiber sensors are effective tools for measuring characters of liquids. These types of sensors are wildly used in biotechnology, beverage and food markets. For a fiber micro drop sensor, the signal of the output light is wavy with two peaks, normally. Carefully analyzing the wavy process can identify the liquid components. Understanding the reason of forming this wavy signal is important to design a suitable sensing head and to choose a suitable signal-processing method. The dripping process of a type of liquids is relative to the characters of the liquid and the shape of the sensing head. The quasi-Gauss model of the light field from the input-fiber end is used to analyse the distribution of the light field in the liquid drop. In addition, considering the characters of the liquid to be measured, the dripping process of the optical signal from the output-fiber end can be expected. The reflection surface of the micro drop varies as serials of spheres with different radiuses and global centers. The intensity of the reflection light changes with the shape of the surface. The varying process of the intensity relates to the tense, refractive index, transmission et al. To support the analyse above, an experimental system is established. In the system, LED is chosen as the light source and the PIN transform the light signal to the electrical signal, which is collected by a data acquisition card. An on-line testing system is made to check the theory discussed above.

  16. Don’t drop the patient: teamwork for cataract surgery

    Directory of Open Access Journals (Sweden)

    Daksha Patel

    2014-04-01

    Full Text Available The purpose of a team is to work together towards a common goal. On an athletics track, relay race teams run with a baton that is passed from one team member to another, without breaking the pace. If the baton is dropped, the team is disqualified.

  17. Evaluation of double drop beads pavement edge lines.

    Science.gov (United States)

    2009-08-01

    This report presents an evaluation of Double Drop Bead (DDB) edge lines used on ALDOT-maintained highways. It compares DDB to three other pavement marking types in terms of service lives, life-cycle costs, and both dry-night retroreflectivity and wet...

  18. Structure formation in soft nanocolloids: liquid-drop model.

    Science.gov (United States)

    Doukas, A-K; Likos, C N; Ziherl, P

    2018-04-25

    Using a model where soft nanocolloids such as spherical polymer brushes and star polymers are viewed as compressible liquid drops, we theoretically explore contact interactions between such particles. By numerically minimizing the phenomenological free energy consisting of bulk and surface terms, we find that at small deformations the drop-drop interaction is pairwise additive and described by a power law. We also propose a theory to describe the small-deformation regime, and the agreement is very good at all drop compressibilities. The large-deformation regime, which is dominated by many-body interactions, is marked by a rich phase diagram which includes the face- and body-centered-cubic, σ, A15, and simple hexagonal lattice as well as isostructural and re-entrant transitions. Most of these features are directly related to the non-convex deformation free energy emerging from many-body effects in the partial-faceting regime. The phase diagram, which depends on just two model parameters, contains many of the condensed phases observed in experiments. We also provide statistical-mechanical arguments that relate the two model parameters to the molecular architecture of the polymeric nanocolloids, chain rigidity, and solvent quality. The model represents a generic framework for the overarching features of the phase behavior of polymeric nanocolloids at high compressions.

  19. Molecular dynamics study of the vaporization of an ionic drop.

    Science.gov (United States)

    Galamba, N

    2010-09-28

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (Na(n)Cl(n))(n=2-4). The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  20. The evaporation of the charged and uncharged water drops ...

    Indian Academy of Sciences (India)

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

    The evaporation of the charged and uncharged water drops suspended in a wind tunnel. Rohini V Bhalwankar, A B Sathe and A K Kamra∗. Indian Institute of Tropical Meteorology, Pune, India. ∗e-mail: kamra@tropmet.res.in. A laboratory experiment has been performed to study the effect of ventilation on the rate of evap-.

  1. Controlling a nuclear reactor with dropped control rods

    International Nuclear Information System (INIS)

    Mc Atee, K.R.; Alsop, B.H.

    1987-01-01

    A control system is described for a nuclear power plant including a reactor with a core having an upper portion and a lower portion and control rods which are inserted into and withdrawn from the core of the reactor vertically to control reactivity in the core. The system comprises: means to measure neutron flux separately in the upper portion and the lower portion of the reactor and to generate from such measurements a signal representative of axial distribution of power between the upper and lower portions of the reactor core; means to detect a dropped control rod in the reactor and to generate a dropped rod signal in response thereto; means to generate an axial power distribution limit signal representative of a critical axial power distribution for a dropped rod condition; means to compare the axial power distribution signal to the axial power distribution limit signal and to generate an axial power distribution out of limits signal when the axial power distribution signal exceeds the axial power distribution limit signal; and means responsive only to the presence of both the dropped rod signal and the axial power distribution out of limits signal to generate a signal for shutting the reactor down

  2. Physiological and biochemical changes during banana ripening and finger drop

    NARCIS (Netherlands)

    Imsabai, W.; Ketsa, S.; Doorn, van W.G.

    2006-01-01

    Fruit drop of banana is due to breaking at the junction of the pedicel and pulp, and we found no true abscission zone. The breakage seems therefore due to weakening of the peel. We investigated pectin hydrolysis and some properties at the rupture zone, using `Hom Thong` (Musa acuminata, AAA Group)

  3. Fragment size distribution in viscous bag breakup of a drop

    Science.gov (United States)

    Kulkarni, Varun; Bulusu, Kartik V.; Plesniak, Michael W.; Sojka, Paul E.

    2015-11-01

    In this study we examine the drop size distribution resulting from the fragmentation of a single drop in the presence of a continuous air jet. Specifically, we study the effect of Weber number, We, and Ohnesorge number, Oh on the disintegration process. The regime of breakup considered is observed between 12 phase Doppler anemometry. Both the number and volume fragment size probability distributions are plotted. The volume probability distribution revealed a bi-modal behavior with two distinct peaks: one corresponding to the rim fragments and the other to the bag fragments. This behavior was suppressed in the number probability distribution. Additionally, we employ an in-house particle detection code to isolate the rim fragment size distribution from the total probability distributions. Our experiments showed that the bag fragments are smaller in diameter and larger in number, while the rim fragments are larger in diameter and smaller in number. Furthermore, with increasing We for a given Ohwe observe a large number of small-diameter drops and small number of large-diameter drops. On the other hand, with increasing Oh for a fixed We the opposite is seen.

  4. Linear Oscillations of a Supported Bubble or Drop

    Czech Academy of Sciences Publication Activity Database

    Vejražka, Jiří; Vobecká, Lucie; Tihon, Jaroslav

    2013-01-01

    Roč. 25, č. 6 (2013), 062102 ISSN 1070-6631 R&D Projects: GA ČR GAP101/11/0806 Grant - others:COST(XE) MP1106 Institutional support: RVO:67985858 Keywords : oscillating bubble or drop * linear oscillations * lagrange equation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.040, year: 2013

  5. Molecular dynamics study of the vaporization of an ionic drop

    Science.gov (United States)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  6. Mathematics Anxiety and the Affective Drop in Performance

    Science.gov (United States)

    Ashcraft, Mark H.; Moore, Alex M.

    2009-01-01

    The authors provide a brief review of the history and assessment of math anxiety, its relationship to personal and educational consequences, and its important impact on measures of performance. Overall, math anxiety causes an "affective drop," a decline in performance when math is performed under timed, high-stakes conditions, both in laboratory…

  7. Playing with Water Drops: From Wetting to Optics through Electrostatics

    Science.gov (United States)

    Domps, A.; Roques-Carmes, T.

    2011-01-01

    We present a consistent series of activities, including experiments and basic computational studies, investigating the shape and optical properties of water drops in connection with novel technological devices. Most of the work can be carried out with simple teaching equipment and is well suited to undergraduate students. Firstly, we show how the…

  8. Vortex-ring-induced large bubble entrainment during drop impact

    KAUST Repository

    Thoraval, Marie-Jean; Li, Yangfan; Thoroddsen, Sigurdur T

    2016-01-01

    , produced in the neck between the drop and the pool, controls the crater deformations and pinchoff. However, it is not the strongest vortex rings that are responsible for the large bubbles, as they interact too strongly with the pool surface and self

  9. Barriers Keep Drops Of Water Out Of Infrared Gas Sensors

    Science.gov (United States)

    Murray, Sean K.

    1996-01-01

    Infrared-sensor cells used for measuring partial pressures of CO(2) and other breathable gases modified to prevent entry of liquid water into sensory optical paths of cells. Hydrophobic membrane prevents drops of water entrained in flow from entering optical path from lamp to infrared detectors.

  10. Monte Carlo studies of nuclei and quantum liquid drops

    Energy Technology Data Exchange (ETDEWEB)

    Pandharipande, V.R.; Pieper, S.C.

    1989-01-01

    The progress in application of variational and Green's function Monte Carlo methods to nuclei is reviewed. The nature of single-particle orbitals in correlated quantum liquid drops is discussed, and it is suggested that the difference between quasi-particle and mean-field orbitals may be of importance in nuclear structure physics. 27 refs., 7 figs., 2 tabs.

  11. Effectiveness of eye drops protective against ultraviolet radiation.

    Science.gov (United States)

    Daxer, A; Blumthaler, M; Schreder, J; Ettl, A

    1998-01-01

    To test the effectiveness of commercially available ultraviolet (UV)-protective eye drops (8-hydroxy-1-methylchinolinium methylsulphate) which are recommended for protection against both solar and artificial UV radiation. The spectral transmission in the wavelength range from 250 to 500 nm was investigated in 1-nm steps using a high-resolution double monochromator with holographic gratings of 2,400 lines/mm and a 1,000-watt halogen lamp as light source. The transmission spectrum was measured for different values of the layer thickness. The transmission of a liquid layer of about 10 microns, which corresponds to the thickness of the human tear film, shows a cut-off at 290 nm with a transmission of about 25-50% at shorter wavelengths. For wavelengths longer than 290 nm the transmission is higher than 90%. The threshold time ratio for keratitis formation with and without eye drops is above 0.93 considering solar radiation on the earth's surface and above 0.65 considering radiation from arc-welding, respectively. The transmission spectrum of the eye drops under realistic conditions does not show a protective effect against solar UV radiation. However, there exists reduction of UVC radiation in the spectral range typical of artificial UV sources such as arc-welding. We cannot recommend the application of these eye drops as an UV-protective aid against eye damage by solar UV radiation.

  12. Sodium-fuel interaction: dropping experiments and subassembly test

    International Nuclear Information System (INIS)

    Holtbecker, H.; Schins, H.; Jorzik, E.; Klein, K.

    1978-01-01

    Nine dropping tests, which bring together 2 to 4 kg of molten UO 2 with 150 l sodium, showed the incoherency and non-violence of these thermal interactions. The pressures can be described by sodium incipient boiling and bubble collapse; the UO 2 fragmentation by thermal stress and bubble collapse impact forces. The mildness of the interaction is principally due to the slowness and incoherency of UO 2 fragmentation. This means that parametric models which assume instantaneous mixing and fragmentation are of no use for the interpretation of dropping experiments. One parametric model, the Caldarola Fuel Coolant Interaction Variable Mass model, is being coupled to the two dimensional time dependent hydrodynamic REXCO-H code. In a first step the coupling is applicated to a monodimensional geometry. A subassembly test is proposed to validate the model. In this test rapid mixing between UO 2 and sodium has to be obtained. Dispersed molten UO 2 fuel is obtained by flashing injected sodium drops inside a UO 2 melt. This flashing is theoretically explained and modelled as a superheat limited explosion. The measured sodium drop dwell times of two experiments are compared to results obtained from the mentioned theory, which is the basis of the Press 2 Code

  13. Emotional Competence and Drop-Out Rates in Higher Education

    Science.gov (United States)

    Kingston, Emma

    2008-01-01

    Purpose: The purpose of this paper is to compare the emotional competence of first year undergraduates enrolled on a high or low drop-out rate (HDR and LDR, respectively) course, at a newly established university within the UK. Design/methodology/approach: A mixed methods approach using both quantitative and qualitative data collection methods was…

  14. Investigating Call Drops with Field Measurements on Commercial Mobile Phones

    DEFF Research Database (Denmark)

    Messina, Alessandro; Caragea, Gabriel; Compta, Pol Torres

    2013-01-01

    can be done per day. In this paper we present a new methodology to investigate call drops by using mobile phones to do the measurements following the concept of citizen sensing. Therefore, a mobile application for Android is made that collects all necessary data and dumps the measurement results...

  15. La Gotita de Agua (The Little Drop of Water).

    Science.gov (United States)

    Palandra, Maria; Puigdollers, Carmen

    This Spanish reader for children in kindergarten and first grade is about a drop of water that comes to life in a trip through the water cycle of evaporation, condensation, and subsequent return to a drier part of the earth's surface environment. The story is suitable for reading aloud or independent reading. The text is entirely in Spanish.…

  16. Drop spreading and penetration into pre-wetted powders

    KAUST Repository

    Marston, Jeremy; Sprittles, James E.; Zhu, Y.; Li, Erqiang; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

    2013-01-01

    We present results from an experimental study of the impact of liquid drops onto powder beds which are pre-wetted with the impacting liquid. Using high-speed video imaging, we study both the dynamics of the initial spreading regime and drainage

  17. A Novel Virus Causes Scale Drop Disease in Lates calcarifer

    NARCIS (Netherlands)

    Groof, A.; Guelen, L.; Deijs, M.; Wal, van der Y.; Miyata, M.; Ng, K.S.; Grinsven, van L.; Simmelink, B.; Biermann, Y.; Grisez, L.; Lent, van J.W.M.; Ronde, de A.; Chang, S.F.; Schrier, C.; Hoek, L.

    2015-01-01

    From 1992 onwards, outbreaks of a previously unknown illness have been reported in Asian seabass (Lates calcarifer) kept in maricultures in Southeast Asia. The most striking symptom of this emerging disease is the loss of scales. It was referred to as scale drop syndrome, but the etiology remained

  18. Drop-out probabilities of IrisPlex SNP alleles

    DEFF Research Database (Denmark)

    Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt

    2013-01-01

    In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop-out...... of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop-out...... when the amount of DNA was greater than 125 pg for 29 cycles of PCR and greater than 62 pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele...

  19. Drop-In Clinics for Environmental Science Students

    Directory of Open Access Journals (Sweden)

    Marcie Lynne Jacklin

    2008-12-01

    Full Text Available This paper describes the use of drop in clinics as a new pedagogical approach in information literacy instruction. Although drop in clinics have been used before for library instruction purposes, they are generally aligned with improvement of student academic writing. In the scenario described in this article, in contrast, the drop in clinic is used in a different manner. The drop in clinic as described here offers students an opportunity to engage in self-directed learning by letting them control the content of the instruction. The clinic is offered to students as a way for them to direct their own learning of the course content. It is facilitated by the librarian but it is not controlled by the librarian. The use of this innovative approach is grounded in the example of environmental science and tourism students at a medium sized university in Ontario and it is an approach that has been jointly promoted to students by both the librarian and the course instructor.

  20. Probing the nanoscale: the first contact of an impacting drop

    KAUST Repository

    Li, Erqiang; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

    2015-01-01

    When a drop impacts onto a solid surface, the lubrication pressure in the air deforms its bottom into a dimple. This makes the initial contact with the substrate occur not at a point but along a ring, thereby entrapping a central disc of air. We use

  1. Leidenfrost drops cooling surfaces: theory and interferometric measurement

    NARCIS (Netherlands)

    Van Limbeek, Michiel A. J.; Klein Schaarsberg, Martin H.; Sobac, Benjamin; Rednikov, Alexey; Sun, Chao; Colinet, Pierre; Lohse, Detlef

    2017-01-01

    When a liquid drop is placed on a highly superheated surface, it can be levitated by its own vapour. This remarkable phenomenon is referred to as the Leidenfrost effect. The thermally insulating vapour film results in a severe reduction of the heat transfer rate compared to experiments at lower

  2. Rod-drop analysis in fast and thermal spectra

    International Nuclear Information System (INIS)

    Broccoli, U.

    1988-01-01

    The application of Carpenter's method to power profiles resulting from simulated or real rod-drop events has been tested. The conditions which allow the errors to be reduced to a minimum are highlighted. The results obtained show a good agreement with simulated and experimental data. (author). 1 ref., 21 figs, 6 tabs

  3. Analysis of Drop Call Probability in Well Established Cellular ...

    African Journals Online (AJOL)

    Technology in Africa has increased over the past decade. The increase in modern cellular networks requires stringent quality of service (QoS). Drop call probability is one of the most important indices of QoS evaluation in a large scale well-established cellular network. In this work we started from an accurate statistical ...

  4. Predictors of postoperative hemoglobin drop after laparoscopic myomectomy.

    Science.gov (United States)

    Watrowski, Rafał; Jäger, Christoph; Forster, Johannes

    2017-01-01

    Laparoscopic myomectomy (LM) can be associated with significant bleeding. To identify factors influencing the postoperative hemoglobin (Hb) drop after LM. This is a retrospective, single-center study. We evaluated data of 150 consecutive patients undergoing LM due to intramural myomas between 2010 and 2015. The median age of the patients was 37 (23-53) years. The mean diameter of the largest myoma was 5.7 ±2.3 (1.5-12) cm. The mean surgical time was 83 ±38 (35-299) min. The median number of sutures was 3 (1-11). The mean postoperative Hb drop was 1.6 ±1.2 (0-6) g/dl, and the mean estimated blood loss was 261 ±159 (50-1700) ml. In the univariate analysis, the postoperative Hb drop correlated with the duration of surgery (p < 0.001), diameter of the largest myoma (p < 0.001), cumulative myoma weight (p < 0.001), and number of sutures (p < 0.001), but not with patients' age or number of intramural myomas. In the multivariable analysis, the surgical time ( β = 0.395, p < 0.001), diameter of the largest myoma ( β = 0.292, p = 0.03) and preoperative Hb concentration ( β = 0.299, p < 0.001) predicted the postoperative Hb change. Surgical time and dominant myoma diameter are independent predictors of the postoperative Hb drop after LM.

  5. Growing bubbles and freezing drops: depletion effects and tip singularities

    NARCIS (Netherlands)

    Enriquez Paz y Puente, O.R.

    2015-01-01

    In this thesis, the author investigates the growth of gas bubbles in a supersaturated solution and the freezing of water drops when placed on a cold plate. Supersaturated solutions are common in nature and industry; perhaps the best know examples are carbonated drinks, such as beer or soda. These

  6. Mode-routed fiber-optic add-drop filter

    Science.gov (United States)

    Moslehi, Behzad (Inventor); Black, Richard James (Inventor); Shaw, Herbert John (Inventor)

    2000-01-01

    New elements mode-converting two-mode grating and mode-filtering two-mode coupler are disclosed and used as elements in a system for communications, add-drop filtering, and strain sensing. Methods of fabrication for these new two-mode gratings and mode-filtering two-mode couplers are also disclosed.

  7. School drop out in Bangladesh: Insights using panel data

    Science.gov (United States)

    Sabates, R.; Hossain, A.; Lewin, K.M.

    2013-01-01

    This paper examines the relative strength of different factors associated with school drop out using data collected between 2007 and 2009 in Bangladesh. A sample of 9046 children, aged 4-15, was selected across six districts for a household survey focusing on children's school access and experiences. Two groups of children were identified: those…

  8. Hydrocarbon Degradation In Poultry Droppings And Cassava Peels ...

    African Journals Online (AJOL)

    This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels (CP) for nutrient-enhanced biodegradation of petroleum hydrocarbon (THC) in a well drained Typic Paleustults using the THC levels and degradation duration as remediation indices. The performance of the organic ...

  9. Degree Flexibility and University Drop-out: The Italian Experience

    Science.gov (United States)

    Di Pietro, Giorgio; Cutillo, Andrea

    2008-01-01

    How to reduce university drop-out is a topic of increasing concern. Although several measures have been the subject of numerous debates, little attention has been given to those impacting on the duration, structure and content of the supply of university education. This paper looks at the Italian experience to see what can be learnt about the…

  10. Capillarity and wetting phenomena drops, bubbles, pearls, waves

    CERN Document Server

    Gennes, Pierre-Gilles; Quéré, David

    2004-01-01

    As I glance out my window in the early morning, I can see beads of droplets gracing a spider web. The film of dew that has settled on the threads is unstable and breaks up spontaneously into droplets. This phenomenon has implications for the treatment of textile fibers (the process known as "oiling"), glass, and carbon. It is no less important when applying mascara! I take my morning shower. The moment I step out, I dry off by way of evaporation (which makes me feel cold) and by dewetting (the process by which dry areas form spontaneously and expand on my skin). As I rush into my car under a pelting rain, my attention is caught by small drops stuck on my windshield. I also notice larger drops rolling down and others larger still that, like snails, leave behind them a trail of water. I ask myself what the difference is between these rolling drops and grains of sand tumbling down an incline. I wonder why the smallest drops remain stuck. The answers to such questions do help car manufacturers treat the surface o...

  11. Two-phase flow boiling pressure drop in small channels

    International Nuclear Information System (INIS)

    Sardeshpande, Madhavi V.; Shastri, Parikshit; Ranade, Vivek V.

    2016-01-01

    Highlights: • Study of typical 19 mm steam generator tube has been undertaken in detail. • Study of two phase flow boiling pressure drop, flow instability and identification of flow regimes using pressure fluctuations is the main focus of present work. • Effect of heat and mass flux on pressure drop and void fraction was studied. • Flow regimes identified from pressure fluctuations data using FFT plots. • Homogeneous model predicted pressure drop well in agreement. - Abstract: Two-phase flow boiling in small channels finds a variety of applications in power and process industries. Heat transfer, boiling flow regimes, flow instabilities, pressure drop and dry out are some of the key issues related to two-phase flow boiling in channels. In this work, the focus is on pressure drop in two-phase flow boiling in tubes of 19 mm diameter. These tubes are typically used in steam generators. Relatively limited experimental database is available on 19 mm ID tube. Therefore, in the present work, the experimental set-up is designed for studying flow boiling in 19 mm ID tube in such a way that any of the different flow regimes occurring in a steam generator tube (from pre-heating of sub-cooled water to dry-out) can be investigated by varying inlet conditions. The reported results cover a reasonable range of heat and mass flux conditions such as 9–27 kW/m 2 and 2.9–5.9 kg/m 2 s respectively. In this paper, various existing correlations are assessed against experimental data for the pressure drop in a single, vertical channel during flow boiling of water at near-atmospheric pressure. A special feature of these experiments is that time-dependent pressures are measured at four locations along the channel. The steady-state pressure drop is estimated and the identification of boiling flow regimes is done with transient characteristics using time series analysis. Experimental data and corresponding results are compared with the reported correlations. The results will be

  12. Model for determining vapor equilibrium rates in the hanging drop method for protein crystal growth

    Science.gov (United States)

    Baird, James K.; Frieden, Richard W.; Meehan, E. J., Jr.; Twigg, Pamela J.; Howard, Sandra B.; Fowlis, William A.

    1987-01-01

    An engineering analysis of the rate of evaporation of solvent in the hanging drop method of protein crystal growth is presented. Results are applied to 18 drop and well arrangements commonly encountered in the laboratory. The chemical nature of the salt, drop size and shape, drop concentration, well size, well concentration, and temperature are taken into account. The rate of evaporation increases with temperature, drop size, and the salt concentration difference between the drop and the well. The evaporation in this model possesses no unique half-life. Once the salt in the drop achieves 80 percent of its final concentration, further evaporation suffers from the law of diminishing returns.

  13. Non-Contact Temperature Requirements (NCTM) for drop and bubble physics

    Science.gov (United States)

    Hmelo, Anthony B.; Wang, Taylor G.

    1989-01-01

    Many of the materials research experiments to be conducted in the Space Processing program require a non-contaminating method of manipulating and controlling weightless molten materials. In these experiments, the melt is positioned and formed within a container without physically contacting the container's wall. An acoustic method, which was developed by Professor Taylor G. Wang before coming to Vanderbilt University from the Jet Propulsion Laboratory, has demonstrated the capability of positioning and manipulating room temperature samples. This was accomplished in an earth-based laboratory with a zero-gravity environment of short duration. However, many important facets of high temperature containerless processing technology have not been established yet, nor can they be established from the room temperature studies, because the details of the interaction between an acoustic field an a molten sample are largely unknown. Drop dynamics, bubble dynamics, coalescence behavior of drops and bubbles, electromagnetic and acoustic levitation methods applied to molten metals, and thermal streaming are among the topics discussed.

  14. Shortness of Breath

    Science.gov (United States)

    ... filled with air (called pneumotho- rax), it will hinder expansion of the lung, resulting in shortness of ... of Chest Physi- cians. Shortness of Breath: Patient Education. http: / / www. onebreath. org/ document. doc? id= 113. ...

  15. Short-term monitoring of benzene air concentration in an urban area: a preliminary study of application of Kruskal-Wallis non-parametric test to assess pollutant impact on global environment and indoor.

    Science.gov (United States)

    Mura, Maria Chiara; De Felice, Marco; Morlino, Roberta; Fuselli, Sergio

    2010-01-01

    In step with the need to develop statistical procedures to manage small-size environmental samples, in this work we have used concentration values of benzene (C6H6), concurrently detected by seven outdoor and indoor monitoring stations over 12 000 minutes, in order to assess the representativeness of collected data and the impact of the pollutant on indoor environment. Clearly, the former issue is strictly connected to sampling-site geometry, which proves critical to correctly retrieving information from analysis of pollutants of sanitary interest. Therefore, according to current criteria for network-planning, single stations have been interpreted as nodes of a set of adjoining triangles; then, a) node pairs have been taken into account in order to estimate pollutant stationarity on triangle sides, as well as b) node triplets, to statistically associate data from air-monitoring with the corresponding territory area, and c) node sextuplets, to assess the impact probability of the outdoor pollutant on indoor environment for each area. Distributions from the various node combinations are all non-Gaussian, in the consequently, Kruskal-Wallis (KW) non-parametric statistics has been exploited to test variability on continuous density function from each pair, triplet and sextuplet. Results from the above-mentioned statistical analysis have shown randomness of site selection, which has not allowed a reliable generalization of monitoring data to the entire selected territory, except for a single "forced" case (70%); most important, they suggest a possible procedure to optimize network design.

  16. Short-term monitoring of benzene air concentration in an urban area: a preliminary study of application of Kruskal-Wallis non-parametric test to assess pollutant impact on global environment and indoor

    Directory of Open Access Journals (Sweden)

    Maria Chiara Mura

    2010-12-01

    Full Text Available In step with the need to develop statistical procedures to manage small-size environmental samples, in this work we have used concentration values of benzene (C6H6, concurrently detected by seven outdoor and indoor monitoring stations over 12 000 minutes, in order to assess the representativeness of collected data and the impact of the pollutant on indoor environment. Clearly, the former issue is strictly connected to sampling-site geometry, which proves critical to correctly retrieving information from analysis of pollutants of sanitary interest. Therefore, according to current criteria for network-planning, single stations have been interpreted as nodes of a set of adjoining triangles; then, a node pairs have been taken into account in order to estimate pollutant stationarity on triangle sides, as well as b node triplets, to statistically associate data from air-monitoring with the corresponding territory area, and c node sextuplets, to assess the impact probability of the outdoor pollutant on indoor environment for each area. Distributions from the various node combinations are all non-Gaussian, in the consequently, Kruskal-Wallis (KW non-parametric statistics has been exploited to test variability on continuous density function from each pair, triplet and sextuplet. Results from the above-mentioned statistical analysis have shown randomness of site selection, which has not allowed a reliable generalization of monitoring data to the entire selected territory, except for a single "forced" case (70%; most important, they suggest a possible procedure to optimize network design.

  17. Student Drop-Out Trends at Sultan Qaboos University and Kuwait University: 2000-2011

    Science.gov (United States)

    Al Ghanboosi, Salim Saleem; Alqahtani, Abdulmuhsen Ayedh

    2013-01-01

    The current study aims to explore the drop-out trends at Sultan Qaboos. University and Kuwait University. Archival data of the period 2000-2011 were used to achieve this goal. Main findings showed that (a) male drop-out rates are higher than female drop-out rates; (b) drop- out rates at scientific colleges are higher; (c) drop-out rates of…

  18. Optimisation of Lagrangian Flash Flood Microsensors Dropped by Unmanned Aerial Vehicle

    KAUST Repository

    Abdulaal, Mohammed

    2014-05-01

    Abstract Physical Sciences and Engineering Division Mechanical Engineering Department Master of Science Optimisation of Lagrangian Flash Flood Microsensors Dropped by Unmanned Aerial Vehicle by Mohammed Abdulaal Floods are the most common natural disasters, causing thousands of casualties every year in the world. In particular, ash ood events are particularly deadly because of the short timescales on which they occur. Classical sensing solutions such as xed wireless sensor networks or satellite imagery are either too expensive or too inaccurate. Nevertheless, Unmanned Aerial Vehicles equipped with mobile microsensors could be capable of sensing ash oods in real time for a low overall cost, saving lives and greatly improving the e ciency of the emergency response. Using ood simulation data, we show that this system could be used to detect ash oods. We also present an ongoing implementation of this system using 3D printed sensors and sensor delivery systems on a UAV testbed as well as some preliminary results.

  19. Experimental study of the thermal interaction for molten tin dropped into water

    International Nuclear Information System (INIS)

    Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

    1975-12-01

    Multiflash photography with extremely short exposure duration times has been used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapor explosions and fragmentation. It was also found that the thermal constraints required to produce vapor explosions could be relaxed by introducing a stable thermal stratification within the coolant. It is shown that the constraints can be relaxed sufficiently to cause vapor explosions for test conditions for which the calculated interface contact temperatures are lower than the homogeneous nucleation temperature of water. This latter finding shows that achievement of limiting coolant superheats associated with spontaneous nucleation is not the only mechanism by which vapor explosions in liquid-liquid systems are possible

  20. Steam explosions of molten iron oxide drops: easier initiation at small pressurizations

    International Nuclear Information System (INIS)

    Nelson, L.S.; Duda, P.M.

    1982-01-01

    Steam explosions caused by hot molten materials contacting liquid water following a possible light water nuclear reactor core overheat have been investigated by releasing single drops of a core melt simulant, molten iron oxide, into liquid water. Small steam explosions were triggered shortly afterwards by applying a pressure pulse to the water. The threshold peak pulse level above which an explosion always occurs was studied at ambient pressures between 0.083 and 1.12 MPa. It was found that the threshold decreased to a minimum in the range 0.2 - 0.8 MPa and then increased again. The effect of easier initiation as ambient pressure increases may have an important role in the triggering and propagation of a large scale steam explosion through a coarsely premixed dispersion of melt in water. (U.K.)

  1. Apparatus for monitoring two-phase flow

    Science.gov (United States)

    Sheppard, John D.; Tong, Long S.

    1977-03-01

    A method and apparatus for monitoring two-phase flow is provided that is particularly related to the monitoring of transient two-phase (liquid-vapor) flow rates such as may occur during a pressurized water reactor core blow-down. The present invention essentially comprises the use of flanged wire screens or similar devices, such as perforated plates, to produce certain desirable effects in the flow regime for monitoring purposes. One desirable effect is a measurable and reproducible pressure drop across the screen. The pressure drop can be characterized for various known flow rates and then used to monitor nonhomogeneous flow regimes. Another useful effect of the use of screens or plates in nonhomogeneous flow is that such apparatus tends to create a uniformly dispersed flow regime in the immediate downstream vicinity. This is a desirable effect because it usually increases the accuracy of flow rate measurements determined by conventional methods.

  2. Apparatus for monitoring two-phase flow

    International Nuclear Information System (INIS)

    Sheppard, J.D.; Tong, L.S.

    1977-01-01

    A method and apparatus for monitoring two-phase flow is provided that is particularly related to the monitoring of transient two-phase (liquid-vapor) flow rates such as may occur during a pressurized water reactor core blow-down. The present invention essentially comprises the use of flanged wire screens or similar devices, such as perforated plates, to produce certain desirable effects in the flow regime for monitoring purposes. One desirable effect is a measurable and reproducible pressure drop across the screen. The pressure drop can be characterized for various known flow rates and then used to monitor nonhomogeneous flow regimes. Another useful effect of the use of screens or plates in nonhomogeneous flow is that such apparatus tends to create a uniformly dispersed flow regime in the immediate downstream vicinity. This is a desirable effect because it usually increases the accuracy of flow rate measurements determined by conventional methods. 3 claims, 9 figures

  3. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  4. Efect of Pressure-Drop Rate on the Isolation of Cananga Oil using Instantaneous Controlled Pressure-Drop Process.

    Czech Academy of Sciences Publication Activity Database

    Kristiawan, M.; Sobolík, Václav; Al-Haddad, M.; Allaf, K.

    2008-01-01

    Roč. 47, 1 (2008) , s. 66-75 ISSN 0255-2701 Institutional research plan: CEZ:AV0Z40720504 Keywords : cananga oil * essential oil isolation * instantaneous controlled pressure drop (DIC) Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.518, year: 2008

  5. A perspective on the interfacial properties of nanoscopic liquid drops

    International Nuclear Information System (INIS)

    Malijevský, Alexandr; Jackson, George

    2012-01-01

    The structural and interfacial properties of nanoscopic liquid drops are assessed by means of mechanical, thermodynamical, and statistical mechanical approaches that are discussed in detail, including original developments at both the macroscopic level and the microscopic level of density functional theory (DFT). With a novel analysis we show that a purely macroscopic (static) mechanical treatment can lead to a qualitatively reasonable description of the surface tension and the Tolman length of a liquid drop; the latter parameter, which characterizes the curvature dependence of the tension, is found to be negative and has a magnitude of about a half of the molecular dimension. A mechanical slant cannot, however, be considered satisfactory for small finite-size systems where fluctuation effects are significant. From the opposite perspective, a curvature expansion of the macroscopic thermodynamic properties (density and chemical potential) is then used to demonstrate that a purely thermodynamic approach of this type cannot in itself correctly account for the curvature correction of the surface tension of liquid drops. We emphasize that any approach, e.g., classical nucleation theory, which is based on a purely macroscopic viewpoint, does not lead to a reliable representation when the radius of the drop becomes microscopic. The description of the enhanced inhomogeneity exhibited by small drops (particularly in the dense interior) necessitates a treatment at the molecular level to account for finite-size and surface effects correctly. The so-called mechanical route, which corresponds to a molecular-level extension of the macroscopic theory of elasticity and is particularly popular in molecular dynamics simulation, also appears to be unreliable due to the inherent ambiguity in the definition of the microscopic pressure tensor, an observation which has been known for decades but is frequently ignored. The union of the theory of capillarity (developed in the nineteenth

  6. Radiation monitoring

    International Nuclear Information System (INIS)

    Larsson, L.Eh.; B'yuli, D.K.; Karmikel, Dzh.Kh.E.

    1985-01-01

    Recommendations on radiation monitoring of personnel, used medical ionizing radiation source, are given. The necessity to carry out radiation monitoring of situation at medical personnel's positions and personnel dosimetry is marked. It is convenient to subdivide radiation monitoring into 3 types: usual, surgical and special. Usual monitoring is connected with current work; surgical monitoring is carried out to receive information during a concrete operation; special monitoring is used to detect possible deviation from standard conditions of work or when suspecting them

  7. Online fatigue crack growth monitoring with clip gauge and direct current potential drop

    OpenAIRE

    De Tender, Steven; Micone, Nahuel; De Waele, Wim

    2016-01-01

    Fatigue is a well-known failure phenomenon which has been and still is extensively studied. Often structures are designed according to the safe-life principle so no crack initiation occurs. Nowadays there is a high emphasis on cost-efficiency, and one might rather opt for a fail-safe design. Therefore a certain amount of crack growth can be allowed in structures, but then a good knowledge of stresses and related crack growth rates is needed. To this end, extensive studies are done to obtain a...

  8. Application of hanging drop technique to optimize human IgG formulations.

    Science.gov (United States)

    Li, Guohua; Kasha, Purna C; Late, Sameer; Banga, Ajay K

    2010-01-01

    The purpose of this work is to assess the hanging drop technique in screening excipients to develop optimal formulations for human immunoglobulin G (IgG). A microdrop of human IgG and test solution hanging from a cover slide and undergoing vapour diffusion was monitored by a stereomicroscope. Aqueous solutions of IgG in the presence of different pH, salt concentrations and excipients were prepared and characterized. Low concentration of either sodium/potassium phosphate or McIlvaine buffer favoured the solubility of IgG. Addition of sucrose favoured the stability of this antibody while addition of NaCl caused more aggregation. Antimicrobial preservatives were also screened and a complex effect at different buffer conditions was observed. Dynamic light scattering, differential scanning calorimetry and size exclusion chromatography studies were performed to further validate the results. In conclusion, hanging drop is a very easy and effective approach to screen protein formulations in the early stage of formulation development.

  9. Containment performance of transportable storage casks at 9m drop test

    Energy Technology Data Exchange (ETDEWEB)

    Tobita, H. [Hitachi Zosen Corp., Osaka (Japan); Araki, K. [Hitachi Zosen Diesel and Engineering Co., Ltd., Tokyo (Japan)

    2004-07-01

    Spent fuel transportable storage casks usually have a double lid closure system, which consists of primary and secondary lids, and gaskets, to keep the containment function during transportation and storage, and to monitor a leakage or containment function during storage. Metal gasket is planning to be used not only during storage but transportation of both before and after storage. As metal gasket will degrade its containment function by creep during storage period of 50 years, relative displacement such as opening and slide displacement between the flange of the containment vessel and the lid should be restricted to a small range. To maintain the containment performance, we provisionally adopted the maximum opening limit of 0.1mm and the maximum slide displacement limit of 3.0mm in the full-scale cask design based on the report of the fundamental experiment on the metal gasket which examines the relation between leakage rate and sealing gap. The purpose of this study is to analyse the behaviour of the sealed parts (lid and vessel body) under 9m-drop impact test conditions and to establish some analytical method to evaluate this behaviour. In this study, the drop test of 1/3scale model of Hitz-B69 cask with the double lids closure system was carried out, the behaviours of the seal part were measured by displacement sensors, and they were compared with the result of the numerical analysis carried out separateley.

  10. The role of antimicrobial drops Okomistin® in combined chronic blepharoconjunctivitis treatment

    Directory of Open Access Journals (Sweden)

    Igor Anatilevich Makarov

    2015-12-01

    Full Text Available Purpose. The evaluation of antimicrobial drops Okomistin® efficacy in combined treatment of chronic blepharoconjunctivitis. Material and methods. 80 patients (160 eyes with chronic blepharoconjunctivitis were monitored. Demodex acne was found in eyelids of 72 eyes, the growth of saprophytic microflora in 28 cases. The complex of treatment and prevention measures consisted of daily compresses of Сalendula aqueous solution, instillations of Okomistin® eye drops, artificial tears. In the research group, the ultrasound eyelid margin micromassage was performed, and eyelid D’Arsonval therapy in demodex acne cases. Results. More rapid acute illness relief was observed in the eyes of patients in whom physiotherapy treatment was performed. Okomistin® instillations allow achieving sterile conjunctival culture in 3-5 days. Combined therapy helps to restore meibomian gland function, to achieve long-term disease remission. Conclusions. Combined use of the Okomistin®, physiotherapy, hygiene procedures, artificial tears is an effective and safe treatment method for chronic blepharoconjunctivitis combined treatment.

  11. Sizing of colloidal particle and protein molecules in a hanging fluid drop

    Science.gov (United States)

    Ansari, Rafat R.; Suh, Kwang I.

    1995-01-01

    We report non-invasive particle size measurements of polystyrene latex colloidal particles and bovine serum albumin (BSA) protein molecules suspended in tiny hanging fluid drops of 30 micro-Liter volume using a newly designed fiber optic probe. The probe is based upon the principles of the technique of dynamic light scattering (DLS). The motivation for this work comes from growing protein crystals in outer space. Protein crystals have been grown previously in hanging drops in microgravity experiments on-board the space shuttle orbiter. However, obtaining quantitative information on nucleation and growth of the protein crystals in real time has always been a desired goal, but hitherto not achieved. Several protein researchers have shown interest in using DLS to monitor crystal growth process in a droplet, but elaborate instrumentation and optical alignment problems have made in-situ applications difficult. We demonstrate that such an experiment is now possible. Our system offers fast (5 seconds) determination of particle size, utilize safe levels of very low laser power (less than or equal to 0.2 mW), a small scattering volume (approximately 2 x 10(exp -5) cu mm) and high spatial coherence (Beta) values. This is a major step forward when compared to currently available DLS systems.

  12. Four-point potential drop measurements for materials characterization

    International Nuclear Information System (INIS)

    Bowler, Nicola

    2011-01-01

    The technique of measuring the voltage difference (potential drop) between two of the four electrodes of a four-point probe, in order to determine conductivity or surface resistivity of a test piece, is well established in the direct-current (dc) or quasi-dc regime. The technique finds wide usage in the semiconductor industry for the purpose of measuring surface resistivity of semiconductors, and also in the measurement of conductivity of metals, particularly of ferromagnetic metals for which conductivity cannot be easily measured using eddy-current nondestructive evaluation (NDE). In these applications, the conductivity of the test piece is deduced from an analytic formula that depends on the geometry of the probe and test piece. Such a formula requires, as an input, the measured value of the potential drop. Several analytical expressions exist for a variety of test-piece geometries and probe arrangements. Recently, it has been shown that broadband measurements of the potential drop, known as 'alternating current potential drop' (ac PD) measurements, can be used not only to obtain the conductivity of a test piece, but also its linear permeability μ. The beauty of this measurement is that the two parameters are completely decoupled in the quasi-static regime. In fact, μ does not appear in the quasi-static expression for σ. Hence, σ may be obtained from low-frequency ac PD measurements and then μ may be deduced as the frequency increases beyond the quasi-static regime, once σ is known. In this review, both dc and ac solutions that are useful in determining the conductivity of metals and semiconductors, and the permeability of ferromagnetic conductors, are summarized. In particular, flat test pieces with arbitrary thickness are considered. At the next level of complexity, a solution for a half-space coated with a surface layer is given, along with a discussion of the use of the four-point potential drop method for determining thickness of a surface layer, such

  13. Influence of turbulence on the drop growth in warm clouds, Part I: comparison of numerically and experimentally determined collision kernels

    Directory of Open Access Journals (Sweden)

    Christoph Siewert

    2014-09-01

    Full Text Available This study deals with the comparison of numerically and experimentally determined collision kernels of water drops in air turbulence. The numerical and experimental setups are matched as closely as possible. However, due to the individual numerical and experimental restrictions, it could not be avoided that the turbulent kinetic energy dissipation rate of the measurement and the simulations differ. Direct numerical simulations (DNS are performed resulting in a very large database concerning geometric collision kernels with 1470 individual entries. Based on this database a fit function for the turbulent enhancement of the collision kernel is developed. In the experiments, the collision rates of large drops (radius >7.5μm$> 7.5\\,\\text{\\textmu{}m}$ are measured. These collision rates are compared with the developed fit, evaluated at the measurement conditions. Since the total collision rates match well for all occurring dissipation rates the distribution information of the fit could be used to enhance the statistical reliability and for the first time an experimental collision kernel could be constructed. In addition to the collision rates, the drop size distributions at three consecutive streamwise positions are measured. The drop size distributions contain mainly small drops (radius <7.5μm$< 7.5\\,\\text{\\textmu{}m}$. The measured evolution of the drop size distribution is confronted with model calculations based on the newly derived fit of the collision kernel. It turns out that the observed fast evolution of the drop size distribution can only be modeled if the collision kernel for small drops is drastically increased. A physical argument for this amplification is missing since for such small drops, neither DNSs nor experiments have been performed. For large drops, for which a good agreement of the collision rates was found in the DNS and the experiment, the time for the evolution of the spectrum in the wind tunnel is too short to draw

  14. Calcium-Phosphate-Osteopontin Particles Reduce Biofilm Formation and pH Drops in in situ-Grown Dental Biofilms

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Ibsen, Casper Jon Steenberg; Birkedal, Henrik

    2017-01-01

    This 2-period crossover study investigated the effect of calcium-phosphate-osteopontin particles on biofilm formation and pH in 48-h biofilms grown in situ. Bovine milk osteopontin is a highly phosphorylated glycoprotein that has been shown to interfere with bacterial adhesion to salivary......-coated surfaces. Calcium-phosphate-osteopontin particles have been shown to reduce biofilm formation and pH drops in a 5-species laboratory model of dental biofilm without affecting bacterial viability. Here, smooth surface biofilms from 10 individuals were treated ex vivo 6 times/day for 30 min with either...... calcium-phosphate-osteopontin particles or sterile saline. After growth, the amount of biofilm formed was determined by confocal microscopy, and pH drops upon exposure to glucose were monitored using confocal-microscopy-based pH ratiometry. A total of 160 biofilms were analysed. No adverse effects...

  15. A pelvic motion driven electrical stimulator for drop-foot treatment.

    Science.gov (United States)

    Chen, Shih-Wei; Chen, Shih-Ching; Chen, Chiun-Fan; Lai, Jin-Shin; Kuo, Te-Son

    2009-01-01

    Foot switches operating with force sensitive resistors placed in the shoe sole were considered as an effective way for driving FES assisted walking systems in gait restoration. However, the reliability and durability of the foot switches run down after a certain number of steps. As an alternative for foot switches, a simple, portable, and easy to handle motion driven electrical stimulator (ES) is provided for drop foot treatment. The device is equipped with a single tri-axis accelerometer worn on the pelvis, a commercial dual channel electrical stimulator, and a controller unit. By monitoring the pelvic rotation and acceleration during a walking cycle, the events including heel strike and toe off of each step is thereby predicted by a post-processing neural network model.

  16. A neutron spectrometer based on temperature variations in superheated drop compositions

    CERN Document Server

    Apfel, R E

    2002-01-01

    The response of superheated drop detectors (SDDs) to neutron radiation varies in a self-consistent manner with variations in temperature and pressure, making such compositions suitable for neutron spectrometry. The advantage of this approach is that the response functions of candidate materials versus energy as the temperature or pressure is varied are nested and have distinct thresholds, with no thermal neutron response. These characteristics permit unfolding without the uncertainties associated with other spectrometry techniques, where multiple solutions are possible, thus requiring an initial guess of the spectrum. A spectrometer was developed based on the well-established technology for acoustic sensing of bubble events interfaced with a proportional-integral-derivative temperature controller. The active monitor for neutrons, called REMbrandt sup T sup M , was used as the platform for controlling temperature on a SDD probe and for data acquisition, thereby automating the process of measuring the neutron e...

  17. ESA Parabolic Flight, Drop Tower and Centrifuge Opportunities for University Students

    Science.gov (United States)

    Callens, Natacha; Ventura-Traveset, Javier; Zornoza Garcia-Andrade, Eduardo; Gomez-Calero, Carlos; van Loon, Jack J. W. A.; Pletser, Vladimir; Kufner, Ewald; Krause, Jutta; Lindner, Robert; Gai, Frederic; Eigenbrod, Christian

    impact on a system over the whole acceleration spectrum, but can address as well specifically problems which require these high g-levels. A wide range of hypergravity exper-iments can be performed in the LDC facility, including biological, biochemical, microbiological, opto-physical, physical, material and fluid sciences, geology or plasma physics. ESA Education Office financially supports the cost of the campaigns, part of the hardware development, as well as necessary travel and accommodation of the student selected teams. An ELGRA (European Low Gravity Research Association) mentor, i.e. a scientist specialized in gravity-related research, support each student team throughout these education programmes. [1] Pletser V., Gharib T., Gai F., Mora C., Rosier P. "The 50 parabolic flight campaigns of the European Space Agency to conduct short duration microgravity research experimentation", Paper IAC-09-A2.5.1, 60th International Astronautical federation Congress, Daejeon, Korea, October 2009. [2] von Kampen P., Kaczmarczik U., Rath H.J. The new Drop Tower catapult system", Acta Astronautica, 59, 1-5, 278-283, 2006. [3] van Loon J. W. A. , Krause J., Cunha H., Goncalves J., Almeida H., Schiller P. "The Large Diameter Centrifuge, LDC, for life and physical sciences and technology", Proc. of the 'Life in Space for Life on Earth Symposium', Angers, France, 22-27 June 2008. (ESA SP-663, December 2008)

  18. Thermoelectric neutron dosimetry: a short introduction

    International Nuclear Information System (INIS)

    Mathieu, F.; Meier, R.; Debrue, J.; Leonard, F.; Schubert, W.

    1977-01-01

    The paper gives a short introduction and state-of-the-art account of an unconventional, non destructive neutron dosimetry method based on monitoring the neutron fluence dependent changes of the thermoelectric properties of base metals and alloys. The basic principles are exposed and illustrated with experimental data obtained during an exploratory irradiation in the BR2 reactor

  19. Finite amplitude effects on drop levitation for material properties measurement

    Science.gov (United States)

    Ansari Hosseinzadeh, Vahideh; Holt, R. Glynn

    2017-05-01

    The method of exciting shape oscillation of drops to extract material properties has a long history, which is most often coupled with the technique of acoustic levitation to achieve non-contact manipulation of the drop sample. We revisit this method with application to the inference of bulk shear viscosity and surface tension. The literature is replete with references to a "10% oscillation amplitude" as a sufficient condition for the application of Lamb's analytical expressions for the shape oscillations of viscous liquids. Our results show that even a 10% oscillation amplitude leads to dynamic effects which render Lamb's results inapplicable. By comparison with samples of known viscosity and surface tension, we illustrate the complicating finite-amplitude effects (mode-splitting and excess dissipation associated with vorticity) that can occur and then show that sufficiently small oscillations allow us to recover the correct material properties using Lamb's formula.

  20. Development of Active Learning Curriculum for CASPER's Microgravity Drop Tower

    Science.gov (United States)

    Carmona-Reyes, Jorge; Wang, Li; York, Judy; Matthews, Lorin; Laufer, Rene; Cook, Mike; Schmoke, Jimmy; Hyde, Truell

    2016-10-01

    As CASPER's new drop tower comes on line, plans for correlated educational research curricula are underway. CASPER's educational research team is working on developing curricula specific to the CASPER drop tower, modeled on a contest currently in use by (BEST) Robotics Inc. within central Texas independent school districts. The curricula integrates age specific use of computer programming software packages such as ``Scratch'' with industry standard communication protocols and augmented reality applications. Content is constructed around an earth and space science framework, covering subjects such as stars and galaxies, matter and energy, fusion and fission at a middle school level. CASPER faculty are partnering with the Region 12 Service Center; this combination provides a wide range of expertise that includes professional development, pedagogical methods, computational thinking in addition to microgravity and space science research expertise. The details of this work will be presented and samples of the manner in which it is impacting the CASPER research and educational outreach partnership will be discussed.