Sample records for accidental drop scenarios

  1. Drop Testing Representative Multi-Canister Overpacks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Snow, Spencer D.; Morton, Dana K.

    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 capablemore » 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.« less

  2. Why Chalk Breaks into Three Pieces When Dropped

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each…

  3. NAPL migration and ecotoxicity of conventional and renewable fuels in accidental spill scenarios.

    PubMed

    Malk, Vuokko; Barreto Tejera, Eduardo; Simpanen, Suvi; Dahl, Mari; Mäkelä, Riikka; Häkkinen, Jani; Kiiski, Anna; Penttinen, Olli-Pekka

    2014-01-01

    Fuels derived from non-petroleum renewable resources have raised interest due to their potential in replacing petroleum-based fuels, but information on their fate and effects in the terrestrial and aquatic environments in accidental spill scenario is limited. In this study, migration of four fuels (conventional diesel, conventional gasoline, renewable diesel NExBTL, and ethanol-blended gasoline RE85 containing maximum 85% ethanol) as non-aqueous phase liquids (NAPL) in soil was demonstrated in a laboratory-scale experiment. Ecotoxicity data was produced for the same fuels. There was no significant difference in migration of conventional and renewable diesel, but gasoline migrated 1.5 times deeper and 7-9 times faster in sand than diesel. RE85 spread horizontally wider but not as deep (p < 0.05) as conventional gasoline. Conventional gasoline was the most toxic (lethal concentration [LC50] 20 mg/kg total hydrocarbon content [THC]) among the studied fuels in soil toxicity test with earthworm Eisenia fetida followed by ethanol-blended gasoline (LC50 1,643 mg/kg THC) and conventional diesel (LC50 2,432 mg/kg THC), although gasoline evaporated fast from soil. For comparison, the toxicity of the water-accommodated fractions (WAF) of the fuels was tested with water flea Daphnia magna and Vibrio fischeri, also demonstrating groundwater toxicity. The WAF of conventional gasoline and RE85 showed almost similar toxicity to both the aquatic test species. EC50 values of 1:10 (by volume) WAF were 9.9 %WAF (gasoline) and 9.3 %WAF (RE85) to D. magna and 9.3 %WAF (gasoline) and 12.3 %WAF (RE85) to V. fischeri. Low solubility decreased toxicity potential of conventional diesel in aquatic environment, but direct physical effects of oil phase pose a threat to organisms in nature. Renewable diesel NExBTL did not show clear toxicity to any test species.

  4. A probabilistic model for accidental cargo oil outflow from product tankers in a ship-ship collision.

    PubMed

    Goerlandt, Floris; Montewka, Jakub

    2014-02-15

    In risk assessment of maritime transportation, estimation of accidental oil outflow from tankers is important for assessing environmental impacts. However, there typically is limited data concerning the specific structural design and tank arrangement of ships operating in a given area. Moreover, there is uncertainty about the accident scenarios potentially emerging from ship encounters. This paper proposes a Bayesian network (BN) model for reasoning under uncertainty for the assessment of accidental cargo oil outflow in a ship-ship collision where a product tanker is struck. The BN combines a model linking impact scenarios to damage extent with a model for estimating the tank layouts based on limited information regarding the ship. The methodology for constructing the model is presented and output for two accident scenarios is shown. The discussion elaborates on the issue of model validation, both in terms of the BN and in light of the adopted uncertainty/bias-based risk perspective. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Drop interaction with solid boundaries in liquid/liquid systems

    NASA Astrophysics Data System (ADS)

    Bordoloi, Ankur Deep

    The present experimental work was motivated primarily by the CO 2 sequestration process. In a possible scenario during this process, gravity driven CO2 bubbles coalesce at an interface near the rock surface. In another scenario, trapped CO2 fluid may escape from a porous matrix overcoming interfacial force inside a pore. Based on these potential scenarios, the current research was divided into two broad experimental studies. In the first part, coalescence at a quiescent interface of two analogous fluids (silicone oil and water/glycerin mixture) was investigated for water/glycerin drops with Bond number (Bo) ~7 and Ohnesorge number ~ 0.01 using high-speed imaging and time-resolved tomographic PIV. Two perturbation cases with a solid particle wetted in oil and water/glycerin placed adjacent to the coalescing drop were considered. The results were compared with coalescence of a single drop and that of a drop neighBored by a second drop of equivalent size. Each perturbing object caused an initial tilting of the drop, influencing its rupture location, subsequent film retraction and eventual collapse behavior. Once tilted, drops typically ruptured near their lowest vertical position which was located either toward or away from the perturbing object depending on the case. The trends in local retraction speed of the ruptured film and the overall dynamics of the collapsing drops were discussed in detail. In the second part, the motion of gravity driven drops (B o~0.8-11) through a confining orifice d/D<1) was studied using high speed imaging and planar PIV. Drops of water/glycerin, surrounded by silicone oil, fall toward and encounter the orifice plate after reaching terminal speed. The effects of surface wettability were investigated for Both round-edged and sharp-edged orifices. For the round-edged case, a thin film of surrounding oil prevented the drop fluid from contacting the orifice surface, such that the flow outcomes of the drops were independent of surface

  6. Social evaluation of intentional, truly accidental, and negligently accidental helpers and harmers by 10-month-old infants.

    PubMed

    Woo, Brandon M; Steckler, Conor M; Le, Doan T; Hamlin, J Kiley

    2017-11-01

    Whereas adults largely base their evaluations of others' actions on others' intentions, a host of research in developmental psychology suggests that younger children privilege outcome over intention, leading them to condemn accidental harm. To date, this question has been examined only with children capable of language production. In the current studies, we utilized a non-linguistic puppet show paradigm to examine the evaluation of intentional and accidental acts of helping or harming in 10-month-old infants. In Experiment 1 (n=64), infants preferred intentional over accidental helpers but accidental over intentional harmers, suggestive that by this age infants incorporate information about others' intentions into their social evaluations. In Experiment 2 (n=64), infants did not distinguish "negligently" accidental from intentional helpers or harmers, suggestive that infants may find negligent accidents somewhat intentional. In Experiment 3 (n=64), we found that infants preferred truly accidental over negligently accidental harmers, but did not reliably distinguish negligently accidental from truly accidental helpers, consistent with past work with adults and children suggestive that humans are particularly sensitive to negligently accidental harm. Together, these results imply that infants engage in intention-based social evaluation of those who help and harm accidentally, so long as those accidents do not stem from negligence. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Youth versus adult "weightlifting" injuries presenting to United States emergency rooms: accidental versus nonaccidental injury mechanisms.

    PubMed

    Myer, Gregory D; Quatman, Carmen E; Khoury, Jane; Wall, Eric J; Hewett, Timothy E

    2009-10-01

    Resistance training has previously been purported to be unsafe and ineffective in children. The purpose of this investigation was to evaluate resistance training-related injuries presenting to U.S. emergency rooms by age, type, and mechanism of injury. We hypothesized that older athletes would sustain greater percentages of joint sprains and muscle strains, whereas younger athletes would sustain a greater percentage of accidental injuries that would result in an increased percentage of fractures in youths. The U.S. Consumer Product Safety Commission (CPSC) National Electronic Injury Surveillance System was queried from 2002 to 2005 using the CPSC code for "Weightlifting." Subjects between the ages of 8 and 30 were grouped by age categories 8 to 13 (elementary/middle school age), 14 to 18 (high school), 19 to 22 (college), and 23 to 30 (adult). Injuries were classified as "accidental" if caused by dropped weight or improper equipment use. Multiple logistic regression was used to compare accidental injuries between age groups. The sample consisted of 4,111 patients. Accidental injuries decreased (p < 0.05) with age: 8 to 13 > 14 to 18 > 19 to 22 years = 23 to 30 years. Conversely, sprain/strain injuries increased in each successive age group (p < 0.05). Evaluation of only the nonaccidental injuries (n = 2,565) showed that the oldest categories (19-22 and 23-30 yr) demonstrated a greater percentage of sprains and strains relative to younger age categories (p < 0.001). Two thirds of the injuries sustained in the 8 to 13 group were to the hand and foot and were most often related to "dropping" and "pinching" in the injury descriptions, and there was an increased percentage of fractures in the 8 to 13 group relative to all other groups (p < 0.001). The study findings indicate that children have lower risk of resistance training-related joint sprains and muscle strains than adults. The majority of youth resistance training injuries are the result of accidents that are

  8. Projecting temperature-related years of life lost under different climate change scenarios in one temperate megacity, China.

    PubMed

    Li, Yixue; Li, Guoxing; Zeng, Qiang; Liang, Fengchao; Pan, Xiaochuan

    2018-02-01

    Temperature has been associated with population health, but few studies have projected the future temperature-related years of life lost attributable to climate change. To project future temperature-related disease burden in Tianjin, we selected years of life lost (YLL) as the dependent variable to explore YLL attributable to climate change. A generalized linear model (GLM) and distributed lag non-linear model were combined to assess the non-linear and delayed effects of temperature on the YLL of non-accidental mortality. Then, we calculated the YLL changes attributable to future climate scenarios in 2055 and 2090. The relationships of daily mean temperature with the YLL of non-accident mortality were basically U-shaped. Both the daily mean temperature increase on high-temperature days and its drop on low-temperature days caused an increase of YLL and non-accidental deaths. The temperature-related YLL will worsen if future climate change exceeds 2 °C. In addition, the adverse effects of extreme temperature on YLL occurred more quickly than that of the overall temperature. The impact of low temperature was greater than that of high temperature. Men were vulnerable to high temperature compared with women. This analysis highlights that the government should formulate environmental policies to reach the Paris Agreement goal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Dispersion modeling of accidental releases of toxic gases - Comparison of the models and their utility for the fire brigades.

    NASA Astrophysics Data System (ADS)

    Stenzel, S.; Baumann-Stanzer, K.

    2009-04-01

    Dispersion modeling of accidental releases of toxic gases - Comparison of the models and their utility for the fire brigades. Sirma Stenzel, Kathrin Baumann-Stanzer In the case of accidental release of hazardous gases in the atmosphere, the emergency responders need a reliable and fast tool to assess the possible consequences and apply the optimal countermeasures. For hazard prediction and simulation of the hazard zones a number of air dispersion models are available. The most model packages (commercial or free of charge) include a chemical database, an intuitive graphical user interface (GUI) and automated graphical output for display the results, they are easy to use and can operate fast and effective during stress situations. The models are designed especially for analyzing different accidental toxic release scenarios ("worst-case scenarios"), preparing emergency response plans and optimal countermeasures as well as for real-time risk assessment and management. There are also possibilities for model direct coupling to automatic meteorological stations, in order to avoid uncertainties in the model output due to insufficient or incorrect meteorological data. Another key problem in coping with accidental toxic release is the relative width spectrum of regulations and values, like IDLH, ERPG, AEGL, MAK etc. and the different criteria for their application. Since the particulate emergency responders and organizations require for their purposes unequal regulations and values, it is quite difficult to predict the individual hazard areas. There are a quite number of research studies and investigations coping with the problem, anyway the end decision is up to the authorities. The research project RETOMOD (reference scenarios calculations for toxic gas releases - model systems and their utility for the fire brigade) was conducted by the Central Institute for Meteorology and Geodynamics (ZAMG) in cooperation with the Vienna fire brigade, OMV Refining & Marketing GmbH and

  10. Composite accidental axions

    NASA Astrophysics Data System (ADS)

    Redi, Michele; Sato, Ryosuke

    2016-05-01

    We present several models where the QCD axion arises accidentally. Confining gauge theories can generate axion candidates whose properties are uniquely determined by the quantum numbers of the new fermions under the Standard Model. The Peccei-Quinn symmetry can emerge accidentally if the gauge theory is chiral. We generalise previous constructions in a unified framework. In some cases these models can be understood as the deconstruction of 5-dimensional gauge theories where the Peccei-Quinn symmetry is protected by locality but more general constructions are possible.

  11. Epidemiology of accidental radiation exposures.

    PubMed Central

    Cardis, E

    1996-01-01

    Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge concerning radiation effects, review major large-scale accidental radiation exposures, and discuss information that could be obtained from studies of accidental exposures and the types of studies that are needed. PMID:8781398

  12. Assessment of the Incentives Created by Public Disclosure of Off-Site Consequence Analysis Information for Reduction in the Risk of Accidental Releases

    EPA Pesticide Factsheets

    The off-site consequence analysis (OCA) evaluates the potential for worst-case and alternative accidental release scenarios to harm the public and environment around the facility. Public disclosure would likely reduce the number/severity of incidents.

  13. 5 CFR 870.206 - Accidental death and dismemberment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Accidental death and dismemberment. 870....206 Accidental death and dismemberment. (a) (1) Accidental death and dismemberment coverage is an automatic part of Basic and Option A insurance for employees. (2) There is no accidental death and...

  14. 5 CFR 870.206 - Accidental death and dismemberment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Accidental death and dismemberment. 870....206 Accidental death and dismemberment. (a)(1) Accidental death and dismemberment coverage is an automatic part of Basic and Option A insurance for employees. (2) There is no accidental death and...

  15. 5 CFR 870.206 - Accidental death and dismemberment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Accidental death and dismemberment. 870....206 Accidental death and dismemberment. (a)(1) Accidental death and dismemberment coverage is an automatic part of Basic and Option A insurance for employees. (2) There is no accidental death and...

  16. 5 CFR 870.206 - Accidental death and dismemberment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Accidental death and dismemberment. 870....206 Accidental death and dismemberment. (a)(1) Accidental death and dismemberment coverage is an automatic part of Basic and Option A insurance for employees. (2) There is no accidental death and...

  17. 5 CFR 870.206 - Accidental death and dismemberment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Accidental death and dismemberment. 870....206 Accidental death and dismemberment. (a)(1) Accidental death and dismemberment coverage is an automatic part of Basic and Option A insurance for employees. (2) There is no accidental death and...

  18. Modeling of occupational exposure to accidentally released manufactured nanomaterials in a production facility and calculation of internal doses by inhalation

    PubMed Central

    Vaquero-Moralejo, Celina; Jaén, María; Lopez De Ipiña Peña, Jesús; Neofytou, Panagiotis

    2016-01-01

    Background Occupational exposure to manufactured nanomaterials (MNMs) and its potential health impacts are of scientific and practical interest, as previous epidemiological studies associate exposure to nanoparticles with health effects, including increased morbidity of the respiratory and the circulatory system. Objectives To estimate the occupational exposure and effective internal doses in a real production facility of TiO2 MNMs during hypothetical scenarios of accidental release. Methods Commercial software for geometry and mesh generation, as well as fluid flow and particle dispersion calculation, were used to estimate occupational exposure to MNMs. The results were introduced to in-house software to calculate internal doses in the human respiratory tract by inhalation. Results Depending on the accidental scenario, different areas of the production facility were affected by the released MNMs, with a higher dose exposure among individuals closer to the particles source. Conclusions Granted that the study of the accidental release of particles can only be performed by chance, this numerical approach provides valuable information regarding occupational exposure and contributes to better protection of personnel. The methodology can be used to identify occupational settings where the exposure to MNMs would be high during accidents, providing insight to health and safety officials. PMID:27670588

  19. Hazard assessment of substances produced from the accidental heating of chemical compounds.

    PubMed

    Lunghi, A; Gigante, L; Cardillo, P; Stefanoni, V; Pulga, G; Rota, R

    2004-12-10

    Accidental events concerning process industries can affect not only the staff working in, but also the environment and people living next to the factory. For this reason a regulation is imposed by the European Community to prevent accidents that could represent a risk for the population and the environment. In particular, Directive 96/82/CE, the so-called 'Seveso II directive', requests a risk analysis involving also the hazardous materials generated in accidental events. Therefore, it is necessary to develop simple and economic procedure to foresee the hazardous materials that can be produced in the case of major accidents, among which the accidental heating of a chemical due to a fire or a runaway reaction is one of the most frequent. The procedure proposed in this work is based on evolved gas analysis methodology that consists in coupling two instruments: a thermogravimetric analyzer or a flash pyrolyzer, that are employed to simulate accident conditions, and a FTIR spectrometer that can be used to detect the evolved gas composition. More than 40 materials have been examined in various accident scenarios and the obtained data have been statistically analyzed in order to identify meaningful correlations between the presence of a chemical group in the molecule of a chemical and the presence of a given hazardous species in the fume produced.

  20. Distinguishing intentional from accidental actions in orangutans (Pongo pygmaeus), chimpanzees (Pan troglodytes), and human children (Homo sapiens).

    PubMed

    Call, J; Tomasello, M

    1998-06-01

    This study investigates the understanding of others' intentions in 2- and 3-year-old children, chimpanzees (Pan troglodytes), and orangutans (Pongo pygmaeus). During training, subjects learned to use a discriminative cue to select a baited box. During testing, the experimenter placed a marker on top of the baited box to inform the subject of the reward's location. However, the experimenter also accidentally dropped the marker on top of an unbaited box, so that during any given trial the experimenter marked 2 boxes, 1 intentionally and 1 accidentally. All 3 species preferentially selected the box the experimenter had marked intentionally (especially during the initial trials), with 3-year-old children presenting the most robust results. These findings suggest that subjects understood something about the experimenter's intentions. The authors speculate that understanding of others' intentions may precede the understanding of others' beliefs both at the ontogenetic and phylogenetic levels.

  1. [Accidental hanging during auto-erotic practices].

    PubMed

    Vieira, D N; da Silva, A G

    1989-01-01

    An unusual case of accidental hanging during autoerotic practices in a 25-year-old male student is described and the autoerotic asphyxia syndrome briefly discussed. The authors stressed the importance of a correct diagnostic of accidental death in these cases.

  2. [THREE CASES OF ACCIDENTAL AUTO-INJECTION OF ADRENALINE].

    PubMed

    Yanagida, Noriyuki; Iikura, Katsuhito; Ogura, Kiyotake; Wang, Ling-jen; Asaumi, Tomoyuki; Sato, Sakura; Ebisawa, Motohiro

    2015-12-01

    Reports on accidental auto-injection of adrenaline are few. We encountered three cases of accidental injection of adrenaline. In this study, we have examined and reported the clinical courses and symptoms of our cases. CASE 1 involved a female physician in her 50s who had attended an explanatory meeting on auto-injection of adrenaline. She mistook EpiPen® to be the EpiPen trainer and accidentally injected herself with 0.3 mg EpiPen®. Her systolic/diastolic pressure peaked at 7 min to reach 144/78 mmHg and decreased to 120/77 mmHg at 14 min. Except for palpitation after 7 min, the only subjective symptom was local pain at the injection site. CASE 2 was noted in a 6-year-old boy. He accidentally pierced his right forefinger with 0.15 mg EpiPen®, and after 20 min, his right forefinger was swollen. The swelling improved 80 min after the accidental injection. CASE 3 was noted in a 4-year-old girl. She accidentally injected herself with 0.15 mg EpiPen®. Her systolic/diastolic pressure peaked at 23 min to reach 123/70 mmHg and decreased to 96/86 mmHg at 28 min. Severe adverse effects of accidental auto-injection of adrenaline were not observed in these three cases. Our findings suggest that while handling adrenaline auto-injectors, we should keep in mind the possibility of accidental injection.

  3. Dispersion modeling of accidental releases of toxic gases - utility for the fire brigades.

    NASA Astrophysics Data System (ADS)

    Stenzel, S.; Baumann-Stanzer, K.

    2009-09-01

    Several air dispersion models are available for prediction and simulation of the hazard areas associated with accidental releases of toxic gases. The most model packages (commercial or free of charge) include a chemical database, an intuitive graphical user interface (GUI) and automated graphical output for effective presentation of results. The models are designed especially for analyzing different accidental toxic release scenarios ("worst-case scenarios”), preparing emergency response plans and optimal countermeasures as well as for real-time risk assessment and management. The research project RETOMOD (reference scenarios calculations for toxic gas releases - model systems and their utility for the fire brigade) was conducted by the Central Institute for Meteorology and Geodynamics (ZAMG) in cooperation with the Viennese fire brigade, OMV Refining & Marketing GmbH and Synex Ries & Greßlehner GmbH. RETOMOD was funded by the KIRAS safety research program of the Austrian Ministry of Transport, Innovation and Technology (www.kiras.at). The main tasks of this project were 1. Sensitivity study and optimization of the meteorological input for modeling of the hazard areas (human exposure) during the accidental toxic releases. 2. Comparison of several model packages (based on reference scenarios) in order to estimate the utility for the fire brigades. For the purpose of our study the following models were tested and compared: ALOHA (Areal Location of Hazardous atmosphere, EPA), MEMPLEX (Keudel av-Technik GmbH), Trace (Safer System), Breeze (Trinity Consulting), SAM (Engineering office Lohmeyer). A set of reference scenarios for Chlorine, Ammoniac, Butane and Petrol were proceed, with the models above, in order to predict and estimate the human exposure during the event. Furthermore, the application of the observation-based analysis and forecasting system INCA, developed in the Central Institute for Meteorology and Geodynamics (ZAMG) in case of toxic release was

  4. Crisis Management of Accidental Extubation in a Prone-Positioned Patient with Klippel-Feil Syndrome.

    PubMed

    Spond, Matthew; Burns, Tyler; Rosenbaum, Thea; Lienhart, Kristen

    2016-06-15

    We present the case of an accidental extubation in a prone-positioned patient with a challenging airway because of Klippel-Feil syndrome and previous cervical spine fusions. The surgical procedure was well underway when this occurred, which added substantially to the difficulties produced by this event. We herein highlight the corrective steps we took in our case. We also recommend the need for a comprehensive preoperative briefing with all operating room personnel together with an action plan for how to prevent this particular scenario.

  5. Load drop evaluation for TWRS FSAR

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 hoistingmore » 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.« less

  6. The characterization and evaluation of accidental explosions

    NASA Technical Reports Server (NTRS)

    Strehlow, R. A.; Baker, W. E.

    1975-01-01

    Accidental explosions are discussed from a number of viewpoints. First, all accidental explosions, intentional explosions and natural explosions are characterized by type. Second, the nature of the blast wave produced by an ideal (point source or HE) explosion is discussed to form a basis for describing how other explosion processes yield deviations from ideal blast wave behavior. The current status blast damage mechanism evaluation is also discussed. Third, the current status of our understanding of each different category of accidental explosions is discussed in some detail.

  7. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic products...

  8. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic products...

  9. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Reporting of accidental radiation occurrences... SERVICES (CONTINUED) RADIOLOGICAL HEALTH RECORDS AND REPORTS Manufacturers' Reports on Accidental Radiation Occurrences § 1002.20 Reporting of accidental radiation occurrences. (a) Manufacturers of electronic products...

  10. Drop impact into a deep pool: vortex shedding and jet formation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agbaglah, G.; Thoraval, M. -J.; Thoroddsen, S. T.

    2015-02-01

    One of the simplest splashing scenarios results from the impact of a single drop on a deep pool. The traditional understanding of this process is that the impact generates an axisymmetric sheet-like jet that later breaks up into secondary droplets. Recently it was shown that even this simplest of scenarios is more complicated than expected because multiple jets can be generated from a single impact event and there are transitions in the multiplicity of jets as the experimental parameters are varied. Here, we use experiments and numerical simulations of a single drop impacting on a deep pool to examine themore » transition from impacts that produce a single jet to those that produce two jets. Using high-speed X-ray imaging methods we show that vortex separation within the drop leads to the formation of a second jet long after the formation of the ejecta sheet. Using numerical simulations we develop a phase diagram for this transition and show that the capillary number is the most appropriate order parameter for the transition.« less

  11. EPIDEMIOLOGY OF ACCIDENTAL POISONING

    PubMed Central

    Bissell, D. M.; McInnes, Robert S.

    1960-01-01

    In San Jose, California, studies of cases of accidental poisoning showed that the greatest hazard was to children 1 through 3 years of age. Drugs accounted for half the cases, household products for another third, and insecticides and rodenticides and others for the remainder. Most often poison material was within easy reach of the children. An analysis of families in which an accident occurred indicated that accidental poisoning might happen to any family. Since there was little after-effect of poisoning in cases in which treatment was obtained promptly, education directed toward getting prompt treatment seems most advisable. Community agencies interested in poison control need to focus their attention on parents of pre-school children. PMID:13801023

  12. Accidental death in autoerotic maneuvers.

    PubMed

    Focardi, Martina; Gualco, Barbara; Norelli, GianAristide

    2008-03-01

    The authors from the Florence Forensic Department present a case that demonstrates the paradigms attached to accidental deaths while performing autoerotic maneuvers. The incidents of such practices are underestimated and are only the tip of the iceberg since they do not represent the cases that are never reported due to successful practice. After analyzing the statistic data, the authors describe the case and discuss about the element that prove the accidental nature of the death and the importance of the correct application of forensic methodology at the scene and in the mortuary.

  13. Impact of a single drop on the same liquid: formation, growth and disintegration of jets

    NASA Astrophysics Data System (ADS)

    Agbaglah, G. Gilou; Deegan, Robert

    2015-11-01

    One of the simplest splashing scenarios results from the impact of a single drop on on the same liquid. The traditional understanding of this process is that the impact generates a jet that later breaks up into secondary droplets. Recently it was shown that even this simplest of scenarios is more complicated than expected because multiple jets can be generated from a single impact event and there are bifurcations in the multiplicity of jets. First, we study the formation, growth and disintegration of jets following the impact of a drop on a thin film of the same liquid using a combination of numerical simulations and linear stability theory. We obtain scaling relations from our simulations and use these as inputs to our stability analysis. We also use experiments and numerical simulations of a single drop impacting on a deep pool to examine the bifurcation from a single jet into two jets. Using high speed X-ray imaging methods we show that vortex separation within the drop leads to the formation of a second jet long after the formation of the ejecta sheet.

  14. About Assessment Criteria of Driver's Accidental Abilities

    ERIC Educational Resources Information Center

    Lobanova, Yuliya I.; Glushko, Kirill V.

    2016-01-01

    The article points at the importance of studying the human factor as a cause of accidents of drivers, especially in loosely structured traffic situations. The description of the experiment on the measurement of driver's accidental abilities is given. Under accidental ability is meant the capability to ensure the security of driving as a behavior…

  15. Accidental awareness during general anaesthesia - a narrative review.

    PubMed

    Tasbihgou, S R; Vogels, M F; Absalom, A R

    2018-01-01

    Unintended accidental awareness during general anaesthesia represents failure of successful anaesthesia, and so has been the subject of numerous studies during the past decades. As return to consciousness is both difficult to describe and identify, the reported incidence rates vary widely. Similarly, a wide range of techniques have been employed to identify cases of accidental awareness. Studies which have used the isolated forearm technique to identify responsiveness to command during intended anaesthesia have shown remarkably high incidences of awareness. For example, the ConsCIOUS-1 study showed an incidence of responsiveness around the time of laryngoscopy of 1:25. On the other hand, the 5th Royal College of Anaesthetists National Audit Project, which reported the largest ever cohort of patients who had experienced accidental awareness, used a system to identify patients who spontaneously self-reported accidental awareness. In this latter study, the incidence of accidental awareness was 1:19,600. In the recently published SNAP-1 observational study, in which structured postoperative interviews were performed, the incidence was 1:800. In almost all reported cases of intra-operative responsiveness, there was no subsequent explicit recall of intra-operative events. To date, there is no evidence that this occurrence has any psychological consequences. Among patients who experience accidental awareness and can later remember details of their experience, the consequences are better known. In particular, when awareness occurs in a patient who has been given neuromuscular blocking agents, it may result in serious sequelae such as symptoms of post-traumatic stress disorder and a permanent aversion to surgery and anaesthesia, and is feared by patients and anaesthetists. In this article, the published literature on the incidence, consequences and management of accidental awareness under general anaesthesia with subsequent recall will be reviewed. © 2017 The Association

  16. Coalescence of a Drop inside another Drop

    NASA Astrophysics Data System (ADS)

    Mugundhan, Vivek; Jian, Zhen; Yang, Fan; Li, Erqiang; Thoroddsen, Sigurdur

    2016-11-01

    Coalescence dynamics of a pendent drop sitting inside another drop, has been studied experimentally and in numerical simulations. Using an in-house fabricated composite micro-nozzle, a smaller salt-water drop is introduced inside a larger oil drop which is pendent in a tank containing the same liquid as the inner drop. On touching the surface of outer drop, the inner drop coalesces with the surrounding liquid forming a vortex ring, which grows in time to form a mushroom-like structure. The initial dynamics at the first bridge opening up is quantified using Particle Image Velocimetry (PIV), while matching the refractive index of the two liquids. The phenomenon is also numerically simulated using the open-source code Gerris. The problem is fully governed by two non-dimensional parameters: the Ohnesorge number and the diameter ratios of the two drops. The validated numerical model is used to better understand the dynamics of the phenomenon. In some cases a coalescence cascade is observed with liquid draining intermittently and the inner drop reducing in size.

  17. Scaling and Multifractality in Road Accidental Distances

    NASA Astrophysics Data System (ADS)

    Qiu, Tian; Wan, Chi; Zou, Xiang-Xiang; Wang, Xiao-Fan

    Accidental distance dynamics is investigated, based on the road accidental data of the Great Britain. The distance distribution of all the districts as an ensemble presents a power law tail, which is different from that of the individual district. A universal distribution is found for different districts, by rescaling the distribution functions of individual districts, which can be well fitted by the Weibull distribution. The male and female drivers behave similarly in the distance distribution. The multifractal characteristic is further studied for the individual district and all the districts as an ensemble, and different behaviors are also revealed between them. The accidental distances of the individual district show a weak multifractality, whereas of all the districts present a strong multifractality when taking them as an ensemble.

  18. Course Management Systems for Learning: Beyond Accidental Pedagogy

    ERIC Educational Resources Information Center

    McGee, Patricia; Carmean, Colleen; Jafari, Ali

    2005-01-01

    "Course Management Systems for Learning: Beyond Accidental Pedagogy" is a comprehensive overview of standards, practices and possibilities of course management systems in higher education. "Course Management Systems for Learning: Beyond Accidental Pedagogy" focuses on what the current knowledge is (in best practices, research, standards and…

  19. The role of environmental accidental risk assessment in the process of granting development consent.

    PubMed

    Kontic, Branko; Gerbec, Marko

    2009-11-01

    Environmental impact assessment (EIA) is a procedure that must be followed for certain types of development before they are granted development consent. The procedure requires the developer to compile an environmental impact report (EIR) describing the likely significant effects of the project on the environment. A regulatory requirement in Slovenia is that an accidental risk assessment for a new installation should be a part of an EIR. The article shows how risk assessment (RA) related to accidental release of methylene diphenyl diisocyanate (MDI) or a polyvalent alcohol mixture from a new planned unit of a chemical factory in the Alpine region of Slovenia was performed in the framework of an EIA for the purpose of obtaining a construction permit. Two accidental scenarios were considered: (a) a spill of 20 m(3) of MDI or polyvalent alcohol mixture into the river Soca (the river runs close to the chemical factory) and (b) a fire in the warehouse storing the raw material, where emission of toxic gases HCN, NO(x), and CO is expected during combustion of MDI. One of the most important results of this case is the agreement among the developer, the competent authority, and a consultant in the field of EIA and RA to positively conclude the licensing process despite the absence of formal (regulatory) limit values for risk. It has been approved that transparent, reasonably uncertain, and semi-quantitative environmental risk assessment is an inevitable component of an EIA, and an essential factor in informed, licensing-related decision making.

  20. The Accidental Transgressor: Morally Relevant Theory of Mind

    PubMed Central

    Killen, Melanie; Mulvey, Kelly Lynn; Richardson, Cameron; Jampol, Noah

    2014-01-01

    To test young children’s false belief theory of mind in a morally relevant context, two experiments were conducted. In Experiment 1, children (N = 162) at 3.5, 5.5, and 7.5 years of age were administered 3 tasks: prototypic moral transgression task, false belief theory of mind task (ToM), and an “accidental transgressor” task, which measured a morally relevant false belief theory of mind (MoToM). Children who did not pass false belief ToM were more likely to attribute negative intentions to an accidental transgressor than children who passed false belief ToM, and to use moral reasons when blaming the accidental transgressor. In Experiment 2, children (N = 46) who did not pass false belief ToM viewed it as more acceptable to punish the accidental transgressor than did participants who passed false belief ToM. Findings are discussed in light of research on the emergence of moral judgment and theory of mind. PMID:21377148

  1. Statistical discrimination of footwear: a method for the comparison of accidentals on shoe outsoles inspired by facial recognition techniques.

    PubMed

    Petraco, Nicholas D K; Gambino, Carol; Kubic, Thomas A; Olivio, Dayhana; Petraco, Nicholas

    2010-01-01

    In the field of forensic footwear examination, it is a widely held belief that patterns of accidental marks found on footwear and footwear impressions possess a high degree of "uniqueness." This belief, however, has not been thoroughly studied in a numerical way using controlled experiments. As a result, this form of valuable physical evidence has been the subject of admissibility challenges. In this study, we apply statistical techniques used in facial pattern recognition, to a minimal set of information gleaned from accidental patterns. That is, in order to maximize the amount of potential similarity between patterns, we only use the coordinate locations of accidental marks (on the top portion of a footwear impression) to characterize the entire pattern. This allows us to numerically gauge how similar two patterns are to one another in a worst-case scenario, i.e., in the absence of a tremendous amount of information normally available to the footwear examiner such as accidental mark size and shape. The patterns were recorded from the top portion of the shoe soles (i.e., not the heel) of five shoe pairs. All shoes were the same make and model and all were worn by the same person for a period of 30 days. We found that in 20-30 dimensional principal component (PC) space (99.5% variance retained), patterns from the same shoe, even at different points in time, tended to cluster closer to each other than patterns from different shoes. Correct shoe identification rates using maximum likelihood linear classification analysis and the hold-one-out procedure ranged from 81% to 100%. Although low in variance, three-dimensional PC plots were made and generally corroborated the findings in the much higher dimensional PC-space. This study is intended to be a starting point for future research to build statistical models on the formation and evolution of accidental patterns.

  2. Bipedal gait model for precise gait recognition and optimal triggering in foot drop stimulator: a proof of concept.

    PubMed

    Shaikh, Muhammad Faraz; Salcic, Zoran; Wang, Kevin I-Kai; Hu, Aiguo Patrick

    2018-03-10

    Electrical stimulators are often prescribed to correct foot drop walking. However, commercial foot drop stimulators trigger inappropriately under certain non-gait scenarios. Past researches addressed this limitation by defining stimulation control based on automaton of a gait cycle executed by foot drop of affected limb/foot only. Since gait is a collaborative activity of both feet, this research highlights the role of normal foot for robust gait detection and stimulation triggering. A novel bipedal gait model is proposed where gait cycle is realized as an automaton based on concurrent gait sub-phases (states) from each foot. The input for state transition is fused information from feet-worn pressure and inertial sensors. Thereafter, a bipedal gait model-based stimulation control algorithm is developed. As a feasibility study, bipedal gait model and stimulation control are evaluated in real-time simulation manner on normal and simulated foot drop gait measurements from 16 able-bodied participants with three speed variations, under inappropriate triggering scenarios and with foot drop rehabilitation exercises. Also, the stimulation control employed in commercial foot drop stimulators and single foot gait-based foot drop stimulators are compared alongside. Gait detection accuracy (98.9%) and precise triggering under all investigations prove bipedal gait model reliability. This infers that gait detection leveraging bipedal periodicity is a promising strategy to rectify prevalent stimulation triggering deficiencies in commercial foot drop stimulators. Graphical abstract Bipedal information-based gait recognition and stimulation triggering.

  3. Accidental poisoning with "Chinese chalk".

    PubMed

    Martínez-Navarrete, Juan; Loria-Castellanos, Jorge; Nava-Ocampo, Alejandro A

    2008-04-01

    We present a 1.5-year old, 11 kg, female infant with a history of bronchial hyper-responsiveness who accidentally ingested half of a "Chinese chalk". A day later, the infant showed vomiting, cough, fever, drowsiness, and irritability and her clinical conditions progressively worsened. She was admitted to the emergency department with cough, respiratory distress, and hepatomegaly. It has been reported that the chalk may contain deltamethrin and cypermethrin. The patient was successfully treated with supportive therapy. This report identifies "Chinese chalk" as a potential source of accidental poisoning in children and should be considered as part of the differential diagnoses in the emergency rooms since poisoning with these compounds may be misdiagnosed as organophosphate poisoning due to the presentation of similar symptoms.

  4. Accidental Nuclear War: The Growing Peril. Part I [and] Part II.

    ERIC Educational Resources Information Center

    Newcombe, Alan, Ed.

    1984-01-01

    Two volumes designed to increase awareness of accidental nuclear war dangers are presented. The first of 5 sections in volume I proposes that although accidental war is preventable, the current arms race and secrecy about accidents and false alarms increase the possibility of an accidental war. Section 2 posits that decreased decision-making time…

  5. Advancement Is Seldom Accidental.

    ERIC Educational Resources Information Center

    Frantzreb, Arthur C.

    1981-01-01

    Success in college goals and programs for institutional advancement is seldom accidental: success in philanthropic support is seen as 90 percent planning and 10 percent implementation. Trustee membership, long-range plans, the motivational case, experienced staff, adequate budgets, prospect research, supportive communication all meld into a plan…

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

    PubMed

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

    1987-08-01

    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 drop jumps the influence of dropping height on the biomechanics of the jumps. Six subjects executed bounce drop jumps from heights of 20 cm (designated here as DJ20), 40 cm (designated here as DJ40), and 60 cm (designated here as DJ60). During jumping, they were filmed, and ground reaction forces were recorded. The results of a biomechanical analysis show no difference between DJ20 and DJ40 in mechanical output about the joints during the push-off phase. Peak values of moment and power output about the ankles during the push-off phase were found to be smaller in DJ60 than in DJ40 (DJ20 = DJ60). The amplitude of joint reaction forces increased with dropping height. During DJ60, the net joint reaction forces showed a sharp peak on the instant that the heels came down on the ground. Based on the results, researchers are advised to limit dropping height to 20 or 40 cm when investigating training effects of the execution of bounce drop jumps.

  7. Degos disease: a new simulator of non-accidental injury.

    PubMed

    Moss, Celia; Wassmer, Evangeline; Debelle, Geoff; Hackett, Scott; Goodyear, Helen; Malcomson, Roger; Ryder, Clive; Sgouros, Spyros; Shahidullah, Hossain

    2009-08-01

    Recent high-profile cases have made paediatricians very aware of the serious implications of either missing or wrongly diagnosing non-accidental injury. Subdural fluid collections in non-mobile infants usually represent haemorrhage caused by non-accidental injury. We report a 6-month-old male who presented to the Accident and Emergency Department of Birmingham Heartlands Hospital with bilateral subdural fluid collections and skin ulcers resembling cigarette burns. Non-accidental injury was considered to be the most likely diagnosis. However, while under observation in hospital, the child's neurological condition deteriorated with progressive cerebral infarctions, and serial photographs of the skin lesions showed failure to heal. The revised diagnosis, confirmed histologically, was Degos disease, an extremely rare and often fatal occlusive vasculopathy. The child was treated palliatively and died 8 weeks after presentation. This report informs doctors of a new simulator of non-accidental injury to be considered in infants with otherwise unexplained subdural fluid collections.

  8. Game theory of pre-emptive vaccination before bioterrorism or accidental release of smallpox.

    PubMed

    Molina, Chai; Earn, David J D

    2015-06-06

    Smallpox was eradicated in the 1970s, but new outbreaks could be seeded by bioterrorism or accidental release. Substantial vaccine-induced morbidity and mortality make pre-emptive mass vaccination controversial, and if vaccination is voluntary, then there is a conflict between self- and group interests. This conflict can be framed as a tragedy of the commons, in which herd immunity plays the role of the commons, and free-riding (i.e. not vaccinating pre-emptively) is analogous to exploiting the commons. This game has been analysed previously for a particular post-outbreak vaccination scenario. We consider several post-outbreak vaccination scenarios and compare the expected increase in mortality that results from voluntary versus imposed vaccination. Below a threshold level of post-outbreak vaccination effort, expected mortality is independent of the level of response effort. A lag between an outbreak starting and a response being initiated increases the post-outbreak vaccination effort necessary to reduce mortality. For some post-outbreak vaccination scenarios, even modest response lags make it impractical to reduce mortality by increasing post-outbreak vaccination effort. In such situations, if decreasing the response lag is impossible, the only practical way to reduce mortality is to make the vaccine safer (greater post-outbreak vaccination effort leads only to fewer people vaccinating pre-emptively). © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  9. Hazards of Improper Dispensary: Literature Review and Report of an Accidental Chloroform Injection.

    PubMed

    Verma, Prashant; Tordik, Patricia; Nosrat, Ali

    2018-06-01

    Several clear, transparent solutions are used in endodontics. Inappropriate dispensing methods can lead to accidental injection or accidental irrigation. These accidents can cause permanent tissue damage including damage to the bone, periodontium, nerves, and vasculature. This article reports on the consequences of an accidental chloroform injection. Nonsurgical retreatment of tooth #8 was planned as part of a restorative treatment plan in a 69-year-old woman. The dentist accidentally injected chloroform instead of local anesthesia because chloroform was loaded into the anesthetic syringe. The patient experienced severe pain and swelling and soft tissue necrosis and suffered permanent sensory and motor nerve damage. A review of the literature was performed on accidents caused by improper dispensary, namely accidental injections and accidental irrigations. The data were extracted and summarized. Sodium hypochlorite, chlorhexidine, formalin, formocresol, 1:1000 adrenaline, benzalkonium chloride, and lighter fuel were accidentally injected as an intraoral nerve block or as infiltration injections. Bone and soft tissue necrosis, tooth loss, and sensory nerve damage (anesthesia and paresthesia) were the most common consequences reported. Such disastrous events can be prevented by appropriate labeling and separate dispensing methods for each solution. There is a need for disseminating information on toxicity and biocompatibility of materials/solutions used in endodontics. The authors recommend training dental students and endodontic residents on immediate and long-term therapeutic management of patients when an accidental injection or accidental irrigation occurs. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Mistakes in diagnosing non-accidental injury: 10 years' experience

    PubMed Central

    Wheeler, David M; Hobbs, Christopher J

    1988-01-01

    Fifty children who were referred to the child abuse team in Leeds over the 10 years 1976-86 with suspected non-accidental injury were found to have conditions which mimicked non-accidental injury. These included impetigo (nine children) and blue spots (five children). Five children who presented with multiple bruising had haemostatic disorders. Eight children had disorders of the bone. Five children had been previously abused physically. Four showed evidence of neglect. One had evidence of non-accidental injury as well as the condition mimicking abuse. It is emphasised that when child abuse is suspected a sensitive and thorough assessment should be carried out by a paediatrician who is experienced in this. ImagesFIG 1 PMID:3133026

  11. Doctor Ward's Accidental Terrarium.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1996-01-01

    Presents the story of the accidental invention of the Wardian case, or terrarium, by Nathaniel Bagshaw Ward. Advocates the use of this story in teaching precollege biology as an illustration of how a chance event can lead to a major scientific advancement and as an example of the common occurrence of multiple discovery in botany. Contains 34…

  12. Are pre-hospital deaths from accidental injury preventable?

    PubMed Central

    Hussain, L. M.; Redmond, A. D.

    1994-01-01

    OBJECTIVE--To determine what proportion of pre-hospital deaths from accidental injury--deaths at the scene of the accident and those that occur before the person has reached hospital--are preventable. DESIGN--Retrospective study of all deaths from accidental injury that occurred between 1 January 1987 and 31 December 1990 and were reported to the coroner. SETTING--North Staffordshire. MAIN OUTCOME MEASURES--Injury severity score, probability of survival (probit analysis), and airway obstruction. RESULTS--There were 152 pre-hospital deaths from accidental injury (110 males and 42 females). In the same period there were 257 deaths in hospital from accidental injury (136 males and 121 females). The average age at death was 41.9 years for those who died before reaching hospital, and their average injury severity score was 29.3. In contrast, those who died in hospital were older and equally likely to be males or females. Important neurological injury occurred in 113 pre-hospital deaths, and evidence of airway obstruction in 59. Eighty six pre-hospital deaths were due to road traffic accidents, and 37 of these were occupants in cars. On the basis of the injury severity score and age, death was found to have been inevitable or highly likely in 92 cases. In the remaining 60 cases death had not been inevitable and airway obstruction was present in up to 51 patients with injuries that they might have survived. CONCLUSION--Death was potentially preventable in at least 39% of those who died from accidental injury before they reached hospital. Training in first aid should be available more widely, and particularly to motorists as many pre-hospital deaths that could be prevented are due to road accidents. PMID:8173428

  13. Diminished Wastewater Treatment: Evaluation of Septic System Performance Under a Climate Change Scenario

    NASA Astrophysics Data System (ADS)

    Cooper, J.; Loomis, G.; Kalen, D.; Boving, T. B.; Morales, I.; Amador, J.

    2015-12-01

    The effects of climate change are expected to reduce the ability of soil-based onsite wastewater treatment systems (OWTS), to treat domestic wastewater. In the northeastern U.S., the projected increase in atmospheric temperature, elevation of water tables from rising sea levels, and heightened precipitation will reduce the volume of unsaturated soil and oxygen available for treatment. Incomplete removal of contaminants may lead to transport of pathogens, nutrients, and biochemical oxygen demand (BOD) to groundwater, increasing the risk to public health and likelihood of eutrophying aquatic ecosystems. Advanced OWTS, which include pre-treatment steps and provide unsaturated drainfields of greater volume relative to conventional OWTS, are expected to be more resilient to climate change. We used intact soil mesocosms to quantify water quality functions for two advanced shallow narrow drainfield types and a conventional drainfield under a current climate scenario and a moderate climate change scenario of 30 cm rise in water table and 5°C increase in soil temperature. While no fecal coliform bacteria (FCB) was released under the current climate scenario, up to 109 CFU FCB/mL (conventional) and up to 20 CFU FCB/mL (shallow narrow) were released under the climate change scenario. Total P removal rates dropped from 100% to 54% (conventional) and 71% (shallow narrow) under the climate change scenario. Total N removal averaged 17% under both climate scenarios in the conventional, but dropped from 5.4% to 0% in the shallow narrow under the climate change scenario, with additional leaching of N in excess of inputs indicating release of previously held N. No significant difference was observed between scenarios for BOD removal. The initial data indicate that while advanced OWTS retain more function under the climate change scenario, all three drainfield types experience some diminished treatment capacity.

  14. Accidental introductions are an important source of invasive plants in the continental United States.

    PubMed

    Lehan, Nora E; Murphy, Julia R; Thorburn, Lukas P; Bradley, Bethany A

    2013-07-01

    Preventing new plant invasions is critical for reducing large-scale ecological change. Most studies have focused on the deliberate introduction of nonnatives via the ornamental plant trade. However, accidental introduction may be an important source of nonnative, invasive plants. Using Web and literature searches, we compiled pathways of introduction to the United States for 1112 nonnative plants identified as invasive in the continental United States. We assessed how the proportion of accidentally and deliberately introduced invasive plants varies over time and space and by growth habit across the lower 48 states. Deliberate introductions of ornamentals are the primary source of invasive plants in the United States, but accidental introductions through seed contaminants are an important secondary source. Invasive forbs and grasses are the most likely to have arrived accidentally through seed contaminants, while almost all nonnative, invasive trees were introduced deliberately. Nonnative plants invading eastern states primarily arrived deliberately as ornamentals, while a high proportion of invasive plants in western states arrived accidentally as seed contaminants. Accidental introductions may be increasing in importance through time. Before 1850, 10 of 89 (11%) of invasive plants arrived accidentally. After 1900, 20 of 65 (31%) arrived accidentally. Recently enacted screening protocols and weed risk assessments aim to reduce the number of potentially invasive species arriving to the United States via deliberate introduction pathways. Increasing proportions of accidentally introduced invasive plants, particularly associated with contaminated seed imports across the western states, suggest that accidental introduction pathways also need to be considered in future regulatory decisions.

  15. Imitation of Intentional and Accidental Actions by Children with Autism

    ERIC Educational Resources Information Center

    D'Entremont, Barbara; Yazbek, Aimee

    2007-01-01

    To determine whether children with autism (CWA) would selectively imitate intentional, as opposed to accidental actions, an experimenter demonstrated either an "intentional" and an "accidental" action or two "intentional" actions on the same toy [Carpenter, Akhtar, & Tomasello ("1998a") "Infant Behavior and Development, 21," 315-330]. CWA tended…

  16. Experiences of Causing an Accidental Death: An Interpretative Phenomenological Analysis

    ERIC Educational Resources Information Center

    Rassool, Sara B.; Nel, Pieter W.

    2012-01-01

    Accidentally killing or feeling responsible for another person's death constitutes an event that is different from many typical traumatic stressors in that the responsibility for causing the trauma is located in the person themselves, rather than another person or persons. Research exploring the perspective of those who have accidentally caused a…

  17. Why Chalk Breaks into Three Pieces When Dropped

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-01-01

    It has been the author's experience over many years, no doubt shared by others, that a stick of chalk usually breaks into three pieces when accidentally dropped onto the floor. I rarely gave it any thought, apart from noting that the fundamental mode of vibration of a freely supported, rigid rod has two nodes at an equal distance from each end. For example, a baseball bat has a node in the barrel (the sweet spot) about 15 cm from the end and another node in the handle. However, chalk is not expected to break at the node points, since maximum stress arises at the antinode in the middle of the chalk where bending is a maximum. Richard Feynman described a similar problem with long sticks of spaghetti.1 He found that they always break into three or more pieces when bent slowly beyond their breaking point, rather than simply breaking in half. He was unable to figure out why, although the problem was solved many years later2 and is nicely illustrated by Vollmer and Mollmann.3

  18. Accidental degeneracies in nonlinear quantum deformed systems

    NASA Astrophysics Data System (ADS)

    Aleixo, A. N. F.; Balantekin, A. B.

    2011-09-01

    We construct a multi-parameter nonlinear deformed algebra for quantum confined systems that includes many other deformed models as particular cases. We demonstrate that such systems exhibit the property of accidental pairwise energy level degeneracies. We also study, as a special case of our multi-parameter deformation formalism, the extension of the Tamm-Dancoff cutoff deformed oscillator and the occurrence of accidental pairwise degeneracy in the energy levels of the deformed system. As an application, we discuss the case of a trigonometric Rosen-Morse potential, which is successfully used in models for quantum confined systems, ranging from electrons in quantum dots to quarks in hadrons.

  19. Reducing the loss of vaccines from accidental freezing in the cold chain: the experience of continuous temperature monitoring in Tunisia.

    PubMed

    Lloyd, John; Lydon, Patrick; Ouhichi, Ramzi; Zaffran, Michel

    2015-02-11

    Accidental freezing of vaccines is a growing threat and a real risk for national immunization programs when the potency of many vaccines can be compromised if these are exposed to sub-zero temperatures in the cold chain. In Tunisia, this issue is compounded by using sub-standard domestic cold chain equipment instead of equipping the program with medical refrigerators designed specifically for storing vaccines and temperature sensitive pharmaceuticals. Against this backdrop, this paper presents the findings of a demonstration project conducted in Tunisia in 2012 that tested the impact of introducing several freeze prevention solutions to mitigate the risk of accidental freezing of vaccines. The main finding is that, despite the continued use of underperforming domestic refrigerators, continuous temperature monitoring using new technologies combined with other technological interventions significantly reduced the prevalence of accidental exposure to freezing temperatures. These improvements were noticed for cold chain storage at regional, district and health center levels, and during the transport legs that were part of the demonstration conducted in the regions of Kasserine in the South-Eastern part of Tunisia. Subsequent to introducing these freeze prevention solutions, the incidence of freeze alarms was reduced and the percent of time the temperatures dropped below the 2 °C recommended threshold. The incidence of freeze alarms at health center level was reduced by 40%. Lastly, the solutions implemented reduced risk of freezing during transport from 13.8% to 1.7%. Although the solution implemented is not optimal in the longer term because domestic refrigerators are used extensively in district stores and health centers, the risk of accidental freezing is significantly reduced by introducing the practice of continuous temperature monitoring as a standard. The management of the cold chain equipment was strengthened as a result which helps protect the potency of

  20. A screening tool to prioritize public health risk associated with accidental or deliberate release of chemicals into the atmosphere

    PubMed Central

    2013-01-01

    The Chemical Events Working Group of the Global Health Security Initiative has developed a flexible screening tool for chemicals that present a risk when accidentally or deliberately released into the atmosphere. The tool is generic, semi-quantitative, independent of site, situation and scenario, encompasses all chemical hazards (toxicity, flammability and reactivity), and can be easily and quickly implemented by non-subject matter experts using freely available, authoritative information. Public health practitioners and planners can use the screening tool to assist them in directing their activities in each of the five stages of the disaster management cycle. PMID:23517410

  1. Drop dynamics

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.

    1981-01-01

    The drop dynamics module is a Spacelab-compatible acoustic positioning and control system for conducting drop dynamics experiments in space. It consists basically of a chamber, a drop injector system, an acoustic positioning system, and a data collection system. The principal means of collecting data is by a cinegraphic camera. The drop is positioned in the center of the chamber by forces created by standing acoustic waves generated in the nearly cubical chamber (about 12 cm on a side). The drop can be spun or oscillated up to fission by varying the phse and amplitude of the acoustic waves. The system is designed to perform its experiments unattended, except for start-up and shutdown events and other unique events that require the attention of the Spacelab payload specialist.

  2. Drop Tower Experiments concerning Fluid Management under Microgravity

    NASA Astrophysics Data System (ADS)

    Gaulke, Diana; Dreyer, Michael

    2012-07-01

    Transport and positioning of liquid under microgravity is done utilizing capillary forces. Therefore, capillary transport processes have to be understood for a wide variety of space applications, ranging from propellant management in tanks of space transportation systems to eating and drinking devices for astronauts. There are two types of liquid transportation in microgravity using capillary forces. First, the driven liquid flow in open channels where the capillary forces at free surfaces ensure a gas and vapor free flow. Here it is important to know the limiting flow rate through such an open channel before the free surface collapses and gas is sucked into the channel. A number of different experiments at the drop tower Bremen, on sounding rockets and at the ISS have been conducted to analyse this phenomenon within different geometries. As result a geometry dependent theory for calculating the maximum flow rate has been found. On the other hand liquid positioning and transportation requires the capillary pressure of curved surfaces to achieve a liquid flow to a desired area. Especially for space applications the weight of structure has to be taken into account for development. For example liquid positioning in tanks can be achieved via a complicated set of structure filling the whole tank resulting in heavy devices not reasonable in space applications. Astrium developed in cooperation with ZARM a propellant management device much smaller than the tank volume and ensuring a gas and vapour free supply of propellant to the propulsion system. In the drop tower Bremen a model of this device was tested concerning different microgravity scenarios. To further decrease weight and ensure functionality within different scenarios structure elements are designed as perforated geometries. Capillary transport between perforated plates has been analyzed concerning the influence of geometrical pattern of perforations. The conducted experiments at the drop tower Bremen show the

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Individual housing-based socioeconomic status predicts risk of accidental falls among adults.

    PubMed

    Ryu, Euijung; Juhn, Young J; Wheeler, Philip H; Hathcock, Matthew A; Wi, Chung-Il; Olson, Janet E; Cerhan, James R; Takahashi, Paul Y

    2017-07-01

    Accidental falls are a major public health concern among people of all ages. Little is known about whether an individual-level housing-based socioeconomic status measure is associated with the risk of accidental falls. Among 12,286 Mayo Clinic Biobank participants residing in Olmsted County, Minnesota, subjects who experienced accidental falls between the biobank enrollment and September 2014 were identified using ICD-9 codes evaluated at emergency departments. HOUSES (HOUsing-based Index of SocioEconomic Status), a socioeconomic status measure based on individual housing features, was also calculated. Cox regression models were utilized to assess the association of the HOUSES (in quartiles) with accidental fall risk. Seven hundred eleven (5.8%) participants had at least one emergency room visit due to an accidental fall during the study period. Subjects with higher HOUSES were less likely to experience falls in a dose-response manner (hazard ratio: 0.58; 95% confidence interval: 0.44-0.76 for comparing the highest to the lowest quartile). In addition, the HOUSES was positively associated with better health behaviors, social support, and functional status. The HOUSES is inversely associated with accidental fall risk requiring emergency care in a dose-response manner. The HOUSES may capture falls-related risk factors through housing features and socioeconomic status-related psychosocial factors. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Procedures, placement, and risks of further abuse after Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation

    PubMed Central

    Davis, P; McClure, R; Rolfe, K; Chessman, N; Pearson, S; Sibert, J; Meadow, R

    1998-01-01

    OBJECTIVES—To investigate outcome, management, and prevention in Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation.
DESIGN—Ascertainment through British Paediatric Surveillance Unit and questionnaires to responding paediatricians.
SETTING—The UK and Republic of Ireland, September 1992 to August 1994.
SUBJECTS—Children under 14 years diagnosed with the above.
MAIN OUTCOME MEASURES—Placement and child protection measures for victims and siblings; morbidity and reabuse rates for victims; abuse of siblings; prosecution of perpetrators.
RESULTS—Outcome data for 119 with median follow up of 24 months (range 12 to 44 months). No previously diagnosed factitious disease was found to have been caused by genuine disease. Forty six children were allowed home without conditions at follow up. Children who had suffered from suffocation, non-accidental poisoning, direct harm, and those under 5 years were less likely to go home.
 Twenty seven (24%) children still had symptoms or signs as a result of the abuse at follow up; 108/120 were originally on a child protection register and 35/111 at follow up. Twenty nine per cent (34/118) of the perpetrators had been prosecuted and most convicted; 17% of the milder cases of Munchausen syndrome by proxy allowed home were reabused. Evidence in siblings suggests that in 50% of families with a suffocated child and 40% with non-accidental poisoning there would be further abuse, some fatal.
CONCLUSIONS—This type of abuse is severe with high mortality, morbidity, family disruption, reabuse, and harm to siblings. A very cautious approach for child protection with reintroduction to home only if circumstances are especially favourable is advised. Paediatric follow up by an expert in child protection should also occur.

 PMID:9613350

  6. Accidental fetal lacerations during cesarean delivery: experience in an Italian level III university hospital.

    PubMed

    Dessole, Salvatore; Cosmi, Erich; Balata, Antonio; Uras, Luisa; Caserta, Donatella; Capobianco, Giampiero; Ambrosini, Guido

    2004-11-01

    The purpose of this study was to investigate the incidence, type, location, and risk factors of accidental fetal lacerations during cesarean delivery. Total deliveries, cesarean deliveries, and neonatal records for documented accidental fetal lacerations were reviewed retrospectively in our level III university hospital. The gestational age, the presenting part of the fetus, the cesarean delivery indication, the type of incision, and the surgeon who performed the procedure were recorded. Cesarean deliveries were divided into scheduled, unscheduled, and emergency procedures. Fetal lacerations were divided into mild, moderate, and severe. Neonatal follow-up examinations regarding laceration sequelae were available for 6 months. Of 14926 deliveries, 3108 women were delivered by cesarean birth (20.82%). Neonatal records documented 97 accidental fetal lacerations. Of these accidental lacerations, 94 were mild; 2 were moderate, and 1 was severe. The overall rate of accidental fetal laceration per cesarean delivery was 3.12%; the accidental laceration rate in the cohort of fetuses was 2.46%. The crude odds ratios were 0.34 for scheduled procedures, 0.57 for unscheduled procedures, and 1.7 for emergency procedures. The risk for fetal accidental lacerations was higher in fetuses who underwent emergency cesarean birth and lower for unscheduled and scheduled cesarean births (P < .001). Fetal accidental laceration may occur during cesarean delivery; the incidence is significantly higher during emergency cesarean delivery compared with elective procedures. The patient should be counseled about the occurrence of fetal laceration during cesarean delivery to avoid litigation.

  7. Hemodialysis as a treatment of severe accidental hypothermia.

    PubMed

    Caluwé, Rogier; Vanholder, Raymond; Dhondt, Annemieke

    2010-03-01

    We describe a case of severe accidental hypothermia (core body temperature 23.2 degrees C) successfully treated with hemodialysis in a diabetic patient with preexisting renal insufficiency. Consensus exists about cardiopulmonary bypass as the treatment of choice in cases of severe accidental hypothermia with cardiac arrest. Prospective randomized controlled trials comparing the different rewarming modalities for hemodynamically stable patients with hypothermia, however, are lacking. In our opinion, the choice of a rewarming technique should be patient tailored, knowing that hemodialysis is an efficient, minimally invasive, and readily available technique with the advantage of providing electrolyte support.

  8. A descriptive study of accidental skeletal injuries and non-accidental skeletal injuries of child maltreatment.

    PubMed

    Ghanem, Maha A H; Moustafa, Tarek A; Megahed, Haidy M; Salama, Naglaa; Ghitani, Sara A

    2018-02-01

    Lack of awareness and recognition of child maltreatment is the major reason behind underreporting. All victims often interact with the health care system for routine or emergency care. In several research works, non-accidental fractures are the second most common injury in maltreated children and it is represented up to one-third of cases. To determine the incidence of different types of accidental and non-accidental skeletal injuries among children, estimate the severity of injuries according to the modified injury severity score and to determine the degree of fractures either closed or opened (Gustiloe-Anderson open fracture classification). Moreover, identifying fractures resulting from child abuse and neglect. This aimed for early recognition of non-accidental nature of fractures in child maltreatment that can prevent further morbidity and mortality. A descriptive study was carried out on all children (109) with skeletal injuries who were admitted to both Main Alexandria and El-Hadara Orthopedic and Traumatology University Hospitals during six months. History, physical examination and investigations were done for the patients. A detailed questionnaire was taken to diagnose child abuse and neglect. Gustiloe-Anderson open fracture classification was used to estimate the degree of open fractures. Out of 109 children, twelve cases (11%) were categorized as child maltreatment. One case was physical abuse, eight cases (7.3%) were child neglect and three cases (2.8%) were labour exploitation. Road traffic accidents (RTA) was the commonest cause of skeletal injuries followed by falling from height. Regarding falls, they included 4 cases of stair falls in neglected children and another four cases of falling from height (balcony/window). The remaining 36 cases of falls were accidental. The skeletal injuries were in the form of fractures in 99 cases, dislocation in two cases, both fracture and/or dislocation in three cases, and bone deformity from brachial plexus injury

  9. 21 CFR 369.9 - General warnings re accidental ingestion by children.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false General warnings re accidental ingestion by... SERVICES (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.9 General warnings re accidental ingestion...

  10. 21 CFR 369.9 - General warnings re accidental ingestion by children.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false General warnings re accidental ingestion by... SERVICES (CONTINUED) DRUGS FOR HUMAN USE INTERPRETATIVE STATEMENTS RE WARNINGS ON DRUGS AND DEVICES FOR OVER-THE-COUNTER SALE Definitions and Interpretations § 369.9 General warnings re accidental ingestion...

  11. Drop-on-demand drop formation of polyethylene oxide solutions

    NASA Astrophysics Data System (ADS)

    Yan, Xuejia; Carr, Wallace W.; Dong, Hongming

    2011-10-01

    The dynamics of drop-on-demand (DOD) drop formation for solutions containing polyethylene oxide (PEO) have been studied experimentally. Using a piezoelectrical actuated inkjet printhead with the nozzle orifice diameter of 53 μm, experiments were conducted for a series of PEO aqueous solutions with molecular weights ranging from 14 to 1000 kg/mol, polydispersity from 1.02 to 2.5, and concentrations from 0.005 to 10 wt. %. The addition of a small amount of PEO can have a significant effect on the DOD drop formation process, increasing breakup time, decreasing primary drop speed, and decreasing the number of satellite drops in some cases. The effects depend on both molecular weight and concentration. At lower molecular weights (14 and 35 kg/mol), the effect of PEO over the dilute solution regime is insignificant even at concentrations large enough that the solution does not fall in the dilute regime. As PEO molecular weight increased, the effects became significant. For monodispersed PEO solutions, breakup time and primary drop speed closely correlated with effective relaxation time but not for polydispersed PEO. Effective relaxation time depended greatly on molecular weight distribution. Viscosity-average molecular weight, used in calculating effective relaxation time for polydispersed PEO solutions, did not adequately account for high molecular fractions in the molecular weight distribution of the polydispersed PEOs. A mixture rule was developed to calculate the effective relaxation times for aqueous solutions containing mixtures of monodispersed PEO, and breakup times and primary drop speeds correlated well with effective relaxation times. For our experiments, DOD drop formation was limited to Deborah number ≲ 23.

  12. Cooperative breakups induced by drop-to-drop interactions in one-dimensional flows of drops against micro-obstacles.

    PubMed

    Schmit, Alexandre; Salkin, Louis; Courbin, Laurent; Panizza, Pascal

    2015-03-28

    Depending on the capillary number at play and the parameters of the flow geometry, a drop may or may not break when colliding with an obstacle in a microdevice. Modeling the flow of one-dimensional trains of monodisperse drops impacting a micro-obstacle, we show numerically that complex dynamics may arise through drop-to-drop hydrodynamic interactions: we observe sequences of breakup events in which the size of the daughter drops created upon breaking mother ones becomes a periodic function of time. We demonstrate the existence of numerous bifurcations between periodic breakup regimes and we establish diagrams mapping the possible breakup dynamics as a function of the governing (physicochemical, hydrodynamic, and geometric) parameters. Microfluidic experiments validate our model as they concur very well with predictions.

  13. Night work, long work weeks, and risk of accidental injuries. A register-based study.

    PubMed

    Larsen, Ann D; Hannerz, Harald; Møller, Simone V; Dyreborg, Johnny; Bonde, Jens Peter; Hansen, Johnni; Kolstad, Henrik A; Hansen, Åse Marie; Garde, Anne Helene

    2017-11-01

    Objectives The aims of this study were to (i) investigate the association between night work or long work weeks and the risk of accidental injuries and (ii) test if the association is affected by age, sex or socioeconomic status. Methods The study population was drawn from the Danish version of the European Labour Force Survey from 1999-2013. The current study was based on 150 438 participants (53% men and 47% women). Data on accidental injuries were obtained at individual level from national health registers. We included all 20-59-year-old employees working ≥32 hours a week at the time of the interview. We used Poisson regression to estimate the relative rates (RR) of accidental injuries as a function of night work or long work weeks (>40 hours per week) adjusted for year of interview, sex, age, socioeconomic status (SES), industry, and weekly working hours or night work. Age, sex and SES were included as two-way interactions. Results We observed 23 495 cases of accidental injuries based on 273 700 person years at risk. Exposure to night work was statistically significantly associated with accidental injuries (RR 1.11, 99% CI 1.06-1.17) compared to participants with no recent night work. No associations were found between long work weeks (>40 hours) and accidental injuries. Conclusion We found a modest increased risk of accidental injuries when reporting night work. No associations between long work weeks and risk of accidental injuries were observed. Age, sex and SES showed no trends when included as two-way interactions.

  14. Youth Versus Adult “Weightlifting” Injuries Presenting to United States Emergency Rooms: Accidental Versus Nonaccidental Injury Mechanisms

    PubMed Central

    Myer, Gregory D.; Quatman, Carmen E.; Khoury, Jane; Wall, Eric J.; Hewett, Timothy E.

    2014-01-01

    Myer, GD, Quatman, CE, Khoury, J, Wall, EJ, and Hewett, TE. Youth versus adult “weightlifting” injuries presenting to united states emergency rooms: accidental versus nonaccidental injury mechanisms. J Strength Cond Res 23(7): 2054–2060, 2009—Resistance training has previously been purported to be unsafe and ineffective in children. The purpose of this investigation was to evaluate resistance training-related injuries presenting to U.S. emergency rooms by age, type, and mechanism of injury. We hypothesized that older athletes would sustain greater percentages of joint sprains and muscle strains, whereas younger athletes would sustain a greater percentage of accidental injuries that would result in an increased percentage of fractures in youths. The U.S. Consumer Product Safety Commission (CPSC) National Electronic Injury Surveillance System was queried from 2002 to 2005 using the CPSC code for “Weightlifting.” Subjects between the ages of 8 and 30 were grouped by age categories 8 to 13 (elementary/middle school age), 14 to 18 (high school), 19 to 22 (college), and 23 to 30 (adult). Injuries were classified as “accidental” if caused by dropped weight or improper equipment use. Multiple logistic regression was used to compare accidental injuries between age groups. The sample consisted of 4, 111 patients. Accidental injuries decreased (p < 0.05) with age: 8 to 13 > 14 to 18 > 19 to 22 years = 23 to 30 years. Conversely, sprain/strain injuries increased in each successive age group (p < 0.05). Evaluation of only the nonaccidental injuries (n = 2, 565) showed that the oldest categories (19–22 and 23–30 yr) demonstrated a greater percentage of sprains and strains relative to younger age categories (p < 0.001). Two thirds of the injuries sustained in the 8 to 13 group were to the hand and foot and were most often related to “dropping” and “pinching” in the injury descriptions, and there was an increased percentage of fractures in the 8 to 13

  15. The big chill: accidental hypothermia.

    PubMed

    Davis, Robert Allan

    2012-01-01

    A potential cause of such emergent issues as cardiac arrhythmias, hypotension, and fluid and electrolyte shifts, accidental hypothermia can be deadly, is common among trauma patients, and is often difficult to recognize. The author discusses predisposing conditions, the classic presentation, and the effects on normal thermoregulatory processes; explains how to conduct a systems assessment of the hypothermic patient; and describes crucial management strategies.

  16. Computer simulations of nematic drops: Coupling between drop shape and nematic order

    NASA Astrophysics Data System (ADS)

    Rull, L. F.; Romero-Enrique, J. M.; Fernandez-Nieves, A.

    2012-07-01

    We perform Monte Carlo computer simulations of nematic drops in equilibrium with their vapor using a Gay-Berne interaction between the rod-like molecules. To generate the drops, we initially perform NPT simulations close to the nematic-vapor coexistence region, allow the system to equilibrate and subsequently induce a sudden volume expansion, followed with NVT simulations. The resultant drops coexist with their vapor and are generally not spherical but elongated, have the rod-like particles tangentially aligned at the surface and an overall nematic orientation along the main axis of the drop. We find that the drop eccentricity increases with increasing molecular elongation, κ. For small κ the nematic texture in the drop is bipolar with two surface defects, or boojums, maximizing their distance along this same axis. For sufficiently high κ, the shape of the drop becomes singular in the vicinity of the defects, and there is a crossover to an almost homogeneous texture; this reflects a transition from a spheroidal to a spindle-like drop.

  17. Effects of drop freezing on microphysics of an ascending cloud parcel under biomass burning conditions

    NASA Astrophysics Data System (ADS)

    Diehl, K.; Simmel, M.; Wurzler, S.

    There is some evidence that the initiation of warm rain is suppressed in clouds over regions with vegetation fires. Thus, the ice phase becomes important as another possibility to initiate precipitation. Numerical simulations were performed to investigate heterogeneous drop freezing for a biomass-burning situation. An air parcel model with a sectional two-dimensional description of the cloud microphysics was employed with parameterizations for immersion and contact freezing which consider the different ice nucleating efficiencies of various ice nuclei. Three scenarios were simulated resulting to mixed-phase or completely glaciated clouds. According to the high insoluble fraction of the biomass-burning particles drop freezing via immersion and contact modes was very efficient. The preferential freezing of large drops followed by riming (i.e. the deposition of liquid drops on ice particles) and the evaporation of the liquid drops (Bergeron-Findeisen process) caused a further decrease of the liquid drops' effective radius in higher altitudes. In turn ice particle sizes increased so that they could serve as germs for graupel or hailstone formation. The effects of ice initiation on the vertical cloud dynamics were fairly significant leading to a development of the cloud to much higher altitudes than in a warm cloud without ice formation.

  18. Accidental Falls Among Geriatric Patients: Can More Be Prevented?

    PubMed Central

    Johnson, Edwin T.

    1985-01-01

    The potential for accidental falls among geriatric patients is of mounting concern. Two hundred forty-one accidental falls over a 12-month period at the VA Medical Center were analyzed retrospectively and the literature reviewed in order to highlight factors that have bearing on the incidence and severity of falls. If a patient's potential for falling could be identified through a grading system based on these premonitory features, preventive measures might be more clearly focused where needed to reduce this frequent hazard in our hospital population. PMID:4046062

  19. Epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation.

    PubMed Central

    McClure, R J; Davis, P M; Meadow, S R; Sibert, J R

    1996-01-01

    A two year prospective study was performed to determine the epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation in the UK and the Republic of Ireland. Cases were notified to the British Paediatric Association Surveillance Unit from September 1992 to August 1994 if a formal case conference had been held for the first time during that period to discuss any of the above conditions. A total of 128 cases were identified: 55 suffered Munchausen syndrome by proxy alone, 15 poisoning, and 15 suffocation; 43 suffered more than one type of abuse. The majority of children were aged under 5 years, the median age being 20 months. On 85% of occasions the perpetrator was the child's mother. In 42% of families with more than one child, a sibling had previously suffered some form of abuse. Eighty five per cent of notifying paediatricians considered the probability of their diagnosis as virtually certain before a case conference was convened. The commonest drugs used to poison were anticonvulsants; opiates were the second commonest. Sixty eight children suffered severe illness of whom eight died. The combined annual incidence of these conditions in children aged under 16 years is at least 0.5/100,000, and for children aged under 1, at least 2.8/100,000. PMID:8813872

  20. Effects of accidental hypothermia on posttraumatic complications and outcome in multiple trauma patients.

    PubMed

    Mommsen, P; Andruszkow, H; Frömke, C; Zeckey, C; Wagner, U; van Griensven, M; Frink, M; Krettek, C; Hildebrand, F

    2013-01-01

    Accidental hypothermia seems to predispose multiple trauma patients to the development of posttraumatic complications, such as Systemic Inflammatory Response Syndrome (SIRS), sepsis, Multiple Organ Dysfunction Syndrome (MODS), and increased mortality. However, the role of accidental hypothermia as an independent prognostic factor is controversially discussed. The aim of the present study was to evaluate the incidence of accidental hypothermia in multiple trauma patients and its effects on the development of posttraumatic complications and mortality. Inclusion criteria for patients in this retrospective study (2005-2009) were an Injury Severity Score (ISS) ≥16, age ≥16 years, admission to our Level I trauma centre within 6h after the accident. Accidental hypothermia was defined as body temperature less than 35°C measured within 2 h after admission, but always before first surgical procedure in the operation theatre. The association between accidental hypothermia and the development of posttraumatic complications as well as mortality was investigated. Statistical analysis was performed with χ(2)-test, Student's t-test, ANOVA and logistic regression. Statistical significance was considered at p<0.05. 310 multiple trauma patients were enrolled in the present study. Patients' mean age was 41.9 (SD 17.5) years, the mean injury severity score was 29.7 (SD 10.2). The overall incidence of accidental hypothermia was 36.8%. The overall incidence of posttraumatic complications was 77.4% (SIRS), 42.9% (sepsis) and 7.4% (MODS), respectively. No association was shown between accidental hypothermia and the development of posttraumatic complications. Overall, 8.7% died during the posttraumatic course. Despite an increased mortality rate in hypothermic patients, hypothermia failed to be an independent risk factor for mortality in multivariate analysis. Accidental hypothermia is very common in multiply injured patients. However, it could be assumed that the increase of

  1. Dental pain as a risk factor for accidental acetaminophen overdose: a case-control study.

    PubMed

    Vogel, Jody; Heard, Kennon J; Carlson, Catherine; Lange, Chad; Mitchell, Garrett

    2011-11-01

    Patients frequent take acetaminophen to treat dental pain. One previous study found a high rate of overuse of nonprescription analgesics in an emergency dental clinic. The purpose of this study is to determine if patients with dental pain are more likely to be treated for accidental acetaminophen poisoning than patients with other types of pain. We conducted a case-control study at 2 urban hospitals. Cases were identified by chart review of patients who required treatment for accidental acetaminophen poisoning. Controls were self-reported acetaminophen users taking therapeutic doses identified during a survey of emergency department patients. For our primary analysis, the reason for taking acetaminophen was categorized as dental pain or not dental pain. Our primary outcome was the odds ratio of accidental overdose to therapeutic users after adjustment for age, sex, alcoholism, and use of combination products using logistic regression. We identified 73 cases of accidental acetaminophen poisoning and 201 therapeutic users. Fourteen accidental overdose patients and 4 therapeutic users reported using acetaminophen for dental pain. The adjusted odds ratio for accidental overdose due to dental pain compared with other reasons for use was 12.8 (95% confidence interval, 4.2-47.6). We found that patients with dental pain are at increased risk to accidentally overdose on acetaminophen compared with patients taking acetaminophen for other reasons. Emergency physicians should carefully question patients with dental pain about overuse of analgesics. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. ARAMIS project: a comprehensive methodology for the identification of reference accident scenarios in process industries.

    PubMed

    Delvosalle, Christian; Fievez, Cécile; Pipart, Aurore; Debray, Bruno

    2006-03-31

    In the frame of the Accidental Risk Assessment Methodology for Industries (ARAMIS) project, this paper aims at presenting the work carried out in the part of the project devoted to the definition of accident scenarios. This topic is a key-point in risk assessment and serves as basis for the whole risk quantification. The first result of the work is the building of a methodology for the identification of major accident hazards (MIMAH), which is carried out with the development of generic fault and event trees based on a typology of equipment and substances. The term "major accidents" must be understood as the worst accidents likely to occur on the equipment, assuming that no safety systems are installed. A second methodology, called methodology for the identification of reference accident scenarios (MIRAS) takes into account the influence of safety systems on both the frequencies and possible consequences of accidents. This methodology leads to identify more realistic accident scenarios. The reference accident scenarios are chosen with the help of a tool called "risk matrix", crossing the frequency and the consequences of accidents. This paper presents both methodologies and an application on an ethylene oxide storage.

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

    NASA Astrophysics Data System (ADS)

    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

  4. Static shape of an acoustically levitated drop with wave-drop interaction

    NASA Astrophysics Data System (ADS)

    Lee, C. P.; Anilkumar, A. V.; Wang, T. G.

    1994-11-01

    The static shape of a drop levitated and flattened by an acoustic standing wave field in air is calculated, requiring self-consistency between the drop shape and the wave. The wave is calculated for a given shape using the boundary integral method. From the resulting radiation stress on the drop surface, the shape is determined by solving the Young-Laplace equation, completing an iteration cycle. The iteration is continued until both the shape and the wave converge. Of particular interest are the shapes of large drops that sustain equilibrium, beyond a certain degree of flattening, by becoming more flattened at a decreasing sound pressure level. The predictions for flattening versus acoustic radiation stress, for drops of different sizes, compare favorably with experimental data.

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

    PubMed

    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.

  6. Scenario of a dirty bomb in an urban environment and acute management of radiation poisoning and injuries.

    PubMed

    Chin, F K C

    2007-10-01

    In the new security environment, there is a clear and present danger of terrorists using non-conventional weapons to inflict maximum psychological and economic damage on their targets. This article examines two scenarios of radiation contamination and injury, one accidental in nature leading to environmental contamination, and another of deliberate intent resulting in injury and death. This article also discusses the management of injury from radiological dispersion devices or dirty bombs, with emphasis on the immediate aftermath as well as strategy recommendations.

  7. Individual dose due to radioactivity accidental release from fusion reactor.

    PubMed

    Nie, Baojie; Ni, Muyi; Wei, Shiping

    2017-04-05

    As an important index shaping the design of fusion safety system, evaluation of public radiation consequences have risen as a hot topic on the way to develop fusion energy. In this work, the comprehensive public early dose was evaluated due to unit gram tritium (HT/HTO), activated dust, activated corrosion products (ACPs) and activated gases accidental release from ITER like fusion reactor. Meanwhile, considering that we cannot completely eliminate the occurrence likelihood of multi-failure of vacuum vessel and tokamak building, we conservatively evaluated the public radiation consequences and environment restoration after the worst hypothetical accident preliminarily. The comparison results show early dose of different unit radioactivity release under different conditions. After further performing the radiation consequences, we find it possible that the hypothetical accident for ITER like fusion reactor would result in a level 6 accident according to INES, not appear level 7 like Chernobyl or Fukushima accidents. And from the point of environment restoration, we need at least 69 years for case 1 (1kg HTO and 1000kg dust release) and 34-52years for case 2 (1kg HTO and 10kg-100kg dust release) to wait the contaminated zone drop below the general public safety limit (1mSv per year) before it is suitable for human habitation. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Involving Parents in Indicated Early Intervention for Childhood PTSD Following Accidental Injury

    ERIC Educational Resources Information Center

    Cobham, Vanessa E.; March, Sonja; De Young, Alexandra; Leeson, Fiona; Nixon, Reginald; McDermott, Brett; Kenardy, Justin

    2012-01-01

    Accidental injuries represent the most common type of traumatic event to which a youth is likely to be exposed. While the majority of youth who experience an accidental injury will recover spontaneously, a significant proportion will go on to develop Post-Traumatic Stress Disorder (PTSD). And yet, there is little published treatment outcome…

  9. Quadricep and hamstring activation during drop jumps with changes in drop height.

    PubMed

    Peng, Hsien-Te; Kernozek, Thomas W; Song, Chen-Yi

    2011-08-01

    Compare the muscle activation patterns of the quadricep-hamstring during drop jumps with increasing demands of drop heights. Observational. University biomechanics laboratory. Fifteen male and eight female college physical education students. Electromyographic activity of the rectus femoris (RF) and biceps femoris (BF) during the landing and takeoff phase of drop jumps from 20 to 60-cm heights. The ground contact time, vertical ground reaction force (vGRF), knee flexion angle during ground contact, and jump height after takeoff were also analyzed. The activation of RF was higher in the drop jump from 60-cm than that from 20- and 30-cm (comparing 107.0 ± 45.9 to 82.3 ± 30.8 and 88.9 ± 38.9 %MVIC, P<.05) during the landing phase. Activation of BF remained similar across all drop heights. Drop jump from 60-cm resulted in greater contact time during takeoff phase and peak vGRF, and resulted in greater maximum knee flexion but straighter knee at ground contact than from lower drop heights. At drop height of 60-cm, the altered knee muscular activation and movement patterns may diminish the effectiveness of plyometric training and increase the potential injury risk of knee. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Comparison of Fucithalmic viscous eye drops and Chloramphenicol eye ointment as a single treatment in corneal abrasion.

    PubMed

    Boberg-Ans, G; Nissen, K R

    1998-02-01

    To compare the healing of the cornea and the incidence of infection after traumatic corneal epithelial defect after single treatment with double bandage combined with either Fucithalmic single unit dose eye drops or chloramphenicol eye ointment. This is a single-centre, randomised, single-blind, parallel-group study of 144 patients with accidental corneal abrasion or corpus alieni cornea who were referred to the Eye Department at Gentofte Hospital. The injured eye was examined with a photo slit-lamp before and 24 hours after treatment. The size of the abrasion was recorded and calculated on a PCX computerized video system and by slit-lamp photography. The Fucithalmic and chloramphenicol ointment treated groups showed no significant difference in corneal healing, local side effects, or signs of local infection.

  11. The accidental mentor: Australian rural nurses developing supportive relationships in the workplace.

    PubMed

    Mills, J E; Francis, K; Bonner, A

    2007-01-01

    Like the fictional 'Accidental Tourist', an author who does not plan to write about travel, the accidental mentor is an experienced rural nurse who does not plan to be a mentor, and yet assumes that role with new or novice rural nurses as a result of them encountering a critical incident. Accidental mentoring is a short-term relationship that provides support for the new or novice nurse in managing the incident, while maintaining their level of confidence. This article describes the findings from a constructivist grounded theory study that examined Australian rural nurses' experiences of mentoring, including evidence for a new concept of mentoring - accidental mentoring. Constructivist grounded theory is a research methodology that focuses on issues of importance for participants around an area of common interest - in this case Australian rural nurse mentoring. In this study, seven participants were interviewed, generating nine transcripts. These were analysed using a process of concurrent data generation and analysis. In addition, the literature regarding rural nurse workforce and mentoring was incorporated as a source of data, using collective frame analysis. Rural nurses live their work, which predisposes them to developing supportive relationships with new or novice rural nurses. Supportive relationships range from preceptoring, to accidental mentoring, mentoring and deep friendship, depending on the level of trust and engagement that is established between the partners and the amount of time they spend together. Accidental mentoring is a short-term relationship that is prompted by experienced rural nurses observing a new or novice rural nurse experiencing a critical incident. Findings are presented that illustrate a new concept of accidental mentoring not present in the current literature around nurse mentoring. A series of recommendations are included that suggest strategies for improved rural nurse retention as an outcome of recognising and developing such

  12. Investigation of the quality of stored red blood cells after simulated air drop in the maritime environment.

    PubMed

    Meli, Athinoula; Hancock, Vicky; Doughty, Heidi; Smedley, Steve; Cardigan, Rebecca; Wiltshire, Michael

    2018-02-01

    Maritime medical capability may be compromised by blood resupply. Air-dropped red blood cells (RBCs) is a possible mitigation factor. This study set out to evaluate RBC storage variables after a simulated parachute air drop into the sea, as limited data exist. The air load construction for the air drop of blood was subject to static drop assessment to simulate a worst-case parachute drop scenario. One control and two test Golden Hour shipping containers were each packaged with 10 RBC units. The control box was not dropped; Test Boxes 1 and 2 were further reinforced with waterproof boxes and underwent a simulated air drop on Day 7 or Day 8 postdonation, respectively. One day after the drop and once a week thereafter until Day 43 of storage, RBCs from each box were sampled and tested for full blood counts, hemolysis, adenosine triphosphate, 2,3-diphosphoglycerate, pH, extracellular potassium, glucose, lactate, deformability, and RBC microvesicles. The packaging configuration completed the air drop with no water ingress or physical damage. All units met UK specifications for volume, hemoglobin, and hemolysis. There were no significant differences for any of the variables studied between RBCs in the control box compared to RBCs in Test Boxes 1 and 2 combined over storage. The test proved that the packaging solution and the impact of a maritime air drop as performed in this study, on Day 7 or Day 8 postdonation, did not affect the in vitro quality of RBCs in SAGM over storage for 35 days. © 2017 AABB.

  13. Micro-explosion of compound drops

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Kuei; Lin, Ta-Hui

    2014-08-01

    Introducing water into spray combustion systems, by either water-in-oil emulsification or supplementary water injection, is one of the major techniques for combustion improvement and NOx reduction. Plentiful researches are available on combustion of water-in-oil emulsion fuel drops. The emulsified liquid is a heterogeneous mixture of immiscible liquids. One component forms the continuous phase and the other component forms the discrete phase. The discrete phase consists of globules of the one fluid that are suspended in the continuous phase fluid. Water-in-oil emulsions are commonly considered for combustion applications because emulsions can result in micro-explosion, thereby reducing the average drop diameter to enhance liquid vaporization, and suppressing the formation of soot and NOx. However, the water addition generally does not exceed about 20% for smooth engine operations[!, 21. The combustion characteristics and micro-explosion of emulsion drop were studied by many researchers. The micro-explosion of water in fuel emulsion drops was caused by very fast growth of superheated water vapor bubbles, its superheat limits must be lower than the boiling point temperature of the fuel. These bubbles were primarily governed by the pressure difference between the superheated vapor and the liquid, and by the inertia imparted to the liquid by the motion of the bubble surface[3 6 In this study, we used a coaxial nozzle to generation the multi-component drop. The different type of water-in-oil fuel drops called the compound drops. Unlike an emulsion drop, a compound drop consists of a water core and a fuel shell, which can originate from the phase separation of emulsion[7, 81 or a water drop colliding with a fuel drop[9, 101 Burning and micro-explosion of compound drops have been found to be distinct from those of emulsion drops[9-111 Wang et al.[9 , 101 studied the combustion characteristics of collision merged alkane-water drops. The merged drops appeared in adhesive

  14. Controlling charge on levitating drops.

    PubMed

    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.

  15. Small-Scale Drop-Size Variability: Empirical Models for Drop-Size-Dependent Clustering in Clouds

    NASA Technical Reports Server (NTRS)

    Marshak, Alexander; Knyazikhin, Yuri; Larsen, Michael L.; Wiscombe, Warren J.

    2005-01-01

    By analyzing aircraft measurements of individual drop sizes in clouds, it has been shown in a companion paper that the probability of finding a drop of radius r at a linear scale l decreases as l(sup D(r)), where 0 less than or equals D(r) less than or equals 1. This paper shows striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and a Poisson distribution of cloud drops, these models illustrate strong drop clustering, especially with larger drops. The degree of clustering is determined by the observed exponents D(r). The strong clustering of large drops arises naturally from the observed power-law statistics. This clustering has vital consequences for rain physics, including how fast rain can form. For radiative transfer theory, clustering of large drops enhances their impact on the cloud optical path. The clustering phenomenon also helps explain why remotely sensed cloud drop size is generally larger than that measured in situ.

  16. Scanning drop sensor

    DOEpatents

    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.

  17. Lifetime of oil drops pressed by buoyancy against a planar interface: Large drops

    NASA Astrophysics Data System (ADS)

    Rojas, Clara; García-Sucre, Máximo; Urbina-Villalba, Germán

    2010-11-01

    In a previous report [C. Rojas, G. Urbina-Villalba, and M. García-Sucre, Phys. Rev. E 81, 016302 (2010)10.1103/PhysRevE.81.016302] it was shown that emulsion stability simulations are able to reproduce the lifetime of micrometer-size drops of hexadecane pressed by buoyancy against a planar water-hexadecane interface. It was confirmed that small drops (ri<10μm) stabilized with β -casein behave as nondeformable particles, moving with a combination of Stokes and Taylor tensors as they approach the interface. Here, a similar methodology is used to parametrize the potential of interaction of drops of soybean oil stabilized with bovine serum albumin. The potential obtained is then employed to study the lifetime of deformable drops in the range 10≤ri≤1000μm . It is established that the average lifetime of these drops can be adequately replicated using the model of truncated spheres. However, the results depend sensibly on the expressions of the initial distance of deformation and the maximum film radius used in the calculations. The set of equations adequate for large drops is not satisfactory for medium-size drops (10≤ri≤100μm) , and vice versa. In the case of large particles, the increase in the interfacial area as a consequence of the deformation of the drops generates a very large repulsive barrier which opposes coalescence. Nevertheless, the buoyancy force prevails. As a consequence, it is the hydrodynamic tensor of the drops which determine the characteristic behavior of the lifetime as a function of the particle size. While the average values of the coalescence time of the drops can be justified by the mechanism of film thinning, the scattering of the experimental data of large drops cannot be rationalized using the methodology previously described. A possible explanation of this phenomenon required elaborate simulations which combine deformable drops, capillary waves, repulsive interaction forces, and a time-dependent surfactant adsorption.

  18. Extension of drop experiments with the MIKROBA balloon drop facility

    NASA Astrophysics Data System (ADS)

    Sommer, K.; Kretzschmar, K.; Dorn, C.

    1992-12-01

    The German balloon drop facility MIKROBA extends the worldwide available drop experiment opportunities to the presently highest usable experimentation time span of 55 s at microgravity conditions better than 0.001 g. The microgravity period is started with the typical quasi-deal step function from 1 to 0 g. MIKROBA allows flexible experiment design, short access time, and easy hands-on payload integration. The transport to the operational height is realized by soft energies and technologies compatible with the earth's environment. Balloon campaigns are not restricted to a certain test range, i.e., several suitable sites are available all over the world. MIKROBA combines negligible mechanical loads at the mission start, typical of all drop facilities, with extremely low drop deceleration loads (less than g), due to the implemented three-stage parachute and airbag recovery subsystem.

  19. [Accidental hypothermia].

    PubMed

    Soteras Martínez, Iñigo; Subirats Bayego, Enric; Reisten, Oliver

    2011-07-09

    Accidental hypothermia is an infrequent and under-diagnosed pathology, which causes fatalities every year. Its management requires thermometers to measure core temperature. An esophageal probe may be used in a hospital situation, although in moderate hypothermia victims epitympanic measurement is sufficient. Initial management involves advance life support and body rewarming. Vigorous movements can trigger arrhythmia which does not use to respond to medication or defibrillation until the body reaches 30°C. External, passive rewarming is the method of choice for mild hypothermia and a supplementary method for moderate or severe hypothermia. Active external rewarming is indicated for moderate or severe hypothermia or mild hypothermia that has not responded to passive rewarming. Active internal rewarming is indicated for hemodynamically stable patients suffering moderate or severe hypothermia. Patients with severe hypothermia, cardiac arrest or with a potassium level below 12 mmol/l may require cardiopulmonary bypass treatment. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  20. Measuring the visual salience of alignments by their non-accidentalness.

    PubMed

    Blusseau, S; Carboni, A; Maiche, A; Morel, J M; Grompone von Gioi, R

    2016-09-01

    Quantitative approaches are part of the understanding of contour integration and the Gestalt law of good continuation. The present study introduces a new quantitative approach based on the a contrario theory, which formalizes the non-accidentalness principle for good continuation. This model yields an ideal observer algorithm, able to detect non-accidental alignments in Gabor patterns. More precisely, this parameterless algorithm associates with each candidate percept a measure, the Number of False Alarms (NFA), quantifying its degree of masking. To evaluate the approach, we compared this ideal observer with the human attentive performance on three experiments of straight contours detection in arrays of Gabor patches. The experiments showed a strong correlation between the detectability of the target stimuli and their degree of non-accidentalness, as measured by our model. What is more, the algorithm's detection curves were very similar to the ones of human subjects. This fact seems to validate our proposed measurement method as a convenient way to predict the visibility of alignments. This framework could be generalized to other Gestalts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Accidental Head Injury: A Real Life Experience.

    ERIC Educational Resources Information Center

    Blakely, Jim

    1988-01-01

    The adult victim of accidental head injury as a result of an automobile accident recounts his experiences as a brain injured adult with such problems as poor balance, poor speech, spasticity, and lack of fine motor movement. He emphasizes his determination to get on with his life. (DB)

  2. Scanning drop sensor

    DOEpatents

    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.

  3. Paediatric femur fractures at the emergency department: accidental or not?

    PubMed Central

    Vrolijk-Bosschaart, Thekla F; Bakx, Roel; Van Rijn, Rick R.

    2016-01-01

    Only a small proportion of all paediatric fractures is caused by child abuse or neglect, especially in highly prevalent long bone fractures. It can be difficult to differentiate abusive fractures from non-abusive fractures. This article focuses on femoral fractures in young children. Based on three cases, this article presents a forensic evidence-based approach to differentiate between accidental and non-accidental causes of femoral fractures. We describe three cases of young children who were presented to the emergency department because of a suspected femur fracture. Although in all cases, the fracture had a similar location and appearance, the clinical history and developmental stage of the child led to three different conclusions. In the first two cases, an accidental mechanism was a plausible conclusion, although in the second case, neglect of parental supervision was the cause for concern. In the third case, a non-accidental injury was diagnosed and appropriate legal prosecution followed. Any doctor treating children should always be aware of the possibility of child abuse and neglect in children with injuries, especially in young and non-mobile children presenting with an unknown trauma mechanism. If a suspicion of child abuse or neglect arises, a thorough diagnostic work-up should be performed, including a full skeletal survey according to the guidelines of the Royal College of Radiologists and the Royal College of Paediatrics and Child Health. In order to make a good assessment, the radiologist reviewing the skeletal survey needs access to all relevant clinical and social information. PMID:26642309

  4. Are the Stress Drops of Small Earthquakes Good Predictors of the Stress Drops of Larger Earthquakes?

    NASA Astrophysics Data System (ADS)

    Hardebeck, J.

    2017-12-01

    Uncertainty in PSHA could be reduced through better estimates of stress drop for possible future large earthquakes. Studies of small earthquakes find spatial variability in stress drop; if large earthquakes have similar spatial patterns, their stress drops may be better predicted using the stress drops of small local events. This regionalization implies the variance with respect to the local mean stress drop may be smaller than the variance with respect to the global mean. I test this idea using the Shearer et al. (2006) stress drop catalog for M1.5-3.1 events in southern California. I apply quality control (Hauksson, 2015) and remove near-field aftershocks (Wooddell & Abrahamson, 2014). The standard deviation of the distribution of the log10 stress drop is reduced from 0.45 (factor of 3) to 0.31 (factor of 2) by normalizing each event's stress drop by the local mean. I explore whether a similar variance reduction is possible when using the Shearer catalog to predict stress drops of larger southern California events. For catalogs of moderate-sized events (e.g. Kanamori, 1993; Mayeda & Walter, 1996; Boyd, 2017), normalizing by the Shearer catalog's local mean stress drop does not reduce the standard deviation compared to the unmodified stress drops. I compile stress drops of larger events from the literature, and identify 15 M5.5-7.5 earthquakes with at least three estimates. Because of the wide range of stress drop estimates for each event, and the different techniques and assumptions, it is difficult to assign a single stress drop value to each event. Instead, I compare the distributions of stress drop estimates for pairs of events, and test whether the means of the distributions are statistically significantly different. The events divide into 3 categories: low, medium, and high stress drop, with significant differences in mean stress drop between events in the low and the high stress drop categories. I test whether the spatial patterns of the Shearer catalog

  5. Risk assessment for stonecutting enterprises Accidental risks in the course of petroleum production and stone extraction

    NASA Astrophysics Data System (ADS)

    Aleksandrova, A. J.; Timofeeva, S. S.

    2018-01-01

    The paper is devoted to the assessment of accidental risks occurring at the works engaged in stone extracting and petroleum production. Two basic kinds of accidents common for stone extracting and petroleum production have been chosen to be discussed in the part under consideration. The most dangerous accidental situation characteristic for a stone milling line is an unsanctioned explosion, UE, of blasting agents used for the development of stone deposits. The analysis of a risk occurrence in certain accidental situations is to be carried out. With reference to petroleum extraction, a combustibles and lubricants (C & L) explosion is the most dangerous of characteristic accidental situations. To reveal the most probable causes of accidental situations to be realized, a graph of cause and effect relations has been constructed for each of the accidental situations most probable causes to real situation of an accident. Disasters of a natural origin are the most probable causes of unsanctioned explosions at the deposits of stone raw materials. Technology related natural disasters are the most probable causes of unsanctioned explosions to be realized at multiple well platforms engaged in petroleum production.

  6. Accidental poisoning with detomidine and butorphanol.

    PubMed

    Hannah, N

    2010-09-01

    This is a case report concerning a veterinarian who spilled detomidine and butorphanol on dermatitic hands while sedating a horse. This resulted in acute poisoning from which the patient spontaneously recovered with supportive management. Veterinarians often suffer from occupational dermatitis and handle strong sedatives with no gloves while working around unpredictable animals. Thus, this group is at risk of accidental self-poisoning from this method.

  7. Accidental hypothermia in a healthy quadriplegic patient.

    PubMed

    Altus, P; Hickman, J W; Nord, H J

    1985-03-01

    An otherwise healthy 28-year-old quadriplegic patient was admitted to the hospital with a core temperature of 76 degrees F secondary to accidental hypothermia. Her neurologic disability was detrimental to thermoregulation by decreasing her ability to shiver actively and to vasoconstrict. The relationship between shivering and thermoregulation is discussed.

  8. Looking Under a Leidenfrost Drop

    NASA Astrophysics Data System (ADS)

    Burton, Justin; Sharpe, Aaron; van der Veen, Roeland; Franco, Andres; Nagel, Sidney

    2011-11-01

    The Leidenfrost effect can be observed when small water drops move around effortlessly without sticking on a hot pan. The transition to a levitated state, where the drops rest on an insulating layer of vapor, occurs at the Leidenfrost temperature. Experiment and theory have examined the lifetime and maximum size of Leidenfrost drops. However, the liquid-vapor interface beneath the drop has not been fully charcterized. We report experiments using laser-light interference to measure the geometry of the liquid-vapor interface. By imaging the interference fringes produced between the bottom surface of the liquid and the hot substrate, we can measure the curvature of the vapor pocket beneath the drop as well as the azimuthal undulations along the neck that sits closest to the surface. From these measurements, we can extrapolate the shape of the bottom of the drop, which fluctuates in time with a period of a few milliseconds for millimeter-sized water drops. Our measurements of the azimuthal neck radius agree with predictions: the difference between the drop and neck radii, (Rd -Rn) ~0.53 λ in the limit of large drops where λ is the capillary length of the fluid. For small drops we recover the result found in that Rn ~Rd2 / λ .

  9. Accidental introductions of natural enemies: causes and implications

    USDA-ARS?s Scientific Manuscript database

    Accidental introductions of natural enemies, including parasitoid and predatory groups, may exceed species introduced intentionally. Several factors favor this: a general surge in international trade; lack of surveillance for species that are not associated with live plants or animals; inability to ...

  10. Two types of Cassie-to-Wenzel wetting transitions on superhydrophobic surfaces during drop impact.

    PubMed

    Lee, Choongyeop; Nam, Youngsuk; Lastakowski, Henri; Hur, Janet I; Shin, Seungwon; Biance, Anne-Laure; Pirat, Christophe; Kim, Chang-Jin C J; Ybert, Christophe

    2015-06-21

    Despite the fact that superhydrophobic surfaces possess useful and unique properties, their practical application has remained limited by durability issues. Among those, the wetting transition, whereby a surface gets impregnated by the liquid and permanently loses its superhydrophobicity, certainly constitutes the most limiting aspect under many realistic conditions. In this study, we revisit this so-called Cassie-to-Wenzel transition (CWT) under the broadly encountered situation of liquid drop impact. Using model hydrophobic micropillar surfaces of various geometrical characteristics and high speed imaging, we identify that CWT can occur through different mechanisms, and at different impact stages. At early impact stages, right after contact, CWT occurs through the well established dynamic pressure scenario of which we provide here a fully quantitative description. Comparing the critical wetting pressure of surfaces and the theoretical pressure distribution inside the liquid drop, we provide not only the CWT threshold but also the hardly reported wetted area which directly affects the surface spoiling. At a later stage, we report for the first time to our knowledge, a new CWT which occurs during the drop recoil toward bouncing. With the help of numerical simulations, we discuss the mechanism underlying this new transition and provide a simple model based on impulse conservation which successfully captures the transition threshold. By shedding light on the complex interaction between impacting water drops and surface structures, the present study will facilitate designing superhydrophobic surfaces with a desirable wetting state during drop impact.

  11. [Impact of heat waves on non-accidental deaths in Jinan, China].

    PubMed

    Zhang, J; Liu, S Q; Zhou, L; Gong, S P; Liu, Y L; Zhang, Y; Zhang, J

    2016-02-20

    To assess the impact of heat waves on non-accidental deaths, and to investigate the influencing factors for deaths caused by heat waves in Jinan, China. Daily death data and meteorological data for summer days with or without heat waves in Jinan from 2012 to 2014 were collected, and a cross-over analysis was conducted to evaluate the influence of heat waves on non-accidental deaths and deaths caused by other reasons. The univariate and multivariate logistic regression models were used to investigate the influencing factors for deaths caused by heat waves. The risks of non-accidental deaths and deaths caused by circulation system diseases during the days with heat waves were 1.82 times(95% CI: 1.47~2.36) and 1.53 times(95% CI: 1.14~2.07) those during the days without heat waves. The multivariate logistic regression analysis showed that old age(≥75 years)(OR=1.184, 95% CI: 1.068~1.313), low educational level(OR=1.187, 95% CI: 1.064~1.324), and deaths outside hospital(OR=1.105, 95% CI: 1.009~1.210) were associated with the high risk of deaths during the days with heat waves. Heat waves significantly increase the risk of non-accidental deaths and deaths caused by circulation system diseases in Jinan, and the deaths during the days with heat waves are related to age, educational level, and place of death.

  12. An alternative approach for computing seismic response with accidental eccentricity

    NASA Astrophysics Data System (ADS)

    Fan, Xuanhua; Yin, Jiacong; Sun, Shuli; Chen, Pu

    2014-09-01

    Accidental eccentricity is a non-standard assumption for seismic design of tall buildings. Taking it into consideration requires reanalysis of seismic resistance, which requires either time consuming computation of natural vibration of eccentric structures or finding a static displacement solution by applying an approximated equivalent torsional moment for each eccentric case. This study proposes an alternative modal response spectrum analysis (MRSA) approach to calculate seismic responses with accidental eccentricity. The proposed approach, called the Rayleigh Ritz Projection-MRSA (RRP-MRSA), is developed based on MRSA and two strategies: (a) a RRP method to obtain a fast calculation of approximate modes of eccentric structures; and (b) an approach to assemble mass matrices of eccentric structures. The efficiency of RRP-MRSA is tested via engineering examples and compared with the standard MRSA (ST-MRSA) and one approximate method, i.e., the equivalent torsional moment hybrid MRSA (ETM-MRSA). Numerical results show that RRP-MRSA not only achieves almost the same precision as ST-MRSA, and is much better than ETM-MRSA, but is also more economical. Thus, RRP-MRSA can be in place of current accidental eccentricity computations in seismic design.

  13. Shaping liquid drops by vibration

    NASA Astrophysics Data System (ADS)

    Pototsky, Andrey; Bestehorn, Michael

    2018-02-01

    We present and analyze a minimal hydrodynamic model of a vertically vibrated liquid drop that undergoes dynamic shape transformations. In agreement with experiments, a circular lens-shaped drop is unstable above a critical vibration amplitude, spontaneously elongating in the horizontal direction. Smaller drops elongate into localized states that oscillate with half of the vibration frequency. Larger drops evolve by transforming into a snake-like structure with gradually increasing length. The worm state is long-lasting with a potential to fragment into smaller drops.

  14. Instant freezing of impacting wax drops

    NASA Astrophysics Data System (ADS)

    Ponomarenko, Alexandre; Virot, Emmanuel; Rubinstein, Shmuel

    2015-11-01

    We present the impact of hot liquid drops of wax on surfaces whose temperature is below the solidifying temperature of the drops. During the fall the drops remain mostly liquid, but upon impact, their temperature quickly decreases resulting in the solidification of the drop. Depending on the impact energy, drops size and the temperature difference between the drop and the surface this results in plethora of solid shapes: simple lenses, triangular drops, spherical caps and popped popcorn shapes.

  15. Experience with intubated patients does not affect the accidental extubation rate in pediatric intensive care units and intensive care nurseries.

    PubMed

    Frank, B S; Lewis, R J

    1997-06-01

    Accidental extubation is a potentially serious event for pediatric or neonatal patients with respiratory failure, especially in clinical settings in which personnel capable of performing reintubation may not be readily available. Thus the rate of accidental extubation in small intensive care units that operate without 24-hour in-house physician availability may be an important quality assurance indicator. The objective of this study were to determine the accidental extubation rate at a single small pediatric intensive care unit (PICU) and compare it with published reports. This study was carried out in a six-bed PICU at Washoe Medical Center in Reno, Nevada, with a relatively low level of patient acuity, as measured by PRISM score and the frequency of intubation, and without 24-hour in-house physician availability. All intubated patients admitted during the 5-year period from January 1, 1989 to December 31, 1993 were included. The primary outcome measure was the occurrence of accidental extubation. We observed only two accidental extubations in 1,749 intubated-patient-days (IPD) (0.114 accidental extubations/100 IPD [95% confidence interval 0.014-0.413 accidental extubations/ 100 IPD]). This rate of accidental extubation was compared with data in published reports from neonatal intensive care units (NICUs) and PICUs, which ranged from 0.14 accidental extubations/100 IPD to 4.36 accidental extubations/100 IPD. The dependence of the observed accidental extubation rate on unit size and institutional experience with intubated patients, as measured by the average number of intubated patients, was examined. We found no evidence that the accidental extubation rate is higher in smaller units or units with less institutional experience. Low rates can be achieved in small units with low acuity.

  16. Accidental Kähler moduli inflation

    NASA Astrophysics Data System (ADS)

    Maharana, Anshuman; Rummel, Markus; Sumitomo, Yoske

    2015-09-01

    We study a model of accidental inflation in type IIB string theory where inflation occurs near the inflection point of a small Kähler modulus. A racetrack structure helps to alleviate the known concern that string-loop corrections may spoil Kähler Moduli Inflation unless having a significant suppression via the string coupling or a special brane setup. Also, the hierarchy of gauge group ranks required for the separation between moduli stabilization and inflationary dynamics is relaxed. The relaxation becomes more significant when we use the recently proposed D-term generated racetrack model.

  17. Electrohydrodynamics of a particle-covered drop

    NASA Astrophysics Data System (ADS)

    Ouriemi, Malika; Vlahovska, Petia

    2014-11-01

    We study the dynamics of a drop nearly-completely covered with a particle monolayer in a uniform DC electric field. The weakly conducting fluid system consists of a silicon oil drop suspended in castor oil. A broad range of particle sizes, conductivities, and shapes is explored. In weak electric fields, the presence of particles increases drop deformation compared to a particle-free drop and suppresses the electrohydrodynamic flow. Very good agreement is observed between the measured drop deformation and the small deformation theory derived for surfactant-laden drops (Nganguia et al., 2013). In stronger electric fields, where drops are expected to undergo Quincke rotation (Salipante and Vlahovska, 2010), the presence of the particles greatly decreases the threshold for rotation and the stationary tilted drop configuration observed for clean drop is replaced by a spinning drop with either a wobbling inclination or a very low inclination. These behaviors resemble the predicted response of rigid ellipsoids in uniform electric fields. At even stronger electric fields, the particles can form dynamic wings or the drop implodes. The similar behavior of particle-covered and surfactant-laden drops provides new insights into understanding stability of Pickering emulsions. Supported by NSF-CBET 1437545.

  18. Patterns of accidental deaths in Kuwait: a retrospective descriptive study from 2003-2009.

    PubMed

    Al-Kandary, Nadia; Al-Waheeb, Salah

    2015-03-28

    Accidents are a preventable cause of death. Unfortunately it accounts for a large number of deaths in many societies. In Kuwait, road traffic accidents (RTA) is the leading cause of death in young people. The study investigated the patterns of accidental deaths in Kuwait, one of the Gulf States which incorporates a wide variety of multi-ethnic communities. The study was retrospective from 2003-2009. Data of forensic cases were collected from the general department of criminal evidence (GDCE) in the ministry of interior (MOI).We attempted to find out causes of accidental death and the prevelance of each cause. Furthermore, the relationship of demographic factors (eg. Age, sex, marital status and nationality) with each cause of accidental death in Kuwait were studied. The material of this study constituted a total of 4886 reported accidental deaths referred for Medico-legal examination. Road traffic accidents was by far the most prevalent cause of death (64.6%) followed by fall from height (13.1%). Poisoning and mine explosions were amongst the least common causes. The government of Kuwait needs to take strong measures to promote safety in the workplace and households by educational campaigns.

  19. Osborn waves in severe accidental hypothermia secondary to prolonged immobilization and malnutrition.

    PubMed

    Rotondi, Francesco; Manganelli, Fiore; Candelmo, Fiore; Marino, Luciano; Di Lorenzo, Emilio; Alfano, Ferdinando; Stanco, Giovanni; Rosato, Giuseppe

    2010-07-01

    We report the case of a 77-year-old man, in whom accidental hypothermia was secondary to prolonged immobilization and malnutrition. The electrocardiogram showed typical Osborn waves, which disappeared with the rewarming of the patient. The diagnosis of hypothermia is easy in patients with a history of prolonged exposure to a cold environment but accidental hypothermia may also occur as a consequence of prolonged immobilization and malnutrition. ECG analysis is very important for a correct and fast diagnosis.

  20. Review on drop towers and long drop tubes

    NASA Technical Reports Server (NTRS)

    Bayuzick, R. J.; Hofmeister, W. H.; Robinson, M. B.

    1987-01-01

    A drop tube is an enclosure in which a molten sample can be solidified while falling; three such large tubes are currently in existence, all at NASA research facilities, and are engaged in combustion and fluid physics-related experiments rather than in materials research. JPL possesses smaller tubes, one of which can be cryogenically cooled to produce glass and metal microshells. A new small drop tube will soon begin operating at NASA Lewis that is equipped with four high-speed two-color pyrometers spaced equidistantly along the column.

  1. Acoustics and hydrodynamics of a drop impact on a water surface

    NASA Astrophysics Data System (ADS)

    Chashechkin, Yu. D.; Prokhorov, V. E.

    2017-01-01

    Hydrodynamic and acoustic processes associated with a drop impact on a water surface were studied experimentally. Acoustic signals were detected underwater (with a hydrophone) and in air (with a microphone), the flow pattern was recorded with a high-speed camera, and the surface perturbation was monitored with a laser detector. The dimensionless parameters of flows (Reynolds, Froude, and Weber numbers) induced by the impact varied with fall height within the ranges of 5000 < Re < 20000, 20 < Fr < 350, and 70 < We < 1000. The sequence of acoustic signals incorporated an impact pulse at the moment of contact between a drop and the surface and a series of acoustic packets attributable to the resonance emission of gas cavities. The top of the impact pulse, which was detected clearly in the entire fall height range, had a complex structure with short high-frequency and longer low-frequency oscillations. The total number and the parameters of emitted acoustic packets depended to a considerable extent on the fall height. The cases of lacking, one-time, and repeated emission of packets were noted in a series of experiments performed at a constant fall height. The analysis of video data showed that the signal variability was induced by considerable differences in the scenarios of water entry of a drop, which assumed an ovoid shape at the end trajectory segment, in the mentioned experiments.

  2. Hanging drop crystal growth apparatus

    NASA Technical Reports Server (NTRS)

    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.

  3. 49 CFR 192.751 - Prevention of accidental ignition.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Prevention of accidental ignition. 192.751 Section 192.751 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE:...

  4. Drop Impact on Hairy Surfaces

    NASA Astrophysics Data System (ADS)

    Nasto, Alice; Hosoi, Anette

    2017-11-01

    Using a combination of experiments and theory, we investigate the effect of a millimeter-scale hairy texture on impact of liquid drops. By varying the speed of the drop at impact and the spacing of the hairs, we observe a variety of behaviors. For dense hairs and low impact velocity, the liquid drop sits on top of the hair, similar to a Cassie-Baxter state. For higher impact velocity, and intermediate to high density of hairs, the drops penetrate through the surface, but the hairs resist their spreading. For low hair density and high impact velocity, the drops impact and splash.

  5. Spreading of Electrolyte Drops on Charged Surfaces: Electric Double Layer Effects on Drop Dynamics

    NASA Astrophysics Data System (ADS)

    Bae, Kyeong; Sinha, Shayandev; Chen, Guang; Das, Siddhartha

    2015-11-01

    Drop spreading is one of the most fundamental topics of wetting. Here we study the spreading of electrolyte drops on charged surfaces. The electrolyte solution in contact with the charged solid triggers the formation of an electric double layer (EDL). We develop a theory to analyze how the EDL affects the drop spreading. The drop dynamics is studied by probing the EDL effects on the temporal evolution of the contact angle and the base radius (r). The EDL effects are found to hasten the spreading behaviour - this is commensurate to the EDL effects causing a ``philic'' tendency in the drops (i.e., drops attaining a contact angle smaller than its equilibrium value), as revealed by some of our recent papers. We also develop scaling laws to illustrate the manner in which the EDL effects make the r versus time (t) variation deviate from the well known r ~tn variation, thereby pinpointing the attainment of different EDL-mediated spreading regimes.

  6. Suicide and accidental deaths in children and adolescents in England and Wales, 2001-2010.

    PubMed

    Windfuhr, Kirsten; While, David; Hunt, Isabelle M; Shaw, Jenny; Appleby, Louis; Kapur, Nav

    2013-12-01

    To investigate the impact of narrative verdicts on suicide statistics among 10-19-year-olds; to identify the number and rate of suicide and accidental deaths, particularly in 10-14-year-olds. National cohort study. England and Wales. Mid-year population estimates from the Office for National Statistics (ONS) were used to calculate rates per 100,000 population for suicide (undetermined and suicide verdicts) and accidental deaths (poisoning, hanging) for those aged 10-14 and 15-19. Trends in rates over time (2001-2010) were investigated using Poisson regression. Interaction tests were carried out to determine differences in trends between the two time periods (2001-2005 and 2006-2010). There were 1523 suicides (2.25/100,000). Suicide rates were highest in those aged 15-19 years (4.04/100,000) and in males (3.14/100,000). Between 2001 and 2010, rates significantly decreased among those aged 15-19 years (incidence rate-ratio (IRR): 0.95; 95% CI 0.93 to 0.97), with no change in rates of accidental deaths (IRR: 1.01, 95% CI 0.95 to 1.07). However, there was a significant interaction between the two time periods for accidental poisonings (2001-2005: IRR: 0.79 (95% CI 0.69 to 0.91); 2006-2010: IRR: 1.01 (95% CI 0.89 to 1.15), interaction p=0.012) and accidental hangings (2001-2005: IRR: 0.93 (95% CI 0.76 to 1.14); 2006-2010: IRR: 1.25 (95% CI 1.04 to 1.49), interaction=0.01) Undetermined deaths significantly decreased among females aged 15-19 yeras (IRR: 0.93; 95% CI 0.88 to 0.98). There were no significant trends among 10-14-year-olds. Rates of suicide are higher among older adolescents and males. There was a significant fall in suicide rates in males aged 15-19 years that was not accounted for by changes in rates of accidental death. The absence of a significant trend in suicide or accidental deaths in those aged 10-14 years may have been the result of small numbers. However, monitoring should continue to identify longitudinal trends in all young people.

  7. Prevention of accidental exposure in radiotherapy: the risk matrix approach.

    PubMed

    Vilaragut, J J; Duménigo, C; Delgado, J M; Morales, J; McDonnell, J D; Ferro, R; Ortiz López, P; Ramírez, M L; Pérez Mulas, A; Papadopulos, S; Gonçalves, M; López Morones, R; Sánchez Cayuela, C; Cascajo Castresana, A; Somoano, F; Álvarez, C; Guillén, A; Rodríguez, M; Pereira, P P; Nader, A

    2013-02-01

    Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.

  8. Accidental Chlorine Gas Intoxication: Evaluation of 39 Patients

    PubMed Central

    Sever, Mustafa; Mordeniz, Cengiz; Sever, Fidan; Dokur, Mehmet

    2009-01-01

    Background Chlorine is a known pulmonary irritant gas that may cause acute damage in the respiratory system. In this paper, the socio-demographic and clinical characteristics of 39 accidentally exposed patients to chlorine gas are reported and different emergency treatment modalities are also discussed. Methods Two emergency departments applications were retrospectively analyzed for evaluation of accidental chlorine gas exposure for year 2007. Patients were classified into 3 groups according to severity of clinical and laboratory findings based on the literature and duration of land of stay in the emergency department. The first group was slightly exposed (discharged within 6 hours), second group moderately exposed (treated and observed for 24 hours), and third group was severely exposed (hospitalized). Most of the patients were initially treated with a combination of humidified oxygen, corticosteroids, and bronchodilators. Results The average age was 17.03 ± 16.01 years (95% CI). Seven (17.9%) of them were female and 29 (74.4%) were children. Twenty-four patients (61.5%) were included in the first, nine (23.1%) were in second and six (15.4%) were in the third group. The presenting symptoms were cough, nausea, and vomiting and conjunctiva hyperemia for the first group, first groups symptoms plus dyspnea for the second group. Second groups symptoms plus palpitation, weakness and chest tightness were for the third group. Cough and dyspnea were seen in 64.1% and 30.8% of the patients respectively. No patients died. Conclusions The authors recommend that non symptomatic or slightly exposed patients do not need any specific treatment or symptomatic treatment is sufficient. Keywords Accidental; Chlorine exposure; Chlorine gas; Chlorine intoxication; Emergency department PMID:22481989

  9. Vibration-Induced Climbing of Drops

    NASA Astrophysics Data System (ADS)

    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.

  10. Rain Drop Charge Sensor

    NASA Astrophysics Data System (ADS)

    S, Sreekanth T.

    begin{center} Large Large Rain Drop Charge Sensor Sreekanth T S*, Suby Symon*, G. Mohan Kumar (1) , S. Murali Das (2) *Atmospheric Sciences Division, Centre for Earth Science Studies, Thiruvananthapuram 695011 (1) D-330, Swathi Nagar, West Fort, Thiruvananthapuram 695023 (2) Kavyam, Manacaud, Thiruvananthapuram 695009 begin{center} ABSTRACT To study the inter-relations with precipitation electricity and precipitation microphysical parameters a rain drop charge sensor was designed and developed at CESS Electronics & Instrumentation Laboratory. Simultaneous measurement of electric charge and fall speed of rain drops could be done using this charge sensor. A cylindrical metal tube (sensor tube) of 30 cm length is placed inside another thick metal cover opened at top and bottom for electromagnetic shielding. Mouth of the sensor tube is exposed and bottom part is covered with metal net in the shielding cover. The instrument is designed in such a way that rain drops can pass only through unhindered inside the sensor tube. When electrically charged rain drops pass through the sensor tube, it is charged to the same magnitude of drop charge but with opposite polarity. The sensor tube is electrically connected the inverted input of a current to voltage converter operational amplifier using op-amp AD549. Since the sensor is electrically connected to the virtual ground of the op-amp, the charge flows to the ground and the generated current is converted to amplified voltage. This output voltage is recorded using a high frequency (1kHz) voltage recorder. From the recorded pulse, charge magnitude, polarity and fall speed of rain drop are calculated. From the fall speed drop diameter also can be calculated. The prototype is now under test running at CESS campus. As the magnitude of charge in rain drops is an indication of accumulated charge in clouds in lightning, this instrument has potential application in the field of risk and disaster management. By knowing the charge

  11. Force-displacement differences in the lower extremities of young healthy adults between drop jumps and drop landings.

    PubMed

    Hackney, James M; Clay, Rachel L; James, Meredith

    2016-10-01

    We measured ground reaction force and lower extremity shortening in ten healthy, young adults in order to compare five trials of drop jumps to drop landings. Our dependent variable was the percentage of displacement (shortening) between the markers on the ASIS and second metatarsal heads on each LE, relative to the maximum shortening (100% displacement) for that trial at the point of greatest ground reaction force. We defined this as "percent displacement at maximum force" (%dFmax). The sample mean %dFmax was 0.73%±0.14% for the drop jumps, and 0.47%±0.09% for the drop landings. The mean within-subject difference score was 0.26%±0.20%. Two-tailed paired t test comparing %dFmax between the drop jump and drop landing yielded P=0.002. For all participants in this study, the %dFmax was greater in drop jumps than in drop landings. This indicates that in drop jumps, the point of maximum force and of maximum shortening was nearly simultaneous, compared to drop landings, where the point of maximum shortening followed that of maximum force by a greater proportion. This difference in force to displacement behavior is explained by linear spring behavior in drop jumps, and linear damping behavior in drop landings. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Drop Tower Physics

    ERIC Educational Resources Information Center

    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…

  13. Accidental poisoning with autumn crocus.

    PubMed

    Gabrscek, Lucija; Lesnicar, Gorazd; Krivec, Bojan; Voga, Gorazd; Sibanc, Branko; Blatnik, Janja; Jagodic, Boris

    2004-01-01

    We describe a case of a 43-yr-old female with severe multiorgan injury after accidental poisoning with Colchicum autumnale, which was mistaken for wild garlic (Allium ursinum). Both plants grow on damp meadows and can be confused in the spring when both plants have leaves but no blossoms. The autumn crocus contains colchicine, which inhibits cellular division. Treatment consisted of supportive care, antibiotic therapy, and granulocyte-directed growth factor. The patient was discharged from the hospital after three weeks. Three years after recovery from the acute poisoning, the patient continued to complain of muscle weakness and intermittent episodes of hair loss.

  14. Duration of time on shift before accidental blood or body fluid exposure for housestaff, nurses, and technicians.

    PubMed

    Green-McKenzie, Judith; Shofer, Frances S

    2007-01-01

    Shift work has been found to be associated with an increased rate of errors and accidents among healthcare workers (HCWs), but the effect of shift work on accidental blood and body fluid exposure sustained by HCWs has not been well characterized. To determine the duration of time on shift before accidental blood and body fluid exposure in housestaff, nurses, and technicians and the proportion of housestaff who sustain a blood and body fluid exposure after 12 hours on duty. This retrospective, descriptive study was conducted during a 24-month period at a large urban teaching hospital. Participants were HCWs who sustained an accidental blood and body fluid exposure. Housestaff were on duty significantly longer than both nursing staff (P=.02) and technicians (P<.0001) before accidental blood and body fluid exposure. Half of the blood and body fluid exposures sustained by housestaff occurred after being on duty 8 hours or more, and 24% were sustained after being on duty 12 hours or more. Of all HCWs, 3% reported an accidental blood and body fluid exposure, with specific rates of 7.9% among nurses, 9.4% among housestaff, and 3% among phlebotomists. Housestaff were significantly more likely to have longer duration of time on shift before blood and body fluid exposure than were the other groups. Almost one-quarter of accidental blood and body fluid exposures to housestaff were incurred after they had been on duty for 12 hours or more. Housestaff sustained a higher rate of accidental blood and body fluid exposures than did nursing staff and technicians.

  15. A prospective cohort study of non-fatal accidental overdose among street youth: the link with suicidal ideation.

    PubMed

    Richer, Isabelle; Bertrand, Karine; Vandermeerschen, Jill; Roy, Elise

    2013-07-01

    Drug overdose and suicide are the two leading causes of death among street youth. The literature discusses the two faces of drug overdose: accidental act and suicide attempt. Some authors have stated that accidental overdoses may be a hidden expression of suicidal ideation. This study longitudinally examined the relationship between recent suicidal ideations and non-fatal accidental drug overdoses among street youth. Between July 2001 and December 2005, 858 street youth (14-23 years old) were recruited for a prospective cohort study. Youth were eligible if, in the previous year, they had been without a place to sleep more than once or had used the services of street youth agencies on a regular basis (≥3). Participants completed baseline questionnaires and follow-up interviews were carried out every 6 months. Mixed-effect logistic regression models were conducted. Apart from suicidal ideation and accidental drug overdose, variables considered in the model were age, sex, problematic alcohol use, homelessness, injection drug use and polydrug use (≥3 drugs). Accidental drug overdose was significantly associated with suicidal ideation (adjusted odds ratio 1.88; 95% confidence interval 1.23-2.54). Homelessness, injection drug use and polydrug use were also significant in the final model. Results show that, during follow up, suicidal ideation independently increased risks of accidental overdose. They also underscore the need for interventions beyond educational prevention. Primary care practitioners should investigate suicidal ideations and behaviours of street youth in treatment for accidental overdose. © 2012 Australasian Professional Society on Alcohol and other Drugs.

  16. Non-accidental salt poisoning.

    PubMed Central

    Meadow, R

    1993-01-01

    The clinical features of 12 children who incurred non-accidental salt poisoning are reported. The children usually presented to hospital in the first six months of life with unexplained hypernatraemia and associated illness. Most of the children suffered repetitive poisoning before detection. The perpetrator was believed to the mother for 10 children, the father for one, and either parent for one. Four children had serum sodium concentrations above 200 mmol/l. Seven children had incurred other fabricated illness, drug ingestion, physical abuse, or failure to thrive/neglect. Two children died; the other 10 remained healthy in alternative care. Features are described that should lead to earlier detection of salt poisoning; the importance of checking urine sodium excretion, whenever hypernatraemia occurs, is stressed. PMID:8503665

  17. Drop "impact" on an airfoil surface.

    PubMed

    Wu, Zhenlong

    2018-06-01

    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 © 2018 Elsevier B.V. All rights reserved.

  18. B-52B/DTV (Drop Test Vehicle) flight test results: Drop test missions

    NASA Technical Reports Server (NTRS)

    Doty, L. J.

    1985-01-01

    The NASA test airplane, B-52B-008, was a carrier for drop tests of the shuttle booster recovery parachute system. The purpose of the test support by Boeing was to monitor the vertical loads on the pylon hooks. The hooks hold the Drop Test Vehicle to the B-52 pylon during drop test missions. The loads were monitored to assure the successful completion of the flight and the safety of the crew.

  19. Self-reported Hearing Difficulty and Risk of Accidental Injury in US Adults, 2007 to 2015.

    PubMed

    Lin, Harrison W; Mahboubi, Hossein; Bhattacharyya, Neil

    2018-03-22

    Accidental injuries are a leading cause of morbidity and mortality in the United States. Hearing problems may be associated with an increased risk for such injuries. To investigate associations between hearing difficulty and risk of accidental injuries among US adults. Cross-sectional analysis of responses of a nationally representative sample of 232.2 million individuals 18 years or older who participated in the National Health Interview Survey from 2007 to 2015 and responded to the questions related to the hearing and injury modules. The main outcome variable was accidental injury in the preceding 3 months. Hearing status was self-reported as "excellent," "good," "a little trouble," "moderate trouble," "a lot of trouble," and "deaf." Prevalence of accidental injuries was analyzed based on demographic characteristics and hearing status. Odds ratios (ORs) and 95% CIs for injuries adjusted for demographics were calculated for degrees of hearing difficulty. A secondary outcome was association of hearing status with type of injury and was classified as driving related, work related, or leisure/sport related. Of 232.2 million US adults, 120.2 million (51.7%) were female, and 116.3 million (50.1%) considered their hearing to be less than excellent. Accidental injuries occurred in 2.8% of survey respondents. In comparison with normal-hearing adults (those with self-rated excellent or good hearing), the odds of accidental injury were higher in those with a little trouble hearing (4.1%; OR, 1.6; 95% CI, 1.5-1.8), moderate trouble hearing (4.2%; OR, 1.7; 95% CI, 1.4-1.9), and a lot of trouble hearing (4.8%; OR, 1.9; 95% CI, 1.6-2.3). Work- and leisure-related injuries were more prevalent among those with self-perceived hearing difficulty. Multivariate analysis, adjusted for age and sex, revealed leisure-related injuries was most consistently associated with various degrees of hearing difficulty. Odds ratios were 1.2 (95% CI, 1.0-1.4) in those with a little trouble hearing

  20. Insomnia medication use and the probability of an accidental event in an older adult population

    PubMed Central

    Avidan, Alon Y; Palmer, Liisa A; Doan, Justin F; Baran, Robert W

    2010-01-01

    Objective: This study examined the risk of accidental events in older adults prescribed a sedating antidepressant, long-acting benzodiazepine, short-acting benzodiazepine, and nonbenzodiazepine, relative to a reference group (selective melatonin receptor agonist). Methods: This was a retrospective cohort analysis of older adults (≥65 years) with newly initiated pharmacological treatment of insomnia. Data were collected from the Thomson MarketScan® Medicare Supplemental and Coordination of Benefits databases (January 1, 2000, through June 30, 2006). Probit models were used to evaluate the probability of an accidental event. Results: Data were analyzed for 445,329 patients. Patients taking a long-acting benzodiazepine (1.21 odds ratio [OR]), short-acting benzodiazepine (1.16 OR), or nonbenzodiazepine (1.12 OR) had a significantly higher probability of experiencing an accidental event during the first month following treatment initiation compared with patients taking the reference medication (P < 0.05 for all). A significantly higher probability of experiencing an accidental event was also observed during the 3-month period following the initiation of treatment (1.62 long-acting benzodiazepine, 1.60 short-acting benzodiazepine, 1.48 nonbenzodiazepine, and 1.56 sedating antidepressant; P < 0.05). Conclusions: Older adults taking an SAD or any of the benzodiazepine receptor agonists appear to have a greater risk of an accidental event compared with a reference group taking an MR. PMID:21701634

  1. The Association between Dust Storms and Daily Non-Accidental Mortality in the United States, 1993-2005.

    PubMed

    Crooks, James Lewis; Cascio, Wayne E; Percy, Madelyn S; Reyes, Jeanette; Neas, Lucas M; Hilborn, Elizabeth D

    2016-11-01

    The impact of dust storms on human health has been studied in the context of Asian, Saharan, Arabian, and Australian storms, but there has been no recent population-level epidemiological research on the dust storms in North America. The relevance of dust storms to public health is likely to increase as extreme weather events are predicted to become more frequent with anticipated changes in climate through the 21st century. We examined the association between dust storms and county-level non-accidental mortality in the United States from 1993 through 2005. Dust storm incidence data, including date and approximate location, are taken from the U.S. National Weather Service storm database. County-level mortality data for the years 1993-2005 were acquired from the National Center for Health Statistics. Distributed lag conditional logistic regression models under a time-stratified case-crossover design were used to study the relationship between dust storms and daily mortality counts over the whole United States and in Arizona and California specifically. End points included total non-accidental mortality and three mortality subgroups (cardiovascular, respiratory, and other non-accidental). We estimated that for the United States as a whole, total non-accidental mortality increased by 7.4% (95% CI: 1.6, 13.5; p = 0.011) and 6.7% (95% CI: 1.1, 12.6; p = 0.018) at 2- and 3-day lags, respectively, and by an average of 2.7% (95% CI: 0.4, 5.1; p = 0.023) over lags 0-5 compared with referent days. Significant associations with non-accidental mortality were estimated for California (lag 2 and 0-5 day) and Arizona (lag 3), for cardiovascular mortality in the United States (lag 2) and Arizona (lag 3), and for other non-accidental mortality in California (lags 1-3 and 0-5). Dust storms are associated with increases in lagged non-accidental and cardiovascular mortality. Citation: Crooks JL, Cascio WE, Percy MS, Reyes J, Neas LM, Hilborn ED. 2016. The association between dust storms

  2. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the Director, Center for Devices and Radiological Health, all accidental radiation occurrences... grounds include, but are not necessarily limited to, professional, scientific, or medical facts or... occurred. (b) Such reports shall be addressed to the Center for Devices and Radiological Health, ATTN...

  3. 21 CFR 1002.20 - Reporting of accidental radiation occurrences.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the Director, Center for Devices and Radiological Health, all accidental radiation occurrences... grounds include, but are not necessarily limited to, professional, scientific, or medical facts or... occurred. (b) Such reports shall be addressed to Food and Drug Administration, Center for Devices and...

  4. Determinants of suicide and accidental or violent death in the Australian HIV Observational Database.

    PubMed

    McManus, Hamish; Petoumenos, Kathy; Franic, Teo; Kelly, Mark D; Watson, Jo; O'Connor, Catherine C; Jeanes, Mark; Hoy, Jennifer; Cooper, David A; Law, Matthew G

    2014-01-01

    Rates of suicide and accidental or violent death remain high in HIV-positive populations despite significantly improved prognosis since the introduction of cART. We conducted a nested case-control study of suicide and accidental or violent death in the Australian HIV Observational Database (AHOD) between January 1999 and March 2012. For each case, 2 controls were matched by clinic, age, sex, mode of exposure and HIV-positive date to adjust for potential confounding by these covariates. Risk of suicide and accidental or violent death was estimated using conditional logistic regression. We included 27 cases (17 suicide and 10 violent/accidental death) and 54 controls. All cases were men who have sex with men (MSM) or MSM/ injecting drug use (IDU) mode of exposure. Increased risk was associated with unemployment (Odds Ratio (OR) 5.86, 95% CI: 1.69-20.37), living alone (OR 3.26, 95% CI: 1.06-10.07), suicidal ideation (OR 6.55, 95% CI: 1.70-25.21), and >2 psychiatric/cognitive risk factors (OR 4.99, 95% CI: 1.17-30.65). CD4 cell count of >500 cells/µL (OR 0.25, 95% CI: 0.07-0.87) and HIV-positive date ≥1990 (1990-1999 (OR 0.31, 95% CI: 0.11-0.89), post-2000 (OR 0.08, 95% CI: 0.01-0.84)) were associated with decreased risk. CD4 cell count ≥500 cells/µL remained a significant predictor of reduced risk (OR 0.15, 95% CI: 0.03-0.70) in a multivariate model adjusted for employment status, accommodation status and HIV-positive date. After adjustment for psychosocial factors, the immunological status of HIV-positive patients contributed to the risk of suicide and accidental or violent death. The number of psychiatric/cognitive diagnoses contributed to the level of risk but many psychosocial factors were not individually significant. These findings indicate a complex interplay of factors associated with risk of suicide and accidental or violent death.

  5. Cervical spine injuries in young children: pattern and outcomes in accidental versus inflicted trauma.

    PubMed

    Baerg, Joanne; Thirumoorthi, Arul; Hazboun, Rajaie; Vannix, Rosemary; Krafft, Paul; Zouros, Alexander

    2017-11-01

    The aim of the study was to compare the cervical spine (c-spine) pattern of injury and outcomes in children below 3 y with a head injury from confirmed inflicted versus accidental trauma. After Institutional Review Board approval, data were prospectively collected between July 2011 and January 2016. Inclusion criteria were age below 3 y, a loss of consciousness, and any one of the following initial head computed tomography (CT) findings (subdural hematoma, intraventricular, intraparenchymal, subarachnoid hemorrhage, or cerebral edema). A protocol of brain and neck magnetic resonance imaging and magnetic resonance angiography was instituted. Brain and neck imaging results, clinical variables, and outcomes were recorded. Data were compared by t-test for continuous and Fisher exact test for categorical variables. 73 children were identified, 52 (71%) with inflicted and 21 (29%) with accidental trauma. The median age was 11 mo; (range: 1-35 mo). Ten (14%) had c-spine injuries, 7/52 (13%) inflicted, and 3/21 (14%) accidental. The mechanism was shaking for all inflicted and motor vehicle accident or pedestrian struck for accidental c-spine injuries. The inflicted group were significantly younger (P = 0.03), had higher Injury Severity Scores (P = 0.02), subdural hematomas (P = 0.03), fractures (P = 0.03), retinal hemorrhages (P = 0.02), brain infarcts (P = 0.01), and required cardiopulmonary resuscitation (P = 0.01). Seven with inflicted trauma died from brain injury (9.5%), one had atlanto-occipital dissociation. Six mortalities (86%) had no c-spine injury. Six with inflicted c-spine injuries survived with neurologic impairment, whereas three with accidental survived without disability, including one atlanto-occipital dissociation. Compared to accidental trauma, young children with inflicted c-spine injuries have more multisystem trauma, long-term disability from brain injury, and an injury pattern consistent with shaking. Copyright © 2017 Elsevier Inc

  6. Accidental Peccei-Quinn Symmetry Protected to Arbitrary Order

    NASA Astrophysics Data System (ADS)

    Di Luzio, Luca; Nardi, Enrico; Ubaldi, Lorenzo

    2017-07-01

    A S U (N )L×S U (N )R gauge theory for a scalar multiplet Y transforming in the bifundamental representation (N ,N ¯) preserves, for N >4 , an accidental U (1 ) symmetry first broken at operator dimension N . A vacuum expectation value for Y can break the symmetry to Hs=S U (N )L+R or to Hh=S U (N -1 )L×S U (N -1 )R×U (1 )L +R . In the first case the accidental U (1 ) gets also broken, yielding a pseudo-Nambu-Goldstone boson with mass suppression controlled by N . In the second case a global U (1 ) remains unbroken. The strong C P problem is solved by coupling Y to new fermions carrying color. The first case allows for a Peccei-Quinn solution with U (1 )PQ protected by the gauge symmetry up to order N . In the second case U (1 ) can get broken by condensates of the new strong dynamics, resulting in a composite axion. By coupling Y to fermions carrying only weak isospin, models for axionlike particles can be constructed.

  7. Accidental Beam Losses and Protection in the LHC

    NASA Astrophysics Data System (ADS)

    Schmidt, R.; Working Group On Machine Protection

    2005-06-01

    At top energy (proton momentum 7 TeV/c) with nominal beam parameters, each of the two LHC proton beams has a stored energy of 350 MJ threatening to damage accelerator equipment in case of accidental beam loss. It is essential that the beams are properly extracted onto the dump blocks in case of failure since these are the only elements that can withstand full beam impact. Although the energy stored in the beams at injection (450 GeV/c) is about 15 times smaller compared to top energy, the beams must still be properly extracted in case of large accidental beam losses. Failures must be detected at a sufficiently early stage and initiate a beam dump. Quenches and power converter failures will be detected by monitoring the correct functioning of the hardware systems. In addition, safe operation throughout the cycle requires the use of beam loss monitors, collimators and absorbers. Ideas of detection of fast beam current decay, monitoring of fast beam position changes and monitoring of fast magnet current changes are discussed, to provide the required redundancy for machine protection.

  8. 49 CFR 178.810 - Drop test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Drop test. 178.810 Section 178.810 Transportation... Drop test. (a) General. The drop test must be conducted for the qualification of all IBC design types... the drop test. (1) Metal, rigid plastic, and composite IBCs intended to contain solids must be filled...

  9. 49 CFR 178.1045 - Drop test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Drop test. 178.1045 Section 178.1045... Containers § 178.1045 Drop test. (a) General. The drop test must be conducted for the qualification of all... subpart. (b) Special preparation for the drop test. Flexible Bulk Containers must be filled to their...

  10. Accidental hanging by a T-shirt collar in a man with morphine intoxication: an unusual case.

    PubMed

    Kodikara, Sarathchandra; Alagiyawanna, Ramesh

    2011-09-01

    Accidental hanging is rare across all age groups, and it is even rarer in the adult population except in autoerotic asphyxia. Few cases have been reported in the literature, which describe unusual patterns of accidental hanging. This article focuses on an unusual pattern of accidental hanging of a 25-year-old man, who was in a state of morphine-induced central nervous system depression and found dead in a sitting position with the collar of his T-shirt hanging off a jutting-out root of a tree. The hanged collar acted as a ligature compressing the neck.

  11. Drop short control of electrode gap

    DOEpatents

    Fisher, Robert W.; Maroone, James P.; Tipping, Donald W.; Zanner, Frank J.

    1986-01-01

    During vacuum consumable arc remelting the electrode gap between a consumable electrode and a pool of molten metal is difficult to control. The present invention monitors drop shorts by detecting a decrease in the voltage between the consumable electrode and molten pool. The drop shorts and their associated voltage reductions occur as repetitive pulses which are closely correlated to the electrode gap. Thus, the method and apparatus of the present invention controls electrode gap based upon drop shorts detected from the monitored anode-cathode voltage. The number of drop shorts are accumulated, and each time the number of drop shorts reach a predetermined number, the average period between drop shorts is calculated from this predetermined number and the time in which this number is accumulated. This average drop short period is used in a drop short period electrode gap model which determines the actual electrode gap from the drop short. The actual electrode gap is then compared with a desired electrode gap which is selected to produce optimum operating conditions and the velocity of the consumable error is varied based upon the gap error. The consumable electrode is driven according to any prior art system at this velocity. In the preferred embodiment, a microprocessor system is utilized to perform the necessary calculations and further to monitor the duration of each drop short. If any drop short exceeds a preset duration period, the consumable electrode is rapidly retracted a predetermined distance to prevent bonding of the consumable electrode to the molten remelt.

  12. 49 CFR 178.965 - Drop test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Drop test. 178.965 Section 178.965 Transportation... Packagings § 178.965 Drop test. (a) General. The drop test must be conducted for the qualification of all...) Special preparation for the drop test. Large Packagings must be filled in accordance with § 178.960. (c...

  13. 49 CFR 178.603 - Drop test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Drop test. 178.603 Section 178.603 Transportation... Packagings and Packages § 178.603 Drop test. (a) General. The drop test must be conducted for the... than flat drops, the center of gravity of the test packaging must be vertically over the point of...

  14. "Self-Shaping" of Multicomponent Drops.

    PubMed

    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.

  15. Biomechanical comparisons of single- and double-legged drop jumps with changes in drop height.

    PubMed

    Wang, L-I; Peng, H-T

    2014-06-01

    The purpose of this study was to compare the biomechanics of single- and double-legged drop jumps (SDJ vs. DDJ) with changes in drop height. Jumping height, ground contact time, reactive strength index, ground reaction force, loading rate of ground reaction force, joint power and stiffness were measured in 12 male college students during SDJ from 20-, 30-, 40-, and 50-cm heights and DDJ from of 20- and 40-cm heights. The peak impact force was increased with the incremental drop height during SDJs. The jumping height and leg and ankle stiffness of SDJ30 were greater than those of SDJ40 and SDJ50. The knee and hip stiffnesses of SDJ30 were greater than those of SDJ50. The impact forces of SDJ30-50 were greater than those of DDJ40. The leg, ankle, knee and hip joint stiffnesses of SDJ20-30 were greater than those of DDJ20 and DDJ40. The propulsive forces of SDJ20-50 were greater than those of DDJ20 and DDJ40. The jumping height of SDJ30 was greater than that of DDJ20. Drop height of 30 cm was recommended during single-legged drop jump with the best biomechanical benefit. Single-legged drop jump from 20-30 cm could provide comparable intensity to double-legged drop jump from 40 cm. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Spatial Distribution of Large Cloud Drops

    NASA Technical Reports Server (NTRS)

    Marshak, A.; Knyazikhin, Y.; Larsen, M.; Wiscombe, W.

    2004-01-01

    By analyzing aircraft measurements of individual drop sizes in clouds, we have shown in a companion paper (Knyazikhin et al., 2004) that the probability of finding a drop of radius r at a linear scale l decreases as l(sup D(r)) where 0 less than or equal to D(r) less than or equal to 1. This paper shows striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and therefore a Poisson distribution of cloud drops, these models show strong drop clustering, the more so the larger the drops. The degree of clustering is determined by the observed exponents D(r). The strong clustering of large drops arises naturally from the observed power-law statistics. This clustering has vital consequences for rain physics explaining how rain can form so fast. It also helps explain why remotely sensed cloud drop size is generally biased and why clouds absorb more sunlight than conventional radiative transfer models predict.

  17. Shaping drops with textured surfaces

    NASA Astrophysics Data System (ADS)

    Ehlinger, Quentin; Biance, Anne-Laure; Ybert, Christophe

    2017-11-01

    When a drop impacts a substrate, it can behave differently depending on the nature of the surface and of the liquid (spreading, bouncing, resting, splashing ...). Understanding these behaviors is crucial to predict the drop morphology during and after impact. Whereas surface wettability has extensively been studied, the effect of surface roughness remains hardly explored. In this work, we consider the impact of a drop in a pure non-wetting situation by using superheated substrates i.e. in the Leidenfrost regime. The surface texture consists of a well-controlled microscopic defect shaped with photolithography on a smooth silicon wafer. Different regimes are observed, depending on the distance between the defect and the impact point and the defect size. Comparing the lamella thickness versus the defect height proves relevant as the transition criteria between regimes. Others characteristics of the drop behavior (direction of satellite droplet ejection, lamella rupture) are also well captured by inertial/capillary models. Drop impacts on multiple defects are also investigated and drop shape well predicted considering the interactions between the local flow and the defects.

  18. Computations of Drop Collision and Coalescence

    NASA Technical Reports Server (NTRS)

    Tryggvason, Gretar; Juric, Damir; Nas, Selman; Mortazavi, Saeed

    1996-01-01

    Computations of drops collisions, coalescence, and other problems involving drops are presented. The computations are made possible by a finite difference/front tracking technique that allows direct solutions of the Navier-Stokes equations for a multi-fluid system with complex, unsteady internal boundaries. This method has been used to examine the various collision modes for binary collisions of drops of equal size, mixing of two drops of unequal size, behavior of a suspension of drops in linear and parabolic shear flows, and the thermal migration of several drops. The key results from these simulations are reviewed. Extensions of the method to phase change problems and preliminary results for boiling are also shown.

  19. The Accidental Transgressor: Morally-Relevant Theory of Mind

    ERIC Educational Resources Information Center

    Killen, Melanie; Mulvey, Kelly Lynn; Richardson, Cameron; Jampol, Noah; Woodward, Amanda

    2011-01-01

    To test young children's false belief theory of mind in a morally relevant context, two experiments were conducted. In Experiment 1, children (N=162) at 3.5, 5.5, and 7.5 years of age were administered three tasks: prototypic moral transgression task, false belief theory of mind task (ToM), and an "accidental transgressor" task, which measured a…

  20. Positive income shocks and accidental deaths among Cherokee Indians: a natural experiment

    PubMed Central

    Bruckner, Tim A; Brown, Ryan A; Margerison-Zilko, Claire

    2011-01-01

    Background Several studies in low-income populations report the somewhat counterintuitive finding that positive income gains adversely affect adult health. The literature posits that receipt of a large portion of annual income increases, in the short term, risk-taking behaviour and/or the consumption of health-damaging goods. This work implies the hypothesis that persons with an unexpected gain in income will exhibit an elevated risk of accidental death—the fifth leading cause of death in the USA. We test this hypothesis directly by capitalizing on a natural experiment in which Cherokee Indians in rural North Carolina received discrete lump sum payments from a new casino. Methods We applied Poisson regression to the monthly count of accidental deaths among Cherokee Indians over 204 months spanning 1990–2006. We controlled for temporal patterns in accidental deaths (e.g. seasonality and trend) as well as changes in population size. Results As hypothesized, the risk of accidental death rises above expected levels during months of the large casino payments (relative risk = 2.62; 95% confidence interval = 1.54–4.47). Exploratory analyses of ethnographic interviews and behavioural surveys support that increased vehicular travel and consumption of health-damaging goods may account for the rise in accident proneness. Conclusions Although long-term income gains may improve health in this population, our findings indicate that acute responses to large income gains, in the short term, increase risk-taking and accident proneness. We encourage further investigation of natural experiments to identify causal economic antecedents of population health. PMID:21527447

  1. The Impacts of Air Temperature on Accidental Casualties in Beijing, China.

    PubMed

    Ma, Pan; Wang, Shigong; Fan, Xingang; Li, Tanshi

    2016-11-02

    Emergency room (ER) visits for accidental casualties, according to the International Classification of Deceases 10th Revision Chapters 19 and 20, include injury, poisoning, and external causes (IPEC). Annual distribution of 187,008 ER visits that took place between 2009 and 2011 in Beijing, China displayed regularity rather than random characteristics. The annual cycle from the Fourier series fitting of the number of ER visits was found to explain 63.2% of its total variance. In this study, the possible effect and regulation of meteorological conditions on these ER visits are investigated through the use of correlation analysis, as well as statistical modeling by using the Distributed Lag Non-linear Model and Generalized Additive Model. Correlation analysis indicated that meteorological variables that positively correlated with temperature have a positive relationship with the number of ER visits, and vice versa. The temperature metrics of maximum, minimum, and mean temperatures were found to have similar overall impacts, including both the direct impact on human mental/physical conditions and indirect impact on human behavior. The lag analysis indicated that the overall impacts of temperatures higher than the 50th percentile on ER visits occur immediately, whereas low temperatures show protective effects in the first few days. Accidental casualties happen more frequently on warm days when the mean temperature is higher than 14 °C than on cold days. Mean temperatures of around 26 °C result in the greatest possibility of ER visits for accidental casualties. In addition, males were found to face a higher risk of accidental casualties than females at high temperatures. Therefore, the IPEC-classified ER visits are not pure accidents; instead, they are associated closely with meteorological conditions, especially temperature.

  2. Large charged drop levitation against gravity

    NASA Technical Reports Server (NTRS)

    Rhim, Won-Kyu; Chung, Sang Kun; Hyson, Michael T.; Trinh, Eugene H.; Elleman, Daniel D.

    1987-01-01

    A hybrid electrostatic-acoustic levitator that can levitate and manipulate a large liquid drop in one gravity is presented. To the authors' knowledge, this is the first time such large drops (up to 4 mm in diameter in the case of water) have been levitated against 1-gravity. This makes possible, for the first time, many new experiments both in space and in ground-based laboratories, such as 1)supercooling and superheating, 2) containerless crystal growth from various salt solutions or melts, 3) drop dynamics of oscillating or rotating liquid drops, 4) drop evaporation and Rayleigh bursting, and 5) containerless material processing in space. The digital control system, liquid drop launch process, principles of electrode design, and design of a multipurpose room temperature levitation chamber are described. Preliminary results that demonstrate drop oscillation and rotation, and crystal growth from supersaturated salt solutions are presented.

  3. Internal Flows in Free Drops (IFFD)

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Sadhal, Satwindar S.; Thomas, D. A.; Crouch, R. K.

    1998-01-01

    Within the framework of an Earth-based research task investigating the internal flows within freely levitated drops, a low-gravity technology development experiment has been designed and carried out within the NASA Glovebox facility during the STS-83 and STS-94 Shuttle flights (MSL-1 mission). The goal was narrowly defined as the assessment of the capabilities of a resonant single-axis ultrasonic levitator to stably position free drops in the Shuttle environment with a precision required for the detailed measurement of internal flows. The results of this entirely crew-operated investigation indicate that the approach is fundamentally sound, but also that the ultimate stability of the positioning is highly dependent on the residual acceleration characteristic of the Spacecraft, and to a certain extent, on the initial drop deployment of the drop. The principal results are: the measured dependence of the residual drop rotation and equilibrium drop shape on the ultrasonic power level, the experimental evaluation of the typical drop translational stability in a realistic low-gravity environment, and the semi-quantitative evaluation of background internal flows within quasi-isothermal drops. Based on these results, we conclude that the successful design of a full-scale Microgravity experiment is possible, and would allow accurate the measurement of thermocapillary flows within transparent drops. The need has been demonstrated, however, for the capability for accurately deploying the drop, for a quiescent environment, and for precise mechanical adjustments of the levitator.

  4. Electrohydrodynamics of a viscous drop with inertia.

    PubMed

    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.

  5. Drop Tower Workshop

    NASA Technical Reports Server (NTRS)

    Urban, David

    2013-01-01

    Ground based microgravity facilities are an important proving ground for space experiments, ground-based research and space hardware risk mitigation. An overview of existing platforms will be discussed with an emphasis on drop tower capabilities. The potential for extension to partial gravity conditions will be discussed. Input will be solicited from attendees for their potential to use drop towers in the future and the need for enhanced capabilities (e.g. partial gravity)

  6. The Drop Tower Bremen -An Overview

    NASA Astrophysics Data System (ADS)

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

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100

  7. The Association between Dust Storms and Daily Non-Accidental Mortality in the United States, 1993–2005

    PubMed Central

    Crooks, James Lewis; Cascio, Wayne E.; Percy, Madelyn S.; Reyes, Jeanette; Neas, Lucas M.; Hilborn, Elizabeth D.

    2016-01-01

    Background: The impact of dust storms on human health has been studied in the context of Asian, Saharan, Arabian, and Australian storms, but there has been no recent population-level epidemiological research on the dust storms in North America. The relevance of dust storms to public health is likely to increase as extreme weather events are predicted to become more frequent with anticipated changes in climate through the 21st century. Objectives: We examined the association between dust storms and county-level non-accidental mortality in the United States from 1993 through 2005. Methods: Dust storm incidence data, including date and approximate location, are taken from the U.S. National Weather Service storm database. County-level mortality data for the years 1993–2005 were acquired from the National Center for Health Statistics. Distributed lag conditional logistic regression models under a time-stratified case-crossover design were used to study the relationship between dust storms and daily mortality counts over the whole United States and in Arizona and California specifically. End points included total non-accidental mortality and three mortality subgroups (cardiovascular, respiratory, and other non-accidental). Results: We estimated that for the United States as a whole, total non-accidental mortality increased by 7.4% (95% CI: 1.6, 13.5; p = 0.011) and 6.7% (95% CI: 1.1, 12.6; p = 0.018) at 2- and 3-day lags, respectively, and by an average of 2.7% (95% CI: 0.4, 5.1; p = 0.023) over lags 0–5 compared with referent days. Significant associations with non-accidental mortality were estimated for California (lag 2 and 0–5 day) and Arizona (lag 3), for cardiovascular mortality in the United States (lag 2) and Arizona (lag 3), and for other non-accidental mortality in California (lags 1–3 and 0–5). Conclusions: Dust storms are associated with increases in lagged non-accidental and cardiovascular mortality. Citation: Crooks JL, Cascio WE, Percy MS, Reyes

  8. [Accidental ingestion of dental prostheses; 2 scenarios in the management and outcome. Case reports].

    PubMed

    Santander-Flores, Selene Artemisa; Mata-Quintero, Carlos Javier; O'Farrill-Anzures, Ricardo; González-Villegas, Paloma; Calvo-Vázquez, Iván; Campos-Serna, Esteban Israel

    Foreign body ingestion is the second cause of endoscopic emergency in the elderly, and dentures are the most frequent accidently ingested objects. Once in the stomach, their expulsion can be expected in 4 to 6 days. The treatment is wait and see in asymptomatic patients, but preventive endoscopic removal can also be performed. To present 2 scenarios of the outcome and treatment in patients with foreign body ingestion. Patient under study due to weight loss, with a denture detected by abdominal x-ray, ingested inadvertently a year ago. A laparotomy was required as extraction by colonoscopy failed, due to excessive inflammation. The second case, of 24-hour onset, was due to the ingestion of a partial denture. As duodenal endoscopy extraction was unsuccessful, the patient was kept under observation. When it did not pass the caecum, it was extracted by colonoscopy, with no further complications and shorter hospital stay. Follow-up can be by simple abdominal x-ray, with endoscopic management if there is insufficient progress. In one of our cases, the outcome was unfavourable due to time of ingestion, and endoscopic management was not possible, whereas in the second case colonoscopy was performed early with success. Proper diagnostic and timely treatment mark the difference in the progression and outcome of the ingestion of foreign bodies. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  9. Drop Ejection From an Oscillating Rod

    NASA Technical Reports Server (NTRS)

    Wilkes, E. D.; Basaran, O. A.

    1999-01-01

    The dynamics of a drop of a Newtonian liquid that is pendant from or sessile on a solid rod that is forced to undergo time-periodic oscillations along its axis is studied theoretically. The free boundary problem governing the time evolution of the shape of the drop and the flow field inside it is solved by a method of lines using a finite element algorithm incorporating an adaptive mesh. When the forcing amplitude is small, the drop approaches a limit cycle at large times and undergoes steady oscillations thereafter. However, drop breakup is the consequence if the forcing amplitude exceeds a critical value. Over a wide range of amplitudes above this critical value, drop ejection from the rod occurs during the second oscillation period from the commencement of rod motion. Remarkably, the shape of the interface at breakup and the volume of the primary drop formed are insensitive to changes in forcing amplitude. The interface shape at times close to and at breakup is a multi-valued function of distance measured along the rod axis and hence cannot be described by recently popularized one-dimensional approximations. The computations show that drop ejection occurs without the formation of a long neck. Therefore, this method of drop formation holds promise of preventing formation of undesirable satellite droplets.

  10. Star-shaped oscillations of Leidenfrost drops

    NASA Astrophysics Data System (ADS)

    Ma, Xiaolei; Liétor-Santos, Juan-José; Burton, Justin C.

    2017-03-01

    We experimentally investigate the self-sustained, star-shaped oscillations of Leidenfrost drops. The drops levitate on a cushion of evaporated vapor over a heated, curved surface. We observe modes with n =2 -13 lobes around the drop periphery. We find that the wavelength of the oscillations depends only on the capillary length of the liquid and is independent of the drop radius and substrate temperature. However, the number of observed modes depends sensitively on the liquid viscosity. The dominant frequency of pressure variations in the vapor layer is approximately twice the drop oscillation frequency, consistent with a parametric forcing mechanism. Our results show that the star-shaped oscillations are driven by capillary waves of a characteristic wavelength beneath the drop and that the waves are generated by a large shear stress at the liquid-vapor interface.

  11. Determinants of Suicide and Accidental or Violent Death in the Australian HIV Observational Database

    PubMed Central

    McManus, Hamish; Petoumenos, Kathy; Franic, Teo; Kelly, Mark D.; Watson, Jo; O’Connor, Catherine C.; Jeanes, Mark; Hoy, Jennifer; Cooper, David A.; Law, Matthew G.

    2014-01-01

    Background Rates of suicide and accidental or violent death remain high in HIV-positive populations despite significantly improved prognosis since the introduction of cART. Methods We conducted a nested case-control study of suicide and accidental or violent death in the Australian HIV Observational Database (AHOD) between January 1999 and March 2012. For each case, 2 controls were matched by clinic, age, sex, mode of exposure and HIV-positive date to adjust for potential confounding by these covariates. Risk of suicide and accidental or violent death was estimated using conditional logistic regression. Results We included 27 cases (17 suicide and 10 violent/accidental death) and 54 controls. All cases were men who have sex with men (MSM) or MSM/ injecting drug use (IDU) mode of exposure. Increased risk was associated with unemployment (Odds Ratio (OR) 5.86, 95% CI: 1.69–20.37), living alone (OR 3.26, 95% CI: 1.06–10.07), suicidal ideation (OR 6.55, 95% CI: 1.70–25.21), and >2 psychiatric/cognitive risk factors (OR 4.99, 95% CI: 1.17–30.65). CD4 cell count of >500 cells/µL (OR 0.25, 95% CI: 0.07–0.87) and HIV-positive date ≥1990 (1990–1999 (OR 0.31, 95% CI: 0.11–0.89), post-2000 (OR 0.08, 95% CI: 0.01–0.84)) were associated with decreased risk. CD4 cell count ≥500 cells/µL remained a significant predictor of reduced risk (OR 0.15, 95% CI: 0.03–0.70) in a multivariate model adjusted for employment status, accommodation status and HIV-positive date. Conclusions After adjustment for psychosocial factors, the immunological status of HIV-positive patients contributed to the risk of suicide and accidental or violent death. The number of psychiatric/cognitive diagnoses contributed to the level of risk but many psychosocial factors were not individually significant. These findings indicate a complex interplay of factors associated with risk of suicide and accidental or violent death. PMID:24586519

  12. Capillary Thinning of Particle-laden Drops

    NASA Astrophysics Data System (ADS)

    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.

  13. Incidence and characteristics of accidental falls in hospitalizations

    PubMed Central

    Kobayashi, Kazuyoshi; Imagama, Shiro; Inagaki, Yuko; Suzuki, Yusuke; Ando, Kei; Nishida, Yoshihiro; Nagao, Yoshimasa; Ishiguro, Naoki

    2017-01-01

    ABSTRACT Aging of the patient population has led to increased occurrence of accidental falls in acute care settings. The aim of this study is to survey the annual occurrence of falls in a university hospital, and to examine procedures to prevent fall. A total of 49,059 inpatients were admitted to our hospital from April 2015 to March 2016. A fall assessment scale was developed to estimate the risk of fall at admission. Data on falls were obtained from the hospital incident reporting system. There were fall-related incidents in 826 patients (1.7%). Most falls occurred in hospital rooms (67%). Adverse events occurred in 101 patients who fell (12%) and were significantly more frequent in patients aged ≥80 years old and in those wearing slippers. The incidence of falls was also significantly higher in patients in the highest risk group. These results support the validity of the risk assessment scale for predicting accidental falls in an acute treatment setting. The findings also clarify the demographic and environmental factors and consequences associated with fall. These results of the study could provide important information for designing effective interventions to prevent fall in elderly patients. PMID:28878434

  14. Metastatic angiosarcoma of the spleen after accidental radiation exposure: a case report.

    PubMed

    Geffen, D B; Zirkin, H J; Mermershtain, W; Cohen, Y; Ariad, S

    1998-04-01

    Angiosarcoma is a rare malignant tumor arising from endothelial cells of blood vessels or lymphatic channels. Therapeutic irradiation, thoriumdioxide administration, pyothorax, and polyvinyl chloride exposure have been shown to be predisposing factors for developing angiosarcoma. Accidental radiation exposure has not been associated with angiosarcoma. We present an unusual case of angiosarcoma of the spleen, with metastases to bone, liver, breast, and bone marrow, in a woman who lived near the Chernobyl nuclear facility in the former Soviet Union at the time of the reactor accident in 1986. To the best of our knowledge, this is the first report of metastatic angiosarcoma after accidental radiation exposure.

  15. Gas Pressure-Drop Experiment

    ERIC Educational Resources Information Center

    Luyben, William L.; Tuzla, Kemal

    2010-01-01

    Most chemical engineering undergraduate laboratories have fluid mechanics experiments in which pressure drops through pipes are measured over a range of Reynolds numbers. The standard fluid is liquid water, which is essentially incompressible. Since density is constant, pressure drop does not depend on the pressure in the pipe. In addition, flow…

  16. Electrohydrodynamic instabilities of viscous drops*

    NASA Astrophysics Data System (ADS)

    Vlahovska, Petia M.

    2016-10-01

    A classic result due to Taylor is that a weakly conducting drop bearing zero net charge placed in a uniform electric field adopts a prolate or oblate spheroidal shape, the flow and shape being axisymmetrically aligned with the applied field. Here I overview some intriguing symmetry-breaking instabilities occurring in strong applied dc fields: Quincke rotation resulting in drop steady tilt or tumbling, and pattern formation on the surface of a particle-coated drop.

  17. Young and juvenile chimpanzees' (Pan troglodytes) reactions to intentional versus accidental and inadvertent actions.

    PubMed

    Povinelli, D J; Perilloux, H K; Reaux, J E; Bierschwale, D T

    1998-02-01

    Chimpanzees were tested for their ability to discriminate between accidental/inadvertent and intentional actions with equivalent adverse consequences. Subjects were first trained to `point' to human trainers in order to receive food rewards. In Experiment 1, six 5-year-old subjects were alternately presented with two unfamiliar human actors. In condition 1, each actor either started to hand a cup of juice to the trainer but then pulled it back and intentionally poured it onto the floor, or accidentally spilled it while handing it to the trainer. In condition 2, the actors either accidentally spilled it as above, or aggressively threw the juice onto the floor. The subjects were then presented with both actors and were allowed to choose between them. In Experiment 2, seven 6-7-year-old chimpanzees were confronted with unfamiliar actors who either (a) intentionally withheld and consumed food intended for the subjects, (b) attempted to hand the intended food to the subjects but were victimized by a third party who consumed the food, or (c) always succeeded in delivering the food to the subjects. In general, the subjects showed little evidence of using the accidental/inadvertent versus intentional distinction in their choices between the actors, although they did display some evidence of favoring the actor involved in the most passive role in both conditions in Experiment 1.

  18. Axisymmetric Liquid Hanging Drops

    ERIC Educational Resources Information Center

    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…

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

    PubMed Central

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

    2016-01-01

    Background and Aims 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. Methods 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. Key Results 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. Conclusions 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

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

    PubMed

    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

  1. Food allergy: practical approach on education and accidental exposure prevention.

    PubMed

    Pádua, I; Moreira, A; Moreira, P; Barros, R

    2016-09-01

    Food allergies are a growing problem and currently the primary treatment of food allergy is avoidance of culprit foods. However, given the lack of information and education and also the ubiquitous nature of allergens, accidental exposures to food allergens are not uncommon. The fear of potential fatal reactions and the need of a proper avoidance leads in most of the cases to the limitation of leisure and social activities. This review aims to be a practical approach on education and accidental exposure prevention regarding activities like shopping, eating out, and travelling. The recommendations are focused especially on proper reading of food labels and the management of the disease, namely in restaurants and airplanes, concerning cross-contact and communication with other stakeholders. The implementation of effective tools is essential to manage food allergy outside home, avoid serious allergic reactions and minimize the disease's impact on individuals' quality of life.

  2. Trapping of drops by wetting defects

    PubMed Central

    't Mannetje, Dieter; Ghosh, Somnath; Lagraauw, Rudy; Otten, Simon; Pit, Arjen; Berendsen, Christian; Zeegers, Jos; van den Ende, Dirk; Mugele, Frieder

    2014-01-01

    Controlling the motion of drops on solid surfaces is crucial in many natural phenomena and technological processes including the collection and removal of rain drops, cleaning technology and heat exchangers. Topographic and chemical heterogeneities on solid surfaces give rise to pinning forces that can capture and steer drops in desired directions. Here we determine general physical conditions required for capturing sliding drops on an inclined plane that is equipped with electrically tunable wetting defects. By mapping the drop dynamics on the one-dimensional motion of a point mass, we demonstrate that the trapping process is controlled by two dimensionless parameters, the trapping strength measured in units of the driving force and the ratio between a viscous and an inertial time scale. Complementary experiments involving superhydrophobic surfaces with wetting defects demonstrate the general applicability of the concept. Moreover, we show that electrically tunable defects can be used to guide sliding drops along actively switchable tracks—with potential applications in microfluidics. PMID:24721935

  3. Fast H-DROP: A thirty times accelerated version of H-DROP for interactive SVM-based prediction of helical domain linkers

    NASA Astrophysics Data System (ADS)

    Richa, Tambi; Ide, Soichiro; Suzuki, Ryosuke; Ebina, Teppei; Kuroda, Yutaka

    2017-02-01

    Efficient and rapid prediction of domain regions from amino acid sequence information alone is often required for swift structural and functional characterization of large multi-domain proteins. Here we introduce Fast H-DROP, a thirty times accelerated version of our previously reported H-DROP (Helical Domain linker pRediction using OPtimal features), which is unique in specifically predicting helical domain linkers (boundaries). Fast H-DROP, analogously to H-DROP, uses optimum features selected from a set of 3000 ones by combining a random forest and a stepwise feature selection protocol. We reduced the computational time from 8.5 min per sequence in H-DROP to 14 s per sequence in Fast H-DROP on an 8 Xeon processor Linux server by using SWISS-PROT instead of Genbank non-redundant (nr) database for generating the PSSMs. The sensitivity and precision of Fast H-DROP assessed by cross-validation were 33.7 and 36.2%, which were merely 2% lower than that of H-DROP. The reduced computational time of Fast H-DROP, without affecting prediction performances, makes it more interactive and user-friendly. Fast H-DROP and H-DROP are freely available from http://domserv.lab.tuat.ac.jp/.

  4. Youth Crime Drop. Report.

    ERIC Educational Resources Information Center

    Butts, Jeffrey A.

    This report examines the recent drop in violent crime in the United States, discussing how much of the decrease seen between 1995-99 is attributable to juveniles (under age 18 years) and older youth (18-24 years). Analysis of current FBI arrest data indicates that not only did America's violent crime drop continue through 1999, but falling youth…

  5. Leidenfrost drops on a heated liquid pool

    NASA Astrophysics Data System (ADS)

    Maquet, L.; Sobac, B.; Darbois-Texier, B.; Duchesne, A.; Brandenbourger, M.; Rednikov, A.; Colinet, P.; Dorbolo, S.

    2016-09-01

    We show that a volatile liquid drop placed at the surface of a nonvolatile liquid pool warmer than the boiling point of the drop can be held in a Leidenfrost state even for vanishingly small superheats. Such an observation points to the importance of the substrate roughness, negligible in the case considered here, in determining the threshold Leidenfrost temperature. A theoretical model based on the one proposed by Sobac et al. [Phys. Rev. E 90, 053011 (2014), 10.1103/PhysRevE.90.053011] is developed in order to rationalize the experimental data. The shapes of the drop and of the liquid substrate are analyzed. The model notably provides scalings for the vapor film thickness profile. For small drops, these scalings appear to be identical to the case of a Leidenfrost drop on a solid substrate. For large drops, in contrast, they are different, and no evidence of chimney formation has been observed either experimentally or theoretically in the range of drop sizes considered in this study. Concerning the evaporation dynamics, the radius is shown to decrease linearly with time whatever the drop size, which differs from the case of a Leidenfrost drop on a solid substrate. For high superheats, the characteristic lifetime of the drops versus the superheat follows a scaling law that is derived from the model, but, at low superheats, it deviates from this scaling by rather saturating.

  6. Forced Oscillations of Supported Drops

    NASA Technical Reports Server (NTRS)

    Wilkes, Edward D.; Basaran, Osman A.

    1996-01-01

    Oscillations of supported liquid drops are the subject of wide scientific interest, with applications in areas as diverse as liquid-liquid extraction, synthesis of ceramic powders, growing of pure crystals in low gravity, and measurement of dynamic surface tension. In this research, axisymmetric forced oscillations of arbitrary amplitude of viscous liquid drops of fixed volume which are pendant from or sessile on a rod with a fixed or moving contact line and surrounded by an inviscid ambient gas are induced by moving the rod in the vertical direction sinusiodally in time. In this paper, a preliminary report is made on the computational analysis of the oscillations of supported drops that have 'clean' interfaces and whose contact lines remain fixed throughout their motions. The relative importance of forcing to damping can be increased by either increasing the amplitude of rod motion A or Reynolds number Re. It is shown that as the ratio of forcing to damping rises, for drops starting from an initial rest state a sharp increase in deformation can occur when they are forced to oscillate in the vicinity of their resonance frequencies, indicating the incipience of hysteresis. However, it is also shown that the existence of a second stable limit cycle and the occurrence of hysteresis can be observed if the drop is subjected to a so-called frequency sweep, where the forcing frequency is first increased and then decreased over a suitable range. Because the change in drop deformation response is abrupt in the vicinity of the forcing frequencies where hysteresis occurs, it should be possible to exploit the phenomenon to accurately measure the viscosity and surface tension of the drop liquid.

  7. A tree branch instead of a ligature: an unusual accidental hanging.

    PubMed

    Vadysinghe, Amal Nishantha; Sivasubramanium, Murugupillai; Jayasooriya, Rankothge Pemasiri

    2017-12-01

    A unique case of accidental hanging due to compression of the neck of an adult by the branches of a coffee tree is reported. The decedent was a 42-year-old male who was found dead in a semi prone position on a slope. His neck was lodged in a wedge formed by two branches of a coffee tree, with his legs angled downwards on the slope. Autopsy revealed two friction abrasions located horizontally on either side of the front of the neck, just above the larynx. The findings were compatible with compression of the neck by the branches of the tree, with the body weight of the decedent contributing to compression. Subsequent complete autopsy examination confirmed the cause of death as hanging. Following an inquest the death was ruled to be accidental.

  8. Scenario analysis of energy-based low-carbon development in China.

    PubMed

    Zhou, Yun; Hao, Fanghua; Meng, Wei; Fu, Jiafeng

    2014-08-01

    China's increasing energy consumption and coal-dominant energy structure have contributed not only to severe environmental pollution, but also to global climate change. This article begins with a brief review of China's primary energy use and associated environmental problems and health risks. To analyze the potential of China's transition to low-carbon development, three scenarios are constructed to simulate energy demand and CO₂ emission trends in China up to 2050 by using the Long-range Energy Alternatives Planning System (LEAP) model. Simulation results show that with the assumption of an average annual Gross Domestic Product (GDP) growth rate of 6.45%, total primary energy demand is expected to increase by 63.4%, 48.8% and 12.2% under the Business as Usual (BaU), Carbon Reduction (CR) and Integrated Low Carbon Economy (ILCE) scenarios in 2050 from the 2009 levels. Total energy-related CO₂ emissions will increase from 6.7 billiontons in 2009 to 9.5, 11, 11.6 and 11.2 billiontons; 8.2, 9.2, 9.6 and 9 billiontons; 7.1, 7.4, 7.2 and 6.4 billiontons in 2020, 2030, 2040 and 2050 under the BaU, CR and ILCE scenarios, respectively. Total CO₂ emission will drop by 19.6% and 42.9% under the CR and ILCE scenarios in 2050, compared with the BaU scenario. To realize a substantial cut in energy consumption and carbon emissions, China needs to make a long-term low-carbon development strategy targeting further improvement of energy efficiency, optimization of energy structure, deployment of clean coal technology and use of market-based economic instruments like energy/carbon taxation. Copyright © 2014. Published by Elsevier B.V.

  9. Internally damped, self-arresting vertical drop-weight apparatus

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Waters, William A. (Inventor); Stockum, Robert W. (Inventor); Walter, Manfred A. (Inventor)

    1994-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  10. Nonlinear oscillations of inviscid free drops

    NASA Technical Reports Server (NTRS)

    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.

  11. PREVENTION REFERENCE MANUAL: CONTROL TECHNOLOGIES, VOL. 2. POST-RELEASE MITIGATION MEASURES FOR CONTROLLING ACCIDENTAL RELEASES OF AIR TOXICS

    EPA Science Inventory

    The volume discusses prevention and protection measures for controlling accidental releases of air toxics. The probability of accidental releases depends on the extent to which deviations (in magnitude and duration) in the process can be tolerated before a loss of chemical contai...

  12. Head-on collision of drops: A numerical investigation

    NASA Technical Reports Server (NTRS)

    Nobari, M. R.; Jan, Y.-J.; Tryggvason, G.

    1993-01-01

    The head-on collision of equal sized drops is studied by full numerical simulations. The Navier-Stokes equations are solved for fluid motion both inside and outside the drops using a front tracking/finite difference technique. The drops are accelerated toward each other by a body force that is turned off before the drops collide. When the drops collide, the fluid between them is pushed outward leaving a thin later bounded by the drop surface. This layer gets progressively thinner as the drops continue to deform and in several of the calculations this double layer is artificially removed once it is thin enough, thus modeling rupture. If no rupture takes place, the drops always rebound, but if the film is ruptured the drops may coalesce permanently or coalesce temporarily and then split again.

  13. 49 CFR 572.102 - Drop test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Drop test. 572.102 Section 572.102 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Free Motion Headform § 572.102 Drop test. (a) When the headform is dropped from a height of 14.8 inches in accordance with paragraph (b) of...

  14. 49 CFR 572.102 - Drop test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Drop test. 572.102 Section 572.102 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Free Motion Headform § 572.102 Drop test. (a) When the headform is dropped from a height of 14.8 inches in accordance with paragraph (b) of...

  15. 49 CFR 572.102 - Drop test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Drop test. 572.102 Section 572.102 Transportation..., DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Free Motion Headform § 572.102 Drop test. (a) When the headform is dropped from a height of 14.8 inches in accordance with paragraph (b) of...

  16. 19 CFR 158.27 - Accidental fire or other casualty.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Casualty, Loss, or Theft While in Customs Custody § 158.27 Accidental fire or other casualty. In the case... submitted: (a) A declaration of the master of the vessel, the conductor or driver of the vehicle, the... merchandise was on board the vessel or vehicle, in the warehouse, or otherwise in his charge, as the case may...

  17. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors.

    PubMed

    Pandit, J J; Andrade, J; Bogod, D G; Hitchman, J M; Jonker, W R; Lucas, N; Mackay, J H; Nimmo, A F; O'Connor, K; O'Sullivan, E P; Paul, R G; Palmer, J H MacG; Plaat, F; Radcliffe, J J; Sury, M R J; Torevell, H E; Wang, M; Hainsworth, J; Cook, T M

    2014-10-01

    We present the main findings of the 5th National Audit Project on accidental awareness during general anaesthesia. Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ~1:19 600 anaesthetics (95% CI 1:16 700-23 450). However, there was considerable variation across subtypes of techniques or subspecialties. The incidence with neuromuscular blockade was ~1:8200 (1:7030-9700), and without it was ~1:135 900 (1:78 600-299 000). The cases of accidental awareness during general anaesthesia reported to 5th National Audit Project were overwhelmingly cases of unintended awareness during neuromuscular blockade. The incidence of accidental awareness during caesarean section was ~1:670 (1:380-1300). Two thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental; rapid sequence induction; obesity; difficult airway management; neuromuscular blockade; and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, most due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex; age (younger adults, but not children); obesity; anaesthetist seniority (junior trainees); previous awareness; out-of-hours operating; emergencies; type of surgery (obstetric, cardiac, thoracic); and use of neuromuscular blockade. The following factors were

  18. 49 CFR 178.603 - Drop test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... aluminum boxes, Composite packagings which are in the shape of a box Five—(one for each drop) First drop... impact. Where more than one orientation is possible for a given drop test, the orientation most likely to... example a closure or, for some 7 cylindrical drums, the welded longitudinal seam of the drum body. Boxes...

  19. Suicide and accidental death in Australia's rural farming communities: a review of the literature.

    PubMed

    Kennedy, Alison J; Maple, Myfanwy J; McKay, Kathy; Brumby, Susan A

    2014-01-01

    Australia's farmers constitute a heterogeneous group within the rural population. This literature review incorporates four broad areas: an understanding of farming communities, families and individuals and the contexts in which they live and work; an exploration of the challenges to morbidity and mortality that these communities face; a description of the patterns of suicide and accidental death in farming communities; and an outline of what is missing from the current body of research. Recommendations will be made on how these gaps may be addressed. In developing this comprehensive literature review, a snowballing and saturation approach was adopted. Initial search terms included suicid*, farm*, accident*, fatal*, death, sudden death, rural OR remote, Australia and NOT Australia. Databases searched included SCOPUS, PubMed, Proquest and SafetyLit; research from 1995 onwards was examined for relevance. Earlier seminal texts were also included. Reference lists of retrieved articles were searched and citations explored for further relevant research material. The primary focus was on Australian peer-reviewed research with supplementary grey literature. International material was used as examples. The literature variously describes farmers as members of both rural farming communities and farming families, and as individuals within an occupational classification. Within each of these classifications, there is evidence of the cumulative impact of a multiplicity of social, geographical and psychological factors relating to work, living and social arrangements that impact the health and wellbeing of Australia's farmers and their families, particularly accidental death and suicide. Research consistently demonstrates traumatic death to be at a greater rate than in the general Australian population, with reductions found more recently in some modes of farming-related accidental death. Patterns of accidental death and suicide are commonly linked to the changing shape of

  20. Electrochemistry in an acoustically levitated drop.

    PubMed

    Chainani, Edward T; Ngo, Khanh T; Scheeline, Alexander

    2013-02-19

    Levitated drops show potential as microreactors, especially when radicals are present as reactants or products. Solid/liquid interfaces are absent or minimized, avoiding adsorption and interfacial reaction of conventional microfluidics. We report amperometric detection in an acoustically levitated drop with simultaneous ballistic addition of reactant. A gold microelectrode sensor was fabricated with a lithographic process; active electrode area was defined by a photosensitive polyimide mask. The microdisk gold working electrode of radius 19 μm was characterized using ferrocenemethanol in aqueous buffer. Using cyclic voltammetry, the electrochemically active surface area was estimated by combining a recessed microdisk electrode model with the Randles-Sevcik equation. Computer-controlled ballistic introduction of reactant droplets into the levitated drop was developed. Chronoamperometric measurements of ferrocyanide added ballistically demonstrate electrochemical monitoring using the microfabricated electrode in a levitated drop. Although concentration increases with time due to drop evaporation, the extent of concentration is predictable with a linear evaporation model. Comparison of diffusion-limited currents in pendant and levitated drops show that convection arising from acoustic levitation causes an enhancement of diffusion-limited current on the order of 16%.

  1. Effects of drop acceleration and deceleration on particle capture in a cross-flow gravity tower at intermediate drop Reynolds numbers.

    PubMed

    Kumar, Anoop; Gupta, S K; Kale, S R

    2007-04-01

    Cross-flow gravity towers are particle scrubbing devices in which water is sprayed from the top into particle-laden flow moving horizontally. Models for predicting particle capture assume drops traveling at terminal velocity and potential flow (ReD > 1000) around it, however, Reynolds numbers in the intermediate range of 1 to 1000 are common in gravity towers. Drops are usually injected at velocities greater than their terminal velocities (as in nozzles) or from near rest (perforated tray) and they accelerate/decelerate to their terminal velocity in the tower. Also, the effects of intermediate drop Reynolds number on capture efficiency have been simulated for (a) drops at their terminal velocity and (b) drops accelerating/decelerating to their terminal velocity. Tower efficiency based on potential flow about the drop is 40%-50% greater than for 200 mm drops traveling at their terminal velocity. The corresponding values for 500 mm drops are about 10%-20%. The drop injection velocity is important operating parameter. Increase in tower efficiency by about 40% for particles smaller than 5 mm is observed for increase in injection velocity from 0 to 20 m/s for 200 and 500mm drops.

  2. The Drop Tower Bremen -Experiment Operation

    NASA Astrophysics Data System (ADS)

    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

  3. 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors.

    PubMed

    Pandit, J J; Andrade, J; Bogod, D G; Hitchman, J M; Jonker, W R; Lucas, N; Mackay, J H; Nimmo, A F; O'Connor, K; O'Sullivan, E P; Paul, R G; Palmer, J H M G; Plaat, F; Radcliffe, J J; Sury, M R J; Torevell, H E; Wang, M; Hainsworth, J; Cook, T M

    2014-10-01

    We present the main findings of the 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia (AAGA). Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ~1:19,600 anaesthetics (95% confidence interval 1:16,700-23,450). However, there was considerable variation across subtypes of techniques or subspecialities. The incidence with neuromuscular block (NMB) was ~1:8200 (1:7030-9700), and without, it was ~1:135,900 (1:78,600-299,000). The cases of AAGA reported to NAP5 were overwhelmingly cases of unintended awareness during NMB. The incidence of accidental awareness during Caesarean section was ~1:670 (1:380-1300). Two-thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental, rapid sequence induction, obesity, difficult airway management, NMB, and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One-third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, mostly due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex, age (younger adults, but not children), obesity, anaesthetist seniority (junior trainees), previous awareness, out-of-hours operating, emergencies, type of surgery (obstetric, cardiac, thoracic), and use of NMB. The following factors were not risk factors for accidental awareness: ASA physical status, race, and use or omission

  4. Accidental falls in hospitalized children: an analysis of the vulnerabilities linked to the presence of caregivers.

    PubMed

    Bagnasco, A; Sobrero, M; Sperlinga, L; Tibaldi, L; Sasso, L

    2010-06-01

    This study stemmed from the data gathered by a research conducted by the coordinator of the Department of Healthcare Services and a group of nurses involved in a research on accidental falls in hospitalized children at the "G. Gaslini" Children's Hospital and Scientific Research Institute in Genoa, Italy. The first retrospective study evaluated the accidental falls in hospitalized children referred to the three-year period 2003-2006, while the second perspective study, referred to the trimester March-May 2007, found that the main cause of falls in children was parent's distraction. The method adopted in the first phase of our study was a proactive risk analysis (The Basics of Healthcare Failure Mode and Effect Analysis), identified in the first place by the VA National Centre for Patient Safety and applied to the "Child and parent hospital admission process". This proactive risk analysis has proven to be very effective in preventing the risk of accidental falls in hospitalized children through effective communication and educational interventions. The second phase of our study consisted of two Focus Groups for accidental traumatic events. The analysis of the results of the study showed how effective communication is instrumental, not only to have a better awareness of the children and their parents during their stay in hospital, but also to implement educational sessions on prevention to reduce the risk of accidental traumatic events. The present study contributes to improve safety and the quality of care by motivating nurses to keep their attention high on falls in hospitalized children, by monitoring and the development of new risk assessment tools.

  5. Accidental fatal lung injury by compressed air: a case report.

    PubMed

    Rayamane, Anand Parashuram; Pradeepkumar, M V

    2015-03-01

    Compressed air is being used extensively as a source of energy at industries and in daily life. A variety of fatal injuries are caused by improper and ignorant use of compressed air equipments. Many types of injuries due to compressed air are reported in the literature such as colorectal injury, orbital injury, surgical emphysema, and so on. Most of these injuries are accidental in nature. It is documented that 40 pounds per square inch pressure causes fatal injuries to the ear, eyes, lungs, stomach, and intestine. Openings of body are vulnerable to injuries by compressed air. Death due to compressed air injuries is rarely reported. Many cases are treated successfully by conservative or surgical management. Extensive survey of literature revealed no reports of fatal injury to the upper respiratory tract and lungs caused by compressed air. Here, we are reporting a fatal event of accidental death after insertion of compressed air pipe into the mouth. The postmortem findings are corroborated with the history and discussed in detail.

  6. Equilibrium shapes of drops on membranes

    NASA Astrophysics Data System (ADS)

    Sharma, Ishan; Nair, Vineet; Shankar, Viswanathan

    2017-11-01

    Equilibrium shapes for axisymmetric sessile and pendant drops placed on / attached to geometrically nonlinear elastic membranes, in horizontal as well as inclined configurations, are obtained. The effective contact angle of the drop with the membrane, its contact radius, the maximum membrane displacement, and the volume of the drop is investigated for various values of Bond Number and membrane tension.

  7. 49 CFR 178.603 - Drop test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the fourth sample). Fifth drop: On a corner (using the fifth sample). Bags—single-ply with a side seam...). Bags—single-ply without a side seam, or multi-ply Three—(two drops per bag) First drop: Flat on a wide...) For a bag, neither the outermost ply nor an outer packaging exhibits any damage likely to adversely...

  8. 49 CFR 178.603 - Drop test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (using the fourth sample). Fifth drop: On a corner (using the fifth sample). Bags—single-ply with a side... samples). Bags—single-ply without a side seam, or multi-ply Three—(two drops per bag) First drop: Flat on... the drum is no longer sift-proof; (3) For a bag, neither the outermost ply nor an outer packaging...

  9. Management of Dropped Skull Flaps.

    PubMed

    Abdelfatah, Mohamed AbdelRahman

    2017-01-01

    Dropping a skull flap on the floor is an uncommon and avoidable mistake in the neurosurgical operating theater. This study retrospectively reviewed all incidents of dropped skull flaps in Ain-Shams University hospitals during a 10-year period to show how to manage this problem and its outcome. Thirty-one incidents of dropped skull flaps occurred from January 2004 to January 2014 out of more than 10,000 craniotomies. Follow-up period varied from 20 to 44 months. The bone flap was dropped while elevating the bone (n = 16), while drilling the bone on the operating table (n = 5), and during insertion of the bone flap (n = 10). Treatment included re-insertion of the skull flap after soaking it in povidone iodine and antibiotic solution (n = 17) or after autoclaving (n = 11), or discarding the skull flap and replacing it with a mesh cranioplasty in the same operation (n = 3). No bone or wound infection was noted during the follow-up period. Management of dropped skull flap is its prevention. Replacement of the skull flap, after decontamination, is an option that avoids the expense and time of cranioplasty.

  10. Accidental degeneracy in photonic bands and topological phase transitions in two-dimensional core-shell dielectric photonic crystals.

    PubMed

    Xu, Lin; Wang, Hai-Xiao; Xu, Ya-Dong; Chen, Huan-Yang; Jiang, Jian-Hua

    2016-08-08

    A simple core-shell two-dimensional photonic crystal is studied where the triangular lattice symmetry and the C6 point group symmetry give rich physics in accidental touching points of photonic bands. We systematically evaluate different types of accidental nodal points at the Brillouin zone center for transverse-magnetic harmonic modes when the geometry and permittivity of the core-shell material are continuously tuned. The accidental nodal points can have different dispersions and topological properties (i.e., Berry phases). These accidental nodal points can be the critical states lying between a topological phase and a normal phase of the photonic crystal. They are thus very important for the study of topological photonic states. We show that, without breaking time-reversal symmetry, by tuning the geometry of the core-shell material, a phase transition into the photonic quantum spin Hall insulator can be achieved. Here the "spin" is defined as the orbital angular momentum of a photon. We study the topological phase transition as well as the properties of the edge and bulk states and their application potentials in optics.

  11. Accidental dural puncture, postdural puncture headache, intrathecal catheters, and epidural blood patch: revisiting the old nemesis.

    PubMed

    Kaddoum, Roland; Motlani, Faisal; Kaddoum, Romeo N; Srirajakalidindi, Arvi; Gupta, Deepak; Soskin, Vitaly

    2014-08-01

    One of the controversial management options for accidental dural puncture in pregnant patients is the conversion of labor epidural analgesia to continuous spinal analgesia by threading the epidural catheter intrathecally. No clear consensus exists on how to best prevent severe headache from occurring after accidental dural puncture. To investigate whether the intrathecal placement of an epidural catheter following accidental dural puncture impacts the incidence of postdural puncture headache (PDPH) and the subsequent need for an epidural blood patch in parturients. A retrospective chart review of accidental dural puncture was performed at Hutzel Women's Hospital in Detroit, MI, USA for the years 2002-2010. Documented cases of accidental dural punctures (N = 238) were distributed into two groups based on their management: an intrathecal catheter (ITC) group in which the epidural catheter was inserted intrathecally and a non-intrathecal catheter (non-ITC) group that received the epidural catheter inserted at different levels of lumbar interspaces. The incidence of PDPH as well as the necessity for epidural blood patch was analyzed using two-tailed Fisher's exact test. In the non-ITC group, 99 (54 %) parturients developed PDPH in comparison to 20 (37 %) in the ITC [odds ratio (OR), 1.98; 95 % confidence interval (CI), 1.06-3.69; P = 0.03]. Fifty-seven (31 %) of 182 patients in the non-ITC group required an epidural blood patch (EBP) (data for 2 patients of 184 were missing). In contrast, 7 (13 %) of parturients in the ITC group required an EBP. The incidence of EBP was calculated in parturients who actually developed headache to be 57 of 99 (57 %) in the non-ITC group versus 7 of 20 (35 %) in the ITC group (OR, 2.52; 95 % CI, 0.92-6.68; P = 0.07). The insertion of an intrathecal catheter following accidental dural puncture decreases the incidence of PDPH but not the need for epidural blood patch in parturients.

  12. Motion of Deformable Drops Through Porous Media

    NASA Astrophysics Data System (ADS)

    Zinchenko, Alexander Z.; Davis, Robert H.

    2017-01-01

    This review describes recent progress in the fundamental understanding of deformable drop motion through porous media with well-defined microstructures, through rigorous first-principles hydrodynamical simulations and experiments. Tight squeezing conditions, when the drops are much larger than the pore throats, are particularly challenging numerically, as the drops nearly coat the porous material skeleton with small surface clearance, requiring very high surface resolution in the algorithms. Small-scale prototype problems for flow-induced drop motion through round capillaries and three-dimensional (3D) constrictions between solid particles, and for gravity-induced squeezing through round orifices and 3D constrictions, show how forcing above critical conditions is needed to overcome trapping. Scaling laws for the squeezing time are suggested. Large-scale multidrop/multiparticle simulations for emulsion flow through a random granular material with multiple drop breakup show that the drop phase generally moves faster than the carrier fluid; both phase velocities equilibrate much faster to the statistical steady state than does the drop-size distribution.

  13. Undercooling of acoustically levitated molten drops

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.; Glicksman, M. E.

    1990-01-01

    It was observed that the acoustically levitated molten SCN (succinonitrile) drops can generally be undercooled to a degree where the impurities in the drop are responsible for the nucleation of the solid phase. However, it was also observed that ultrasound occasionally terminates undercooling of the levitated drops by initiating the nucleation of the solid at an undercooling level which is lower than that found for the nucleation catalyzed by the impurities in the drop. This premature nucleation can be explained by thermodynamic considerations which predict an increase in effective undercooling of the liquid upon the collapse of cavities. Pre-existing gas microbubbles which grow under the influence of ultrasound are suggested as the source of cavitation. The highly undercooled SCN drops can be utilized to measure the growth velocity of the solid in the deeply undercooled region including the hypercooled region.

  14. The possible equilibrium shapes of static pendant drops

    NASA Astrophysics Data System (ADS)

    Sumesh, P. T.; Govindarajan, Rama

    2010-10-01

    Analytical and numerical studies are carried out on the shapes of two-dimensional and axisymmetric pendant drops hanging under gravity from a solid surface. Drop shapes with both pinned and equilibrium contact angles are obtained naturally from a single boundary condition in the analytical energy optimization procedure. The numerical procedure also yields optimum energy shapes, satisfying Young's equation without the explicit imposition of a boundary condition at the plate. It is shown analytically that a static pendant two-dimensional drop can never be longer than 3.42 times the capillary length. A related finding is that a range of existing solutions for long two-dimensional drops correspond to unphysical drop shapes. Therefore, two-dimensional drops of small volume display only one static solution. In contrast, it is known that axisymmetric drops can display multiple solutions for a given volume. We demonstrate numerically that there is no limit to the height of multiple-lobed Kelvin drops, but the total volume is finite, with the volume of successive lobes forming a convergent series. The stability of such drops is in question, though. Drops of small volume can attain large heights. A bifurcation is found within the one-parameter space of Laplacian shapes, with a range of longer drops displaying a minimum in energy in the investigated space. Axisymmetric Kelvin drops exhibit an infinite number of bifurcations.

  15. Drops moving along and across a filament

    NASA Astrophysics Data System (ADS)

    Sahu, Rakesh P.; Sinha-Ray, Suman; Yarin, Alexander; Pourdeyhimi, Behnam

    2013-11-01

    The present work is devoted to the experimental study of oil drop motion both along and across a filament due to the air jet blowing. In case of drop moving along the filament, phenomena such as drop stick-slip motion, shape oscillations, shedding of a tail along the filament, the tail capillary instability and drop recoil motion were observed which were rationalized in the framework of simplified models. Experiments with cross-flow of the surrounding gas relative to the filament with an oil drop on it were conducted, with air velocity in the range of 7.23 to 22.7 m s-1. The Weber number varied from 2 to 40 and the Ohnesorge number varied from 0.07 to 0.8. The lower and upper critical Weber numbers were introduced to distinguish between the beginning of the drop blowing off the filament and the onset of the bag-stamen breakup. The range of the Weber number between these two critical values is filled with three types of vibrational breakup: V1 (a balloon-like drop being blown off), V2 (a drop on a single stamen being blown off), and V3 (a drop on a double stamen being blown off). The Weber number/Ohnesorge number plane was delineated into domains of different breakup regimes. The work is supported by the Nonwovens Cooperative Research Center (NCRC).

  16. Factors perceived as being related to accidental falls by persons with multiple sclerosis.

    PubMed

    Nilsagård, Ylva; Denison, Eva; Gunnarsson, Lars-Gunnar; Boström, Katrin

    2009-01-01

    This study explores and describes factors that persons with multiple sclerosis (MS) perceive as being related to accidental falls. A qualitative content analysis with primarily deductive approach was conducted using the International Classification of Functioning, Disability and Health. Twelve persons with MS, and identified as fallers, were interviewed. Factors perceived to cause accidental falls that had not previously been targeted in MS populations in relation to falls were identified as divided attention, reduced muscular endurance, fatigue and heat sensitivity. Previously reported risk factors such as changed gait pattern, limited walking ability, impaired proprioception, vision and spasticity were supported. Activities involving walking, recreation and leisure, maintaining and changing body position, lifting or carrying, taking care of the home, washing the body, moving around, preparing meals and housekeeping were limited and considered to be risk activities. Supportive persons and assistive device reduced falls, and unsuitable physical environments and climate conditions induced falls. Several preventative strategies were described as partially compensating for the impairments, limitations and restrictions. Investigating accidental falls using the perspective of the patient gave important information about variables not earlier targeted in MS research.

  17. Towards "DRONE-BORNE" Disaster Management: Future Application Scenarios

    NASA Astrophysics Data System (ADS)

    Tanzi, Tullio Joseph; Chandra, Madhu; Isnard, Jean; Camara, Daniel; Sebastien, Olivier; Harivelo, Fanilo

    2016-06-01

    Information plays a key role in crisis management and relief efforts for natural disaster scenarios. Given their flight properties, UAVs (Unmanned Aerial Vehicles) provide new and interesting perspectives on the data gathering for disaster management. A new generation of UAVs may help to improve situational awareness and information assessment. Among the advantages UAVs may bring to the disaster management field, we can highlight the gain in terms of time and human resources, as they can free rescue teams from time-consuming data collection tasks and assist research operations with more insightful and precise guidance thanks to advanced sensing capabilities. However, in order to be useful, UAVs need to overcome two main challenges. The first one is to achieve a sufficient autonomy level, both in terms of navigation and interpretation of the data sensed. The second major challenge relates to the reliability of the UAV, with respect to accidental (safety) or malicious (security) risks. This paper first discusses the potential of UAV in assisting in different humanitarian relief scenarios, as well as possible issues in such situations. Based on recent experiments, we discuss the inherent advantages of autonomous flight operations, both lone flights and formation flights. The question of autonomy is then addressed and a secure embedded architecture and its specific hardware capabilities is sketched out. We finally present a typical use case based on the new detection and observation abilities that UAVs can bring to rescue teams. Although this approach still has limits that have to be addressed, technically speaking as well as operationally speaking, it seems to be a very promising one to enhance disaster management efforts activities.

  18. Accidental Outcomes Guide Punishment in a “Trembling Hand” Game

    PubMed Central

    Cushman, Fiery; Dreber, Anna; Wang, Ying; Costa, Jay

    2009-01-01

    How do people respond to others' accidental behaviors? Reward and punishment for an accident might depend on the actor's intentions, or instead on the unintended outcomes she brings about. Yet, existing paradigms in experimental economics do not include the possibility of accidental monetary allocations. We explore the balance of outcomes and intentions in a two-player economic game where monetary allocations are made with a “trembling hand”: that is, intentions and outcomes are sometimes mismatched. Player 1 allocates $10 between herself and Player 2 by rolling one of three dice. One die has a high probability of a selfish outcome, another has a high probability of a fair outcome, and the third has a high probability of a generous outcome. Based on Player 1's choice of die, Player 2 can infer her intentions. However, any of the three die can yield any of the three possible outcomes. Player 2 is given the opportunity to respond to Player 1's allocation by adding to or subtracting from Player 1's payoff. We find that Player 2's responses are influenced substantially by the accidental outcome of Player 1's roll of the die. Comparison to control conditions suggests that in contexts where the allocation is at least partially under the control of Player 1, Player 2 will punish Player 1 accountable for unintentional negative outcomes. In addition, Player 2's responses are influenced by Player 1's intention. However, Player 2 tends to modulate his responses substantially more for selfish intentions than for generous intentions. This novel economic game provides new insight into the psychological mechanisms underlying social preferences for fairness and retribution. PMID:19707578

  19. Extrapyramidal symptoms following accidental ingestion of risperidone in a child.

    PubMed

    Cheslik, T A; Erramouspe, J

    1996-04-01

    To describe the development of extrapyramidal symptoms (EPS) precipitated by an accidental overdose of risperidone in a 3.5-year-old boy. The boy presented to the emergency department with bilateral upward eye gaze, jerky movements of his extremities, and motor restlessness following an accidental ingestion of a single 4-mg risperidone tablet. Decontamination with NaCl 0.9% lavage and activated charcoal with sorbitol was performed. His symptoms responded immediately to intravenous diphenhydramine (on 3 different occasions) during his first 9.5 hours of hospitalization. He experienced no additional EPS, and was discharged home approximately 33 hours following initial presentation. At home, he received three oral doses of diphenhydramine in the 24 hours following hospital discharge because of hand tremor, total body shivering, and eye wandering. These signs resolved without further complications. Although the incidence of EPS associated with therapeutic risperidone use is low, its occurrence following overdose is less clearly defined. This represents the first published case, to our knowledge, of risperidone overdose in a child and highlights the potential for dystonic reactions at low doses in this population. Seven intentional overdoses of risperidone in adults (aged 21-68 y) have been reported in the literature and are reviewed. Amounts ingested ranged from 5 to 270 mg. All adult patients appeared to have a relatively benign course. Reported symptoms included drowsiness, slurred speech, altered levels of consciousness, hypertension, tachycardia, electrocardiogram abnormalities, atypical motor behavior, tremors, and other EPS (not specified). Accidental ingestion of low doses of risperidone can cause EPS in children that may respond well to an anticholinergic agent. Overdose management includes gastrointestinal lavage, activated charcoal with cathartic, cardiovascular monitoring, and supportive therapy.

  20. A case of an accidental exposure to a veterinary insecticide product formulation.

    PubMed

    Sidhu, K S; Collisi, M B

    1989-02-01

    A veterinary technician while opening a package was accidentally exposed to a commercial canned product formulation containing insecticides and solvents. The patient was twice briefly treated and released as an outpatient from 2 different hospitals on the first and second day after the exposure. However, on the fourth day, as some of the symptoms (headache, nausea, vomiting, diarrhea, difficult breathing) persisted, the patient was admitted to another hospital. The patient was treated for exposure to organophosphates and solvents and was released after 13 days. The patient developed diabetes insipidus, a condition which lasted for approximately 1 year. The cause of the temporary development of diabetes insipidus is not understood. There is a need to prevent and minimize such accidental exposures in future.

  1. Parental cannabis abuse and accidental intoxications in children: prevention by detecting neglectful situations and at-risk families.

    PubMed

    Pélissier, Fanny; Claudet, Isabelle; Pélissier-Alicot, Anne-Laure; Franchitto, Nicolas

    2014-12-01

    Cannabis intoxication in toddlers is rare and mostly accidental. Our objectives were to focus on the characteristics and management of children under the age of 6 years who were admitted to our emergency department with cannabis poisoning reported as accidental by parents, and to point out the need to consider accidental cannabis ingestions as an indicator of neglect. The medical records of children hospitalized for cannabis poisoning in a pediatric emergency department from January 2007 to November 2012 were retrospectively evaluated. Data collected included age, sex, drug ingested, source of drug, intentional versus accidental ingestion, pediatric intensive care unit or hospital admission, treatment and length of hospital stay, toxicology results, and rate of child protectives services referral. Twelve toddlers (4 boys and 8 girls; mean age, 16.6 months) were included. All had ingested cannabis. Their parents reported the ingestion. Seven children experienced drowsiness or hypotonia. Three children were given activated charcoal. Blood screening for cannabinoids, performed in 2 cases, was negative in both, and urine samples were positive in 7 children (70%). All children had favorable outcomes after being hospitalized from 2 to 48 hours. Nine children were referred to social services for further assessment before discharge. Cannabis intoxication in children should be reported to child protection services with the aim of prevention, to detect situations of neglect and at-risk families. Legal action against the parents may be considered. Accidental intoxication and caring parents should be no exception to this rule.

  2. Orion Swing Drop 6

    NASA Image and Video Library

    2017-09-25

    Water impact test of an 18,000-pound (8,165 kilogram) test version of the Orion spacecraft at NASA's Langley Research Center. NASA is swing drop testing this Orion capsule mock-up at Langley's Hydro Impact Basin to certify the actual Orion spacecraft for water landings. In a series of tests, Orion is being dropped in a variety of different conditions to help fine-tune NASA's predictions of Orion's landing loads.

  3. Self-Diffusion of Drops in a Dilute Sheared Emulsion

    NASA Technical Reports Server (NTRS)

    Loewenberg, Michael; Hinch, E. J.

    1996-01-01

    Self-diffusion coefficients that describe cross-flow migration of non-Brownian drops in a dilute sheared emulsion were obtained by trajectory calculations. A boundary integral formulation was used to describe pairwise interactions between deformable drops; interactions between undeformed drops were described with mobility functions for spherical drops. The results indicate that drops have large anisotropic self-diffusivities which depend strongly on the drop viscosity and modestly on the shear-rate. Pairwise interactions between drops in shear-flow do not appreciably promote drop breakup.

  4. DIME Students Witness Test Drop

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Students watch a test run on their experiment before the actual drop. They designed and built their apparatus to fit within a NASA-provided drop structure. This was part of the second Dropping in a Microgravity Environment (DIME) competition held April 23-25, 2002, at NASA's Glenn Research Center. Competitors included two teams from Sycamore High School, Cincinnati, OH, and one each from Bay High School, Bay Village, OH, and COSI Academy, Columbus, OH. DIME is part of NASA's education and outreach activities. Details are on line at http://microgravity.grc.nasa.gov/DIME_2002.html.

  5. Drop trampoline

    NASA Astrophysics Data System (ADS)

    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.

  6. Thermocapillary reorientation of Janus drops

    NASA Astrophysics Data System (ADS)

    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.

  7. Drop Spreading with Random Viscosity

    NASA Astrophysics Data System (ADS)

    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.

  8. Static structure of a pointed charged drop

    NASA Astrophysics Data System (ADS)

    Fernandez de La Mora, Juan

    2017-11-01

    The static equilibrium structure of an equipotential drop with two symmetric Taylor cones is computed by assigning a charge distribution along the z axis q (z) = ∑Bn (L2 -z2)n + 1 / 2 . Taylor's local equilibrium at the poles z = L , - L fixes two of the Bn coefficients as a function of the other, determined by minimizing stress imbalance. Just two optimally chosen terms in the Bn expansion yield imperceptible errors. Prior work has argued that an exploding drop initially carrying Rayleigh's charge qR is quasi static. Paradoxically, quasi-static predictions on the size of the progeny drops emitted during a Coulombic explosion disagree with observations. The static drop structure found here also models poorly a Coulomb explosion having an equatorial over polar length ratio (0.42) and the a drop charge exceeding those observed (0.28-0.36 and qR / 2). Our explanation for this paradox is that, while the duration tc of a Coulomb explosion is much larger than the charge relaxation time, the dynamic time scale for drop elongation is typically far longer than tc. Therefore, the pressure distribution within the exploding drop is not uniform. A similar analysis for a drop in an external field fits well the experimental shape.

  9. A soft porous drop in linear flows

    NASA Astrophysics Data System (ADS)

    Young, Yuan-Nan; Miksis, Michael; Mori, Yoichiro; Shelley, Michael

    2017-11-01

    The cellular cytoplasm consists a viscous fluid filled with fibrous networks that also have their own dynamics. Such fluid-structure interactions have been modeled as a soft porous material immersed in a viscous fluid. In this talk we focus on the hydrodynamics of a viscous drop filled with soft porous material inside. Suspended in a Stokes flow, such a porous viscous drop is allowed to deform, both the drop interface and the porous structures inside. Special focus is on the deformation dynamics of both the porosity and the shape of the drop under simple flows such as a uniform streaming flow and linear flows. We examine the effects of flow boundary conditions at interface between the porous drop and the surrounding viscous fluid. We also examine the dynamics of a porous drop with active stress from the porous network.

  10. CPAS Preflight Drop Test Analysis Process

    NASA Technical Reports Server (NTRS)

    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.

  11. Flow visualization and characterization of evaporating liquid drops

    NASA Technical Reports Server (NTRS)

    Chao, David F. (Inventor); Zhang, Nengli (Inventor)

    2004-01-01

    An optical system, consisting of drop-reflection image, reflection-refracted shadowgraphy and top-view photography, is used to measure the spreading and instant dynamic contact angle of a volatile-liquid drop on a non-transparent substrate. The drop-reflection image and the shadowgraphy is shown by projecting the images of a collimated laser beam partially reflected by the drop and partially passing through the drop onto a screen while the top view photograph is separately viewed by use of a camera video recorder and monitor. For a transparent liquid on a reflective solid surface, thermocapillary convection in the drop, induced by evaporation, can be viewed nonintrusively, and the drop real-time profile data are synchronously recorded by video recording systems. Experimental results obtained from this technique clearly reveal that evaporation and thermocapillary convection greatly affect the spreading process and the characteristics of dynamic contact angle of the drop.

  12. Blood drop patterns: Formation and applications.

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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

  14. Thermocapillary Migration and Interactions of Bubbles and Drops

    NASA Technical Reports Server (NTRS)

    Subramaniam, R. Shankar; Balasubramaniam, R.; Wozniak, G.; Hadland, P. H.

    1999-01-01

    Experiments were performed aboard the LMS mission of the Space Shuttle in summer 1996 in the BDPU on isolated air bubbles and Fluorinert FC-75 drops as well as on interacting bubbles/drops migrating in a temperature gradient in a Dow-Corning DC-200 series silicone oil of nominal viscosity 10 centistokes. The data, recorded in the form of videotape images as well as cine images in selected runs, have been analyzed. The behavior of the isolated objects is consistent with earlier observations made aboard the IML-2 mission while the range of Reynolds and Marangoni numbers has been extended substantially over that in the IML-2 experiments. Large bubbles were found to be slightly deformed to an oblate shape while no deformation could be detected in the case of similarly large drops. Results on interacting drops and bubbles display interesting and unanticipated features. In some experiments, drops are found to follow a three-dimensional trajectory. In others, trailing drops and bubbles are found to move off the axis of the cell when migrating behind a leading drop or bubble which moves along the axis. In this type of run, if the trailing drop is sufficiently large, it is found to pass the leading drop. Finally, behavior similar to that observed in IML-2, namely that a small leading drop slows the movement of a larger trailing drop moving along the cell axis, was observed as well.

  15. [The accidental detection of apical periodontitis].

    PubMed

    Wesselink, P R

    2011-04-01

    Accidental detection of an asymptomatic apical periodontitis raises the question whether this lesion should be treated or not. Arguments favouring treatment are that the inflammation may cause pain in the future, may enlarge or may negatively affect the host's resistance. Reasons for not treating may be that treatment weakens the tooth, may cause iatrogenic damage and that treatment is expensive and burdensome for the patient and does not lead in all cases to complete healing. Scientific evidence supporting either choice, whether treating the lesion or not, is lacking. In making such decisions, therefore, personal judgments by the patient and the dentist concerning the impact on the quality of life of the patient play an important role.

  16. Accidental mechanical asphyxia of children in Germany between 2000 and 2008.

    PubMed

    Meyer, F S; Trübner, K; Schöpfer, J; Zimmer, G; Schmidt, E; Püschel, K; Vennemann, M; Bajanowski, T; Althaus, L; Bach, P; Banaschak, S; Cordes, O; Dettmeyer, S R; Dressler, J; Gahr, B; Grellner, W; Héroux, V; Mützel, E; Tatschner, T; Zack, F; Zedler, B

    2012-09-01

    Accidents constitute one of the greatest risks to children, yet there are few medical reports that discuss the subject of accidental asphyxia. However, a systematic analysis of all documented cases in Germany over the years 2000-2008 has now been conducted, aiming at identifying patterns of accidental asphyxia, deducing findings, defining avoidance measures and recommending ways of increasing product safety and taking possible precautions. The analysis is based on a detailed retrospective analysis of all 91 relevant autopsy reports from 24 different German forensic institutes. A variety of demographic and morphological data was systematically collected and analysed. In 84 of the 91 cases, the sex of the victim was reported, resulting in a total of 57 boys (68 %) and 27 girls (32 %). The age spread ranged between 1 day and 14 years, with an average of 5.9 years. Most accidents occurred in the first year of life (20 %) or between the ages of 1 and 2 years (13 %). In 46 % of cases, the cause of death was strangulation, with the majority occurring in the home environment. In 31 % of all cases, the cause of death was positional asphyxia, the majority resulting from chest compression. In 23 % of cases, the cause of death was aspiration, mainly of foreign bodies. Today, accidental asphyxiation is a rare cause of death in children in Germany. Nevertheless, the majority of cases could have been avoided. Future incidence can be reduced by implementing two major precautions: increasing product safety and educating parents of potentially fatal risks. Specific recommendations relate to children's beds, toys and food.

  17. [Cardiac arrest due to accidental hypothermia and prolonged cardiopulmonary resuscitation].

    PubMed

    Kot, P; Botella, J

    2010-11-01

    In cardiac arrest produced by accidental hypothermia, cardiopulmonary resuscitation must be prolonged until normal body temperature is achieved. There are different rewarming methods. In theory, the more invasive ones are elective in patients with cardiac arrest because of their higher rewarming speed. However, it has not been proven that these methods are better than the non-invasive ones. We present a case report of a patient with cardiac arrest due to accidental hypothermia who was treated without interruption for three hours with heart massage. This is the longest successful cardiopulmonary resuscitation known up-to-date in Spain. In order to rewarm the body, a combination of non-invasive methods was used: active external rewarming with convective warm air, gastric and bladder lavage with warm saline solution and intravenous warm saline infusion. This case shows that it is possible to treat hypothermic cardiac arrest successfully through these rewarming methods, which are both easy to apply and feasible in any hospital. Copyright © 2009 Elsevier España, S.L. y SEMICYUC. All rights reserved.

  18. Evaluation of exposure scenarios on intentional microbiological contamination in a drinking water distribution network.

    PubMed

    Schijven, Jack; Forêt, Jean Marie; Chardon, Jurgen; Teunis, Peter; Bouwknegt, Martijn; Tangena, Ben

    2016-06-01

    Drinking water distribution networks are vulnerable to accidental or intentional contamination events. The objective of this study was to investigate the effects of seeding duration and concentration, exposure pathway (ingestion via drinking of water and tooth brushing and inhalation by taking a shower) and pathogen infectivity on exposure and infection risk in the case of an intentional pathogenic contamination in a drinking water distribution network. Seeding of a pathogen for 10 min and 120 min, and subsequent spreading through a drinking water distribution network were simulated. For exposure via drinking, actual data on drinking events and volumes were used. Ingestion of a small volume of water by tooth brushing twice a day by every person in the network was assumed. Inhalation of contaminated aerosol droplets took place when taking a shower. Infection risks were estimated for pathogens with low (r = 0.0001) and high (r = 0.1) infectivity. In the served population (48 000 persons) and within 24 h, about 1400 persons were exposed to the pathogen by ingestion of water in the 10-min seeding scenario and about 3400 persons in the 120-min scenario. The numbers of exposed persons via tooth brushing were about the same as via drinking of water. Showering caused (inhalation) exposure in about 450 persons in the 10-min scenario and about 1500 in the 120-min scenario. Regardless of pathogen infectivity, if the seeding concentration is 10(6) pathogens per litre or more, infection risks are close to one. Exposure by taking a shower is of relevance if the pathogen is highly infectious via inhalation. A longer duration of the seeding of a pathogen increases the probability of exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Pollination drop in Juniperus communis: response to deposited material.

    PubMed

    Mugnaini, Serena; Nepi, Massimo; Guarnieri, Massimo; Piotto, Beti; Pacini, Ettore

    2007-12-01

    The pollination drop is a liquid secretion produced by the ovule and exposed outside the micropyle. In many gymnosperms, pollen lands on the surface of the pollination drop, rehydrates and enters the ovule as the drop retracts. The objective of this work was to study the formation of the pollination drop in Juniperus communis, its carbohydrate composition and the response to deposition of conspecific pollen, foreign pollen and other particulate material, in an attempt to clarify the mechanism of pollination drop retraction. Branches with female cones close to pollination drop secretion were collected. On the first day of pollination drop exposure, an eyelash mounted on a wooden stick with paraffin was used to collect pollen or silica gel particles, which were then deposited by contact with the drop. Volume changes in pollination drops were measured by using a stereomicroscope with a micrometer eyepiece 3 h after deposition. The volume of non-pollinated control drops was also recorded. On the first day of secretion, drops were also collected for sugar analysis by high-performance liquid chromatography. The pollination drop persisted for about 12 d if not pollinated, and formed again after removal for up to four consecutive days. After pollination with viable conspecific pollen, the drop retracted quickly and did not form again. Partial withdrawal occurred after deposition of other biological and non-biological material. Fructose was the dominant sugar; glucose was also present but at a much lower percentage. Sugar analysis confirmed the general trend of fructose dominance in gymnosperm pollination drops. Complete pollination drop withdrawal appears to be triggered by a biochemical mechanism resulting from interaction between pollen and drop constituents. The results of particle deposition suggest the existence of a non-specific, particle-size-dependent mechanism that induces partial pollination drop withdrawal. These results suggest that the non-specific response

  20. Pollination Drop in Juniperus communis: Response to Deposited Material

    PubMed Central

    Mugnaini, Serena; Nepi, Massimo; Guarnieri, Massimo; Piotto, Beti; Pacini, Ettore

    2007-01-01

    Background and Aims The pollination drop is a liquid secretion produced by the ovule and exposed outside the micropyle. In many gymnosperms, pollen lands on the surface of the pollination drop, rehydrates and enters the ovule as the drop retracts. The objective of this work was to study the formation of the pollination drop in Juniperus communis, its carbohydrate composition and the response to deposition of conspecific pollen, foreign pollen and other particulate material, in an attempt to clarify the mechanism of pollination drop retraction. Method Branches with female cones close to pollination drop secretion were collected. On the first day of pollination drop exposure, an eyelash mounted on a wooden stick with paraffin was used to collect pollen or silica gel particles, which were then deposited by contact with the drop. Volume changes in pollination drops were measured by using a stereomicroscope with a micrometer eyepiece 3 h after deposition. The volume of non-pollinated control drops was also recorded. On the first day of secretion, drops were also collected for sugar analysis by high-performance liquid chromatography. Key Results The pollination drop persisted for about 12 d if not pollinated, and formed again after removal for up to four consecutive days. After pollination with viable conspecific pollen, the drop retracted quickly and did not form again. Partial withdrawal occurred after deposition of other biological and non-biological material. Fructose was the dominant sugar; glucose was also present but at a much lower percentage. Conclusions Sugar analysis confirmed the general trend of fructose dominance in gymnosperm pollination drops. Complete pollination drop withdrawal appears to be triggered by a biochemical mechanism resulting from interaction between pollen and drop constituents. The results of particle deposition suggest the existence of a non-specific, particle-size-dependent mechanism that induces partial pollination drop withdrawal

  1. Directional motion of impacting drops on dual-textured surfaces.

    PubMed

    Vaikuntanathan, V; Sivakumar, D

    2012-09-01

    In this work, we analyze the directional movement of impacting liquid drops on dual-textured solid surfaces comprising two different surface morphologies: a textured surface and a smooth surface. The dynamics of liquid drops impacting onto the junction line between the two parts of the dual-textured surfaces is studied experimentally for varying drop impact velocity. The dual-textured surfaces used here featured a variation in their textures' geometrical parameters as well as their surface chemistry. Two types of liquid drop differing in their surface tension were used. The impact process develops a net horizontal drop velocity towards the higher-wettability surface portion and results in a bulk movement of the impacting drop liquid. The final distance moved by the impacting drop from the junction line decreases with increasing impacting drop Weber number We. A fully theoretical model, employing a balance of forces acting at the drop contact line as well as energy conservation, is formulated to determine the variation, with We, of net horizontal drop velocity and subsequent movement of the impacting drop on the dual-textured surfaces.

  2. A case of pediatric age anticholinergic intoxication due to accidental Datura stramonium ingestion admitting with visual hallucination.

    PubMed

    Şanlıdağ, Burçin; Derinöz, Okşan; Yıldız, Nagehan

    2014-01-01

    Datura stramonium (DS) is a hallucinogenic plant that can produce anticholinergic toxicity because of its significant concentrations of toxic alkaloids, such as atropine, hyoscyamine, and scopolamine. DS grows in both rural and urban areas in Turkey. Clinical findings of toxicity are similar to those of atropine toxicity. DS abuse is common among adolescents because of its hallucinatory effects. However, accidental DS poisoning from contaminated food is very rare. Accidental poisonings are commonly seen among children. Children are more prone to the toxic effects of atropine; ingestion of even a small amount can cause serious central nervous system symptoms. Treatment is supportive; antidote treatment is given rarely. An eight-year-old male with accidental DS poisoning who presented to the Pediatric Emergency Department with aggression, agitation, delirium, and visual hallucinations is reported.

  3. Runge-Lenz vector, accidental SU(2) symmetry, and unusual multiplets for motion on a cone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Al-Hashimi, M.H.; Wiese, U.-J.

    2008-01-15

    We consider a particle moving on a cone and bound to its tip by 1/r or harmonic oscillator potentials. When the deficit angle of the cone divided by 2{pi} is a rational number, all bound classical orbits are closed. Correspondingly, the quantum system has accidental degeneracies in the discrete energy spectrum. An accidental SU(2) symmetry is generated by the rotations around the tip of the cone as well as by a Runge-Lenz vector. Remarkably, some of the corresponding multiplets have fractional 'spin' and unusual degeneracies.

  4. Accidental Release of Chlorine from a Storage Facility and an On-Site Emergency Mock Drill: A Case Study

    PubMed Central

    Soman, Ambalathumpara Raman; Sundararaj, Gopalswamy

    2015-01-01

    In the current industrial scenario there is a serious need for formulating strategies to handle hazardous substances in the safest way. Manufacture, storage, and use of hazardous substances pose a serious risk to industry, people, and the environment. Accidental release of toxic chemicals can lead to emergencies. An emergency response plan (ERP) is inevitable to minimize the adverse effects of such releases. The on-site emergency plan is an integral component of any process safety and risk management system. This paper deals with an on-site emergency response plan for a chlorine manufacturing industry. It was developed on the basis of a previous study on chlorine release and a full scale mock drill has been conducted for testing the plan. Results indicated that properly trained personnel can effectively handle each level of incidents occurring in the process plant. As an extensive guideline to the district level government authorities for off-site emergency planning, risk zone has also been estimated with reference to a chlorine exposure threshold of 3 ppm. PMID:26171416

  5. Air cushioning in drop impact

    NASA Astrophysics Data System (ADS)

    de Ruiter, Jolet; Oh, Jung; van den Ende, Dirk; Mugele, Frieder

    2011-11-01

    Liquid drops impacting on solid surfaces deform under the influence of the ambient gas that needs to be squeezed out before a true solid-liquid contact can be established. We demonstrate experimentally the existence of this theoretically predicted air layer and follow its evolution with time for moderate impact speeds (We ~ 1 ... 10) using reflection interference microscopy with a thickness resolution of approximately 10nm. For a wide range of fluid properties (ρ, γ, η) we find a very robust generic behavior that includes the predicted formation of a dimple in the center of the drop with a local minimum of the air film thickness at its boundary. Depending on We as well as the fluid properties, a skating layer of more or less constant thickness as well as a second local minimum of the air film thickness farther away from the drop center develop in time. Eventually, solid-liquid contact is generated via random nucleation event. The nucleation spot spreads across the drop-substrate interface within a few milliseconds. This process can lead to the entrapment of an air bubble.

  6. Parametric resonance in acoustically levitated water drops

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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.

  7. Dark scenarios

    NASA Astrophysics Data System (ADS)

    Ahonen, Pasi; Alahuhta, Petteri; Daskala, Barbara; Delaitre, Sabine; Hert, Paul De; Lindner, Ralf; Maghiros, Ioannis; Moscibroda, Anna; Schreurs, Wim; Verlinden, Michiel

    In this chapter, we present four "dark scenarios" that highlight the key socio-economic, legal, technological and ethical risks to privacy, identity, trust, security and inclusiveness posed by new AmI technologies. We call them dark scenarios, because they show things that could go wrong in an AmI world, because they present visions of the future that we do not want to become reality. The scenarios expose threats and vulnerabilities as a way to inform policy-makers and planners about issues they need to take into account in developing new policies or updating existing legislation. Before presenting the four scenarios and our analysis of each, we describe the process of how we created the scenarios as well as the elements in our methodology for analysing the scenarios.

  8. A multi-stage drop-the-losers design for multi-arm clinical trials.

    PubMed

    Wason, James; Stallard, Nigel; Bowden, Jack; Jennison, Christopher

    2017-02-01

    Multi-arm multi-stage trials can improve the efficiency of the drug development process when multiple new treatments are available for testing. A group-sequential approach can be used in order to design multi-arm multi-stage trials, using an extension to Dunnett's multiple-testing procedure. The actual sample size used in such a trial is a random variable that has high variability. This can cause problems when applying for funding as the cost will also be generally highly variable. This motivates a type of design that provides the efficiency advantages of a group-sequential multi-arm multi-stage design, but has a fixed sample size. One such design is the two-stage drop-the-losers design, in which a number of experimental treatments, and a control treatment, are assessed at a prescheduled interim analysis. The best-performing experimental treatment and the control treatment then continue to a second stage. In this paper, we discuss extending this design to have more than two stages, which is shown to considerably reduce the sample size required. We also compare the resulting sample size requirements to the sample size distribution of analogous group-sequential multi-arm multi-stage designs. The sample size required for a multi-stage drop-the-losers design is usually higher than, but close to, the median sample size of a group-sequential multi-arm multi-stage trial. In many practical scenarios, the disadvantage of a slight loss in average efficiency would be overcome by the huge advantage of a fixed sample size. We assess the impact of delay between recruitment and assessment as well as unknown variance on the drop-the-losers designs.

  9. Accidental poisoning with Veratrum album mistaken for wild garlic (Allium ursinum).

    PubMed

    Gilotta, Irene; Brvar, Miran

    2010-11-01

    Veratrum album (white or false hellebore) is a poisonous plant containing steroidal alkaloids that cause nausea, vomiting, headache, visual disturbances, paresthesia, dizziness, bradycardia, atrioventricular block, hypotension, and syncope. It is regularly mistaken for Gentiana lutea (yellow gentian). We report accidental poisoning with V. album mistaken for Allium ursinum (wild garlic), a wild plant used in soups and salads in Central Europe. Four adults (24-45 years) accidentally ingested V. album mistaken for A. ursinum in self-prepared salads and soups. Within 15-30 min of ingestion they developed nausea, vomiting, and abdominal pain. At the same time dizziness, tingling, dimmed and jumping vision, transient blindness, and confusion appeared. On arrival at the ED, all patients had sinus bradycardia and hypotension. Following treatment the patients were discharged well 24-48 h after ingestion. In patients presenting with gastrointestinal, neurological, and cardiovascular symptoms a history of wild plant ingestion suggests possible poisoning with V. album mistaken for wild garlic.

  10. Photonic crystal surface-emitting lasers enabled by an accidental Dirac point

    DOEpatents

    Chua, Song Liang; Lu, Ling; Soljacic, Marin

    2014-12-02

    A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-plane feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.

  11. Future water demand in California under a broad range of land use scenarios

    NASA Astrophysics Data System (ADS)

    Wilson, T. S.; Sleeter, B. M.; Cameron, D. R.

    2016-12-01

    California continues to be gripped by the most severe drought on record. Most general circulation models agree the state will continue to warm this century and research suggests persistent, long-term droughts may become the new normal, exacerbating an already uncertain water supply future. Population increases and agricultural intensification will likely stress existing, highly variable inter-annual water supplies even further in coming decades. Using the Land Use and Carbon Scenario Simulator (LUCAS) model, we explore a wide range of potential water demand futures from 2012 to 2062 based on 8 alternative, spatially-explicit (1 km) land use scenarios and land-use related water demand. Scenarios include low and high rates for urbanization, agricultural expansion, and agricultural contraction as well as lowest and highest rates for the combined suite of anthropogenic land uses. Land change values were sampled from county-level historical (1991-2012) land change data and county-level average water use data for urban areas (i.e. municipal and industrial) and annual and perennial cropland. We modeled 100 Monte Carlo simulations for each scenario to better characterize and capture model uncertainty and a range of potential future outcomes. Results show water demand in Mediterranean California was lowest in the low anthropogenic change scenario, dropping an average 2.7 million acre feet (MAF) by 2062. The highest water demand was seen in the high urbanization (+3.2 MAF), high agricultural expansion (+4.1 MAF), and the high anthropogenic (+4.3 MAF) scenarios. Results provide water managers and policy makers with information on diverging land use and water use futures, based on observed land change and water use trends, helping better inform land and resource management decisions.

  12. Bittering agents in the prevention of accidental poisoning: children's reactions to denatonium benzoate (Bitrex).

    PubMed Central

    Sibert, J R; Frude, N

    1991-01-01

    The responses of young children to Denatonium Benzoate (Bitrex) were observed, in order to assess the potential of this bittering agent in the prevention of accidental poisoning. Thirty-three children aged 17-36 months were offered orange juice containing Bitrex (in a concentration of 10 parts per million). Of the 30 children who took some of this juice, only seven were willing to take more than 10 gm. A variety of negative verbal and non-verbal responses were noted. It is suggested that the highly unpalatable nature of Bitrex makes this compound a useful additive that could well prevent accidental poisoning from household products of mild to moderate toxicity. PMID:1854387

  13. Transient electrohydrodynamics of a liquid drop.

    PubMed

    Esmaeeli, Asghar; Sharifi, Payam

    2011-09-01

    The transient behavior of a leaky dielectric liquid drop under a uniform electric field of small strength is investigated. It is shown that for small distortion from a spherical shape, the drop deforms to an ellipsoid, and the deformation time history is represented by D=D(∞)[1-exp(-t/τ)], where D(∞) is the steady-state deformation and τ=(aμ(o)/γ)(19μ+16)(2μ+3)/(40μ+40)is the characteristic time, a, γ, μ(o) and μ being the drop radius, the surface tension, the viscosity of ambient fluid, and ratio of the drop viscosity to that of the ambient fluid, respectively. The contributions of the net normal and tangential electrical stresses in the degree of deformation and fluid flow strength are also determined.

  14. Apoptosis and accidental cell death in cultured human keratinocytes after thermal injury.

    PubMed

    Matylevitch, N P; Schuschereba, S T; Mata, J R; Gilligan, G R; Lawlor, D F; Goodwin, C W; Bowman, P D

    1998-08-01

    The respective roles of apoptosis and accidental cell death after thermal injury were evaluated in normal human epidermal keratinocytes. By coupling the LIVE/DEAD fluorescence viability assay with the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and ultrastructural morphology, these two processes could be distinguished. Cells were grown on glass coverslips with a microgrid pattern so that the results of several staining procedures performed sequentially could be visualized in the same cells after heating at temperatures of up to 72 degrees C for 1 second. After exposure to temperatures of 58 to 59 degrees C, cells died predominantly by apoptosis; viable cells became TUNEL positive, indicating degradation of DNA. After exposure to temperatures of 60 to 66 degrees C, both TUNEL-positive viable cells and TUNEL-positive nonviable cells were observed, indicating that apoptosis and accidental cell death were occurring simultaneously. Cells died almost immediately after exposure to temperatures above 72 degrees C, presumably from heat fixation. The fluorescent mitochondrial probe MitoTracker Orange indicated that cells undergoing apoptosis became TUNEL positive before loss of mitochondrial function. Nucleosomal fragmentation of DNA analyzed by enzyme-linked immunosorbent assay and gel electrophoresis occurred after exposure to temperatures of 58 to 59 degrees C. The characteristic morphological findings of cells undergoing apoptosis, by transmission electron microscopy, included cellular shrinkage, cytoplasmic budding, and relatively intact mitochondria. Depending on temperature and time of exposure, normal human epidermal keratinocytes may die by apoptosis, accidental cell death, or heat fixation.

  15. Levitation of a drop over a film flow

    NASA Astrophysics Data System (ADS)

    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.

  16. Clustering of particles and pathogens within evaporating drops

    NASA Astrophysics Data System (ADS)

    Park, Jaebum; Kim, Ho-Young

    2017-11-01

    The evaporation of sessile suspension drops leads to accumulation of the particles around the pinned contact line, which is widely termed the coffee ring effect. However, the evaporation behavior of a liquid drop containing a small number of particles with the size comparable to the host drop is unclear yet. Thus, here we investigate the motion and spatial distribution of large particles within a sessile drop. The spherical particles cluster only when their initial distance is below a critical value, which is a function of the diameter and wettability of particle as well as the surface tension and size of the host drop. We rationalize such a critical distance for self-assembly based on the balance of the capillary force and the frictional resistance to sliding and rolling of the particles on a solid substrate. We further discuss the physical significance of this drop-mediated ``Cheerios effect'' in connection with the fate of pathogens residing in drops as a result of sneezing and coughing.

  17. Modeling drop impacts on inclined flowing soap films

    NASA Astrophysics Data System (ADS)

    Basu, Saikat; Yawar, Ali; Concha, Andres; Bandi, Mahesh

    2015-11-01

    Small drops impinging on soap films flowing at an angle primarily exhibit three fundamental regimes of post-impact dynamics: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow, and (c) it pierces through the film. During impact, the drop deforms along with a simultaneous, almost elastic deformation of the film transverse to the stream direction. Hence, the governing dynamics for this interaction present the rare opportunity to explore the in-tandem effects of elasticity and hydrodynamics alike. In this talk, we outline the analytical framework to study the drop impact dynamics. The model assumes a deformable drop and a deformable three-dimensional soap film and invokes a parametric study to qualify the three mentioned impact types. The physical parameters include the impact angle, drop impact speed, and the diameters of the drop prior to and during impact when it deforms and spreads out. Our model system offers a path towards optimization of interactions between a spray and a flowing liquid.

  18. PREVENTION REFERENCE MANUAL: CHEMICAL SPECIFIC. VOLUME 2. CONTROL OF ACCIDENTAL RELEASES OF CHLORINE (SCAQMD) (SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT)

    EPA Science Inventory

    The manual discusses reducing the risk associated with an accidental release of chlorine. It identifies some of the potential causes of accidental releases that apply to the processes that use chlorine. It also identifies examples of potential causes, as well as measures that may...

  19. 49 CFR 572.102 - Drop test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... surface when the midsagittal plane is vertical. (4) Drop the headform from the specified height by means... test. (a) When the headform is dropped from a height of 14.8 inches in accordance with paragraph (b) of...

  20. Scenario planning.

    PubMed

    Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

    2011-03-01

    In facing future developments in health care, scenario planning offers a complementary approach to traditional strategic planning. Whereas traditional strategic planning typically consists of predicting the future at a single point on a chosen time horizon and mapping the preferred plans to address such a future, scenario planning creates stories about multiple likely potential futures on a given time horizon and maps the preferred plans to address the multiple described potential futures. Each scenario is purposefully different and specifically not a consensus worst-case, average, or best-case forecast; nor is scenario planning a process in probabilistic prediction. Scenario planning focuses on high-impact, uncertain driving forces that in the authors' example affect the field of radiology. Uncertainty is the key concept as these forces are mapped onto axes of uncertainty, the poles of which have opposed effects on radiology. One chosen axis was "market focus," with poles of centralized health care (government control) vs a decentralized private market. Another axis was "radiology's business model," with one pole being a unified, single specialty vs a splintered, disaggregated subspecialty. The third axis was "technology and science," with one pole representing technology enabling to radiology vs technology threatening to radiology. Selected poles of these axes were then combined to create 3 scenarios. One scenario, termed "entrepreneurialism," consisted of a decentralized private market, a disaggregated business model, and threatening technology and science. A second scenario, termed "socialized medicine," had a centralized market focus, a unified specialty business model, and enabling technology and science. A third scenario, termed "freefall," had a centralized market focus, a disaggregated business model, and threatening technology and science. These scenarios provide a range of futures that ultimately allow the identification of defined "signposts" that can

  1. Drop impact on spherical soft surfaces

    NASA Astrophysics Data System (ADS)

    Chen, Simeng; Bertola, Volfango

    2017-08-01

    The impact of water drops on spherical soft surfaces is investigated experimentally through high-speed imaging. The effect of a convex compliant surface on the dynamics of impacting drops is relevant to various applications, such as 3D ink-jet printing, where drops of fresh material impact on partially cured soft substrates with arbitrary shape. Several quantities which characterize the morphology of impacting drops are measured through image-processing, including the maximum and minimum spreading angles, length of the wetted curve, and dynamic contact angle. In particular, the dynamic contact angle is measured using a novel digital image-processing scheme based on a goniometric mask, which does not require edge fitting. It is shown that the surface with a higher curvature enhances the retraction of the spreading drop; this effect may be due to the difference of energy dissipation induced by the curvature of the surface. In addition, the impact parameters (elastic modulus, diameter ratio, and Weber number) are observed to significantly affect the dynamic contact angle during impact. A quantitative estimation of the deformation energy shows that it is significantly smaller than viscous dissipation.

  2. Scenario management and automated scenario generation

    NASA Astrophysics Data System (ADS)

    McKeever, William; Gilmour, Duane; Lehman, Lynn; Stirtzinger, Anthony; Krause, Lee

    2006-05-01

    The military planning process utilizes simulation to determine the appropriate course of action (COA) that will achieve a campaign end state. However, due to the difficulty in developing and generating simulation level COAs, only a few COAs are simulated. This may have been appropriate for traditional conflicts but the evolution of warfare from attrition based to effects based strategies, as well as the complexities of 4 th generation warfare and asymmetric adversaries have placed additional demands on military planners and simulation. To keep pace with this dynamic, changing environment, planners must be able to perform continuous, multiple, "what-if" COA analysis. Scenario management and generation are critical elements to achieving this goal. An effects based scenario generation research project demonstrated the feasibility of automated scenario generation techniques which support multiple stove-pipe and emerging broad scope simulations. This paper will discuss a case study in which the scenario generation capability was employed to support COA simulations to identify plan effectiveness. The study demonstrated the effectiveness of using multiple simulation runs to evaluate the effectiveness of alternate COAs in achieving the overall campaign (metrics-based) objectives. The paper will discuss how scenario generation technology can be employed to allow military commanders and mission planning staff to understand the impact of command decisions on the battlespace of tomorrow.

  3. Evaluation of wheelchair drop seat crashworthiness.

    PubMed

    Bertocci, G; Ha, D; van Roosmalen, L; Karg, P; Deemer, E

    2001-05-01

    Wheelchair seating crash performance is critical to protecting wheelchair users who remain seated in their wheelchairs during transportation. Relying upon computer simulation and sled testing seat loads associated with a 20 g/48 kph (20 g/30 mph) frontal impact and 50th percentile male occupant were estimated to develop test criteria. Using a static test setup we evaluated the performance of various types of commercially available drop seats against the loading test criteria. Five different types of drop seats (two specimens each) constructed of various materials (i.e. plastics, plywood, metal) were evaluated. Two types of drop seats (three of the total 10 specimens) met the 16650 N (3750 lb) frontal impact test criteria. While additional validation of the test protocol is necessary, this study suggests that some drop seat designs may be incapable of withstanding crash level loads.

  4. U. S. plastics demand drops sharply

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    According to the Society of the Plastics Industry, plastics demand dropped sharply in the U.S. during second-quarter 1980. U.S. exports of themoplastics are down slightly from year-ago levels, and PVC and low-density polyethylene (LDPE) exports are increasing strongly, but strong exports can not offset a weak domestic market. The weakness in domestic PVC sales is due mostly to large drops in contruction pipe (-49%) and automotive uses, its leading markets, in the last year. LDPE sales have dropped 3% over the year, and 8% in film, LPDE's largest market. Polypropylene's two largest U.S. markets, molding and fibers, have also droppedmore » sharply. Epoxy resin showed a May 1979 to May 1980 gain of 28% in exports, but three other thermosets, polyesters, urea-melamine, and phenolics, have dropped sharply since May 1979.« less

  5. Accidental poisoning with deadly nightshade berries: a case report.

    PubMed

    Trabattoni, G; Visintini, D; Terzano, G M; Lechi, A

    1984-12-01

    A case of acute accidental poisoning with deadly nightshade (Atropa belladonna) berries is reported. The patient was an elderly but healthy man who soon recovered. On the one hand, the clinical picture looked similar to that of delirium tremens; on the other, there were myoclonic jerks and signs of extrapyramidal involvement to suggest the onset of subacute dementia. The electroencephalogram findings confirmed those already reported during experimentally induced intoxication after ingestion of atropine in man.

  6. Preventing Accidental Ignition of Upper-Stage Rocket Motors

    NASA Technical Reports Server (NTRS)

    Hickman, John; Morgan, Herbert; Cooper, Michael; Murbach, Marcus

    2005-01-01

    A report presents a proposal to reduce the risk of accidental ignition of certain upper-stage rocket motors or other high energy hazardous systems. At present, mechanically in-line initiators are used for initiation of many rocket motors and/or other high-energy hazardous systems. Electrical shorts and/or mechanical barriers, which are the basic safety devices in such systems, are typically removed as part of final arming or pad preparations while personnel are present. At this time, static discharge, test equipment malfunction, or incorrect arming techniques can cause premature firing. The proposal calls for a modular out-of-line ignition system incorporating detonating-cord elements, identified as the donor and the acceptor, separated by an air gap. In the safe configuration, the gap would be sealed with two shields, which would prevent an accidental firing of the donor from igniting the system. The shields would be removed to enable normal firing, in which shrapnel generated by the donor would reliably ignite the acceptor to continue the ordnance train. The acceptor would then ignite a through bulkhead initiator (or other similar device), which would ignite the motor or high-energy system. One shield would be remotely operated and would be moved to the armed position when a launch was imminent or conversely returned to the safe position if the launch were postponed. In the event of failure of the remotely operated shield, the other shield could be inserted manually to safe the system.

  7. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  8. Quantum-Size Dependence of the Energy for Vacancy Formation in Charged Small Metal Clusters. Drop Model

    NASA Astrophysics Data System (ADS)

    Pogosov, V. V.; Reva, V. I.

    2018-04-01

    Self-consistent computations of the monovacancy formation energy are performed for Na N , Mg N , and Al N (12 < N ≤ 168) spherical clusters in the drop model for stable jelly. Scenarios of the Schottky vacancy formation and "bubble vacancy blowing" are considered. It is shown that the asymptotic behavior of the size dependences of the energy for the vacancy formation by these two mechanisms is different and the difference between the characteristics of a charged and neutral cluster is entirely determined by the difference between the ionization potentials of clusters and the energies of electron attachment to them.

  9. Dropping macadamia nuts-in-shell reduces kernel roasting quality.

    PubMed

    Walton, David A; Wallace, Helen M

    2010-10-01

    Macadamia nuts ('nuts-in-shell') are subjected to many impacts from dropping during postharvest handling, resulting in damage to the raw kernel. The effect of dropping on roasted kernel quality is unknown. Macadamia nuts-in-shell were dropped in various combinations of moisture content, number of drops and receiving surface in three experiments. After dropping, samples from each treatment and undropped controls were dry oven-roasted for 20 min at 130 °C, and kernels were assessed for colour, mottled colour and surface damage. Dropping nuts-in-shell onto a bed of nuts-in-shell at 3% moisture content or 20% moisture content increased the percentage of dark roasted kernels. Kernels from nuts dropped first at 20%, then 10% moisture content, onto a metal plate had increased mottled colour. Dropping nuts-in-shell at 3% moisture content onto nuts-in-shell significantly increased surface damage. Similarly, surface damage increased for kernels dropped onto a metal plate at 20%, then at 10% moisture content. Postharvest dropping of macadamia nuts-in-shell causes concealed cellular damage to kernels, the effects not evident until roasting. This damage provides the reagents needed for non-enzymatic browning reactions. Improvements in handling, such as reducing the number of drops and improving handling equipment, will reduce cellular damage and after-roast darkening. Copyright © 2010 Society of Chemical Industry.

  10. Small-amplitude oscillations of electrostatically levitated drops

    NASA Astrophysics Data System (ADS)

    Feng, J. Q.; Beard, K. V.

    1990-07-01

    The nature of axisymmetric oscillations of electrostatically levitated drops is examined using an analytical method of multiple-parameter perturbations. The solution for the quiescent equilibrium shape exhibits both stretching of the drop surface along the direction of the externally applied electric field and asymmetry about the drop's equatorial plane. In the presence of electric and gravitational fields, small-amplitude oscillations of charged drops differ from the linear modes first analyzed by Rayleigh. The oscillatory response at each frequency consists of several Legendre polynomials rather than just one, and the characteristic frequency for each axisymmetric mode decreases from that calculated by Rayleigh as the electric field strength increases. This lowering of the characteristic frequencies is enhanced by the net electric charge required for levitation against gravity. Since the contributions of the various forces appear explicitly in the analytic solutions, physical insight is readily gained into their causative role in drop behavior.

  11. Accidental hypothermia in Poland – estimation of prevalence, diagnostic methods and treatment.

    PubMed

    Kosiński, Sylweriusz; Darocha, Tomasz; Gałązkowski, Robert; Drwiła, Rafał

    2015-02-06

    The incidence of hypothermia is difficult to evaluate, and the data concerning the morbidity and mortality rates do not seem to fully represent the problem. The aim of the study was to estimate the actual prevalence of accidental hypothermia in Poland, as well as the methods of diagnosis and management procedures used in emergency rooms (ERs). A specially designed questionnaire, consisting of 14 questions, was mailed to all the 223 emergency rooms (ER) in Poland. The questions concerned the incidence, methods of diagnosis and risk factors, as well as the rewarming methods used and available measurement instruments. The analysis involved data from 42 ERs providing emergency healthcare for the population of 5,305,000. The prevalence of accidental hypothermia may have been 5.05 cases per 100.000 residents per year. Among the 268 cases listed 25% were diagnosed with codes T68, T69 or X31, and in 75% hypothermia was neither included nor assigned a code in the final diagnosis. The most frequent cause of hypothermia was exposure to cold air alongside ethanol abuse (68%). Peripheral temperature was measured in 57%, core temperature measurement was taken in 29% of the patients. Peripheral temperature was measured most often at the axilla, while core temperature measurement was predominantly taken rectally. Mild hypothermia was diagnosed in 75.5% of the patients, moderate (32-28°C) in 16.5%, while severe hypothermia (less than 28°C) in 8% of the cases. Cardiopulmonary resuscitation was carried out in 7.5% of the patients. The treatment involved mainly warmed intravenous fluids (83.5%) and active external rewarming measures (70%). In no case was extracorporeal rewarming put to use. The actual incidence of accidental hypothermia in Polish emergency departments may exceed up to four times the official data. Core temperature is taken only in one third of the patients, the treatment of hypothermic patients is rarely conducted in intensive care wards and extracorporeal rewarming

  12. Mixing in Sessile Drops Merging on a Surface

    NASA Astrophysics Data System (ADS)

    Anna, Shelley; Zhang, Ying; Oberdick, Samuel; Garoff, Stephen

    2011-11-01

    We investigate the mixing of two sessile drops that merge on a surface. The drops consist of low viscosity glycerol-water mixtures deposited on a silicone elastomer surface with contact angle near 90°. We observe the shape of the drops and the location of their intersection by placing a fluorescent dye in one drop and using a laser light sheet to image a plane perpendicular to the surface. The initial healing of the meniscus bridge between the merging drops, and the damping of capillary waves appearing on their surfaces occur on timescales comparable to the inertio-capillary relaxation time. However, the interface between the two fluids remains sharp, broadening diffusively over several minutes. The shape of the merged drops and the boundary between them also continues to evolve on a timescale of minutes. This later motion is controlled by gravity, capillary pressure, and viscous stresses. Images of the 3D drop shape indicate that small contact line motions are correlated to the slow relaxation. Although the two drops contain identical liquids except for the presence of the dye, the shape of the interface consistently evolves asymmetrically, assuming a characteristic crescent shape. We note that very tiny surface tension gradients can produce an asymmetric flow like the one observed here. We characterize the long timescale flow as a function of the drop sizes, and we use numerical simulations to aid in elucidating the essential physics.

  13. Community Mental Health Services: Dropping-In and Dropping-Out.

    ERIC Educational Resources Information Center

    Lonigan, Christopher J.; Muzekari, Louis H.

    A number of studies have examined variables that discriminate individuals who drop out of mental health programs. However, relatively little attention has been focused on determining characteristics of individuals who fail to follow through after their initial contact with mental health services. This study was designed to provide a profile of…

  14. Electrowetting-driven spreading and jumping of drops in oil

    NASA Astrophysics Data System (ADS)

    Hong, Jiwoo; Lee, Sang Joon

    2013-11-01

    Electrowetting-based practical applications include digital microfluidics, liquid lenses, and reflective displays. Most of them are performed in water/oil system, because oil medium reduces the contact-angle hysteresis and prevents drop evaporation. In this study, the effects of drop volume, oil viscosity, and applied voltage on the dynamic behaviors of spreading drops, such as transition of spreading pattern and response time, are investigated. Interestingly, jumping phenomena of drops are observed in oil when the applied voltage is turned off after reaching the electrowetted equilibrium radius of drops. A numerical model to predict the transient behavior of jumping drops is formulated based on the phase-field method. The numerical results for the transient deformation of jumping drops show quantitative agreement with the experimental results.

  15. Accidental displacement of a high-speed handpiece bur during mandibular third molar surgery: a case report.

    PubMed

    Yalcin, Serhat; Aktas, Irem; Emes, Yusuf; Atalay, Belir

    2008-03-01

    Removal of third molars is one of the most common surgical procedures performed in oral and maxillofacial surgery. This procedure may result in a number of major and minor complications. Accidental displacement of impacted third molars is a complication that occasionally occurs during these operations, but accidental displacement of a high-speed handpiece bur has never been reported in literature before. The aim of this article is to present a rare and previously unreported case of a foreign body in the submandibular space and to review the possible complications seen after third molar surgery.

  16. Measuring the force of drag on air sheared sessile drops

    NASA Astrophysics Data System (ADS)

    Milne, Andrew J. B.; Fleck, Brian; Amirfazli, Alidad

    2012-11-01

    To blow a drop along or off of a surface (i.e. to shed the drop), the drag force on the drop (based on flow conditions, drop shape, and fluid properties) must overcome the adhesion force between the drop and the surface (based on surface tension, drop shape, and contact angle). While the shedding of sessile drops by shear flow has been studied [Milne, A. J. B. & Amirfazli, A. Langmuir 25, 14155 (2009).], no independent measurements of the drag or adhesion forces have been made. Likewise, analytic predictions are limited to hemispherical drops and low air velocities. We present, therefore, measurements of the drag force on sessile drops at air velocities up to the point of incipient motion. Measurements were made using a modified floating element shear sensor in a laminar low speed wind tunnel to record drag force over the surface with the drop absent, and over the combined system of the surface and drop partially immersed in the boundary layer. Surfaces of different wettabilities were used to study the effects of drop shape and contact angles, with drop volume ranged between approximately 10 and 100 microlitres. The drag force for incipient motion (which by definition equals the maximum of the adhesion force) is compared to simplified models for drop adhesion such as that of Furmidge

  17. Review of intentionally self-inflicted, accidental and iatrogetic foreign objects in the genitourinary tract.

    PubMed

    Rieder, Jocelyn; Brusky, John; Tran, Viet; Stern, Karen; Aboseif, Sherif

    2010-01-01

    Retrospective evaluation of a series of patients presenting with genitourinary foreign objects. From 1997 to 2007, 11 men and 2 women were treated for a variety of foreign objects in the genitourinary tract. Medical records were reviewed for presentation, diagnosis, mental status, drug dependency, treatment, and follow-up. 13 patients were seen for removal of the foreign objects or for treatment of the sequela. These objects were intentionally self-inflicted, accidentally introduced or iatrogenic in nature. Intentional objects included: safety pins, screwdriver, marbles, pen cap, pencils, straw, cocaine, stiff metal wire and part of a pizza mixer. Accidental objects included: magnets, female catheter, urinary incontinence devices and part of a Foley catheter. The iatrogenic object was a reservoir from an inflatable penile implant. Smaller noninjurious objects were retrieved cystoscopically or at the bedside; larger objects or objects associated with trauma to the urethra needed open and reconstructive operations. Generally thought to be self-inflicted for personal gratification, the source of genitourinary objects can also be accidental or iatrogenic. The most traumatic injuries are purposely self-inflicted and found in patients who remove the objects themselves. These patients are at higher risk of permanent urethral damage needing complex surgical treatment and follow-up. Copyright (c) 2010 S. Karger AG, Basel.

  18. Open Scenario Study: IDA Open Scenario Repository User’s Manual

    DTIC Science & Technology

    2010-01-01

    Thomason, Study Co-Lead Zachary S. Rabold, Sub-Task Lead Ylli Bajraktari Rachel D. Dubin Mary Catherine Flythe Open Scenario Study: IDA Open Scenario... Bajraktari Rachel D. Dubin Mary Catherine Flythe Open Scenario Study: IDA Open Scenario Repository User’s Manual iii Preface This document reports the...vii Appendices A. Identifying Scenario Components...........................................................A-1 B . Acronyms

  19. Thyrotoxicosis Presenting as Unilateral Drop Foot

    PubMed Central

    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. PMID:28768980

  20. Thyrotoxicosis Presenting as Unilateral Drop Foot.

    PubMed

    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.

  1. Apoptosis and Accidental Cell Death in Cultured Human Keratinocytes after Thermal Injury

    PubMed Central

    Matylevitch, Natalia P.; Schuschereba, Steven T.; Mata, Jennifer R.; Gilligan, George R.; Lawlor, David F.; Goodwin, Cleon W.; Bowman, Phillip D.

    1998-01-01

    The respective roles of apoptosis and accidental cell death after thermal injury were evaluated in normal human epidermal keratinocytes. By coupling the LIVE/DEAD fluorescence viability assay with the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and ultrastructural morphology, these two processes could be distinguished. Cells were grown on glass coverslips with a microgrid pattern so that the results of several staining procedures performed sequentially could be visualized in the same cells after heating at temperatures of up to 72°C for 1 second. After exposure to temperatures of 58 to 59°C, cells died predominantly by apoptosis; viable cells became TUNEL positive, indicating degradation of DNA. After exposure to temperatures of 60 to 66°C, both TUNEL-positive viable cells and TUNEL-positive nonviable cells were observed, indicating that apoptosis and accidental cell death were occurring simultaneously. Cells died almost immediately after exposure to temperatures above 72°C, presumably from heat fixation. The fluorescent mitochondrial probe MitoTracker Orange indicated that cells undergoing apoptosis became TUNEL positive before loss of mitochondrial function. Nucleosomal fragmentation of DNA analyzed by enzyme-linked immunosorbent assay and gel electrophoresis occurred after exposure to temperatures of 58 to 59°C. The characteristic morphological findings of cells undergoing apoptosis, by transmission electron microscopy, included cellular shrinkage, cytoplasmic budding, and relatively intact mitochondria. Depending on temperature and time of exposure, normal human epidermal keratinocytes may die by apoptosis, accidental cell death, or heat fixation. PMID:9708816

  2. Accidental strangulation in children by the automatic closing of a car window.

    PubMed

    Serena, Kailene; Piva, Jefferson Pedro; Andreolio, Cinara; Carvalho, Paulo Roberto Antonacci; Rocha, Tais Sica da

    2018-03-01

    Among the main causes of death in our country are car accidents, drowning and accidental burns. Strangulation is a potentially fatal injury and an important cause of homicide and suicide among adults and adolescents. In children, its occurrence is usually accidental. However, in recent years, several cases of accidental strangulation in children around the world have been reported. A 2-year-old male patient was strangled in a car window. The patient was admitted to the pediatric intensive care unit with a Glasgow Coma Scale score of 8 and presented with progressive worsening of respiratory dysfunction and torpor. The patient also presented acute respiratory distress syndrome, acute pulmonary edema and shock. He was managed with protective mechanical ventilation, vasoactive drugs and antibiotic therapy. He was discharged from the intensive care unit without neurological or pulmonary sequelae. After 12 days of hospitalization, he was discharged from the hospital, and his state was very good. The incidence of automobile window strangulation is rare but of high morbidity and mortality due to the resulting choking mechanism. Fortunately, newer cars have devices that stop the automatic closing of the windows if resistance is encountered. However, considering the severity of complications strangulated patients experience, the intensive neuro-ventilatory and hemodynamic management of the pathologies involved is important to reduce morbidity and mortality, as is the need to implement new campaigns for the education of parents and caregivers of children, aiming to avoid easily preventable accidents and to optimize safety mechanisms in cars with electric windows.

  3. B-52B-008/DTV (Drop Test Vehicle) configuration 1 (with and without fins) flight test results - captive flight and drop test missions

    NASA Technical Reports Server (NTRS)

    Quade, D. A.

    1978-01-01

    The B-52B-008 drop test consisted of one takeoff roll to 60 KCAS, two captive flights to accomplish limited safety of flight flutter and structural demonstration testing, and seven drop test flights. Of the seven drop test missions, one flight was aborted due to the failure of the hook mechanism to release the drop test vehicle (DTV); but the other six flights successfully dropped the DTV.

  4. Drop impact on inclined superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Choi, Wonjae; Leclear, Sani; Leclear, Johnathon; Abhijeet, .; Park, Kyoo-Chul

    We report an empirical study and dimensional analysis on the impact patterns of water drops on inclined superhydrophobic surfaces. While the classic Weber number determines the spreading and recoiling dynamics of a water drop on a horizontal / smooth surface, for a superhydrophobic surface, the dynamics depends on two distinct Weber numbers, each calculated using the length scale of the drop or of the pores on the surface. Impact on an inclined superhydrophobic surface is even more complicated, as the velocity that determines the Weber number is not necessarily the absolute speed of the drop but the velocity components normal and tangential to the surface. We define six different Weber numbers, using three different velocities (absolute, normal and tangential velocities) and two different length scales (size of the drop and of the texture). We investigate the impact patterns on inclined superhydrophobic surfaces with three different types of surface texture: (i) posts, (ii) ridges aligned with and (iii) ridges perpendicular to the impact direction. Results suggest that all six Weber numbers matter, but affect different parts of the impact dynamics, ranging from the Cassie-Wenzel transition, maximum spreading, to anisotropic deformation. We acknowledge financial support from the Office of Naval Research (ONR) through Contract 3002453812.

  5. Bubble and Drop Nonlinear Dynamics (BDND)

    NASA Technical Reports Server (NTRS)

    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.

  6. Modeling of drop breakup in the bag breakup regime

    NASA Astrophysics Data System (ADS)

    Wang, C.; Chang, S.; Wu, H.; Xu, J.

    2014-04-01

    Several analytic models for predicting the drop deformation and breakup have been developed over the last three decades, but modeling drop breakup in the bag-type regime is less reported. In this Letter, a breakup model has been proposed to predict the drop deformation length and breakup time in the bag-type breakup regime in a more accurate manner. In the present model, the drop deformation which is approximately as the displacement of the centre of mass (c. m.) along the axis located at the centre of the drop, and the movement of c. m. is obtained by solving the pressure balance equation. The effects of the drop deformation on the drop external aerodynamic force are considered in this model. Drop breakup occurs when the deformation length reaches the maximum value and the maximum deformation length is a function of Weber number. The performance and applicability of the proposed breakup model are tested against the published experimental data.

  7. Why Do Students Drop Advanced Mathematics?

    ERIC Educational Resources Information Center

    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.

  8. An integrated decision model for the application of airborne sensors for improved response to accidental and terrorist chemical vapor releases

    NASA Astrophysics Data System (ADS)

    Kapitan, Loginn

    This research created a new model which provides an integrated approach to planning the effective selection and employment of airborne sensor systems in response to accidental or intentional chemical vapor releases. The approach taken was to use systems engineering and decision analysis methods to construct a model architecture which produced a modular structure for integrating both new and existing components into a logical procedure to assess the application of airborne sensor systems to address chemical vapor hazards. The resulting integrated process model includes an internal aggregation model which allowed differentiation among alternative airborne sensor systems. Both models were developed and validated by experts and demonstrated using appropriate hazardous chemical release scenarios. The resultant prototype integrated process model or system fills a current gap in capability allowing improved planning, training and exercise for HAZMAT teams and first responders when considering the selection and employment of airborne sensor systems. Through the research process, insights into the current response structure and how current airborne capability may be most effectively used were generated. Furthermore, the resultant prototype system is tailorable for local, state, and federal application, and can potentially be modified to help evaluate investments in new airborne sensor technology and systems. Better planning, training and preparedness exercising holds the prospect for the effective application of airborne assets for improved response to large scale chemical release incidents. Improved response will result in fewer casualties and lives lost, reduced economic impact, and increased protection of critical infrastructure when faced with accidental and intentional terrorist release of hazardous industrial chemicals. With the prospect of more airborne sensor systems becoming available, this prototype system integrates existing and new tools into an effective

  9. The Illustrated Topology of Liquid Drops during Formation

    ERIC Educational Resources Information Center

    Libii, Josue Njock

    2004-01-01

    High-speed photography can show that the shape often used for a newly forming drop is wrong. Knowledge of drop behaviour is important for inkjet printers, and a close look at the formation of drops as given here can enhance critical observation, thinking and analysis.

  10. Influence of interfacial viscosity on the dielectrophoresis of drops

    NASA Astrophysics Data System (ADS)

    Mandal, Shubhadeep; Chakraborty, Suman

    2017-05-01

    The dielectrophoresis of a Newtonian uncharged drop in the presence of an axisymmetric nonuniform DC electric field is studied analytically. The present study is focused on the effects of interfacial viscosities on the dielectrophoretic motion and shape deformation of an isolated suspended drop. The interfacial viscosities generate surface-excess viscous stress which is modeled as a two-dimensional Newtonian fluid which obeys the Boussinesq-Scriven constitutive law with constant values of interfacial tension, interfacial shear, and dilatational viscosities. In the regime of small drop deformation, we have obtained analytical solution for the drop velocity and deformed shape by neglecting surface charge convection and fluid inertia. Our study demonstrates that the drop velocity is independent of the interfacial shear viscosity, while the interfacial dilatational viscosity strongly affects the drop velocity. The interfacial viscous effects always retard the dielectrophoretic motion of a perfectly conducting/dielectric drop. Notably, the interfacial viscous effects can retard or augment the dielectrophoretic motion of a leaky dielectric drop depending on the electrohydrodynamic properties. The shape deformation of a leaky dielectric drop is found to decrease (or increase) due to interfacial shear (or dilatational) viscosity.

  11. Drop impact onto a thin film: Miscibility effect

    NASA Astrophysics Data System (ADS)

    Chen, Ningli; Chen, H.; Amirfazli, A.

    2017-09-01

    In this work a systematic experimental study was performed to understand the process of liquid drop impact onto a thin film made of a different liquid from drop. The drop and film liquids can be miscible or immiscible. Three general outcomes of deposition, crown formation without splashing, and splashing, were observed in the advancing phase of the drop impact onto a solid surface covered by either a miscible or an immiscible thin film. However, for a miscible film, a larger Weber number and film thickness are needed for the formation of a crown and splashing comparing with immiscible cases. The advancing phase of drop impact onto a thin immiscible film with a large viscosity is similar to that of drop impact onto a dry surface; for a miscible film viscous film, the behavior is far from that of a dry surface. The behavior of liquid lamella in the receding phase of drop impact onto a thin miscible film is reported for the first time. The results show that immiscibility is not a necessary condition for the existence of a receding phase. The existence of a receding phase is highly dependent on the interfacial tension between the drop and the film. The miscibility can significantly affect the receding morphology as it will cause mixing of the two liquids.

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

    PubMed

    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.

  13. Internally damped, self-arresting vertical drop-weight impact test apparatus

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Waters, Jr., William A. (Inventor); Stockum, Robert W. (Inventor); Walter, Manfred A. (Inventor)

    1996-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  14. Internally damped, self-arresting vertical drop-weight impact test apparatus

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Waters, Jr., William A. (Inventor); Stockum, Robert W. (Inventor); Water, Manfred A. (Inventor)

    1995-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  15. Hanging drop crystal growth apparatus and method

    NASA Technical Reports Server (NTRS)

    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.

  16. Accidental contamination of a German town's drinking water with sodium hydroxide.

    PubMed

    Lendowski, Luba; Färber, Harald; Holy, Andreas; Darius, Anke; Ehrich, Bernd; Wippermann, Christine; Küfner, Bernd; Exner, Martin

    2015-05-01

    Case report of a very serious drinking water incident putting up to 50,000 inhabitants of a town near Bonn in North Rhine-Westphalia, Germany at risk. A concentrated solution of highly alkaline water by sodium hydroxide was accidentally washed into the town's drinking water at a pumping station and increased the pH-value of the water to 12. Residents who came into contact with the contaminated water immediately had a toxic reaction. The incident was detected by complaints from customers and after that was stopped within several hours. The pipes were flushed and the customers were warned not to use the water till the all clear. After this immediate management there was an investigation and the cause of the incident was detected as an accidental release of accumulated sodium hydroxide (NaOH) solution. The lack of a network alarm system and the automatic cut-off mechanisms as deficiencies in the design of the station were rectified by the water company immediately after the incident. Copyright © 2015 Elsevier GmbH. All rights reserved.

  17. Drops spreading on flexible fibers

    NASA Astrophysics Data System (ADS)

    Somszor, Katarzyna; Boulogne, François; Sauret, Alban; Dressaire, Emilie; Stone, Howard

    2015-11-01

    Fibrous media are encountered in many engineered systems such as textile, paper and insulating materials. In most of these materials, fibers are randomly oriented and form a complex network in which drops of wetting liquid tend to accumulate at the nodes of the network. Here we investigate the role of the fiber flexibility on the spreading of a small volume of liquid on a pair of crossed flexible fibers. A drop of silicone oil is dispensed at the point of contact of the fibers and we characterize the liquid morphologies as we vary the volume of liquid, the angle between the fibers, and the length and bending modulus of the fibers. Drop morphologies previously reported for rigid fibers, i.e. a drop, a column and a mixed morphology, are also observed on flexible fibers with modified domains of existence. Moreover, at small inclination angles of the fibers, a new behavior is observed: the fibers bend and collapse. Depending on the volume, the liquid can adopt a column or a mixed morphology on the collapsed fibers. We rationalize our observations with a model based on energetic considerations. Our study suggests that the fiber flexibility adds a rich variety of behaviors that can be crucial for industrial applications.

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

    PubMed

    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.

  19. Drop tower with no aerodynamic drag

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1981-01-01

    Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

  20. Accidental Bolt Gun Injury to Femur - A Case Report.

    PubMed

    Kattimani, Ravi Prasad; Shetty, Sanath; Mirza, Humayun

    2016-01-01

    Bolt gun or slaughterer's guns are used in meat industry for "humane killing" of animals. Injuries caused by bolt gun are rare, reported exclusively from central European countries. We report a case of 28 year old male, who accidentally shot himself with a bolt gun to his right thigh. A 28 years old male presented to our Accident and Emergency department after accidental injury to his right thigh with bolt gun. He had an entry wound measuring 2 cm in length and 1 cm in breadth over anterior aspect of lower one third of thigh at lower and sustained Grade II compound fracture of right femur shaft at distal one third. The wound was treated with multiple debridements, negative pressure wound therapy and intravenous antibiotics based on culture and sensitivity. Bolt gun or slaughterer's guns are weapons used in meat industry for slaughtering animals. Wounds inflicted by bolt guns have specific morphological feature, distinctive from wounds made by other kinds of hand firearms. Most of the time wound will be infected at presentation. Lesions caused by these weapons are likely to have a more serious character than is to be expected from the size of the entrance wound. The mainstay of treatment is liberal wound exploration, multiple debridement's and intra venous antibiotics based on culture reports to treat infection and prevent morbidity.

  1. Studying the field induced breakup of acoustically levitated drops

    NASA Astrophysics Data System (ADS)

    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

  2. Best Measuring Time for a Millikan Oil Drop Experiment

    ERIC Educational Resources Information Center

    Kapusta, J. I.

    1975-01-01

    In a Millikan oil drop experiment, there is a best measuring time for observing the drop, due to Brownian motion of the drop and the experimenter's reaction time. Derives an equation for the relative error in the measurement of the drop's excess charge, and obtains a formula for the best measuring time. (Author/MLH)

  3. Motion of a drop driven by substrate vibrations

    NASA Astrophysics Data System (ADS)

    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.

  4. Symmetry breaking in drop bouncing on curved surfaces

    PubMed Central

    Liu, Yahua; Andrew, Matthew; Li, Jing; Yeomans, Julia M.; Wang, Zuankai

    2015-01-01

    The impact of liquid drops on solid surfaces is ubiquitous in nature, and of practical importance in many industrial processes. A drop hitting a flat surface retains a circular symmetry throughout the impact process. Here we show that a drop impinging on Echevaria leaves exhibits asymmetric bouncing dynamics with distinct spreading and retraction along two perpendicular directions. This is a direct consequence of the cylindrical leaves that have a convex/concave architecture of size comparable to the drop. Systematic experimental investigations on mimetic surfaces and lattice Boltzmann simulations reveal that this novel phenomenon results from an asymmetric momentum and mass distribution that allows for preferential fluid pumping around the drop rim. The asymmetry of the bouncing leads to ∼40% reduction in contact time. PMID:26602170

  5. The new Drop Tower catapult system

    NASA Astrophysics Data System (ADS)

    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

  6. Electrohydrodynamics of drops in strong uniform dc electric fields

    NASA Astrophysics Data System (ADS)

    Salipante, Paul F.; Vlahovska, Petia M.

    2010-11-01

    Drop deformation in an uniform dc electric field is a classic problem. The pioneering work of Taylor demonstrated that for weakly conducting media, the drop fluid undergoes a toroidal flow and the drop adopts a prolate or oblate spheroidal shape, the flow and shape being axisymmetrically aligned with the applied field. However, recent studies have revealed a nonaxisymmetric rotational flow in strong fields, similar to the rotation of solid dielectric particles observed by Quincke in the 19th century. We present a systematic experimental study of this phenomenon, which highlights the importance of charge convection along the drop surface. The critical electric field, drop inclination angle, and rate of rotation are measured. We find that for small, high viscosity drops, the threshold field strength is well approximated by the Quincke rotation criterion. Reducing the viscosity ratio shifts the onset for rotation to stronger fields. The drop inclination angle increases with field strength. The rotation rate is approximately given by the inverse Maxwell-Wagner polarization time. Novel features are also observed such as a hysteresis in the tilt angle for large low-viscosity drops.

  7. A case of accidental fatal aluminum phosphide poisoning involving humans and dogs.

    PubMed

    Behera, Chittaranjan; Krishna, Karthik; Bhardwaj, Daya Nand; Rautji, Ravi; Kumar, Arvind

    2015-05-01

    Aluminum phosphide is one of the commonest poisons encountered in agricultural areas, and manner of death in the victims is often suicidal and rarely homicidal or accidental. This paper presents an unusual case, where two humans (owner and housemaid) and eight dogs were found dead in the morning hours inside a room of a house, used as shelter for stray dogs. There was allegation by the son of the owner that his father had been killed. Crime scene visit by forensic pathologists helped to collect vital evidence. Autopsies of both the human victims and the dogs were conducted. Toxicological analysis of viscera, vomitus, leftover food, and chemical container at the crime scene tested positive for aluminum phosphide. The cause of death in both humans and dogs was aluminum phosphide poisoning. Investigation by police and the forensic approach to the case helped in ascertaining the manner of death, which was accidental. © 2015 American Academy of Forensic Sciences.

  8. Difficulties in funding of VA-ECMO therapy for patients with severe accidental hypothermia.

    PubMed

    Kosiński, Sylweriusz; Darocha, Tomasz; Jarosz, Anna; Czerw, Aleksandra; Podsiadło, Paweł; Sanak, Tomasz; Gałązkowski, Robert; Piątek, Jacek; Konstanty-Kalandyk, Janusz; Ziętkiewicz, Mirosław; Kusza, Krzysztof; Krzych, Łukasz J; Drwiła, Rafał

    2017-01-01

    Severe accidental hypothermia is defined as a core temperature below 28 Celsius degrees. Within the last years, the issue of accidental hypothermia and accompanying cardiac arrest has been broadly discussed and European Resuscitation Council (ERC) Guidelines underline the importance of Extracorporeal Rewarming (ECR) in treatment of severely hypothermic victims. The study aimed to evaluate the actual costs of ECR with VA-ECMO and of further management in the Intensive Care Unit of patients admitted to the Severe Accidental Hypothermia Centre in Cracow, Poland. We carried out the economic analysis of 31 hypothermic adults in stage III-IV (Swiss Staging) treated with VA ECMO. Twenty-nine individuals were further managed in the Intensive Care Unit. The actual treatment costs were evaluated based on current medication, equipment, and dressing pricing. The costs incurred by the John Paul II Hospital were then collated with the National Health Service (NHS) funding, assessed based on current financial contract. In most of the cases, the actual treatment cost was greater than the funding received by around 10000 PLN per patient. The positive financial balance was achieved in only 4 (14%) individuals; other 25 cases (86%) showed a financial loss. Performed analysis clearly shows that hospitals undertaking ECR may experience financial loss due to implementation of effective treatment recommended by international guidelines. Thanks to new NHS funding policy since January 2017 such loss can be avoided, what shall encourage hospitals to perform this expensive, yet effective method of treatment.

  9. 14 CFR 23.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Reserve energy absorption drop test. 23.727... Construction Landing Gear § 23.727 Reserve energy absorption drop test. (a) If compliance with the reserve energy absorption requirement in § 23.723(b) is shown by free drop tests, the drop height may not be less...

  10. 14 CFR 23.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reserve energy absorption drop test. 23.727... Construction Landing Gear § 23.727 Reserve energy absorption drop test. (a) If compliance with the reserve energy absorption requirement in § 23.723(b) is shown by free drop tests, the drop height may not be less...

  11. 14 CFR 23.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Reserve energy absorption drop test. 23.727... Construction Landing Gear § 23.727 Reserve energy absorption drop test. (a) If compliance with the reserve energy absorption requirement in § 23.723(b) is shown by free drop tests, the drop height may not be less...

  12. 14 CFR 23.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Reserve energy absorption drop test. 23.727... Construction Landing Gear § 23.727 Reserve energy absorption drop test. (a) If compliance with the reserve energy absorption requirement in § 23.723(b) is shown by free drop tests, the drop height may not be less...

  13. 14 CFR 23.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Reserve energy absorption drop test. 23.727... Construction Landing Gear § 23.727 Reserve energy absorption drop test. (a) If compliance with the reserve energy absorption requirement in § 23.723(b) is shown by free drop tests, the drop height may not be less...

  14. Ground Motion Prediction Equations Empowered by Stress Drop Measurement

    NASA Astrophysics Data System (ADS)

    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. Drops in Space: Super Oscillations and Surfactant Studies

    NASA Technical Reports Server (NTRS)

    Apfel, Robert E.; Tian, Yuren; Jankovsky, Joseph; Shi, Tao; Chen, X.; Holt, R. Glynn; Trinh, Eugene; Croonquist, Arvid; Thornton, Kathyrn C.; Sacco, Albert, Jr.; hide

    1996-01-01

    An unprecedented microgravity observation of maximal shape oscillations of a surfactant-bearing water drop the size of a ping pong ball was observed during a mission of Space Shuttle Columbia as part of the second United States Microgravity Laboratory-USML-2 (STS-73, October 20-November 5, 1995). The observation was precipitated by the action of an intense sound field which produced a deforming force on the drop. When this deforming force was suddenly reduced, the drop executed nearly free and axisymmetric oscillations for several cycles, demonstrating a remarkable amplitude of nonlinear motion. Whether arising from the discussion of modes of oscillation of the atomic nucleus, or the explosion of stars, or how rain forms, the complex processes influencing the motion, fission, and coalescence of drops have fascinated scientists for centuries. Therefore, the axisymmetric oscillations of a maximally deformed liquid drop are noteworthy, not only for their scientific value but also for their aesthetic character. Scientists from Yale University, the Jet Propulsion Laboratory (JPL) and Vanderbilt University conducted liquid drop experiments in microgravity using the acoustic positioning/manipulation environment of the Drop Physics Module (DPM). The Yale/JPL group's objectives were to study the rheological properties of liquid drop surfaces on which are adsorbed surfactant molecules, and to infer surface properties such as surface tension, Gibb's elasticity, and surface dilatational viscosity by using a theory which relies on spherical symmetry to solve the momentum and mass transport equations.

  16. Coalescence of viscous drops translating through a capillary tube

    NASA Astrophysics Data System (ADS)

    AlMatroushi, Eisa; Borhan, Ali

    2014-03-01

    An experimental study of the interaction and coalescence of viscous drops moving through a cylindrical capillary tube under low Reynolds number conditions is presented. The combined pressure- and buoyancy-driven motion of drops in a Newtonian continuous phase is examined. The interaction between two drops is quantified using image analysis, and measurements of the coalescence time are reported for various drop size ratios, Bond numbers, and viscosity ratios. The time scale for coalescence in the non-axisymmetric configuration is found to be substantially larger than that for coalescence in the axisymmetric configuration. Measurements of the radius of the liquid film formed between the two drops at the instant of apparent contact are used in conjunction with a planar film drainage model to predict the dependence of the coalescence time on drop size ratio for coalescence of low viscosity-ratio drops in the axisymmetric configuration.

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

    PubMed

    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.

  18. Self-propulsion of Leidenfrost Drops between Non-Parallel Structures.

    PubMed

    Luo, Cheng; Mrinal, Manjarik; Wang, Xiang

    2017-09-20

    In this work, we explored self-propulsion of a Leidenfrost drop between non-parallel structures. A theoretical model was first developed to determine conditions for liquid drops to start moving away from the corner of two non-parallel plates. These conditions were then simplified for the case of a Leidenfrost drop. Furthermore, ejection speeds and travel distances of Leidenfrost drops were derived using a scaling law. Subsequently, the theoretical models were validated by experiments. Finally, three new devices have been developed to manipulate Leidenfrost drops in different ways.

  19. Coalescence of Drops of a Power-law Fluid

    NASA Astrophysics Data System (ADS)

    Kamat, Pritish; Thete, Sumeet; Basaran, Osman

    2014-11-01

    Drop coalescence is crucial in a host of industrial, household, and natural processes that involve dispersions. Coalescence is a rate-controlling process in breaking emulsions and strongly influences drop-size-distributions in sprays. In a continuum approach, coalescence begins by the formation of a microscopic, non-slender bridge connecting the two drops. Indefinitely large axial curvature at the neck results in local lowering of pressure that drives fluid from the bulk of the drops toward the neck, thereby causing the bridge radius r (t) and height z (t) to increase in time t. The coalescence of Newtonian drops in air has heretofore been thoroughly studied. Here, we extend these earlier studies by analyzing the coalescence of drops of power-law fluids because many fluids encountered in real applications, including cosmetic creams, shampoos, grease, and paint, exhibit power-law (deformation-rate thinning) rheology. On account of the non-slender geometry of the liquid bridge connecting the two drops (z << r) , we analyze the resulting free surface flow problem by numerical simulation. Among other results, we present and discuss the nature of flows and scaling behaviors for r and z as functions of the initial viscosity and power-law index (0 < n <= 1) .

  20. Model of Mixing Layer With Multicomponent Evaporating Drops

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Le Clercq, Patrick

    2004-01-01

    A mathematical model of a three-dimensional mixing layer laden with evaporating fuel drops composed of many chemical species has been derived. The study is motivated by the fact that typical real petroleum fuels contain hundreds of chemical species. Previously, for the sake of computational efficiency, spray studies were performed using either models based on a single representative species or models based on surrogate fuels of at most 15 species. The present multicomponent model makes it possible to perform more realistic simulations by accounting for hundreds of chemical species in a computationally efficient manner. The model is used to perform Direct Numerical Simulations in continuing studies directed toward understanding the behavior of liquid petroleum fuel sprays. The model includes governing equations formulated in an Eulerian and a Lagrangian reference frame for the gas and the drops, respectively. This representation is consistent with the expected volumetrically small loading of the drops in gas (of the order of 10 3), although the mass loading can be substantial because of the high ratio (of the order of 103) between the densities of liquid and gas. The drops are treated as point sources of mass, momentum, and energy; this representation is consistent with the drop size being smaller than the Kolmogorov scale. Unsteady drag, added-mass effects, Basset history forces, and collisions between the drops are neglected, and the gas is assumed calorically perfect. The model incorporates the concept of continuous thermodynamics, according to which the chemical composition of a fuel is described probabilistically, by use of a distribution function. Distribution functions generally depend on many parameters. However, for mixtures of homologous species, the distribution can be approximated with acceptable accuracy as a sole function of the molecular weight. The mixing layer is initially laden with drops in its lower stream, and the drops are colder than the gas

  1. Accidental Strangulation Due to Entrapment of Saree in Crop Thrasher Machine in an Elderly Women Working at Agricultural Field.

    PubMed

    Parchake, Manoj Bhausaheb; Kumre, Vikas; Kachare, Rajesh V

    2016-09-01

    Strangulation is generally considered as homicidal death and in accidental strangulation circumstantial evidence alone can point toward the accidental nature of incidence. In present case, a 71-year-old woman, wearing a saree (garment worn by traditional women in India) working in agricultural field, got entangled in the crop thrasher machine and got strangled. Immediately, she was taken to the nearest hospital, where she survived for 6 to 8 hours and then died. The autopsy reveals cross ribbon-shaped ligature mark on neck and anterior chest along with 1 puncture wound at the right lateral aspect of the neck. A lack of proper precaution and safety measures at agricultural field are other contributing factors. Accidental strangulation by saree is extremely rare, hence, this case is presented for its rarity and pattern of injury.

  2. Pendant-Drop Surface-Tension Measurement On Molten Metal

    NASA Technical Reports Server (NTRS)

    Man, Kin Fung; Thiessen, David

    1996-01-01

    Method of measuring surface tension of molten metal based on pendant-drop method implemented in quasi-containerless manner and augmented with digital processing of image data. Electrons bombard lower end of sample rod in vacuum, generating hanging drop of molten metal. Surface tension of drop computed from its shape. Technique minimizes effects of contamination.

  3. The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

    DOE PAGES

    O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; ...

    2016-09-28

    Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. Here, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide rangemore » of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. Furthermore, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2°C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. In order to serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit

  4. The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.

    2016-01-01

    Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate amore » wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially

  5. The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; Eyring, Veronika; Friedlingstein, Pierre; Hurtt, George; Knutti, Reto; Kriegler, Elmar; Lamarque, Jean-Francois; Lowe, Jason; Meehl, Gerald A.; Moss, Richard; Riahi, Keywan; Sanderson, Benjamin M.

    2016-09-01

    Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit

  6. Distinguishing between microscale gaseous bubbles and liquid drops

    NASA Astrophysics Data System (ADS)

    Tan, Beng Hau; An, Hongjie; Chan, Chon U.; Ohl, Claus-Dieter

    2015-11-01

    In recent years, there has been strong research interest in decorating surfaces with tiny bubbles and drops due to their potential applications in reducing slippage in micro and nanofluidic devices. Both nanobubbles and nanodrops are typically nucleated by exchanging fluids over a suitable substrate. However, the nucleation experiments present many challenges, such as reproducibility and the possibility of contamination. The use of one-use plastic syringes and needle cannulas in nucleation experiments can introduce polymeric contamination. A contaminated experiment may nucleate bubbles, drops or both. Moreover, it is surprisingly difficult to distinguish between bubbles and drops under the usual atomic force microscopy or optical techniques. Here we present an experimental study comparing bubbles and oil (PDMS) drops on an atomically smooth surface (HOPG). Instead of nucleating the objects via solvent exchange, we directly introduced bubbles via electrolysis, and oil drops by injecting a dilute solution. Contrary to previous reports, we find that under careful AFM characterisation, liquid drops and gaseous bubbles respond differently to a change in imaging force, and moreover present different characteristic force curves.

  7. Morphology of viscoplastic drop impact on viscoplastic surfaces.

    PubMed

    Chen, Simeng; Bertola, Volfango

    2017-01-25

    The impact of viscoplastic drops onto viscoplastic substrates characterized by different magnitudes of the yield stress is investigated experimentally. The interaction between viscoplastic drops and surfaces has an important application in additive manufacturing, where a fresh layer of material is deposited on a partially cured or dried layer of the same material. So far, no systematic studies on this subject have been reported in literature. The impact morphology of different drop/substrate combinations, with yield stresses ranging from 1.13 Pa to 11.7 Pa, was studied by high speed imaging for impact Weber numbers between 15 and 85. Experimental data were compared with one of the existing models for Newtonian drop impact onto liquid surfaces. Results show the magnitude of the yield stress of drop/substrate strongly affects the final shape of the impacting drop, permanently deformed at the end of impact. The comparison between experimental data and model predictions suggests the crater evolution model is only valid when predicting the evolution of the crater at sufficiently high Weber numbers.

  8. Circumstances of Accidental Poisoning in Childhood

    PubMed Central

    Jackson, R. H.; Walker, J. H.; Wynne, N. A.

    1968-01-01

    Of 377 children with accidental poisoning, the commonest ages were 1, 2, and 3. The most important contributory factor was that the poison was kept in an inappropriate place. Most containers were closed, but the children found them easy to open. In some cases the container itself was unsuitable for the contents. The frequency of poisoning in childhood might be reduced in six main ways: (1) a reduction in the quantity of drugs kept in the home; (2) the provision of drug cupboards; (3) the provision of containers that are difficult for children to open, or individually foil-wrapping tablets; (4) making tablets less attractive to children; (5) clear identification of potential poisons; and (6) increasing parental awareness of the circumstances under which poisoning occurs. A plea is made for further sociomedical research into the prevention of poisoning. PMID:5682329

  9. Acoustic forcing of a liquid drop

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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. Three dimensional drop tracking flow chamber for coalescence studies

    DOE PAGES

    Grillet, Anne M.; Brooks, Carlton F.; Bourdon, Chris J.; ...

    2007-09-12

    Here, we have developed a novel flow chamber which imposes a controlled axisymmetric stagnation flow to enable the study of external flow effects on coalescence dynamics. This system allows for the first time the precise positioning of a drop in a three dimensional flow and additionally enforces a highly symmetric flow around the drop. We focus on the study of a single drop approaching a stationary flat plane as this is analogous to two drops approaching each other. A single drop is created and then guided along the unsteady center line of a stagnation flow. The real time computer controlmore » algorithm analyzes video images of the drop in two orthogonal planes and manipulates flow restricting valves along the four outlets of the flow. We demonstrate using particle image velocimetry that the computer control not only controls the drop position but also ensures a symmetric flow inside the flow chamber. Finally, this chamber will enable a detailed investigation of the drainage of the thin film between the drop and the lower surface in order to probe the effect of external flow on coalescence.« less

  13. Profiles of electrified drops and bubbles

    NASA Technical Reports Server (NTRS)

    Basaran, O. A.; Scriven, L. E.

    1982-01-01

    Axisymmetric equilibrium shapes of conducting drops and bubbles, (1) pendant or sessile on one face of a circular parallel-plate capacitor or (2) free and surface-charged, are found by solving simultaneously the free boundary problem consisting of the augmented Young-Laplace equation for surface shape and the Laplace equation for electrostatic field, given the surface potential. The problem is nonlinear and the method is a finite element algorithm employing Newton iteration, a modified frontal solver, and triangular as well as quadrilateral tessellations of the domain exterior to the drop in order to facilitate refined analysis of sharply curved drop tips seen in experiments. The stability limit predicted by this computer-aided theoretical analysis agrees well with experiments.

  14. A drop in uniaxial and biaxial nonlinear extensional flows

    NASA Astrophysics Data System (ADS)

    Favelukis, M.

    2017-08-01

    In this theoretical report, we explore small deformations of an initially spherical drop subjected to uniaxial or biaxial nonlinear extensional creeping flows. The problem is governed by the capillary number (Ca), the viscosity ratio (λ), and the nonlinear intensity of the flow (E). When the extensional flow is linear (E = 0), the familiar internal circulations are obtained and the same is true with E > 0, except that the external and internal flow rates increase with increasing E. If E < 0, the external flow consists of some unconnected regions leading to the same number of internal circulations (-3/7 < E < 0) or twice the number of internal circulations (E < -3/7), when compared to the linear case. The shape of the deformed drop is represented in terms of a modified Taylor deformation parameter, and the conditions for the breakup of the drop by a center pinching mechanism are also established. When the flow is linear (E = 0), the literature predicts prolate spheroidal drops for uniaxial flows (Ca > 0) and oblate spheroidal drops for biaxial flows (Ca < 0). For the same |Ca|, if E > 0, the drop is more elongated than the linear case, while E < 0 results in less elongated drops than the linear case. Compared to the linear case, for both uniaxial and biaxial extensional flows, E > 0 tends to facilitate drop breakup, while E < 0 makes drop breakup more difficult.

  15. Assessing the probability of infection by Salmonella due to sewage sludge use in agriculture under several exposure scenarios for crops and soil ingestion.

    PubMed

    Krzyzanowski, Flávio; de Souza Lauretto, Marcelo; Nardocci, Adelaide Cássia; Sato, Maria Inês Zanoli; Razzolini, Maria Tereza Pepe

    2016-10-15

    A deeper understanding about the risks involved in sewage sludge practice in agriculture is required. The aims of the present study were to determine the annual risk of infection of consuming lettuce, carrots and tomatoes cultivated in soil amended with sewage sludge. The risk to agricultural workers of accidental ingestion of sludge or amended soil was also investigated. A Quantitative Microbial Risk Assessment was conducted based on Salmonella concentrations from five WWTPs were used to estimate the probability of annual infection associated with crops and soil ingestion. The risk of infection was estimated for nine exposure scenarios considering concentration of the pathogen, sewage sludge dilution in soil, variation of Salmonella concentration in soil, soil attachment to crops, seasonal average temperatures, hours of post-harvesting exposure, Salmonella regrowth in lettuce and tomatoes, Salmonella inhibition factor in carrots, crop ingestion and frequency of exposure, sludge/soil ingestion by agricultural workers and frequency of exposure. Annual risks values varied across the scenarios evaluated. Highest values of annual risk were found for scenarios in which the variation in the concentration of Salmonella spp. in both soil and crops (scenario 1) and without variation in the concentration of Salmonella spp. in soil and variation in crops (scenario 3) ranging from 10(-3) to 10(-2) for all groups considered. For agricultural workers, the highest annual risks of infection were found when workers applied sewage sludge to agricultural soils (2.26×10(-2)). Sensitivity analysis suggests that the main drivers for the estimated risks are Salmonella concentration and ingestion rate. These risk values resulted from conservative scenarios since some assumptions were derived from local or general studies. Although these scenarios can be considered conservative, the sensitivity analysis yielded the drivers of the risks, which can be useful for managing risks from the

  16. Relationship between fine particulate matter, weather condition and daily non-accidental mortality in Shanghai, China: A Bayesian approach.

    PubMed

    Fang, Xin; Fang, Bo; Wang, Chunfang; Xia, Tian; Bottai, Matteo; Fang, Fang; Cao, Yang

    2017-01-01

    There are concerns that the reported association of ambient fine particulate matter (PM2.5) with mortality might be a mixture of PM2.5 and weather conditions. We evaluated the effects of extreme weather conditions and weather types on mortality as well as their interactions with PM2.5 concentrations in a time series study. Daily non-accidental deaths, individual demographic information, daily average PM2.5 concentrations and meteorological data between 2012 and 2014 were obtained from Shanghai, China. Days with extreme weather conditions were identified. Six synoptic weather types (SWTs) were generated. The generalized additive model was set up to link the mortality with PM2.5 and weather conditions. Parameter estimation was based on Bayesian methods using both the Jeffreys' prior and an informative normal prior in a sensitivity analysis. We estimate the percent increase in non-accidental mortality per 10 μg/m3 increase in PM2.5 concentration and constructed corresponding 95% credible interval (CrI). In total, 336,379 non-accidental deaths occurred during the study period. Average daily deaths were 307. The results indicated that per 10 μg/m3 increase in daily average PM2.5 concentration alone corresponded to 0.26-0.35% increase in daily non-accidental mortality in Shanghai. Statistically significant positive associations between PM2.5 and mortality were found for favorable SWTs when considering the interaction between PM2.5 and SWTs. The greatest effect was found in hot dry SWT (percent increase = 1.28, 95% CrI: 0.72, 1.83), followed by warm humid SWT (percent increase = 0.64, 95% CrI: 0.15, 1.13). The effect of PM2.5 on non-accidental mortality differed under specific extreme weather conditions and SWTs. Environmental policies and actions should take into account the interrelationship between the two hazardous exposures.

  17. Relationship between fine particulate matter, weather condition and daily non-accidental mortality in Shanghai, China: A Bayesian approach

    PubMed Central

    Wang, Chunfang; Xia, Tian; Bottai, Matteo; Fang, Fang; Cao, Yang

    2017-01-01

    There are concerns that the reported association of ambient fine particulate matter (PM2.5) with mortality might be a mixture of PM2.5 and weather conditions. We evaluated the effects of extreme weather conditions and weather types on mortality as well as their interactions with PM2.5 concentrations in a time series study. Daily non-accidental deaths, individual demographic information, daily average PM2.5 concentrations and meteorological data between 2012 and 2014 were obtained from Shanghai, China. Days with extreme weather conditions were identified. Six synoptic weather types (SWTs) were generated. The generalized additive model was set up to link the mortality with PM2.5 and weather conditions. Parameter estimation was based on Bayesian methods using both the Jeffreys’ prior and an informative normal prior in a sensitivity analysis. We estimate the percent increase in non-accidental mortality per 10 μg/m3 increase in PM2.5 concentration and constructed corresponding 95% credible interval (CrI). In total, 336,379 non-accidental deaths occurred during the study period. Average daily deaths were 307. The results indicated that per 10 μg/m3 increase in daily average PM2.5 concentration alone corresponded to 0.26–0.35% increase in daily non-accidental mortality in Shanghai. Statistically significant positive associations between PM2.5 and mortality were found for favorable SWTs when considering the interaction between PM2.5 and SWTs. The greatest effect was found in hot dry SWT (percent increase = 1.28, 95% CrI: 0.72, 1.83), followed by warm humid SWT (percent increase = 0.64, 95% CrI: 0.15, 1.13). The effect of PM2.5 on non-accidental mortality differed under specific extreme weather conditions and SWTs. Environmental policies and actions should take into account the interrelationship between the two hazardous exposures. PMID:29121092

  18. Accidental acute alcohol intoxication in infants: review and case report.

    PubMed

    Minera, Gabriella; Robinson, Evan

    2014-11-01

    Acute alcohol intoxication in children younger than 18 months old is both rarely documented and rarely fatal. Previous case reports suggest hypoglycemia and faster than normal rates of alcohol elimination found in children with acute alcohol intoxication compared with adults, but data are lacking. A 2-month-old infant presented with a decreased mental status after accidental ingestion of alcohol. He was diagnosed with acute alcohol intoxication, with a blood alcohol level of 330 mg/dL and was hyperglycemic (167 mg/dL). Alcohol elimination rate was calculated to be 21.6 mg/dL/h, similar to that in adults. To our knowledge, this case is the second youngest documented patient with accidental alcohol intoxication via ingestion in the United States. We present a rare case report of acute alcohol intoxication in an infant and a review of the literature. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although rare in the literature, poison control data suggests that alcohol poisoning in very young children is not rare. Emergency physicians should be prepared for the management of infants with alcohol poisoning. This case report and review brings attention to this subject and briefly discusses ethanol metabolism in infants. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Dropping out from School. Policy Brief Number 8

    ERIC Educational Resources Information Center

    Hunt, Frances

    2009-01-01

    While initial access to education is increasing in many countries, drop out rates continue to be high. This seriously affects MDG and EFA goals around educational access. This briefing paper looks at the issue of dropping out from school. It is based on the CREATE Pathways to Access Research Monograph, "Dropping out from school: a cross…

  20. 49 CFR 178.965 - Drop test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Water/anti-freeze solutions with a minimum specific gravity of 0.95 for testing at −18 °C (0 °F) or... of 0.45 cubic meters (15.9 cubic feet) or less must be subject to an additional drop test. (e) Drop... having essentially the same physical characteristics. (3) The specific gravity and viscosity of a...

  1. 49 CFR 178.965 - Drop test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Water/anti-freeze solutions with a minimum specific gravity of 0.95 for testing at −18 °C (0 °F) or... of 0.45 cubic meters (15.9 cubic feet) or less must be subject to an additional drop test. (e) Drop... having essentially the same physical characteristics. (3) The specific gravity and viscosity of a...

  2. 49 CFR 178.965 - Drop test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Water/anti-freeze solutions with a minimum specific gravity of 0.95 for testing at −18 °C (0 °F) or... of 0.45 cubic meters (15.9 cubic feet) or less must be subject to an additional drop test. (e) Drop... having essentially the same physical characteristics. (3) The specific gravity and viscosity of a...

  3. Drops and Bubble in Materials Science

    NASA Technical Reports Server (NTRS)

    Doremus, R. H.

    1982-01-01

    The formation of extended p-n junctions in semiconductors by drop migration, mechanisms and morphologies of migrating drops and bubbles in solids and nucleation and corrections to the Volmer-Weber equations are discussed. Bubble shrinkage in the processing of glass, the formation of glass microshells as laser-fusion targets, and radiation-induced voids in nuclear reactors were examined.

  4. Accidental sodium hypochlorite-induced skin injury during endodontic treatment.

    PubMed

    Serper, Ahmet; Ozbek, Murat; Calt, Semra

    2004-03-01

    A case of accidental skin injury caused by leakage of sodium hypochlorite solution from the rubber dam during root canal preparation is reported. After placement of a rubber dam and initiation of root canal treatment, the patient complained of a burning sensation with sodium hypochlorite irrigation. The complaints were ignored by the practitioner, and a skin rash developed on and around the patient's chin, followed by scab formation. The patient required medical treatment with topical Hamamelis virginiana extract for 2 weeks, with full recovery.

  5. Propelling a water drop with the vapor-mediated Marangoni effect

    NASA Astrophysics Data System (ADS)

    Kim, Seungho; Kim, Ho-Young

    2013-11-01

    We show that a water drop on solid surfaces can be propelled just by placing a volatile alcohol drop nearby. It is found to be because the water-air interface near the alcohol drop mixes with alcohol vapor, thereby locally lowering the surface tension. The surface-tension-gradient induces the motion of the water drop, enabling the trajectory control of water drops through the motion of remote alcohol drops. This vapor-mediated Marangoni effect also gives rise to other interesting interfacial flow phenomena, such as nucleation of holes on a water film and ballooning of a water drop hanging from a syringe needle with the approach of an alcohol drop. We visualize such interfacial dynamics with a high-speed camera and rationalize their salient features by scaling analysis. This work was supported by the National Research Foundation of Korea (grant no. 2012-008023).

  6. Proceedings of the Second International Colloquium on Drops and Bubbles

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H. (Editor)

    1982-01-01

    Applications of bubble and drop technologies are discussed and include: low gravity manufacturing, containerless melts, microballoon fabrication, ink printers, laser fusion targets, generation of organic glass and metal shells, and space processing. The fluid dynamics of bubbles and drops were examined. Thermomigration, capillary flow, and interfacial tension are discussed. Techniques for drop control are presented and include drop size control and drop shape control.

  7. ACCIDENTAL DUPLICATION: MR Imaging Findings in Children with Spasmus Nutans.

    PubMed

    Bowen, Meredith; Peragallo, Jason; Kralik, Stephen F; Poretti, Andrea; Huisman, Thierry A G M; Soares, Bruno P

    2017-06-03

    The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.jaapos.2017.03.001. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  8. Infant homicide and accidental death in the United States, 1940-2005: ethics and epidemiological classification.

    PubMed

    Riggs, Jack E; Hobbs, Gerald R

    2011-07-01

    Potential ethical issues can arise during the process of epidemiological classification. For example, unnatural infant deaths are classified as accidental deaths or homicides. Societal sensitivity to the physical abuse and neglect of children has increased over recent decades. This enhanced sensitivity could impact reported infant homicide rates. Infant homicide and accident mortality rates in boys and girls in the USA from 1940 to 2005 were analysed. In 1940, infant accident mortality rates were over 20 times greater than infant homicide rates in both boys and girls. After about 1980, when the ratio of infant accident mortality rates to infant homicide rates decreased to less than five, and the sum of infant accident and homicide rates became relatively constant, further decreases in infant accident mortality rates were associated with increases in reported infant homicide rates. These findings suggest that the dramatic decline of accidental infant mortality and recent increased societal sensitivity to child abuse may be related to the increased infant homicide rates observed in the USA since 1980 rather than an actual increase in societal violence directed against infants. Ethical consequences of epidemiological classification, involving the principles of beneficence, non-maleficence and justice, are suggested by observed patterns in infant accidental deaths and homicides in the USA from 1940 to 2005.

  9. On the rising motion of a drop in stratified fluids

    NASA Astrophysics Data System (ADS)

    Bayareh, M.; Doostmohammadi, A.; Dabiri, S.; Ardekani, A. M.

    2013-10-01

    The rising dynamics of a deformable drop in a linearly stratified fluid is numerically obtained using a finite-volume/front-tracking method. Our results show that the drag coefficient of a spherical drop in a stratified fluid enhances as C_{d,s}/C_{d,h}-1˜ Fr_d^{-2.86} for drop Froude numbers in the range of 4 < Frd < 16. The role of the deformability of the drop on the temporal evolution of the motion is investigated along with stratification and inertial effects. We also present the important role of stratification on the transient rising motion of the drop. It is shown that a drop can levitate in the presence of a vertical density gradient. The drop undergoes a fading oscillatory motion around its neutrally buoyant position except for high viscosity ratio drops where the oscillation occurs around a density level lighter than the neutral buoyancy level. In addition, a detailed characterization of the flow signature of a rising drop in a linearly stratified fluid including the buoyancy induced vortices and the resultant buoyant jet is presented.

  10. Thermocapillary Migration and Interactions of Bubbles and Drops

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, R.; Lacy, Claud E.; Wozniak, Guenter; Subramanian, R. Shankar

    1996-01-01

    When a drop or bubble is placed in another fluid and subjected to the action of a temperature gradient, the drop will move. Such motion is a direct consequence of the variation of interfacial tension with temperature, and is termed thermocapillary migration. This paper discusses results from experiments conducted in reduced gravity on the thermocapillary motion of bubbles and drops.

  11. Drop deployment system for crystal growth apparatus

    NASA Technical Reports Server (NTRS)

    Rhodes, Percy H. (Inventor); Snyder, Robert S. (Inventor); Pusey, Marc L. (Inventor)

    1992-01-01

    This invention relates to a crystal growth apparatus (10) generally used for growing protein crystals wherein a vapor diffusion method is used for growing the crystals. In this apparatus, a precipitating solution and a solution containing dissolved crystalline material are stored in separate vials (12, 14), each having a resilient diaphragm (28) across one end and an opening (24) with a puncturable septum (26) thereacross at an opposite end. The vials are placed in receptacles (30) having a manifold (41) with a manifold diaphragm (42) in contact with the vial diaphragm at one end of the receptacle and a hollow needle (36) for puncturing the septum at the other end of the manifold. The needles of each vial communicate with a ball mixer (40) that mixes the precipitate and protein solutions and directs the mixed solution to a drop support (64) disposed in a crystal growth chamber (16), the drop support being a tube with an inner bevelled surface (66) that provides more support for the drop (68) than the tubes of the prior art. A sealable storage region (70) intermediate the drop support and mixer provides storage of the drop (68) and the grown crystals.

  12. Spread of pathogens through rain drop impact

    NASA Astrophysics Data System (ADS)

    Kim, Seungho; Gruszewski, Hope; Gidley, Todd; Schmale, David G., III; Jung, Sunghwan

    2017-11-01

    Rain drop impact can disperse micron-sized pathogenic particles over long distances. In this study, we aim to elucidate mechanisms for disease dispersal when a rain drop impacts a particle-laden solid surface. Three different dispersal types were observed depending on whether the dispersed glass particles were dry or wet. For a dry particle dispersal, the movement of contact line made the particles initially jump off the surface with relatively high velocity. Then, air vortex was formed due to the air current entrained along with the falling drop, and advected the particles with relatively low velocity. For a wet particle dispersal, the contact line of a spreading liquid became unstable due to the presence of the particles on the substrate. This caused splashing at the contact line and ejected liquid droplets carrying the particles. Finally, we released a drop onto wheat plants infected with the rust fungus, Puccinia triticina, and found that nearly all of the satellite droplets from a single drop contained at least one rust spore. Also, we visualized such novel dispersal dynamics with a high-speed camera and characterized their features by scaling models. This research was partially supported by National Science Foundation Grant CBET-1604424.

  13. Water drop dynamics on a granular layer

    NASA Astrophysics Data System (ADS)

    Llorens, Coraline; Biance, Anne-Laure; Ybert, Christophe; Pirat, Christophe; Liquids; Interfaces Team

    2015-11-01

    Liquid drop impacts, either on a solid surface or a liquid bath, have been studied for a while and are still subject of intense research. Less is known concerning impacts on granular layers that are shown to exhibit an intermediate situation between solid and liquid. In this study, we focus on water drop impacts on granular matter made of micrometer-sized spherical glass beads. In particular, we investigate the overall dynamics arising from the interplay between liquid and grains throughout the impact. Depending on the relevant parameters (impact velocity, drop and grain sizes, as well as their wetting properties), various behaviors are evidenced. In particular, the behavior of the beads at the liquid-gas interface (ball-bearing vs imbibition) is shown to greatly affect the spreading dynamics of the drop, as well as satellite droplets formation, beads ejection, and the final crater morphology.

  14. Dying scenarios improve recall as much as survival scenarios.

    PubMed

    Burns, Daniel J; Hart, Joshua; Kramer, Melanie E

    2014-01-01

    Merely contemplating one's death improves retention for entirely unrelated material learned subsequently. This "dying to remember" effect seems conceptually related to the survival processing effect, whereby processing items for their relevance to being stranded in the grasslands leads to recall superior to that of other deep processing control conditions. The present experiments directly compared survival processing scenarios with "death processing" scenarios. Results showed that when the survival and dying scenarios are closely matched on key dimensions, and possible congruency effects are controlled, the dying and survival scenarios produced equivalently high recall levels. We conclude that the available evidence (cf. Bell, Roer, & Buchner, 2013; Klein, 2012), while not definitive, is consistent with the possibility of overlapping mechanisms.

  15. Analysis of hospital admissions due to accidental non-fire-related carbon monoxide poisoning in England, between 2001 and 2010

    PubMed Central

    Ghosh, Rebecca E.; Close, Rebecca; McCann, Lucy J.; Crabbe, Helen; Garwood, Kevin; Hansell, Anna L.; Leonardi, Giovanni

    2016-01-01

    Background Accidental non-fire-related (ANFR) carbon monoxide (CO) poisoning is a cause of fatalities and hospital admissions. This is the first study that describes the characteristics of ANFR CO hospital admissions in England. Methods Hospital Episode Statistics (HES) inpatient data for England between 2001 and 2010 were used. ANFR CO poisoning admissions were defined as any mention of ICD-10 code T58: toxic effect of CO and X47: accidental poisoning by gases or vapours, excluding ICD-10 codes potentially related to fires (X00-X09, T20-T32 and Y26). Results There were 2463 ANFR CO admissions over the 10-year period (annual rate: 0.49/100 000); these comprised just under half (48.7%) of all non-fire-related (accidental and non-accidental) CO admissions. There was seasonal variability, with more admissions in colder winter months. Higher admission rates were observed in the north of England. Just over half (53%) of ANFR admissions were male, and the highest rates of ANFR admissions were in those aged >80 years. Conclusion The burden of ANFR CO poisoning is preventable. The results of this study suggest an appreciable burden of CO and highlight differences that may aid targeting of public health interventions. PMID:25755248

  16. Electrohydrodynamics of drops covered with small particles

    NASA Astrophysics Data System (ADS)

    Ouriemi, Malika; Vlahovska, Petia

    2013-11-01

    A weakly conductive drop immersed in a more conductive liquid first undergoes an oblate deformation, and then experiences a rotation similar to Quincke rotation when submitted to an increasing DC uniform electrical field. We present an experimental study of a drop with an interface partially or completely covered with microscopic particles. Depending on the field intensity, the surface coverage, and the characteristics of the particles, the drop exhibits: (i) prolate deformation, (ii) emergence of pattern of sustained particle motions, or (iii) decrease of the electrical field that induces rotation.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  20. Electrohydrodynamic generation of millimetric drops and control of electrification

    NASA Astrophysics Data System (ADS)

    Yun, Sungchan

    2017-07-01

    We report a simple method for millimetric drop generation by electrohydrodynamic (EHD) detachment using a conventional nozzle-ring device. The EHD detachment method provides distinct features of uniform-size and controlled electrification of millimetric drops. The drop dynamics of detachment and shape oscillation are recorded using a high-speed camera and analyzed for several dc voltages applied to the electrode. Experimental studies show that an oscillation frequency can be closely related to the amount of electric charge, which can be explained based on both effective interfacial tension and inviscid Rayleigh and Lamb frequency. Furthermore, we present a concept to generate a neutral drop by adjusting the duration time of a pulse signal and discuss a drop oscillation induced by the detachment. This study can provide potential implications for drop manipulation, such as transporting, merging, and mixing, in microfluidic platforms.

  1. Heat loss and drag of spherical drop tube samples

    NASA Technical Reports Server (NTRS)

    Wallace, D. B.

    1982-01-01

    Analysis techniques for three aspects of the performance of the NASA/MSFC 32 meter drop tube are considered. Heat loss through the support wire in a pendant drop sample, temperature history of a drop falling through the drop tube when the tube is filled with helium gas at various pressures, and drag and resulting g-levels experienced by a drop falling through the tube when the tube is filled with helium gas at various pressures are addressed. The developed methods apply to systems with sufficiently small Knudsen numbers for which continuum theory may be applied. Sample results are presented, using niobium drops, to indicate the magnitudes of the effects. Helium gas at one atmosphere pressure can approximately double the amount of possible undercooling but it results in an apparent gravity levels of up to 0.1 g.

  2. Accidental sulfur mustard exposure: A case report.

    PubMed

    Schmidt, Annette; Steinritz, Dirk; Rudolf, Klaus-Dieter; Thiermann, Horst; Striepling, Enno

    2018-09-01

    The clinical progression following a sulfur mustard-induced skin exposure is well documented in the literature. Upon skin contact and a characteristic latency period, sulfur mustard (SM) causes erythema, blister formation and ulceration, which is associated with wound healing disorders that may require surgical treatment. Here, we present a case report of accidental exposure to SM in a laboratory setting which required surgical treatment of the skin. The case was illustrated at close intervals over a period of two years and underlines that exposure to SM has to be taken into account when typical clinical symptoms occur. Moreover skin grafts appear to be effective in SM-induced non healing skin ulcerations. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The accidental (acoustical) tourist

    NASA Astrophysics Data System (ADS)

    Van Kirk, Wayne

    2002-11-01

    The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm<\\/A>), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

  4. [A correct understanding of preservatives in eye drops].

    PubMed

    Liu, Zuguo; Huang, Caihong

    2015-09-01

    Eye drops are the most commonly used preparations in ophthalmology. Preservatives are usually added in order to protect eye drops against pathogenic organisms and increase the solubility of the drugs in multi-dose containers. Ophthalmologists have paid a lot of attention to the preservatives in eye drops because they remain one of the main reasons for ocular surface damage, and even may lead to serious visual impairment in patients with inappropriate use of eye drops. However, it should be noted that the dangers of preservatives become overstated nowadays. It is necessary to completely evaluate the effects of preservatives in ophthalmic preparations, so that ophthalmologists can guide patients to correctly select eye drops containing preservatives and avoid dangerous side effects, according to their eye disease situation, state of tear function and ocular surface changes, cultural background and financial income, cost and benefit and convenience of the use of drugs, and other factors. The direction of the future development in this field is to establish the clinical guideline for use of eye drops containing preservatives, carry out continuing education courses on preservatives and develop ideal preservatives.

  5. Microwave Dielectric Heating of Drops in Microfluidic Devices†

    PubMed Central

    Issadore, David; Humphry, Katherine J.; Brown, Keith A.; Sandberg, Lori; Weitz, David; Westervelt, Robert M.

    2010-01-01

    We present a technique to locally and rapidly heat water drops in microfluidic devices with microwave dielectric heating. Water absorbs microwave power more efficiently than polymers, glass, and oils due to its permanent molecular dipole moment that has a large dielectric loss at GHz frequencies. The relevant heat capacity of the system is a single thermally isolated picoliter drop of water and this enables very fast thermal cycling. We demonstrate microwave dielectric heating in a microfluidic device that integrates a flow-focusing drop maker, drop splitters, and metal electrodes to locally deliver microwave power from an inexpensive, commercially available 3.0 GHz source and amplifier. The temperature of the drops is measured by observing the temperature dependent fluorescence intensity of cadmium selenide nanocrystals suspended in the water drops. We demonstrate characteristic heating times as short as 15 ms to steady-state temperatures as large as 30°C above the base temperature of the microfluidic device. Many common biological and chemical applications require rapid and local control of temperature, such as PCR amplification of DNA, and can benefit from this new technique. PMID:19495453

  6. The Role of Drag Force in Shedding of Multiple Sessile Drops

    NASA Astrophysics Data System (ADS)

    Razzaghi, Aysan; Banitabaei, Sayyed Hossein; Amirfazli, Alidad; -Team

    2017-11-01

    A sessile drop placed on a solid surface can shed, if the drag force due to a shearing airflow overcomes the drop adhesion to the surface. Sessile drop shedding is of importance due to its applications in condensation, fuel cells, icing, etc. Majority of the studies so far have considered the shedding of a single sessile droplet; however, in the applications above, multiple sessile droplets appear on a surface. Shedding of sessile drops in different arrangements, i.e. tandem, side by side, triangle, and rectangle have been investigated both experimentally and through VOF simulations. The minimum air velocity (Ucr) at which the drop(s) at the upstream dislodge from the surface was measured. Drops were placed in a wind tunnel with increasing air velocity at a rate of 1m/s2. It has been found that Ucr, deviates from its value for a single drop due to presence of the neighboring drops. The amount of the deviation is closely related to the flow pattern and interaction of drop wakes which are elucidated numerically. The interacting wakes change the drag force on the drops. Generally, the adhesion force is not affected by presence of other drops. As such, when the drops' wakes are interacting strongly, Ucr can increase by 45%.

  7. Accidental overdose of insufflated colchicine.

    PubMed

    Baldwin, L R; Talbert, R L; Samples, R

    1990-01-01

    An accidental overdose of colchicine by nasal insufflation occurred when the colchicine was mistaken for methamphetamine. Colchicine insufflation is not believed to be a common practice among drug abusers; however, its physical appearance was similar enough to methamphetamine for it to be mistaken for that drug of abuse. In this case a 29-year-old White man presented to the emergency room 3 days after he 'snorted' approximately 200mg of colchicine powder. The colchicine was used as a 'root stimulator' in gardening by the patient's brother and stored in the same cabinet as the methamphetamine. Within 24 hours of exposure the patient began experiencing gastrointestinal distress and myalgia, which eventually prompted him to seek medical attention. The clinical course included hypocalcaemia (69 mg/L--day 5), hypophosphataemia (10 mg/L--day 5) and thrombocytopenia (19 X 10(3)/mm3 - day 8), all of which are consistent with colchicine toxicity. The patient improved with supportive care and electrolyte replacement, and was discharged after an 8-day hospitalisation.

  8. Soft Listeria: actin-based propulsion of liquid drops.

    PubMed

    Boukellal, Hakim; Campás, Otger; Joanny, Jean-François; Prost, Jacques; Sykes, Cécile

    2004-06-01

    We study the motion of oil drops propelled by actin polymerization in cell extracts. Drops deform and acquire a pearlike shape under the action of the elastic stresses exerted by the actin comet, a tail of cross-linked actin filaments. We solve this free boundary problem and calculate the drop shape taking into account the elasticity of the actin gel and the variation of the polymerization velocity with normal stress. The pressure balance on the liquid drop imposes a zero propulsive force if gradients in surface tension or internal pressure are not taken into account. Quantitative parameters of actin polymerization are obtained by fitting theory to experiment.

  9. Computational analysis of drop formation before and after the first singularity: the fate of free and satellite drops during simple dripping and DOD drop formation

    NASA Astrophysics Data System (ADS)

    Chen, Alvin U.; Basaran, Osman A.

    2000-11-01

    Drop formation from a capillary --- dripping mode --- or an ink jet nozzle --- drop-on-demand (DOD) mode --- falls into a class of scientifically challenging yet practically useful free surface flows that exhibit a finite time singularity, i.e. the breakup of an initially single liquid mass into two or more fragments. While computational tools to model such problems have been developed recently, they lack the accuracy needed to quantitatively predict all the dynamics observed in experiments. Here we present a new finite element method (FEM) based on a robust algorithm for elliptic mesh generation and remeshing to handle extremely large interface deformations. The new algorithm allows continuation of computations beyond the first singularity to track fates of both primary and any satellite drops. The accuracy of the computations is demonstrated by comparison of simulations with experimental measurements made possible with an ultra high-speed digital imager capable of recording 100 million frames per second.

  10. PREVENTION REFERENCE MANUAL: CHEMICAL SPECIFIC, VOLUME 14: CONTROL OF ACCIDENTAL RELEASES OF PHOSGENE

    EPA Science Inventory

    The report, discussing phosgene, is one of a series addressing the prevention of accidental releases of toxic chemicals. Phosgene, a highly reactive and corrosive liquid that boils at room temperature has an Immediately Dangerous to Life and Health (lDLH) conctntration of 2 ppm, ...

  11. Quantifying and valuing potential climate change impacts on coral reefs in the United States: comparison of two scenarios.

    PubMed

    Lane, Diana R; Ready, Richard C; Buddemeier, Robert W; Martinich, Jeremy A; Shouse, Kate Cardamone; Wobus, Cameron W

    2013-01-01

    The biological and economic values of coral reefs are highly vulnerable to increasing atmospheric and ocean carbon dioxide concentrations. We applied the COMBO simulation model (COral Mortality and Bleaching Output) to three major U.S. locations for shallow water reefs: South Florida, Puerto Rico, and Hawaii. We compared estimates of future coral cover from 2000 to 2100 for a "business as usual" (BAU) greenhouse gas (GHG) emissions scenario with a GHG mitigation policy scenario involving full international participation in reducing GHG emissions. We also calculated the economic value of changes in coral cover using a benefit transfer approach based on published studies of consumers' recreational values for snorkeling and diving on coral reefs as well as existence values for coral reefs. Our results suggest that a reduced emissions scenario would provide a large benefit to shallow water reefs in Hawaii by delaying or avoiding potential future bleaching events. For Hawaii, reducing emissions is projected to result in an estimated "avoided loss" from 2000 to 2100 of approximately $10.6 billion in recreational use values compared to a BAU scenario. However, reducing emissions is projected to provide only a minor economic benefit in Puerto Rico and South Florida, where sea-surface temperatures are already close to bleaching thresholds and coral cover is projected to drop well below 5% cover under both scenarios by 2050, and below 1% cover under both scenarios by 2100.

  12. Quantifying and Valuing Potential Climate Change Impacts on Coral Reefs in the United States: Comparison of Two Scenarios

    PubMed Central

    Lane, Diana R.; Ready, Richard C.; Buddemeier, Robert W.; Martinich, Jeremy A.; Shouse, Kate Cardamone; Wobus, Cameron W.

    2013-01-01

    The biological and economic values of coral reefs are highly vulnerable to increasing atmospheric and ocean carbon dioxide concentrations. We applied the COMBO simulation model (COral Mortality and Bleaching Output) to three major U.S. locations for shallow water reefs: South Florida, Puerto Rico, and Hawaii. We compared estimates of future coral cover from 2000 to 2100 for a “business as usual” (BAU) greenhouse gas (GHG) emissions scenario with a GHG mitigation policy scenario involving full international participation in reducing GHG emissions. We also calculated the economic value of changes in coral cover using a benefit transfer approach based on published studies of consumers' recreational values for snorkeling and diving on coral reefs as well as existence values for coral reefs. Our results suggest that a reduced emissions scenario would provide a large benefit to shallow water reefs in Hawaii by delaying or avoiding potential future bleaching events. For Hawaii, reducing emissions is projected to result in an estimated “avoided loss” from 2000 to 2100 of approximately $10.6 billion in recreational use values compared to a BAU scenario. However, reducing emissions is projected to provide only a minor economic benefit in Puerto Rico and South Florida, where sea-surface temperatures are already close to bleaching thresholds and coral cover is projected to drop well below 5% cover under both scenarios by 2050, and below 1% cover under both scenarios by 2100. PMID:24391717

  13. EDITORIAL: Where next with global environmental scenarios? Where next with global environmental scenarios?

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian; Pulver, Simone; Van Deveer, Stacy; Garb, Yaakov

    2008-12-01

    Scenarios have become a standard tool in the portfolio of techniques that scientists and policy-makers use to envision and plan for the future. Defined as plausible, challenging and relevant stories about how the future might unfold that integrate quantitative models with qualitative assessments of social and political trends, scenarios are a central component in assessment processes for a range of global issues, including climate change, biodiversity, agriculture, and energy. Yet, despite their prevalence, systematic analysis of scenarios is in its beginning stages. Fundamental questions remain about both the epistemology and scientific credibility of scenarios and their roles in policymaking and social change. Answers to these questions have the potential to determine the future of scenario analyses. Is scenario analysis moving in the direction of earth system governance informed by global scenarios generated through increasingly complex and comprehensive models integrating socio-economic and earth systems? Or will global environmental scenario analyses lose favour compared to more focused, policy-driven, regionally specific modelling? These questions come at an important time for the climate change issue, given that the scenario community, catalyzed by the Intergovernmental Panel on Climate Change (IPCC), is currently preparing to embark on a new round of scenario development processes aimed at coordinating research and assessment, and informing policy, over the next five to ten years. These and related questions about where next to go with global environmental scenarios animated a workshop held at Brown University (Note1) that brought together leading practitioners and scholars of global environmental change scenarios from research, policy-making, advocacy, and business settings. The workshop aimed to provide an overview of current practices/best practices in scenario production and scenario use across a range of global environmental change arenas. Participants

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

    PubMed

    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.

  15. Sound field inside acoustically levitated spherical drop

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Wei, B.

    2007-05-01

    The sound field inside an acoustically levitated small spherical water drop (radius of 1mm) is studied under different incident sound pressures (amplitude p0=2735-5643Pa). The transmitted pressure ptr in the drop shows a plane standing wave, which varies mainly in the vertical direction, and distributes almost uniformly in the horizontal direction. The maximum of ptr is always located at the lowermost point of the levitated drop. Whereas the secondary maximum appears at the uppermost point if the incident pressure amplitude p0 is higher than an intermediate value (3044Pa), in which there exists a pressure nodal surface in the drop interior. The value of the maximum ptr lies in a narrow range of 2489-3173Pa, which has a lower limit of 2489Pa when p0=3044Pa. The secondary maximum of ptr is rather small and only remarkable at high incident pressures.

  16. Annual Occurrence of Meteorite-Dropping Fireballs

    NASA Astrophysics Data System (ADS)

    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.

  17. Simulations of Evaporating Multicomponent Fuel Drops

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Le Clercq, Patrick

    2005-01-01

    A paper presents additional information on the subject matter of Model of Mixing Layer With Multicomponent Evaporating Drops (NPO-30505), NASA Tech Briefs, Vol. 28, No. 3 (March 2004), page 55. To recapitulate: A mathematical model of a three-dimensional mixing layer laden with evaporating fuel drops composed of many chemical species has been derived. The model is used to perform direct numerical simulations in continuing studies directed toward understanding the behaviors of sprays of liquid petroleum fuels in furnaces, industrial combustors, and engines. The model includes governing equations formulated in an Eulerian and a Lagrangian reference frame for the gas and drops, respectively, and incorporates a concept of continuous thermodynamics, according to which the chemical composition of a fuel is described by use of a distribution function. In this investigation, the distribution function depends solely on the species molar weight. The present paper reiterates the description of the model and discusses further in-depth analysis of the previous results as well as results of additional numerical simulations assessing the effect of the mass loading. The paper reiterates the conclusions reported in the cited previous article, and states some new conclusions. Some new conclusions are: 1. The slower evaporation and the evaporation/ condensation process for multicomponent-fuel drops resulted in a reduced drop-size polydispersity compared to their single-component counterpart. 2. The inhomogeneity in the spatial distribution of the species in the layer increases with the initial mass loading. 3. As evaporation becomes faster, the assumed invariant form of the molecular- weight distribution during evaporation becomes inaccurate.

  18. Self-reported incidence of accidental exposures to patients' blood and body fluids by resident doctors in Nigeria.

    PubMed

    Olubuyide, I O; Olawuyi, F

    1995-08-01

    An anonymous survey of 149 resident doctors was conducted to estimate the extent of accidental exposures to blood and body fluids of patients over a one-year period. There was a total of 1142 exposures. Ninety-three percent of respondents reported one or more exposure incident(s). Analysis of events and procedures leading to accidental exposures revealed that recapping needles was involved in 17%, suturing accounted for 14%, setting up intravenous lines 11%, cuts with scalpel 9% and phlebotomy 9%. Surgical residents had a threefold greater risk of exposure compared with medicine residents. No trend was found for accidental exposures by level of residency training. Seventy-four percent of the residents used universal precautions 50% or less of the time. Only half of the doctors could recall formal instruction on correct course of action after exposure and 5% of them had as undergraduates hepatitis B vaccine prior to the commencement of venepuncture duties. All but one of the residents' exposures were not reported to the Staff Medical Services Department. The doctor who reported was neither tested for hepatitis B virus or human immunodeficiency virus nor was he properly treated. Only 5 (4.6%) of the contaminating patients were evaluated serologically for their status of these viruses. These data emphasize the need for increased efforts toward improved early and continuing education, prevention and correct management of accidental exposures to blood or body fluids of patients by resident doctors in Nigeria. No recent study exists that exclusively addresses this problem in doctors in tropical Africa.

  19. Liquid toroidal drop under uniform electric field

    NASA Astrophysics Data System (ADS)

    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.

  20. Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

    PubMed

    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.

  1. Analysis of Drop Shapes during Electrowetting on a Dielectric

    NASA Astrophysics Data System (ADS)

    Daneshbod, Yousef

    2005-03-01

    Electrowetting refers to the electrostatic control of the interfacial energy of a liquid on a solid, primarily used for the transport of micro-liter volumes of drops on surfaces with embedded electrode arrays. In the present work, the drop is modeled as a two-dimensional lens-like conductor immersed in an infinite dielectric medium slightly above a planar conductor. A matched asymptotic expansion is used to approximate the electrostatic field surrounding the drop. The outer problem models the drop as a conducting circular segment resting on the conducting plane, each maintained at a separate constant potential. The inner problem corrects the region near the edge of the drop by modeling it as an infinite planar conducting wedge lying slightly above the conducting plane. By matching the inner and outer solutions, the charge density along the entire surface of the drop can be approximated, enabling the calculation of the total capacitance of the system. An energy minimization method similar to that of Shapiro et al. [J. Appl. Phys., 93, 5794 (2003)] is applied to the total energy consisting of the liquid/gas, liquid/solid and solid/gas surface energies, together with the electrostatic contribution, subject to the constraint that the drop volume remains constant. A modified form of the Young-Lippmann equation is thus derived that includes the contribution from the extra capacitance of the drop obtained via matched asymptotics.

  2. Ground Based Studies of Thermocapillary Flows in Levitated Drops

    NASA Technical Reports Server (NTRS)

    Sadhal, Satwindar Singh; Trinh, Eugene H.

    1996-01-01

    Ground-based experiments together with analytical studies are presently being conducted for levitated drops. Both acoustic and electrostatic techniques are being employed to achieve levitation of drops in a gaseous environment. The scientific effort is principally on the thermal and the fluid phenomena associated with the local heating of levitated drops, both at 1-g and at low-g. In particular, the thermocapillary flow associated with local spot heating is being studied. Fairly stable acoustic levitation of drops has been achieved with some exceptions when random rotational motion of the drop persists. The flow visualization has been carried out by light scattering from smoke particles for the exterior flow and fluorescent tracer particles in the drop. The results indicate a lack of axial symmetry in the internal flow even though the apparatus and the heating are symmetric. The theoretical studies for the past year have included fundamental analyses of acoustically levitated spherical drops. The flow associated with a particle near the velocity antinode is being investigated by the singular perturbation technique. As a first step towards understanding the effect of the particle displacement from the antinode, the flow field about the node has been calculated for the first time. The effect of the acoustic field on the interior of a liquid drop has also been investigated. The results predict that the internal flow field is very weak.

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

    PubMed Central

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

    2009-01-01

    Background 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). Scope 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). Conclusions 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

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

    PubMed

    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

  5. Legal update. Definition of accident--accidental death and dismemberment--alcohol-related automobile collision--foreseeability of death as result of driving while intoxicated.

    PubMed

    2011-01-01

    LaAsmar v. Phelps Dodge Corp. Life, Accidental Death & Dismemberment & Dependent Life Ins. Plan, 605 F3d 789, 2010 WL 1794437(10th Cir. 2010). A death caused by an alcohol-related automobile collision qualifies as an "accident" that would require payment of accidental death and dismemberment plan benefits.

  6. Controlling Vapor Pressure In Hanging-Drop Crystallization

    NASA Technical Reports Server (NTRS)

    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.

  7. Cavity optomechanics in a levitated helium drop

    NASA Astrophysics Data System (ADS)

    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.

  8. Drop evaporation in a single-axis acoustic levitator

    NASA Technical Reports Server (NTRS)

    Lierke, E. G.; Croonquist, A. P.

    1990-01-01

    A 20 kHz single-axis acoustic positioner is used to levitate aqueous-solution drops (volumes less than or approximately equal to 100 micro-liters). Drop evaporation rates are measured under ambient, isothermal conditions for different relative humidities. Acoustic convection around the levitated sample enhances the mass loss over that due to natural convection and diffusion. A theoretical treatment of the mass flow is developed in analogy to previous studies of the heat transfer from a sphere in an acoustic field. Predictions of the enhanced mass loss, in the form of Nusselt (Sherwood) numbers, are compared with observed rages of drop shrinking. The work is part of an ESA crystal growth from levitated solution drops.

  9. 14 CFR 29.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reserve energy absorption drop test. 29.727 Section 29.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION....727 Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as...

  10. 14 CFR 27.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Reserve energy absorption drop test. 27.727 Section 27.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows...

  11. 14 CFR 27.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Reserve energy absorption drop test. 27.727 Section 27.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows...

  12. 14 CFR 27.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Reserve energy absorption drop test. 27.727 Section 27.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows...

  13. 14 CFR 29.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Reserve energy absorption drop test. 29.727 Section 29.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION....727 Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as...

  14. 14 CFR 27.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reserve energy absorption drop test. 27.727 Section 27.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows...

  15. 14 CFR 27.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Reserve energy absorption drop test. 27.727 Section 27.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows...

  16. 14 CFR 29.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Reserve energy absorption drop test. 29.727 Section 29.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION....727 Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as...

  17. 14 CFR 29.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Reserve energy absorption drop test. 29.727 Section 29.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION....727 Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as...

  18. 14 CFR 29.727 - Reserve energy absorption drop test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Reserve energy absorption drop test. 29.727 Section 29.727 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION....727 Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as...

  19. Observation of ice nucleation in acoustically levitated water drops

    NASA Astrophysics Data System (ADS)

    Lü, Y. J.; Xie, W. J.; Wei, B.

    2005-10-01

    The supercooling and nucleation of acoustically levitated water drops were investigated at two different sound pressure levels (SPL). These water drops were supercooled by 13to16K at the low SPL of 160.6dB, whereas their supercoolings varied from 5to11K at the high SPL of 164.4dB. The maximum supercooling obtained in the experiments is 32K. Statistical analyses based on the classical nucleation theory reveal that the occurrence of ice nucleation in water drops is mainly confined to the surface region under acoustic levitation conditions and the enlargement of drop surface area caused by the acoustic radiation pressure reduces water supercoolability remarkably. A comparison of the nucleation rates at the two SPLs indicates that the sound pressure can strengthen the surface-dominated nucleation of water drops. The acoustic stream around levitated water drops and the cavitation effect associated with ultrasonic field are the main factors that induce surface-dominated nucleation.

  20. Simple, robust storage of drops and fluids in a microfluidic device.

    PubMed

    Boukellal, Hakim; Selimović, Seila; Jia, Yanwei; Cristobal, Galder; Fraden, Seth

    2009-01-21

    We describe a single microfluidic device and two methods for the passive storage of aqueous drops in a continuous stream of oil without any external control but hydrodynamic flow. Advantages of this device are that it is simple to manufacture, robust under operation, and drops never come into contact with each other, making it unnecessary to stabilize drops against coalescence. In one method the device can be used to store drops that are created upstream from the storage zone. In the second method the same device can be used to simultaneously create and store drops from a single large continuous fluid stream without resorting to the usual flow focusing or T-junction drop generation processes. Additionally, this device stores all the fluid introduced, including the first amount, with zero waste. Transport of drops in this device depends, however, on whether or not the aqueous drops wet the device walls. Analysis of drop transport in these two cases is presented. Finally, a method for extraction of the drops from the device is also presented, which works best when drops do not wet the walls of the chip.

  1. Lubrication model for evaporation of binary sessile drops

    NASA Astrophysics Data System (ADS)

    Williams, Adam; Sáenz, Pedro; Karapetsas, George; Matar, Omar; Sefiane, Khellil; Valluri, Prashant

    2017-11-01

    Evaporation of a binary mixture sessile drop from a solid substrate is a highly dynamic and complex process with flow driven both thermal and solutal Marangoni stresses. Experiments on ethanol/water drops have identified chaotic regimes on both the surface and interior of the droplet, while mixture composition has also been seen to govern drop wettability. Using a lubrication-type approach, we present a finite element model for the evaporation of an axisymmetric binary drop deposited on a heated substrate. We consider a thin drop with a moving contact line, taking also into account the commonly ignored effects of inertia which drives interfacial instability. We derive evolution equations for the film height, the temperature and the concentration field considering that the mixture comprises two ideally mixed volatile components with a surface tension linearly dependent on both temperature and concentration. The properties of the mixture such as viscosity also vary locally with concentration. We explore the parameter space to examine the resultant effects on wetting and evaporation where we find qualitative agreement with experiments in both these areas. This enables us to understand the nature of the instabilities that spontaneously emerge over the drop lifetime. EPSRC - EP/K00963X/1.

  2. Afterlife of a Drop Impacting a Liquid Pool

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  4. Thermocapillary motion of deformable drops

    NASA Technical Reports Server (NTRS)

    Haj-Hariri, Hossein; Shi, Qingping; Borhan, Ali

    1994-01-01

    The thermocapillary motion of initially spherical drops/bubbles driven by a constant temperature gradient in an unbounded liquid medium is simulated numerically. Effects of convection of momentum and energy, as well as shape deformations, are addressed. The method used is based on interface tracking on a base cartesian grid, and uses a smeared color or indicator function for the determination of the surface topology. Quad-tree adaptive refinement of the cartesian grid is implemented to enhance the fidelity of the surface tracking. It is shown that convection of energy results in a slowing of the drop, as the isotherms get wrapped around the front of the drop. Shape deformation resulting from inertial effects affect the migration velocity. The physical results obtained are in agreement with the existing literature. Furthermore, remarks are made on the sensitivity of the calculated solutions to the smearing of the fluid properties. Analysis and simulations show that the migration velocity depends very strongly on the smearing of the interfacial force whereas it is rather insensitive to the smearing of other properties, hence the adaptive grid.

  5. The Scotch Broom gall mite: Accidental introduction to classical biological control agent?

    Treesearch

    J. Andreas; T. Wax; E. Coombs; J. Gaskin; G. Markin; S. Sing

    2013-01-01

    The gall mite, Aceria genistae (Nal.) Castagnoli s.l., an accidentally introduced natural enemy of Scotch broom (Cytisus scoparius (L.) Link), was first discovered in the Portland OR and Tacoma WA region in 2005. It has since been reported from southern British Columbia to southern Oregon. Observationally, the mite appears to reduce Scotch broom seed production and at...

  6. Breath Figures under Electrowetting: Electrically Controlled Evolution of Drop Condensation Patterns

    NASA Astrophysics Data System (ADS)

    Baratian, Davood; Dey, Ranabir; Hoek, Harmen; van den Ende, Dirk; Mugele, Frieder

    2018-05-01

    We show that electrowetting (EW) with structured electrodes significantly modifies the distribution of drops condensing onto flat hydrophobic surfaces by aligning the drops and by enhancing coalescence. Numerical calculations demonstrate that drop alignment and coalescence are governed by the drop-size-dependent electrostatic energy landscape that is imposed by the electrode pattern and the applied voltage. Such EW-controlled migration and coalescence of condensate drops significantly alter the statistical characteristics of the ensemble of droplets. The evolution of the drop size distribution displays self-similar characteristics that significantly deviate from classical breath figures on homogeneous surfaces once the electrically induced coalescence cascades set in beyond a certain critical drop size. The resulting reduced surface coverage, coupled with earlier drop shedding under EW, enhances the net heat transfer.

  7. Vertical vibration dynamics of acoustically levitated drop containing two immiscible liquids

    NASA Astrophysics Data System (ADS)

    Zang, Duyang; Zhai, Zhicong; Li, Lin; Lin, Kejun; Li, Xiaoguang; Geng, Xingguo

    2016-09-01

    We have studied the levitation and oscillation dynamics of complex drops containing two immiscible liquids. Two types of drops, core-shell drop and abnormal-shaped drop, have been obtained depending on the levitation procedures. The oscillation dynamics of the drops have been studied using a high speed camera. It has been found that the oscillation of the abnormal-shaped drop has a longer oscillation period and decays much faster than that of the core-shell drop, which cannot be accounted for by the air resistance itself. The acoustic streaming induced by ultrasound may bring an additional force against the motion of the drop due to the Bernoulli effect. This is responsible for the enhanced damping during the oscillation in acoustic levitation.

  8. Evaporation of pure liquid sessile and spherical suspended drops: a review.

    PubMed

    Erbil, H Yildirim

    2012-01-15

    A sessile drop is an isolated drop which has been deposited on a solid substrate where the wetted area is limited by a contact line and characterized by contact angle, contact radius and drop height. Diffusion-controlled evaporation of a sessile drop in an ambient gas is an important topic of interest because it plays a crucial role in many scientific applications such as controlling the deposition of particles on solid surfaces, in ink-jet printing, spraying of pesticides, micro/nano material fabrication, thin film coatings, biochemical assays, drop wise cooling, deposition of DNA/RNA micro-arrays, and manufacture of novel optical and electronic materials in the last decades. This paper presents a review of the published articles for a period of approximately 120 years related to the evaporation of both sessile drops and nearly spherical droplets suspended from thin fibers. After presenting a brief history of the subject, we discuss the basic theory comprising evaporation of micrometer and millimeter sized spherical drops, self cooling on the drop surface and evaporation rate of sessile drops on solids. The effects of drop cooling, resultant lateral evaporative flux and Marangoni flows on evaporation rate are also discussed. This review also has some special topics such as drop evaporation on superhydrophobic surfaces, determination of the receding contact angle from drop evaporation, substrate thermal conductivity effect on drop evaporation and the rate evaporation of water in liquid marbles. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. The Flow Induced by the Coalescence of Two Initially Stationary Drops

    NASA Technical Reports Server (NTRS)

    Nobari, M. R.; Tryggvason, G.

    1994-01-01

    The coalescence of two initially stationary drops of different size is investigated by solving the unsteady, axisymmetric Navier-Stokes equations numerically, using a Front-Tracking/Finite Difference method. Initially, the drops are put next to each other and the film between them ruptured. Due to surface tension forces, the drops coalesce rapidly and the fluid from the small drop is injected into the larger one. For low nondimensional viscosity, or Ohnesorge number, little mixing takes place and the small drop fluid forms a blob near the point where the drops touched initially. For low Ohnesorge number, on the other hand, the small drop forms a jet that penetrates far into the large drop. The penetration depth also depends on the size of the drops and shows that for a given fluid of sufficiently low viscosity, there is a maximum penetration depth for intermediate size ratios.

  10. Bubble, Drop and Particle Unit (BDPU)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This section of the Life and Microgravity Spacelab (LMS) publication includes the following articles entitled: (1) Oscillatory Thermocapillary Instability; (2) Thermocapillary Convection in Multilayer Systems; (3) Bubble and Drop Interaction with Solidification Front; (4) A Liquid Electrohydrodynamics Experiment; (5) Boiling on Small Plate Heaters under Microgravity and a Comparison with Earth Gravity; (6) Thermocapillary Migration and Interactions of Bubbles and Drops; and (7) Nonlinear Surface Tension Driven Bubble Migration

  11. Automated single cell sorting and deposition in submicroliter drops

    NASA Astrophysics Data System (ADS)

    Salánki, Rita; Gerecsei, Tamás; Orgovan, Norbert; Sándor, Noémi; Péter, Beatrix; Bajtay, Zsuzsa; Erdei, Anna; Horvath, Robert; Szabó, Bálint

    2014-08-01

    Automated manipulation and sorting of single cells are challenging, when intact cells are needed for further investigations, e.g., RNA or DNA sequencing. We applied a computer controlled micropipette on a microscope admitting 80 PCR (Polymerase Chain Reaction) tubes to be filled with single cells in a cycle. Due to the Laplace pressure, fluid starts to flow out from the micropipette only above a critical pressure preventing the precise control of drop volume in the submicroliter range. We found an anomalous pressure additive to the Laplace pressure that we attribute to the evaporation of the drop. We have overcome the problem of the critical dropping pressure with sequentially operated fast fluidic valves timed with a millisecond precision. Minimum drop volume was 0.4-0.7 μl with a sorting speed of 15-20 s per cell. After picking NE-4C neuroectodermal mouse stem cells and human primary monocytes from a standard plastic Petri dish we could gently deposit single cells inside tiny drops. 94 ± 3% and 54 ± 7% of the deposited drops contained single cells for NE-4C and monocytes, respectively. 7.5 ± 4% of the drops contained multiple cells in case of monocytes. Remaining drops were empty. Number of cells deposited in a drop could be documented by imaging the Petri dish before and after sorting. We tuned the adhesion force of cells to make the manipulation successful without the application of microstructures for trapping cells on the surface. We propose that our straightforward and flexible setup opens an avenue for single cell isolation, critically needed for the rapidly growing field of single cell biology.

  12. Method for reducing pressure drop through filters, and filter exhibiting reduced pressure drop

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sappok, Alexander; Wong, Victor

    Methods for generating and applying coatings to filters with porous material in order to reduce large pressure drop increases as material accumulates in a filter, as well as the filter exhibiting reduced and/or more uniform pressure drop. The filter can be a diesel particulate trap for removing particulate matter such as soot from the exhaust of a diesel engine. Porous material such as ash is loaded on the surface of the substrate or filter walls, such as by coating, depositing, distributing or layering the porous material along the channel walls of the filter in an amount effective for minimizing ormore » preventing depth filtration during use of the filter. Efficient filtration at acceptable flow rates is achieved.« less

  13. Spreading of a pendant liquid drop underneath a textured substrate

    NASA Astrophysics Data System (ADS)

    Mistry, Aashutosh; Muralidhar, K.

    2018-04-01

    A pendant drop spreading underneath a partially wetting surface from an initial shape to its final equilibrium configuration and contact angle is studied. A mathematical formulation that quantifies spreading behavior of liquid drops over textured surfaces is discussed. The drop volume and the equilibrium contact angle are treated as parameters in the study. The unbalanced force at the three-phase contact line is modeled as being proportional to the degree of departure from the equilibrium state. Model predictions are verified against the available experimental data in the literature. Results show that the flow dynamics is strongly influenced by the fluid properties, drop volume, and contact angle of the liquid with the partially wetting surface. The drop exhibits rich dynamical behavior including inertial oscillations and gravitational instability, given that gravity tries to detach the drop against wetting contributions. Flow characteristics of drop motion, namely, the radius of the footprint, slip length, and dynamic contact angle in the pendant configuration are presented. Given the interplay among the competing time-dependent forces, a spreading drop can momentarily be destabilized and not achieve a stable equilibrium shape. Instability is then controlled by the initial drop shape as well. The spreading model is used to delineate stable and unstable regimes in the parameter space. Predictions of the drop volume based on the Young-Laplace equation are seen to be conservative relative to the estimates of the dynamical model discussed in the present study.

  14. Analysis of hospital admissions due to accidental non-fire-related carbon monoxide poisoning in England, between 2001 and 2010.

    PubMed

    Ghosh, Rebecca E; Close, Rebecca; McCann, Lucy J; Crabbe, Helen; Garwood, Kevin; Hansell, Anna L; Leonardi, Giovanni

    2016-03-01

    Accidental non-fire-related (ANFR) carbon monoxide (CO) poisoning is a cause of fatalities and hospital admissions. This is the first study that describes the characteristics of ANFR CO hospital admissions in England. Hospital Episode Statistics (HES) inpatient data for England between 2001 and 2010 were used. ANFR CO poisoning admissions were defined as any mention of ICD-10 code T58: toxic effect of CO and X47: accidental poisoning by gases or vapours, excluding ICD-10 codes potentially related to fires (X00-X09, T20-T32 and Y26). There were 2463 ANFR CO admissions over the 10-year period (annual rate: 0.49/100 000); these comprised just under half (48.7%) of all non-fire-related (accidental and non-accidental) CO admissions. There was seasonal variability, with more admissions in colder winter months. Higher admission rates were observed in the north of England. Just over half (53%) of ANFR admissions were male, and the highest rates of ANFR admissions were in those aged >80 years. The burden of ANFR CO poisoning is preventable. The results of this study suggest an appreciable burden of CO and highlight differences that may aid targeting of public health interventions. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health.

  15. On the autonomous motion of active drops or bubbles.

    PubMed

    Ryazantsev, Yuri S; Velarde, Manuel G; Guzman, Eduardo; Rubio, Ramón G; Ortega, Francisco; Montoya, Juan-Jose

    2018-05-19

    Thermo-capillary stresses on the surface of a drop can be the result of a non-isothermal surface chemical conversion of a reactant dissolved in the host fluid. The strength of heat production (with e.g. absorption) on the surface is ruled by the diffusion of the reactant and depends on the state of motion of the drop. Such thermo-capillary stresses can provoke the motion of the drop or its motionless state in the presence of an external body force. If in the balance of forces, including indeed viscous drag, the net resultant force vanishes there is the possibility of autonomous motion with constant velocity of the drop. Focusing on drops with radii in the millimeter range provided here is a quantitative study of the possibility of such autonomous motion when the drop, considered as active unit, is seat of endo- or exo-thermic reactive processes that dominate its motion. The framework is restricted to Stokes flows in the hydrodynamics, negligible heat Peclet number while the solute Peclet number is considered very high. A boundary layer approximation is used in the description of reactant diffusion. Those processes eventually end up in the action being expressed by surface tension gradients and the Marangoni effect. Explicit expressions of the force acting on the drop and the velocity fields inside and outside the drop are provided. Some significant particular cases are discussed to illustrate the usefulness of the theory. Copyright © 2018. Published by Elsevier Inc.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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.

  17. The initial regime of drop coalescence

    NASA Astrophysics Data System (ADS)

    Anthony, Christopher; Harris, Michael; Basaran, Osman

    2017-11-01

    Drop coalescence plays a key role in both industry and nature. Consequently, study of the phenomenon has been the focus of numerous experimental, computational and theoretical works to date. In coalescence, two drops come into contact and a liquid bridge forms between them. As time advances, this bridge grows from microscopic to macroscopic scales. Despite the large volume of work dedicated to this problem, currently experiment, theory, and computation are not in perfect agreement with respect to the earliest times following the initial contact of the drops. Experiments report an initial regime where the radius of the connecting bridge grows linearly in time before a transition to either a Stokes regime or an inertial regime where either viscous or inertial forces balance capillary force. In the initial linear regime, referred to as the inertially-limited viscous regime, all three forces are thought to be important. This is in contrast to theory which predicts that all coalescence events begin in the Stokes regime. We use high accuracy numerical simulation to show that the existing discrepancy in the literature can be resolved by paying careful attention to the initial conditions that set the shape and size of the bridge connecting the two drops.

  18. Fact Sheet: Clean Air Act Section 112(r): Accidental Release Prevention / Risk Management Plan Rule

    EPA Pesticide Factsheets

    EPA is required to publish regulations and guidance for chemical accident prevention at facilities that pose the greatest risk of harm from accidental releases of regulated flammable and toxic substances above threshold quantities.

  19. Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia.

    PubMed

    Zafren, Ken; Giesbrecht, Gordon G; Danzl, Daniel F; Brugger, Hermann; Sagalyn, Emily B; Walpoth, Beat; Weiss, Eric A; Auerbach, Paul S; McIntosh, Scott E; Némethy, Mária; McDevitt, Marion; Dow, Jennifer; Schoene, Robert B; Rodway, George W; Hackett, Peter H; Bennett, Brad L; Grissom, Colin K

    2014-12-01

    To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. Copyright © 2014 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  20. Surfactant-Enhanced Benard Convection on an Evaporating Drop

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed

    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.

  2. Drop impact and wettability: From hydrophilic to superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Antonini, Carlo; Amirfazli, Alidad; Marengo, Marco

    2012-10-01

    Experiments to understand the effect of surface wettability on impact characteristics of water drops onto solid dry surfaces were conducted. Various surfaces were used to cover a wide range of contact angles (advancing contact angle from 48° to 166°, and contact angle hysteresis from 5° to 56°). Several different impact conditions were analyzed (12 impact velocities on 9 different surfaces, among which 2 were superhydrophobic). Results from impact tests with millimetric drops show that two different regimes can be identified: a moderate Weber number regime (30 < We < 200), in which wettability affects both drop maximum spreading and spreading characteristic time; and a high Weber number regime (We > 200), in which wettability effect is secondary, because capillary forces are overcome by inertial effects. In particular, results show the role of advancing contact angle and contact angle hysteresis as fundamental wetting parameters to allow understanding of different phases of drop spreading and beginning of recoiling. It is also shown that drop spreading on hydrophilic and superhydrophobic surfaces occurs with different time scales. Finally, if the surface is superhydrophobic, eventual impalement, i.e., transition from Cassie to Wenzel wetting state, which might occur in the vicinity of the drop impact area, does not influence drop maximum spreading.

  3. Interpreting energy scenarios

    NASA Astrophysics Data System (ADS)

    Iyer, Gokul; Edmonds, James

    2018-05-01

    Quantitative scenarios from energy-economic models inform decision-making about uncertain futures. Now, research shows the different ways these scenarios are subsequently used by users not involved in their initial development. In the absence of clear guidance from modellers, users may place too much or too little confidence in scenario assumptions and results.

  4. Drop tube technical tasks

    NASA Technical Reports Server (NTRS)

    Workman, G. L.

    1986-01-01

    Criteria, using fundamental thermochemical dynamics, were developed to assist a scientist using the Drop Tube Facility in designing a good experiment. The types of parameters involved in designing the experiments include the type of furnace, the type of atmosphere, and in general which materials are better behaved than others as determined by past experience in the facility. One of the major advantages of the facility lies in its ability to provide large undercoolings in the cooling curve during the drops. A beginning was to consider the effect of oxygen and other gases upon the amount of undercooling observed. The starting point of the thermochemistry was given by Ellingham and later transformed into what is known as the Richardson Chart. The effect of surface oxidations upon the nucleation phenomena can be observed in each specimen.

  5. Oblique drop impact onto a deep liquid pool

    NASA Astrophysics Data System (ADS)

    Gielen, Marise V.; Sleutel, Pascal; Benschop, Jos; Riepen, Michel; Voronina, Victoria; Visser, Claas Willem; Lohse, Detlef; Snoeijer, Jacco H.; Versluis, Michel; Gelderblom, Hanneke

    2017-08-01

    Oblique impact of drops onto a solid or liquid surface is frequently observed in nature. Most studies on drop impact and splashing, however, focus on perpendicular impact. Here we study oblique impact of 100 μ m drops onto a deep liquid pool, where we quantify the splashing threshold, maximum cavity dimensions and cavity collapse by high-speed imaging above and below the water surface. Gravity can be neglected in these experiments. Three different impact regimes are identified: smooth deposition onto the pool, splashing in the direction of impact only, and splashing in all directions. We provide scaling arguments that delineate these regimes by accounting for the drop impact angle and Weber number. The angle of the axis of the cavity created below the water surface follows the impact angle of the drop irrespectively of the Weber number, while the cavity depth and its displacement with respect to the impact position do depend on the Weber number. Weber number dependency of both the cavity depth and displacement is modeled using an energy argument.

  6. Scaling during capillary thinning of particle-laden drops

    NASA Astrophysics Data System (ADS)

    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.

  7. Non-contact temperature measurement of a falling drop

    NASA Technical Reports Server (NTRS)

    Hofmeister, William; Bayuzick, R. J.; Robinson, M. B.

    1989-01-01

    The 105 meter drop tube at NASA-Marshall has been used in a number of experiments to determine the effects of containerless, microgravity processing on the undercooling and solidification behavior of metals and alloys. These experiments have been limited, however, because direct temperature measurement of the falling drops has not been available. Undercooling and nucleation temperatures are calculated from thermophysical properties based on droplet cooling models. In most cases these properties are not well known, particularly in the undercooled state. This results in a large amount of uncertainty in the determination of nucleation temperatures. If temperature measurement can be accomplished then the thermal history of the drops could be well documented. This would lead to a better understanding of the thermophysical and thermal radiative properties of undercooled melts. An effort to measure the temperature of a falling drop is under way. The technique uses two color pyrometry and high speed data acquisition. The approach is presented along with some preliminary data from drop tube experiments. The results from droplet cooling models is compared with noncontact temperature measurements.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nelsen, Nicholas H.; Kolb, James D.; Kulkarni, Akshay G.

    Mechanical component response to shock environments must be predictable in order to ensure reliability and safety. Whether the shock input results from accidental drops during transportation to projectile impact scenarios, the system must irreversibly transition into a safe state that is incapable of triggering the component . With this critical need in mind, the 2017 Nuclear Weapons Summer Product Realization Institute (NW SPRINT) program objective sought the design of a passive shock failsafe with emphasis on additively manufactured (AM) components. Team Advanced and Exploratory (A&E) responded to the challenge by designing and delivering multiple passive shock sensing mech anisms thatmore » activate within a prescribed mechanical shock threshold. These AM failsafe designs were tuned and validated using analytical and computational techniques including the shock response spectrum (SRS) and finite element analysis (FEA). After rapid prototyping, the devices experienced physical shock tests conducted on Sandia drop tables to experimentally verify performance. Keywords: Additive manufacturing, dynamic system, failsafe, finite element analysis, mechanical shock, NW SPRINT, shock respon se spectrum« less

  10. Microscopic description of a drop on a solid surface.

    PubMed

    Ruckenstein, Eli; Berim, Gersh O

    2010-06-14

    Two approaches recently suggested for the treatment of macro- or nanodrops on smooth or rough, planar or curved, solid surfaces, based on fluid-fluid and fluid-solid interaction potentials are reviewed. The first one employs the minimization of the total potential energy of a drop by assuming that the drop has a well defined profile and a constant liquid density in its entire volume with the exception of the monolayer nearest to the surface where the density has a different value. As a result, a differential equation for the drop profile as well as the necessary boundary conditions are derived which involve the parameters of the interaction potentials and do not contain such macroscopic characteristics as the surface tensions. As a consequence, the macroscopic and microscopic contact angles which the drop profile makes with the surface can be calculated. The macroscopic angle is obtained via the extrapolation of the circular part of the drop profile valid at some distance from the surface up to the solid surface. The microscopic angle is formed at the intersection of the real profile (which is not circular near the surface) with the surface. The theory provides a relation between these two angles. The ranges of the microscopic parameters of the interaction potentials for which (i) the drop can have any height (volume), (ii) the drop can have a restricted height but unrestricted volume, and (iii) a drop cannot be formed on the surface were identified. The theory was also extended to the description of a drop on a rough surface. The second approach is based on a nonlocal density functional theory (DFT), which accounts for the inhomogeneity of the liquid density and temperature effects, features which are missing in the first approach. Although the computational difficulties restrict its application to drops of only several nanometers, the theory can be applied indirectly to macrodrops by calculating the surface tensions and using the Young equation to determine the

  11. THE DROP DURING LESS THAN 300 DAYS OF A DUSTY WHITE DWARF'S INFRARED LUMINOSITY

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, S.; Jura, M., E-mail: sxu@astro.ucla.edu, E-mail: jura@astro.ucla.edu

    2014-09-10

    We report Spitzer/Infrared Array Camera photometry of WD J0959–0200, a white dwarf that displays excess infrared radiation from a disk, likely produced by a tidally disrupted planetesimal. We find that in 2010, the fluxes in both 3.6 μm and 4.5 μm decreased by ∼35% in less than 300 days. The drop in the infrared luminosity is likely due to an increase of the inner disk radius from one of two scenarios: (1) a recent planetesimal impact; (2) instability in the circumstellar disk. The current situation is tantalizing; high-sensitivity, high-cadence infrared studies will be a new tool to study the interplay between a diskmore » and its host white dwarf star.« less

  12. Cooling and solidification of liquid-metal drops in a gaseous atmosphere

    NASA Technical Reports Server (NTRS)

    Mccoy, J. K.; Markworth, A. J.; Collings, E. W.; Brodkey, R. S.

    1992-01-01

    The free fall of a liquid-metal drop, heat transfer from the drop to its environment, and solidification of the drop are described for both gaseous and vacuum atmospheres. A simple model, in which the drop is assumed to fall rectilinearly, with behavior like that of a rigid particle, is developed to describe cooling behavior. Recalescence of supercooled drops is assumed to occur instantaneously when a specified temperature is passed. The effects of solidification and experimental parameters on drop cooling are calculated and discussed. Major results include temperature as a function of time, and of drag, time to complete solidification, and drag as a function of the fraction of the drop solidified.

  13. Evaporation kinetics in the hanging drop method of protein crystal growth

    NASA Technical Reports Server (NTRS)

    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; these results are applied to 18 different drop and well arrangements commonly encountered in the laboratory, taking into account the chemical nature of the salt, the drop size and shape, the drop concentration, the well size, the well concentration, and the temperature. It is found that the rate of evaporation increases with temperature, drop size, and with the salt concentration difference between the drop and the well. The evaporation possesses no unique half-life. Once the salt in the drop achieves about 80 percent of its final concentration, further evaporation suffers from the law of diminishing returns.

  14. Wrapping a liquid drop with a thin elastic sheet

    NASA Astrophysics Data System (ADS)

    Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Chris; Russell, Thomas; Menon, Narayanan

    2014-11-01

    We study the wrapping of a liquid drop by an initially-planar ultrathin (~ 100 nm) circular sheet. These elastic sheets can completely relax compressive stresses by forming wrinkles. In the experiment, we find that when a small fraction of the drop is covered, the overall shape of the sheet (i.e. averaging over the wrinkles) is axisymmetric. As we shrink the drop further, the sheet develops radial folds that break the axisymmetry of the sheet and the drop. Our data are consistent with a model where the sheet selects the shape that minimizes the exposed liquid surface area. We thus identify a ``geometric wrapping'' regime, where the partially-wrapped shape depends only on the relative radii of the sheet and the drop; the global breaking of axisymmetry is independent of the elastic energy of the deformed sheet. This regime requires that bending energy is negligible compared to surface energy, in contrast to the ``capillary origami'' regime where the static shape of the drop comes from a balance of bending and capillary forces.

  15. Accidental cut-throat injuries from the broken windshield of an auto rickshaw: Two unusual cases.

    PubMed

    Swain, Rajanikanta; Dhaka, Shivani; Sharma, Munish; Bakshi, Mantaran Singh; Murty, O P; Sikary, Asit Kumar

    2018-01-01

    Accidental cut-throat injuries are extremely rare and usually involve a sharp-edged weapon. In this paper, two cases of a cut-throat wound to two auto-rickshaw drivers are presented where the broken windshield of the auto-rickshaws was responsible for the wounds. In both the cases, fatal incised wounds were present over the neck, cutting the soft tissue along with the major vessels. The death occurred due to exsanguination caused by neck-vessel injury in one case and trachea along with neck-vessel injury in the second case. Although the wounds on the neck initially suggested homicide, they were found to have occurred accidentally as a result of a road traffic accident involving a head-on collision of auto rickshaws. The injuries were inflicted by the shattered glass of the windshield.

  16. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, T.R.

    1980-04-01

    An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

  17. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, Terry R. [Berkeley, CA

    1980-04-01

    An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

  18. [Preliminary exploration on knockout drops (Meng Han Agents)].

    PubMed

    Zhang, Z

    1996-05-01

    This author points out, based on relevant materials, that knockout drops were vertigo powder. Due to homophonic reasons in Chinese language, the term "mingxuan" was transliterated into the former Chinese term (menghan). Knockout drops for medicinal use were merely made up of compound recipes containing stramonium flowers. The knockout drops in old fictions and opera books were powder of stramonium flower. The ingredients and application of such recipes are discussed here, the anti-remedies for such recipes are also mentioned.

  19. Charged drop dynamics experiment using an electrostatic-acoustic hybrid system

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Chung, S. K.; Trinh, E. H.; Elleman, D. D.

    1987-01-01

    The design and the performance of an electrostatic-acoustic hybrid system and its application to a charge drop rotation experiment are presented. This system can levitate a charged drop electrostatically and induce drop rotation or oscillation by imposing an acoustic torque or an oscillating acoustic pressure. Using this system, the equilibrium shapes and stability of a rotating charged drop were experimentally investigated. A 3 mm size water drop was rotated as a rigid body and its gyrostatic equilibrium shapes were observed. Families of axisymmetric shapes, two-lobed shapes, and eventual fissioning have been observed. With the assumption of 'effective surface tension' in which the surface charge simply modified the surface tension of neutral liquid, the results agree exceptionally well with the Brown and Scriven's (1980) prediction for uncharged drops.

  20. Oscillations of a deformed liquid drop in an acoustic field

    NASA Astrophysics Data System (ADS)

    Shi, Tao; Apfel, Robert E.

    1995-07-01

    The oscillations of an axially symmetric liquid drop in an acoustic standing wave field in air have been studied using the boundary integral method. The interaction between the drop oscillation and sound field has been included in this analysis. Our computations focus on the frequency shift of small-amplitude oscillations of an acoustically deformed drop typical of a drop levitated in air. In the presence or absence of gravity, the trend and the magnitude of the frequency shift have been given in terms of drop size, drop deformation, and the strength of the sound field. Our calculations are compared with experiments performed on the United States Microgravity Laboratory (USML-1) and with ground-based measurements, and are found to be in good agreement within the accuracy of the experimental data.

  1. Accidental strangulation of a mentally retarded patient by a clothing collar: a case report.

    PubMed

    Hitosugi, Masahito; Yokoyama, Tomoko; Kido, Masahito; Kawato, Hitoshi; Matsushima, Kazumi; Nagai, Toshiaki; Tokudome, Shogo

    2006-07-01

    A 40-year-old mentally retarded woman died of accidental strangulation in a nursing home. She was found in a kneeling position with her hands on her knees and the collar of her clothing compressing the front and sides of the neck. Before the accident, a nurse had dressed the patient in one-piece overall-style pyjamas put on back to front so that she could not remove the garment herself. The post-mortem findings and reconstruction of the scene of death suggested that the patient had been strangled by the collar of her backward-facing clothing while in a kneeling position. Because patients with psychiatric illnesses may have a limited ability to recognize or communicate symptoms of physical danger, they must be closely monitored by knowledgeable medical and nursing staff. This case highlights the importance of preventing the accidental deaths of mentally retarded patients in nursing homes.

  2. Accidental ingestion of BiTine ring and a note on inefficient ring separation forceps.

    PubMed

    Baghele, Om Nemichand; Baghele, Mangala Om

    2011-01-01

    Accidental ingestion of medium-to-large instruments is relatively uncommon during dental treatment but can be potentially dangerous. A case of BiTine ring ingestion is presented with a note on inefficient ring separation forceps. A 28-year-old male patient accidentally ingested the BiTine ring (2 cm diameter, 0.5 cm outward projections) while it was being applied to a distoproximal cavity in tooth # 19. The ring placement forceps were excessively flexible; bending of the beaks towards the ring combined with a poor no-slippage mechanism led to sudden disengagement of the ring and accelerated movement towards the pharynx. We followed the patient with bulk forming agents and radiographs. Fortunately the ring passed out without any complications. Checking equipment and methods is as important as taking precautions against any preventable medical emergency. It is the responsibility of the clinician to check, verify and then use any instrument/equipment.

  3. Young Women of Alaska Speak Out about Dropping Out.

    ERIC Educational Resources Information Center

    Bruce, Lauren

    This report is the result of taped interviews with 115 Alaskan teenage women who have dropped out of "regular" public school. Two results of the study stand out: first, the majority of the students wanted a diploma, but nonetheless felt compelled to drop out; second (the reason most girls gave for dropping out): no one cared. However,…

  4. Validation of an All-Pressure Fluid Drop Model: Heptane Fluid Drops in Nitrogen

    NASA Technical Reports Server (NTRS)

    Harstad, K.; Bellan, J.; Bulzan, Daniel L. (Technical Monitor)

    2000-01-01

    Despite the fact that supercritical fluids occur both in nature and in industrial situations, the fundamentals of their behavior is poorly understood because supercritical fluids combine the characteristics of both liquids and gases, and therefore their behavior is not intuitive. There are several specific reasons for the lack of understanding: First, data from (mostly optical) measurements can be very misleading because regions of high density thus observed are frequently identified with liquids. A common misconception is that if in an experiment one can optically identify "drops" and "ligaments", the observed fluid must be in a liquid state. This inference is incorrect because in fact optical measurements detect any large change (i.e. gradients) in density. Thus, the density ratio may be well below Omicron(10(exp 3)) that characterizes its liquid/gas value, but the measurement will still identify a change in the index of refraction providing that the change is sudden (steep gradients). As shown by simulations of supercritical fluids, under certain conditions the density gradients may remain large during the supercritical binary fluids mixing, thus making them optically identifiable. Therefore, there is no inconsistency between the optical observation of high density regions and the fluids being in a supercritical state. A second misconception is that because a fluid has a liquid-like density, it is appropriate to model it as a liquid. However, such fluids may have liquid-like densities while their transport properties differ from those of a liquid. Considering that the critical pressure of most fuel hydrocarbons used in Diesel and gas turbine engines is in the range of 1.5 - 3 MPa, and the fact that the maximum pressure attained in these engines is about 6 Mps, it is clear that the fuel in the combustion chamber will experience both subcritical and supercritical conditions. Studies of drop behavior over a wide range of pressures were performed in the past

  5. On the collapse pressure of armored bubbles and drops.

    PubMed

    Pitois, O; Buisson, M; Chateau, X

    2015-05-01

    Drops and bubbles wrapped in dense monolayers of hydrophobic particles are known to sustain a significant decrease of their internal pressure. Through dedicated experiments we investigate the collapse behavior of such armored water drops as a function of the particle-to-drop size ratio in the range 0.02-0.2. We show that this parameter controls the behavior of the armor during the deflation: at small size ratios the drop shrinkage proceeds through the soft crumpling of the monolayer, at intermediate ratios the drop becomes faceted, and for the largest studied ratios the armor behaves like a granular arch. The results show that each of the three morphological regimes is characterized by an increasing magnitude of the collapse pressure. This increase is qualitatively modeled thanks to a mechanism involving out-of-plane deformations and particle disentanglement in the armor.

  6. Liquid drop stability for protein crystal growth in microgravity

    NASA Technical Reports Server (NTRS)

    Owen, Robert B.; Broom, Beth H.; Snyder, Robert S.; Daniel, Ron

    1987-01-01

    It is possible to grow protein crystals for biomedical research in microgravity by deploying a protein-rich solution from a syringe, forming a drop in which crystallization can occur with the proper degree of supersaturation. Drop stability is critical to the success of this research, due to the large drop sizes which can be achieved in space. In order to determine the type of syringe tips most suitable to support these large drops, tests were performed during brief periods of weightlessness onboard the NASA KC-135 low-gravity simulation aircraft. The drops were analyzed using three simple models in which the samples were approximated by modified pendulum and spring systems. It was concluded that the higher frequency systems were the most stable, indicating that of the syringes utilized, a disk-shaped configuration provided the most stable environment of low-gravity protein crystal growth.

  7. [Accidental injection of sodium hypochlorite in inferior alveolar nerve block anesthesia].

    PubMed

    Hongyan, Li; Jian, Xu; Baorong, Zhang; Yue, Jia; Minhua, Liu; Yilang, Luo; Jing, Zhao

    2016-12-01

    Sodium hypochlorite (NaClO) has been widely used in clinical practice as one of the most efficient root canal irrigants. Its properties include broad-spectrum antimicrobial activity and ability to dissolve necrotic tissues. However, when used improperly, NaClO can cause a series of adverse reactions, such as mucosal inflammation, irritation, or injury. This paper presents a case of accidental injection of NaClO in inferior alveolar nerve block anesthesia.

  8. Rain drop size densities over land and over sea

    NASA Astrophysics Data System (ADS)

    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

  9. PREVENTION REFERENCE MANUAL: CHEMICAL SPECIFIC, VOLUME 13: CONTROL OF ACCIDENTAL RELEASES OF METHYL ISOCYANATE

    EPA Science Inventory

    This is one of a series of manuals addressing accidental releases of toxic chemicals. Methyl isocyanite (MIC) has an Immediately Dangerous to Life and Health (IDLH) concentration of 20 ppm, making it a substantially acute toxic hazard. Reducing the risk associated with an acciden...

  10. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC Operations...

  11. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC Operations...

  12. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC Operations...

  13. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC Operations...

  14. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC Operations...

  15. 14 CFR 27.725 - Limit drop test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... introduced into the drop test by appropriate energy absorbing devices or by the use of an effective mass. (c... critical from the standpoint of the energy to be absorbed by it. (d) When an effective mass is used in...=specified free drop height (inches). L=ration of assumed rotor lift to the rotorcraft weight. d=deflection...

  16. 14 CFR 27.725 - Limit drop test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... introduced into the drop test by appropriate energy absorbing devices or by the use of an effective mass. (c... critical from the standpoint of the energy to be absorbed by it. (d) When an effective mass is used in...=specified free drop height (inches). L=ration of assumed rotor lift to the rotorcraft weight. d=deflection...

  17. 14 CFR 27.725 - Limit drop test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... introduced into the drop test by appropriate energy absorbing devices or by the use of an effective mass. (c... critical from the standpoint of the energy to be absorbed by it. (d) When an effective mass is used in...=specified free drop height (inches). L=ration of assumed rotor lift to the rotorcraft weight. d=deflection...

  18. Breakup of a thin drop under a stagnation point flow

    NASA Astrophysics Data System (ADS)

    Hooshanginejad, Alireza; Lee, Sungyon; Shelley, Michael

    2017-11-01

    Recent studies by Hooshanginejad and Lee (2017) have demonstrated complex depinning behaviors of a partially wetting droplet under wind. Motivated by this study, we examine the coupled evolution of a 2D thin drop and external wind, when it is initially held against a fast stagnation point flow. Our drop lubrication model employs the potential flow and Prandtl boundary layer theory for outer flow to compute the internal drop flow corresponding to drop deformations. Furthermore, both the analytical and numerical steady state solutions provide a partial prediction for the drop's final shape and help identify the range of droplet sizes that undergo a breakup for the given flow condition.

  19. On the scale dependence of earthquake stress drop

    NASA Astrophysics Data System (ADS)

    Cocco, Massimo; Tinti, Elisa; Cirella, Antonella

    2016-10-01

    We discuss the debated issue of scale dependence in earthquake source mechanics with the goal of providing supporting evidence to foster the adoption of a coherent interpretative framework. We examine the heterogeneous distribution of source and constitutive parameters during individual ruptures and their scaling with earthquake size. We discuss evidence that slip, slip-weakening distance and breakdown work scale with seismic moment and are interpreted as scale dependent parameters. We integrate our estimates of earthquake stress drop, computed through a pseudo-dynamic approach, with many others available in the literature for both point sources and finite fault models. We obtain a picture of the earthquake stress drop scaling with seismic moment over an exceptional broad range of earthquake sizes (-8 < MW < 9). Our results confirm that stress drop values are scattered over three order of magnitude and emphasize the lack of corroborating evidence that stress drop scales with seismic moment. We discuss these results in terms of scale invariance of stress drop with source dimension to analyse the interpretation of this outcome in terms of self-similarity. Geophysicists are presently unable to provide physical explanations of dynamic self-similarity relying on deterministic descriptions of micro-scale processes. We conclude that the interpretation of the self-similar behaviour of stress drop scaling is strongly model dependent. We emphasize that it relies on a geometric description of source heterogeneity through the statistical properties of initial stress or fault-surface topography, in which only the latter is constrained by observations.

  20. Why Doesn't the "High School Drop Out Rate" Drop?

    ERIC Educational Resources Information Center

    Truby, William F.

    2016-01-01

    This article provides information, questions, and answers about current approaches to dropping the dropout rate of our students. For example, our current model of education is based on the mass production or assembly line model promoted by Henry Ford back in early years of the 1900s (1900-1920). This model served both factory production and…

  1. The future of scenarios: issues in developing new climate change scenarios

    NASA Astrophysics Data System (ADS)

    Pitcher, Hugh M.

    2009-04-01

    In September, 2007, the IPCC convened a workshop to discuss how a new set of scenarios to support climate model runs, mitigation analyses, and impact, adaptation and vulnerability research might be developed. The first phase of the suggested new approach is now approaching completion. This article discusses some of the issues raised by scenario relevant research and analysis since the last set of IPCC scenarios were created (IPCC SRES, 2000) that will need to be addressed as new scenarios are developed by the research community during the second phase. These include (1) providing a logic for how societies manage to transition from historical paths to the various future development paths foreseen in the scenarios, (2) long-term economic growth issues, (3) the appropriate GDP metric to use (purchasing power parity or market exchange rates), (4) ongoing issues with moving from the broad geographic and time scales of the emission scenarios to the finer scales needed for impacts, adaptation and vulnerability analyses and (5) some possible ways to handle the urgent request from the policy community for some guidance on scenario likelihoods. The challenges involved in addressing these issues are manifold; the reward is greater credibility and deeper understanding of an analytic tool that does much to form the context within which many issues in addition to the climate problem will need to be addressed.

  2. Spontaneous formation of nanostructures inside inkjet-printed colloidal drops

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Thorne, Nathaniel; Sun, Ying

    2013-11-01

    Nanostructures formed in inkjet-printed colloidal drops are systematically examined with different substrates and ink formulations. Various deposition patterns from multi-ring, radial spoke, firework to spider web, foam and island structures are observed. With a high particle loading, deposition transitions from multi-ring near the drop edge to spider web and finally to foam and islands in the center of the drop with 20 nm sulfate-modified polystyrene particles. At the same particle loading, 200 nm particles self-assemble into radial spokes at the drop edge and islands in the center, due to reduced contact line pinning resulted from less particles. In drops with a low particle concentration, due to fingering instability of the contact line, 20 nm particles form radial spokes enclosed by a ring, while 200 nm particles assemble into firework-like structures without a ring. Moreover, at a high particle loading, ruptures are observed on the multi-ring structure formed by 20 nm carboxylic-modified particles, due to stronger capillary forces from the contact line. Furthermore, for a drop printed on a less hydrophilic substrate, the interparticle interactions enable a more uniform deposition rather than complex nanostructures.

  3. Studies of the Stability and Dynamics of Levitated Drops

    NASA Technical Reports Server (NTRS)

    Anikumar, A.; Lee, Chun Ping; Wang, T. G.

    1996-01-01

    This is a review of our experimental and theoretical studies relating to equilibrium and stability of liquid drops, typically of low viscosity, levitated in air by a sound field. The major emphasis here is on the physical principles and understanding behind the stability of levitated drops. A comparison with experimental data is also given, along with some fascinating pictures from high-speed photography. One of the aspects we shall deal with is how a drop can suddenly burst in an intense sound field; a phenomenon which can find applications in atomization technology. Also, we are currently investigating the phenomenon of suppression of coalescence between drops levitated in intense acoustic fields.

  4. No clinically relevant effects in children after accidental ingestion of Panaeolina foenisecii (lawn mower's mushroom).

    PubMed

    Schenk-Jaeger, Katharina M; Hofer-Lentner, Katharina E; Plenert, Bettina; Eckart, Dagmar; Haberl, Bettina; Schulze, Gabriele; Borchert-Avalone, Janine; Stedtler, Uwe; Pfab, Rudolph

    2017-03-01

    Panaeolina foenisecii is one of the most common and widely distributed lawn mushrooms in Europe and North America, and frequently involved in accidental mushroom ingestion, mainly in children. Nevertheless, there is contradictory information regarding the toxicity profile of P. foenisecii in the literature. Objective of the study was to assess clinical effects with particular attention on psychoactive properties of P. foenisecii in case of accidental oral exposure. This observational case series is based on prospectively collected data on mushroom poisoning using a structured data collection form, and it was performed in seven poisons centres in Germany and Switzerland. Inclusion criteria were accidental ingestion of at least one cap of P. foenisecii identified by a mycologist, and a follow up of at least 4 hours. Nineteen cases met all inclusion criteria, and only children were involved with a mean age of 3 years. They ingested 1-2 mushrooms in 14 cases and 3-5 mushrooms in five cases. Three patients received a single dose of activated charcoal. Sixteen out of 19 cases did not develop any symptoms, 2/19 complained of minor abdominal discomfort. One child was temporarily mildly hyperactive, and this was the only patient observed in a hospital for 12 hours. None of the children showed signs of hallucinations. This multicentre study demonstrates that the typically small amounts of P. foenisecii ingested by children probably do not lead to clinically significant symptoms.

  5. Accidental poisoning in childhood: five year urban population study with 15 year analysis of fatality.

    PubMed Central

    Pearn, J; Nixon, J; Ansford, A; Corcoran, A

    1984-01-01

    Patterns of accidental poisoning in children are changing dramatically. A five year population study (1977-81) was undertaken in urban children from Brisbane (population 1 000 000). A total of 2098 children were poisoned during this period with only one fatality, which represents a dramatic reduction in mortality. Over the past 15 years (1968-82) 13 children have died from accidental poisoning from this population, and two were murdered with drugs. A study of secular trends has indicated that peak incidence occurred in 1979, and the rate has been falling progressively since. The current age corrected rate of poisoning is 393 per 100 000 children per year (0-5 year olds). The rank order of poisons, drugs, and chemicals causing hospital admission and death is: petroleum distillates 13%; antihistamines 9%; benzodiazepines 9%; bleach and detergents 7%; and aspirin 6%. The ratio of fatalities to ingestions requiring hospital admission was calculated to give an index of a practical danger of noxious agents to which children are currently exposed and the rank order is: cardiotoxic drugs, one fatality to 25 ingestions; tricyclic antidepressants, one to 44; sympathomimetic drugs, one to 54; caustic soda, one to 68; aspirin, one fatality to 350 ingestions. Accidental poisoning of children leading to death has been reduced because patterns of drug prescriptions have changed, packaging of dangerous drugs has been made safer, and substances such as kerosene have been coloured blue. PMID:6140065

  6. Initial Microstructure Evaluation of a U3Si2 + W Fuel Pin Fabricated Via Arc Melt Gravity Drop Casting

    NASA Astrophysics Data System (ADS)

    Hoggan, Rita E.; Harp, Jason M.

    2018-02-01

    Injection casting has historically been used to fabricate metallic nuclear fuel on a large scale. Casting of intermetallic fuel forms, such as U3Si2, may be an alternative pathway for fabrication of fuel pins to powder metallurgy. To investigate casting on a small scale, arc melt gravity drop casting was employed to cast a one-off pin of U3Si2 for evaluation as a fabrication method for U3Si2 as a light water reactor fuel. The pin was sectioned and examined via optical microscopy and scanning electron microscopy equipped with energy dispersive x-ray spectroscopy (EDS). Image analysis was used to estimate the volume fraction of phase impurities as well as porosity. The primary phase determined by EDS was U3Si2 with U-O and U-Si-W phase impurities. Unusually high levels of tungsten were observed because of accidental tungsten introduction during arc melting. No significant changes in microstructure were observed after annealing a section of the pin at 800°C for 72 h. The average density of the sectioned specimens was 12.4 g/cm3 measured via Archimedes principle immersion density and He gas displacement.

  7. Accidental Discovery of Information on the User-Defined Social Web: A Mixed-Method Study

    ERIC Educational Resources Information Center

    Lu, Chi-Jung

    2012-01-01

    Frequently interacting with other people or working in an information-rich environment can foster the "accidental discovery of information" (ADI) (Erdelez, 2000; McCay-Peet & Toms, 2010). With the increasing adoption of social web technologies, online user-participation communities and user-generated content have provided users the…

  8. PREVENTION REFERENCE MANUAL: CHEMICAL SPECIFIC. VOL. 15: CONTROL OF ACCIDENTAL RELEASES OF SULFUR TRIOXIDE

    EPA Science Inventory

    The report, discussing sulfur trioxide (SO3), is one of a series addressing the prevention of accidental releases of toxic chemicals. SO3, a clear oily liquid or solid at typical ambient conditions, has an Immediately Dangerous to Life and Health (IDLH) concentration of 20 ppm, w...

  9. SUMMARY OF ACCIDENTAL RELEASES OF RADIOACTIVITY DETECTED OFF THE NEVADA TEST SITE, 1963-1986

    EPA Science Inventory

    Of the more than 450 underground nuclear explosives tests conducted at the Nevada Test Site from August 1963 (signing of the Limited Test Ban Treaty) through the end of 1986, only 23 accidentally released radioactivity that was detectable beyond the boundary of the NTS. Of these ...

  10. Measurement of an Evaporating Drop on a Reflective Substrate

    NASA Technical Reports Server (NTRS)

    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. Creatin-kinase elevation after accidental ingestion of almotriptan in an 18-month-old girl.

    PubMed

    Castagno, E; Lupica, M; Viola, S; Savino, F; Miniero, R

    2014-02-01

    Few studies have been published to demonstrate tolerability and efficacy of almotriptan in adolescents and children with migraine, particularly in the first years of life, though preliminary results are favorable. We report the case of an 18-month-old infant with elevation of serum levels of creatin-kinase after the accidental ingestion of almotriptan. A previously healthy 18-month-old girl (weight: 13 kg) was admitted to our Department four hours after the accidental ingestion of 6.25 mg of almotriptan (0.48 mg/kg), without any specific symptom. The performed investigations showed high serum levels of creatin-kinase (CK) (527 IU/L; normal values: 24-170 IU/L). Transaminase, creatinine, aldolase, myoglobin and troponin T serum levels were normal. The electrocardiogram proved negative. Initial management consisted of parenteral rehydration with saline solution. CK levels lowered significantly at 12 hours (455 IU/L) and at 65 hours (188 IU/L) after the ingestion. No symptoms were observed before discharge and on follow-up.

  12. Dropping In a Microgravity Environment (DIME) Contest

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The first NASA Dropping In a Microgravity Environment (DIME) student competition pilot project came to a conclusion at the Glenn Research Center in April 2001. The competition involved high-school student teams who developed the concept for a microgravity experiment and prepared an experiment proposal. The two student teams - COSI Academy, sponsored by the Columbus Center of Science and Industry, and another team from Cincinnati, Ohio's Sycamore High School, designed a microgravity experiment, fabricated the experimental apparatus, and visited NASA Glenn to operate their experiment in the 2.2 Second Drop Tower. Sandi Thompson of the National Center for Microgravity Research GRC makes a final adjustment to the drop package. This image is from a digital still camera; higher resolution is not available.

  13. Dropping In a Microgravity Environment (DIME) contest

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The first NASA Dropping In a Microgravity Environment (DIME) student competition pilot project came to a conclusion at the Glenn Research Center in April 2001. The competition involved high-school student teams who developed the concept for a microgravity experiment and prepared an experiment proposal. The two student teams - COSI Academy, sponsored by the Columbus Center of Science and Industry, and another team from Cincinnati, Ohio's Sycamore High School, designed a microgravity experiment, fabricated the experimental apparatus, and visited NASA Glenn to operate their experiment in the 2.2 Second Drop Tower. Here, students are briefed by NASA engineer Daniel Dietrich at the top of the drop tower. This image is from a digital still camera; higher resolution is not available.

  14. Dropping In a Microgravity Environment (DIME) Contest

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The first NASA Dropping In a Microgravity Environment (DIME) student competition pilot project came to a conclusion at the Glenn Research Center in April 2001. The competition involved high-school student teams who developed the concept for a microgravity experiment and prepared an experiment proposal. The two student teams - COSI Academy, sponsored by the Columbus Center of Science and Industry, and another team from Cincinnati, Ohio's Sycamore High School, designed a microgravity experiment, fabricated the experimental apparatus, and visited NASA Glenn to operate their experiment in the 2.2 Second Drop Tower. Meredith Mendenhall of Sycamore High School, Cincinnati, Ohio, flips on a tape recorder in preparation for a drop. This image is from a digital still camera; higher resolution is not available.

  15. A deformable surface model for real-time water drop animation.

    PubMed

    Zhang, Yizhong; Wang, Huamin; Wang, Shuai; Tong, Yiying; Zhou, Kun

    2012-08-01

    A water drop behaves differently from a large water body because of its strong viscosity and surface tension under the small scale. Surface tension causes the motion of a water drop to be largely determined by its boundary surface. Meanwhile, viscosity makes the interior of a water drop less relevant to its motion, as the smooth velocity field can be well approximated by an interpolation of the velocity on the boundary. Consequently, we propose a fast deformable surface model to realistically animate water drops and their flowing behaviors on solid surfaces. Our system efficiently simulates water drop motions in a Lagrangian fashion, by reducing 3D fluid dynamics over the whole liquid volume to a deformable surface model. In each time step, the model uses an implicit mean curvature flow operator to produce surface tension effects, a contact angle operator to change droplet shapes on solid surfaces, and a set of mesh connectivity updates to handle topological changes and improve mesh quality over time. Our numerical experiments demonstrate a variety of physically plausible water drop phenomena at a real-time rate, including capillary waves when water drops collide, pinch-off of water jets, and droplets flowing over solid materials. The whole system performs orders-of-magnitude faster than existing simulation approaches that generate comparable water drop effects.

  16. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent and medicolegal issues.

    PubMed

    Cook, T M; Andrade, J; Bogod, D G; Hitchman, J M; Jonker, W R; Lucas, N; Mackay, J H; Nimmo, A F; O'Connor, K; O'Sullivan, E P; Paul, R G; Palmer, J H MacG; Plaat, F; Radcliffe, J J; Sury, M R J; Torevell, H E; Wang, M; Hainsworth, J; Pandit, J J

    2014-10-01

    The 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland into accidental awareness during general anaesthesia yielded data related to psychological aspects from the patient, and the anaesthetist, perspectives; patients' experiences ranged from isolated auditory or tactile sensations to complete awareness. A striking finding was that 75% of experiences were for < 5 min, yet 51% of patients (95% CI 43-60%) experienced distress and 41% (95% CI 33-50%) suffered longer-term adverse effect. Distress and longer-term harm occurred across the full range of experiences but were particularly likely when the patient experienced paralysis (with or without pain). The patient's interpretation of what is happening at the time of the awareness seemed central to later impact; explanation and reassurance during suspected accidental awareness during general anaesthesia or at the time of report seemed beneficial. Quality of care before the event was judged good in 26%, poor in 39% and mixed in 31%. Three quarters of cases of accidental awareness during general anaesthesia (75%) were judged preventable. In 12% of cases of accidental awareness during general anaesthesia, care was judged good and the episode not preventable. The contributory and human factors in the genesis of the majority of cases of accidental awareness during general anaesthesia included medication, patient and education/training. The findings have implications for national guidance, institutional organisation and individual practice. The incidence of 'accidental awareness' during sedation (~1:15 000) was similar to that during general anaesthesia (~1:19 000). The project raises significant issues about information giving and consent for both sedation and anaesthesia. We propose a novel approach to describing sedation from the patient's perspective which could be used in communication and consent. Eight (6%) of the patients had resorted

  17. Instrumentation and telemetry systems for free-flight drop model testing

    NASA Technical Reports Server (NTRS)

    Hyde, Charles R.; Massie, Jeffrey J.

    1993-01-01

    This paper presents instrumentation and telemetry system techniques used in free-flight research drop model testing at the NASA Langley Research Center. The free-flight drop model test technique is used to conduct flight dynamics research of high performance aircraft using dynamically scaled models. The free-flight drop model flight testing supplements research using computer analysis and wind tunnel testing. The drop models are scaled to approximately 20 percent of the size of the actual aircraft. This paper presents an introduction to the Free-Flight Drop Model Program which is followed by a description of the current instrumentation and telemetry systems used at the NASA Langley Research Center, Plum Tree Test Site. The paper describes three telemetry downlinks used to acquire the data, video, and radar tracking information from the model. Also described are two telemetry uplinks, one used to fly the model employing a ground-based flight control computer and a second to activate commands for visual tracking and parachute recovery of the model. The paper concludes with a discussion of free-flight drop model instrumentation and telemetry system development currently in progress for future drop model projects at the NASA Langley Research Center.

  18. Analysis of random drop for gateway congestion control. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Hashem, Emam Salaheddin

    1989-01-01

    Lately, the growing demand on the Internet has prompted the need for more effective congestion control policies. Currently No Gateway Policy is used to relieve and signal congestion, which leads to unfair service to the individual users and a degradation of overall network performance. Network simulation was used to illustrate the character of Internet congestion and its causes. A newly proposed gateway congestion control policy, called Random Drop, was considered as a promising solution to the pressing problem. Random Drop relieves resource congestion upon buffer overflow by choosing a random packet from the service queue to be dropped. The random choice should result in a drop distribution proportional to the bandwidth distribution among all contending TCP connections, thus applying the necessary fairness. Nonetheless, the simulation experiments demonstrate several shortcomings with this policy. Because Random Drop is a congestion control policy, which is not applied until congestion has already occurred, it usually results in a high drop rate that hurts too many connections including well-behaved ones. Even though the number of packets dropped is different from one connection to another depending on the buffer utilization upon overflow, the TCP recovery overhead is high enough to neutralize these differences, causing unfair congestion penalties. Besides, the drop distribution itself is an inaccurate representation of the average bandwidth distribution, missing much important information about the bandwidth utilization between buffer overflow events. A modification of Random Drop to do congestion avoidance by applying the policy early was also proposed. Early Random Drop has the advantage of avoiding the high drop rate of buffer overflow. The early application of the policy removes the pressure of congestion relief and allows more accurate signaling of congestion. To be used effectively, algorithms for the dynamic adjustment of the parameters of Early Random Drop

  19. Drop Fragmentation at Impact onto a Bath of an Immiscible Liquid

    NASA Astrophysics Data System (ADS)

    Lhuissier, H.; Sun, C.; Prosperetti, A.; Lohse, D.

    2013-06-01

    The impact of a drop onto a deep bath of an immiscible liquid is studied with emphasis on the drop fragmentation into a collection of noncoalescing daughter drops. At impact the drop flattens and spreads at the surface of the crater it transiently opens in the bath and reaches a maximum deformation, which gets larger with increasing impact velocity, before surface tension drives its recession. This recession can promote the fragmentation by two different mechanisms: At moderate impact velocity, the drop recession converges to the axis of symmetry to form a jet which then fragments by a Plateau-Rayleigh mechanism. At higher velocity the edge of the receding drop destabilizes and shapes into radial ligaments which subsequently fragment. For this latter mechanism the number N∝We3 and the size distribution of the daughter drops p(d)∝d-4 as a function of the impact Weber number We are explained on the basis of the observed spreading of the drop. The universality of this model for the fragmentation of receding liquid sheets might be relevant for other configurations.

  20. Successful Thrombolysis and Spasmolysis of Acute Leg Ischemia after Accidental Intra-arterial Injection of Dissolved Flunitrazepam Tablets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Radeleff, B., E-mail: Boris_radeleff@med.uni-heidelberg.de; Stampfl, U.; Sommer, C.-M.

    2011-10-15

    A 37-year-old man with known intravenous drug abuse presented in the surgical ambulatory care unit with acute leg ischemia after accidental intra-arterial injection of dissolved flunitrazepam tablets into the right femoral artery. A combination of anticoagulation, vasodilatation, and local selective and superselective thrombolysis with urokinase was performed to salvage the leg. As a result of the severe ischemia-induced pain, the patient had to be monitored over the complete therapy period on the intensive care unit with permanent administration of intravenous fluid and analgetics. We describe the presenting symptoms and the interventional technique, and we discuss the recent literature regarding themore » management of accidental intra-arterial injection of dissolved flunitrazepam tablets.« less

  1. Queues with Dropping Functions and General Arrival Processes

    PubMed Central

    Chydzinski, Andrzej; Mrozowski, Pawel

    2016-01-01

    In a queueing system with the dropping function the arriving customer can be denied service (dropped) with the probability that is a function of the queue length at the time of arrival of this customer. The potential applicability of such mechanism is very wide due to the fact that by choosing the shape of this function one can easily manipulate several performance characteristics of the queueing system. In this paper we carry out analysis of the queueing system with the dropping function and a very general model of arrival process—the model which includes batch arrivals and the interarrival time autocorrelation, and allows for fitting the actual shape of the interarrival time distribution and its moments. For such a system we obtain formulas for the distribution of the queue length and the overall customer loss ratio. The analytical results are accompanied with numerical examples computed for several dropping functions. PMID:26943171

  2. 75 FR 31288 - Plant-Verified Drop Shipment (PVDS)-Nonpostal Documentation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-03

    ... POSTAL SERVICE 39 CFR Part 111 Plant-Verified Drop Shipment (PVDS)--Nonpostal Documentation AGENCY... 8125, Plant-Verified Drop Shipment (PVDS) Verification and Clearance, is the sole source of evidence... induction points of plant-verified drop shipment mailings, the Postal Service is adopting this final rule to...

  3. Acoustically levitated dancing drops: Self-excited oscillation to chaotic shedding.

    PubMed

    Lin, Po-Cheng; I, Lin

    2016-02-01

    We experimentally demonstrate self-excited oscillation and shedding of millimeter-sized water drops, acoustically levitated in a single-node standing waves cavity, by decreasing the steady acoustic wave intensity below a threshold. The perturbation of the acoustic field by drop motion is a possible source for providing an effective negative damping for sustaining the growing amplitude of the self-excited motion. Its further interplay with surface tension, drop inertia, gravity and acoustic intensities, select various self-excited modes for different size of drops and acoustic intensity. The large drop exhibits quasiperiodic motion from a vertical mode and a zonal mode with growing coupling, as oscillation amplitudes grow, until falling on the floor. For small drops, chaotic oscillations constituted by several broadened sectorial modes and corresponding zonal modes are self-excited. The growing oscillation amplitude leads to droplet shedding from the edges of highly stretched lobes, where surface tension no longer holds the rapid expanding flow.

  4. Acoustically levitated dancing drops: Self-excited oscillation to chaotic shedding

    NASA Astrophysics Data System (ADS)

    Lin, Po-Cheng; I, Lin

    2016-02-01

    We experimentally demonstrate self-excited oscillation and shedding of millimeter-sized water drops, acoustically levitated in a single-node standing waves cavity, by decreasing the steady acoustic wave intensity below a threshold. The perturbation of the acoustic field by drop motion is a possible source for providing an effective negative damping for sustaining the growing amplitude of the self-excited motion. Its further interplay with surface tension, drop inertia, gravity and acoustic intensities, select various self-excited modes for different size of drops and acoustic intensity. The large drop exhibits quasiperiodic motion from a vertical mode and a zonal mode with growing coupling, as oscillation amplitudes grow, until falling on the floor. For small drops, chaotic oscillations constituted by several broadened sectorial modes and corresponding zonal modes are self-excited. The growing oscillation amplitude leads to droplet shedding from the edges of highly stretched lobes, where surface tension no longer holds the rapid expanding flow.

  5. Clinical perspectives on osteogenesis imperfecta versus non-accidental injury.

    PubMed

    Pereira, Elaine Maria

    2015-12-01

    Although non-accidental injuries (NAI) are more common in cases of unexplained fractures than rare disorders such as osteogenesis imperfecta (OI), ruling out OI and other medical causes of fracture is always indicated. The majority of OI patients can be diagnosed with the help of family history, physical examination, and radiographic findings. In particular, there are a few radiological findings which are seen more commonly in NAI than in OI which may help guide clinician considerations regarding the probability of either of these diagnoses. At the same time, molecular testing still merits careful consideration in cases with unexplained fractures without obvious additional signs of abuse. © 2015 Wiley Periodicals, Inc.

  6. Effect of a multi-level education intervention model on knowledge and attitudes of accidental injuries in rural children in Zunyi, Southwest China.

    PubMed

    Cao, Bo-Ling; Shi, Xiu-Quan; Qi, Yong-Hong; Hui, Ya; Yang, Hua-Jun; Shi, Shang-Peng; Luo, Li-Rong; Zhang, Hong; Wang, Xin; Yang, Ying-Ping

    2015-04-08

    To explore the effect of a school-family-individual (SFI) multi-level education intervention model on knowledge and attitudes about accidental injuries among school-aged children to improve injury prevention strategies and reduce the incidence of pediatric injuries. The random sample of rural school-aged children were recruited by using a multistage, stratified, cluster sampling method in Zunyi, Southwest China from 2012 to 2014, and 2342 children were randomly divided into intervention and control groups. Then children answered a baseline survey to collect knowledge and attitude scores (KAS) of accidental injuries. In the intervention group, children, their parents/guardians and the school received a SFI multi-level education intervention, which included a children's injury-prevention poster at schools, an open letter about security instruction for parents/guardians and multiple-media health education (Microsoft PowerPoint lectures, videos, handbooks, etc.) to children. Children in the control group were given only handbook education. After 16 months, children answered a follow-up survey to collect data on accidental injury types and accidental injury-related KAS for comparing the intervention and control groups and baseline and follow-up data. The distribution of gender was not significantly different while age was different between the baseline and follow-up survey. At baseline, the mean KAS was lower for the intervention than control group (15.37 ± 3.40 and 18.35 ± 5.01; p < 0.001). At follow-up, the mean KAS was higher for the intervention than control group (21.16 ± 3.05 and 20.02 ± 3.40; p < 0.001). The increase in KAS in the intervention and control groups was significant (p < 0.001; KAS: 5.79 vs. 1.67) and suggested that children's injury-related KAS improved in the intervention group. Moreover, the KAS between the groups differed for most subtypes of incidental injuries (based on International Classification of Diseases 10, ICD-10) (p < 0.05). Before

  7. [Study on occupational safety climate in different types of enterprises and its relationship with occupational accidental injury].

    PubMed

    Liu, Xinxia; Huang, Guoxian; Wang, Shuyu; Guo, Zhiping; Zhou, Yuchao; Chen, Weiqing

    2014-04-01

    To evaluate the occupational safety climate in different types of enterprises and its relationship with occupational accidental injury. A cross-sectional survey based on self-report questionnaires was performed among 3311 front-line workers from 54 medium and small-sized manufacturing enterprises of different types in Zhongshan, China to investigate the socio-demographic characteristics, safety climate experience in workplace, and incidence of occupational accidental injury in the past year. Analysis of the data revealed that employees in different types of companies perceived different levels of safety climate, according to the scores on four subscales; the European and American enterprises had significantly better safety climate than the Hong Kong and Chinese private enterprises (P < 0.01). The self-reported rates of occupational injury were 3.38%, 4.76%, and 6.72%, respectively, for European and American, Hong Kong, and Chinese private enterprises (χ(2) = 6.78, P < 0.05). After control of such factors as age, sex, income, education level, and marriage, the logistic regression analysis showed that the risk of occupational accidental injury in the European and American enterprises was significantly lower than that in the Chinese private enterprises (OR = 0.57, 95%CI = 0.35-0.91). The type of enterprise influences the occupational safety climate and incidence of occupational injury among workers.

  8. Optimizing Decision Preparedness by Adapting Scenario Complexity and Automating Scenario Generation

    NASA Technical Reports Server (NTRS)

    Dunne, Rob; Schatz, Sae; Flore, Stephen M.; Nicholson, Denise

    2011-01-01

    Klein's recognition-primed decision (RPD) framework proposes that experts make decisions by recognizing similarities between current decision situations and previous decision experiences. Unfortunately, military personnel arQ often presented with situations that they have not experienced before. Scenario-based training (S8T) can help mitigate this gap. However, SBT remains a challenging and inefficient training approach. To address these limitations, the authors present an innovative formulation of scenario complexity that contributes to the larger research goal of developing an automated scenario generation system. This system will enable trainees to effectively advance through a variety of increasingly complex decision situations and experiences. By adapting scenario complexities and automating generation, trainees will be provided with a greater variety of appropriately calibrated training events, thus broadening their repositories of experience. Preliminary results from empirical testing (N=24) of the proof-of-concept formula are presented, and future avenues of scenario complexity research are also discussed.

  9. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Lock, electric, forced drop. 236.758 Section 236.758 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically...

  10. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Lock, electric, forced drop. 236.758 Section 236.758 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically...

  11. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Lock, electric, forced drop. 236.758 Section 236.758 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically...

  12. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric, forced drop. 236.758 Section 236.758 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is mechanically...

  13. Dancing drops over vibrating substrates

    NASA Astrophysics Data System (ADS)

    Borcia, Rodica; Borcia, Ion Dan; Helbig, Markus; Meier, Martin; Egbers, Christoph; Bestehorn, Michael

    2017-04-01

    We study the motion of a liquid drop on a solid plate simultaneously submitted to horizontal and vertical harmonic vibrations. The investigation is done via a phase field model earlier developed for describing static and dynamic contact angles. The density field is nearly constant in every bulk region (ρ = 1 in the liquid phase, ρ ≈ 0 in the vapor phase) and varies continuously from one phase to the other with a rapid but smooth variation across the interfaces. Complicated explicit boundary conditions along the interface are avoided and captured implicitly by gradient terms of ρ in the hydrodynamic basic equations. The contact angle θ is controlled through the density at the solid substrate ρ S , a free parameter varying between 0 and 1 [R. Borcia, I.D. Borcia, M. Bestehorn, Phys. Rev. E 78, 066307 (2008)]. We emphasize the swaying and the spreading modes, earlier theoretically identified by Benilov and Billingham via a shallow-water model for drops climbing uphill along an inclined plane oscillating vertically [E.S. Benilov, J. Billingham, J. Fluid Mech. 674, 93 (2011)]. The numerical phase field simulations will be completed by experiments. Some ways to prevent the release of the dancing drops along a hydrophobic surface into the gas atmosphere are also discussed in this paper.

  14. La Gocciolina (The Little Drop of Water).

    ERIC Educational Resources Information Center

    Palandra, Maria

    This primary level reader in Italian intended for use in a bilingual education setting, is about the life cycle of a drop of water. The drop of water is personified and the story tells of its adventures as it travels from the top of the lake to the bottom, its meeting with the inhabitants of the lake, and its trip to the clouds. After deciding not…

  15. Thermally driven oscillations and wave motion of a liquid drop

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Hendricks, R. C.; Schoessow, G. J.

    1977-01-01

    In the state of Leidenfrost boiling, liquid drops are observed to vibrate in a variety of modal patterns. Theories are presented which predict the frequency of oscillation and show that the observed modal patterns of drops correspond to the minimum energy oscillatory excitation state. High-speed photographic techniques were used to record these motions and substantiate the theories. An incipient temperature was also found for water drops in film boiling below which free oscillations do not exist. In addition to these oscillations, photographic sequences are presented which show that wave motion can exist along the circumference of the drop. Following the study of free oscillations, the system was mounted on a shaker table and the drop subjected to a range of forced frequencies and accelerations.

  16. Thermally Driven Oscillations and Wave Motion of a Liquid Drop

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Hendricks, R. C.; Schoessow, G. J.

    1977-01-01

    In the state of Leidenfrost boiling, liquid drops are observed to vibrate in a variety of modal patterns. Theories are presented which predict the frequency of oscillation and show that the observed model patterns of drops correspond to the minimum energy oscillatory excitation state. High-speed photographic techniques were used to record these motions and substantiate the theories. An incipient temperature was also found for water drops in film boiling below which free oscillations do not exist. In addition to these oscillations, photographic sequences are presented which show that wave motion can exist along the circumference of the drop. Following the study of free oscillations, the system was mounted on a shaker table and the drop subjected to a range of forced frequencies and accelerations.

  17. Drop impact on thin liquid films using TIRM

    NASA Astrophysics Data System (ADS)

    Pack, Min; Ying Sun Team

    2015-11-01

    Drop impact on thin liquid films is relevant to a number of industrial processes such as pesticide spraying and repellent surface research such as self-cleaning applications. In this study, we systematically investigate the drop impact dynamics on thin liquid films on plain glass substrates by varying the film thickness, viscosity and impact velocity. High speed imaging is used to track the droplet morphology and trajectory over time as well as observing instability developments at high Weber number impacts. Moreover, the air layer between the drop and thin film upon drop impact is probed by total internal reflection microscopy (TIRM) where the grayscale intensity is used to measure the air layer thickness and spreading radius over time. For low We impact on thick films (We ~ 10), the effect of the air entrainment is pronounced where the adhesion of the droplet to the wall is delayed by the air depletion and liquid film drainage, whereas for high We impact (We >100) the air layer is no longer formed and instead, the drop contact with the wall is limited only to the film drainage for all film thicknesses. In addition, the maximum spreading radius of the droplet is analyzed for varying thin film thickness and viscosity.

  18. When a water drop freezes before it solidifies

    NASA Astrophysics Data System (ADS)

    Kavehpour, Pirouz; Davis, Stephen; Tavakoli, Faryar

    2012-11-01

    When a drop of liquid is placed on a substrate which temperature is below the melting point of the liquid, one would expect the drop to solidify instantaneously. However, many liquids, such as water, must be subcooled to solidify below its melting temperature due to homogeneous nucleation's high activation energy. Most of the drop solidification research, particularly for water, phase change is assumed to occur at equilibrium freezing temperature; however, this is not the case. We found that after a certain degree of supercooling, a kinetic based nucleation begins and latent heat of fusion is suddenly liberated, causing an increase in liquid temperature. At the end of this stage, approximately 20% of the drop is crystallized. This phenomenon is known among metallurgists as recalescence. This is followed by a slow solidification process at the melting point. As a water droplet spreads on a cold substrate, its contact line stops just prior to freezing inception from the liquid-solid interface. In this study, we assert that recalescence prior to solidification may be the cause of water's sudden immobility, which results in a fixed contact angle and droplet diameter. In our experiments, the nucleation front initiates from the trijunction point and propagates to the drop volume.

  19. Role of Structural Asymmetry in Controlling Drop Spacing in Microfluidic Ladder Networks

    NASA Astrophysics Data System (ADS)

    Wang, William; Maddala, Jeevan; Vanapalli, Siva; Rengasamy, Raghunathan

    2012-02-01

    Manipulation of drop spacing is crucial to many processes in microfluidic devices including drop coalescence, detection and storage. Microfluidic ladder networks ---where two droplet-carrying parallel channels are connected by narrow bypass channels through which the motion of drops is forbidden---have been proposed as a means to control relative separation between pairs of drops. Prior studies in microfluidic ladder networks with vertical bypasses, which possess fore-aft structural symmetry, have revealed that pairs of drops can only undergo reduction in drop spacing at the ladder exit. We investigate the dynamics of drops in microfluidic ladder networks with both vertical and slanted bypasses. Our analytical results indicate that unlike symmetric ladder networks, structural asymmetry introduced by a single slanted bypass can be used to modulate the relative spacing between drops, enabling them to contract, synchronize, expand or even flip at the ladder exit. Our experiments confirm all the behaviors predicted by theory. Numerical analysis further shows that ladders containing several identical bypasses can only linearly transform the input drop spacing. Finally, we find that ladders with specific combinations of vertical and slanted bypasses can generate non-linear transformation of input drop spacing, despite the absence of drop decision-making events at the bypass junctions.

  20. Dropping In a Microgravity Environment (DIME) contest

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The first NASA Dropping In a Microgravity Environment (DIME) student competition pilot project came to a conclusion at the Glenn Research Center in April 2001. The competition involved high-school student teams who developed the concept for a microgravity experiment and prepared an experiment proposal. The two student teams - COSI Academy, sponsored by the Columbus Center of Science and Industry, and another team from Cincinnati, Ohio's Sycamore High School, designed a microgravity experiment, fabricated the experimental apparatus, and visited NASA Glenn to operate their experiment in the 2.2 Second Drop Tower. Here students from Sycamore High School in Cincinnati, Ohio, talk with Dr. Dennis Stocker, one of Glenn's lead microgravity scientists, about the uses of the drop tower. This image is from a digital still camera; higher resolution is not available.