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Sample records for retards dna breakdown

  1. Sequence-influenced interactions of oligoacridines with DNA detected by retarded gel electrophorectic migrations

    International Nuclear Information System (INIS)

    Nielsen, P.E.; Zhen, W.; Henriksen, U.; Buchardt, O.

    1988-01-01

    The authors have found that di-, tri-, tetra-, and hexa-9-acridinylamines are so efficiently associated with DNA during electrophoresis in polyacrylamide or agarose gels that they retard its migration. The retardation is roughly proportional to the reagent to base pair ratio, and the magnitude of the retardation indicates that a combined charge neutralization/helix extension mechanism is mainly responsible for the effect. Furthermore, DNA sequence dependent differences are observed. Thus, the pUC 19 restriction fragments (HaeIII or AluI), which in the native state comigrate upon gel electrophoretic analysis, could be separated in the presence of a diacridine, and specific DNA fragments responded differently to different diacridines. These results suggest that the effect also is due to a contribution from the DNA conformation and that the DNA conformation dynamics are influenced differently upon binding of different diacridines. They foresee three applications of this observation: (1) in analytical gel electrophoretic separation of otherwise comigrating DNA molecules, (2) in studies of polyintercalator-DNA interaction, and (3) in measurements of polyintercalator-induced DNA unwinding

  2. Mitotic effects of monochromatic ultraviolet radiation at 225, 265, and 280 nm on eleven stages of the cell cycle of the grasshopper neuroblast in culture. I. Overall retardation from the stage irradiated to nuclear membrane breakdown

    International Nuclear Information System (INIS)

    Carlson, J.G.

    1976-01-01

    Neuroblasts of Chortophaga viridifasciata (DeGeer) in culture were exposed to different doses of 225, 265, or 280 nm ultraviolet radiations at 11 different stages and substages of the mitotic cycle and individually selected cells were timed to breakdown of the nuclear membrane. Comparisons of the effectiveness of different wavelengths on the different stages were based on the dose that reduced the cell progression rate to 67 percent of normal (D 67 ) and the slope of the regression line, i.e., the control to treated time (C/T) ratio change/erg/mm 2 at the D 67 level. Cells of the prereplication period (metaphase + anaphase + early telophase) and the S phase (middle and late telophase + interphase + very early prophase) are equally sensitive to uv and contrast sharply with the much lower sensitivity of those in the postreplication period (early and middle prophase). This can best be interpreted if chromosomal DNA is the chromophore for uv-induced mitotic retardation. Cells in the prereplication period at exposure show no wavelength effect. In the S phase all stages except middle telophase and all stages combined are significantly more sensitive to 265 and 280 nm than to 225 nm. Of the postreplication stages, early prophase is retarded significantly more by 280 than by 225 or 265 nm. The C/T ratio/erg/mm 2 is greater after exposure to 265 nm at all prereplication and replication stages, but exhibits no consistent wavelength pattern during the postreplication period. Evidence based on the orientation of the neuroblast with respect to the uv-source suggests that the chromophore for mitotic retardation does not reside within the centrosome and related structures, but may be present, at least partly, in the nucleolus

  3. Retardation of experimental tumorigenesis and reduction in DNA adducts by turmeric and curcumin.

    Science.gov (United States)

    Krishnaswamy, K; Goud, V K; Sesikeran, B; Mukundan, M A; Krishna, T P

    1998-01-01

    Turmeric and its active principle curcumin have been extensively investigated for their antimutagenic and antioxidant effects in bacterial and animal systems. Because oral cancers are common in India, an experimental model of 7,12-dimethylbenzanthracene-induced buccal pouch tumors in Syrian Golden hamsters was used to evaluate the tumor retardation effects of turmeric and curcumin. Turmeric and/or curcumin was administered in the diet and/or applied locally for 14 weeks along with 7,12-dimethylbenzanthracene. After the experimental period, the animals were sacrificed and oral pouches were examined for tumor number and size. DNA adducts were estimated by 32P postlabel assay in the cheek pouches. Neoplastic changes were graded by histopathology. The results of the study suggest that turmeric or curcumin in the diet and/or applied locally significantly reduced DNA adducts at the target site. Tumor number and tumor burden were significantly lower (p curcumin (p curcumin administered in the diet or applied as paint may have a plausible chemopreventive effect on oral precancerous lesions.

  4. Fish DNA-modified clays: Towards highly flame retardant polymer nanocomposite with improved interfacial and mechanical performance

    Science.gov (United States)

    Zabihi, Omid; Ahmadi, Mojtaba; Khayyam, Hamid; Naebe, Minoo

    2016-12-01

    Deoxyribonucleic Acid (DNA) has been recently found to be an efficient renewable and environmentally-friendly flame retardant. In this work, for the first time, we have used waste DNA from fishing industry to modify clay structure in order to increase the clay interactions with epoxy resin and take benefit of its additional thermal property effect on thermo-physical properties of epoxy-clay nanocomposites. Intercalation of DNA within the clay layers was accomplished in a one-step approach confirmed by FT-IR, XPS, TGA, and XRD analyses, indicating that d-space of clay layers was expanded from ~1.2 nm for pristine clay to ~1.9 nm for clay modified with DNA (d-clay). Compared to epoxy nanocomposite containing 2.5%wt of Nanomer I.28E organoclay (m-clay), it was found that at 2.5%wt d-clay loading, significant enhancements of ~14%, ~6% and ~26% in tensile strength, tensile modulus, and fracture toughness of epoxy nanocomposite can be achieved, respectively. Effect of DNA as clay modifier on thermal performance of epoxy nanocomposite containing 2.5%wt d-clay was evaluated using TGA and cone calorimetry analysis, revealing significant decreases of ~4000 kJ/m2 and ~78 kW/m2 in total heat release and peak of heat release rate, respectively, in comparison to that containing 2.5%wt of m-clay.

  5. Preliminary studies on DNA retardation by MutS applied to the detection of point mutations in clinical samples

    International Nuclear Information System (INIS)

    Stanislawska-Sachadyn, Anna; Paszko, Zygmunt; Kluska, Anna; Skasko, Elzibieta; Sromek, Maria; Balabas, Aneta; Janiec-Jankowska, Aneta; Wisniewska, Alicja; Kur, Jozef; Sachadyn, Pawel

    2005-01-01

    MutS ability to bind DNA mismatches was applied to the detection of point mutations in PCR products. MutS recognized mismatches from single up to five nucleotides and retarded the electrophoretic migration of mismatched DNA. The electrophoretic detection of insertions/deletions above three nucleotides is also possible without MutS, thanks to the DNA mobility shift caused by the presence of large insertion/deletion loops in the heteroduplex DNA. Thus, the method enables the search for a broad range of mutations: from single up to several nucleotides. The mobility shift assays were carried out in polyacrylamide gels stained with SYBR-Gold. One assay required 50-200 ng of PCR product and 1-3 μg of Thermus thermophilus his 6 -MutS protein. The advantages of this approach are: the small amounts of DNA required for the examination, simple and fast staining, no demand for PCR product purification, no labelling and radioisotopes required. The method was tested in the detection of cancer predisposing mutations in RET, hMSH2, hMLH1, BRCA1, BRCA2 and NBS1 genes. The approach appears to be promising in screening for unknown point mutations

  6. Loss of p53 induces M-phase retardation following G2 DNA damage checkpoint abrogation.

    Science.gov (United States)

    Minemoto, Yuzuru; Uchida, Sanae; Ohtsubo, Motoaki; Shimura, Mari; Sasagawa, Toshiyuki; Hirata, Masato; Nakagama, Hitoshi; Ishizaka, Yukihito; Yamashita, Katsumi

    2003-04-01

    Most cell lines that lack functional p53 protein are arrested in the G2 phase of the cell cycle due to DNA damage. When the G2 checkpoint is abrogated, these cells are forced into mitotic catastrophe. A549 lung adenocarcinoma cells, in which p53 was eliminated with the HPV16 E6 gene, exhibited efficient arrest in the G2 phase when treated with adriamycin. Administration of caffeine to G2-arrested cells induced a drastic change in cell phenotype, the nature of which depended on the status of p53. Flow cytometric and microscopic observations revealed that cells that either contained or lacked p53 resumed their cell cycles and entered mitosis upon caffeine treatment. However, transit to the M phase was slower in p53-negative cells than in p53-positive cells. Consistent with these observations, CDK1 activity was maintained at high levels, along with stable cyclin B1, in p53-negative cells. The addition of butyrolactone I, which is an inhibitor of CDK1 and CDK2, to the p53-negative cells reduced the floating round cell population and induced the disappearance of cyclin B1. These results suggest a relationship between the p53 pathway and the ubiquitin-mediated degradation of mitotic cyclins and possible cross-talk between the G2-DNA damage checkpoint and the mitotic checkpoint.

  7. Isolation of anonymous DNA sequences from within a submicroscopic X chromosomal deletion in a patient with choroideremia, deafness, and mental retardation

    International Nuclear Information System (INIS)

    Nussbaum, R.L.; Lesko, J.G.; Lewis, R.A.; Ledbetter, S.A.; Ledbetter, D.H.

    1987-01-01

    Choroideremia, an X-chromosome linked retinal dystrophy of unknown pathogenesis, causes progressive nightblindness and eventual central blindness in affected males by the third to fourth decade of life. Choroideremia has been mapped to Xq13-21 by tight linkage to restriction fragment length polymorphism loci. The authors have recently identified two families in which choroideremia is inherited with mental retardation and deafness. In family XL-62, an interstitial deletion Xq21 is visible by cytogenetic analysis and two linked anonymous DNA markers, DXYS1 and DXS72, are deleted. In the second family, XL-45, an interstitial deletion was suspected on phenotypic grounds but could not be confirmed by high-resolution cytogenetic analysis. They used phenol-enhanced reassociation of 48,XXXX DNA in competition with excess XL-45 DNA to generate a library of cloned DNA enriched for sequences that might be deleted in XL-45. Two of the first 83 sequences characterized from the library were found to be deleted in probands from family XL-45 as well as from family XL-62. Isolation of these sequences proves that XL-45 does contain a submicroscopic deletion and provides a starting point for identifying overlapping genomic sequences that span the XL-45 deletion. Each overlapping sequence will be studied to identify exons from the choroideremia locus

  8. Experimental intrauterine growth retardation.

    Science.gov (United States)

    van Marthens, E; Harel, S; Zamenshof, S

    1975-01-01

    The effects of experimental intrauterine growth retardation on subsequent fetal development, especially with respect to brain development, were studied in a new animal model. The rabbit was chosen since it has a perinatal pattern of brain development similar to that of the human. Experimental ischemia was induced during the last trimester by ligation of spiral arterioles and the differential effects on fetal development at term (30th gestational day) are reported. Specific brain regions were examined for wet weight, total cell number (DNA) and total protein content. Highly significant decreases in all these parameters were found in both the cortex and cerebellum following experimental intrauterine growth retardation; these two organs were differentially affected. The prospects and advantages of using this animal model for the study of the postnatal "catch-up growth" are discussed.

  9. AC BREAKDOWN IN GASES

    Science.gov (United States)

    electron- emission (multipactor) region, and (3) the low-frequency region. The breakdown mechanism in each of these regions is explained. An extensive bibliography on AC breakdown in gases is included.

  10. High frequency breakdown voltage

    International Nuclear Information System (INIS)

    Chu, Thanh Duy.

    1992-03-01

    This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O degrees C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f c , the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f ce , is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions' concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance

  11. Rational design and evolutional fine tuning of Saccharomyces cerevisiae for biomass breakdown.

    Science.gov (United States)

    Hasunuma, Tomohisa; Ishii, Jun; Kondo, Akihiko

    2015-12-01

    Conferring biomass hydrolysis activity on yeast through genetic engineering has paved the way for the development of groundbreaking processes for producing liquid fuels and commodity chemicals from lignocellulosic biomass. However, the overproduction and misfolding of heterologous and endogenous proteins can trigger cellular stress, increasing the metabolic burden and retarding growth. Improving the efficiency of lignocellulosic breakdown requires engineering of yeast secretory pathway based on system-wide metabolic analysis as well as DNA constructs for enhanced cellulase gene expression with advanced molecular biology tools. Also, yeast is subjected to severe stress due to toxic compounds generated during lignocellulose pretreatment in consolidated saccharification and fermentation processes. The prospect for development of robust yeast strains makes combining evolutionary and rational engineering strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. On dielectric breakdown statistics

    International Nuclear Information System (INIS)

    Tuncer, Enis; James, D Randy; Sauers, Isidor; Ellis, Alvin R; Pace, Marshall O

    2006-01-01

    In this paper, we investigate the dielectric breakdown data of some insulating materials and focus on the applicability of the two- and three-parameter Weibull distributions. A new distribution function is also proposed. In order to assess the model distribution's trustworthiness, we employ the Monte Carlo technique and, randomly selecting data-subsets from the whole dielectric breakdown data, determine whether the selected probability functions accurately describe the breakdown data. The utility and strength of the proposed expression are illustrated distinctly by the numerical procedure. The proposed expression is shown to be a valuable alternative to the Weibull ones

  13. Product Work Breakdown Structure

    National Research Council Canada - National Science Library

    Okayama, Y; Chirillo, L. D

    1980-01-01

    .... Any such subdivision scheme is a work breakdown structure. Traditional shipbuilders employ work subdivisions by ships functional systems which are natural and appropriate for estimating and for early design stages...

  14. Electrical breakdown in vacuum

    International Nuclear Information System (INIS)

    Beukema, G.P.

    1980-01-01

    The main part of this thesis is dedicated to the field enhancement factor; in particular to the study of the origin, alteration and influence on the breakdown properties of different materials. This work required the examination of large surface areas on the same microscopic scale on which the relevant phenomena occur. (Pre)-breakdown measurements are described in which the anode condition does not play a role in the initiation of a breakdown, while the cathode can be considered as a broad-area electrode. The influence of adsorbed gases on pre-breakdown currents is investigated. It is shown that ions, released by field emission electrons from adsorbed layers on the anode change the emitting properties of a well-conditioned cathode if the current density at the anode is small. A new experimental arrangement is outlined to better distinguish between the different parameters which are important for the initiation of electrical breakdown. Comparative measurements between stainless steel and titanium electrodes are described to study the influence of either the cathode or the anode upon the initiation of a breakdown. (Auth.)

  15. Impulse breakdown of liquids

    CERN Document Server

    Ushakov, Vasily Y

    2007-01-01

    The book describes the main physical processes and phenomena in pulsed electric breakdown. The knowledge and the control of the electric breakdown of liquids is important not only for the insulation inside power systems but it is also used for the creation and information of high voltage and high current pulses. Such high-voltage micro- and nanosecond pulses find wide application in experimental physics, electro discharge technology, physics of dielectrics, radar detection and ranging, high-speed photography. The nature of charge carriers, mechanism of formation and evolution of the gas phase,

  16. Beauty in the Breakdown

    Science.gov (United States)

    Brisco, Nicole

    2008-01-01

    Most human beings look at erosion as the destruction of a surface, but artists can see that erosion often creates indefinable beauty. Where do you see beauty in the breakdown? In this article, the author presents an innovative lesson that would allow students to observe both human and physical nature. In this activity students will create a work…

  17. Fire retardant formulations

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to compositions where a substrate is liable to catch fire such as bituminous products, paints, carpets or the like. The invention relates to a composition comprising 40-95 weight % of a substrate to be rendered fire resistant such as bituminous material or paint......, carpets which substrate is mixed with 5-60 weight % of a fire retardant component. The invention relates to a fire retardant component comprising or being constituted of attapulgite, and a salt being a source of a blowing or expanding agent, where the attapulgite and the salt are electrostatically...... connected by mixing and subjecting the mixture of the two components to agitation. Also, the invention relates to compositions comprising 40-95 weight % of a substrate to be rendered fire resistant mixed with 5-60 weight % of a fire retardant according to claim 1 or 2, which fire retardant component...

  18. Fire retardant polyisocyanurate foam

    Science.gov (United States)

    Riccitiello, S. R.; Parker, J. A.

    1972-01-01

    Fire retardant properties of low density polymer foam are increased. Foam has pendant nitrile groups which form thermally-stable heterocyclic structures at temperature below degradation temperature of urethane linkages.

  19. Radiation and mental retardation

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1988-01-01

    A brief article discusses mental retardation in children who had been exposed to ionizing radiation in utero. The time of greatest sensitivity is between the 8th and 15th week after conception and the time of lesser sensitivity between the 16th and 25th weeks. An examination of the thresholds for exposure indicate that severe mental retardation would not result from any present environmental exposures of the public. (U.K.)

  20. Gas breakdown in tokamaks

    International Nuclear Information System (INIS)

    Abramov, V.A.; Pogutse, O.P.; Yurchenko, Eh.I.

    1975-01-01

    The initial stage of the charge development in a tokomak is considered theoretically. It is supposed that all electrons produced in neutral gas ionisation process are in the regime of an almost continuous acceleration. The production time of a given electron density is calculated as a function of the neutral gas density and of parameters of the vortex electric field. The mechanism of plasma escape on walls is considered. It is shown that the escaping time is defined by a specific inertial flow of plasma and depends on whether chamber walls are metal or dielectric. The criterion of the gas breakdown in a toroidal system is formulated. The developed theory is shown to explain a strong dependence of the breakdown on the gas initial density [ru

  1. PHENIX Work Breakdown Structure

    International Nuclear Information System (INIS)

    1994-02-01

    The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds are shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M ampersand S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M ampersand S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry

  2. Epidemiology of Mental Retardation.

    Science.gov (United States)

    Heber, Rick

    Prevalence data on mental retardation is presented including international estimates on general prevalence, age directions, geographical variations within the United States, racial and ethnic variations, economic class distributions, family variations, and population distribution in institutions. Statistics are also provided in areas of specific…

  3. Breakdowns in collaborative information seeking

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2010-01-01

    Collaborative information seeking is integral to many professional activities. In hospital work, the medication process encompasses continual seeking for information and collaborative grounding of information. This study investigates breakdowns in collaborative information seeking through analyses...... of the use of the electronic medication record adopted in a Danish healthcare region and of the reports of five years of medication incidents at Danish hospitals. The results show that breakdowns in collaborative information seeking is a major source of medication incidents, that most of these breakdowns...... are breakdowns in collaborative grounding rather than information seeking, that the medication incidents mainly concern breakdowns in the use of records as opposed to oral communication, that the breakdowns span multiple degrees of separation between clinicians, and that the electronic medication record has...

  4. COLOUR LEARNING IN RETARDED CHILDREN*

    African Journals Online (AJOL)

    COLOUR LEARNING IN RETARDED CHILDREN* !\\'fRS E. K~SEBOOM, Principal, ADS. LEVIN, M.B., M.R.C.P., D.C.H., Hon. Medical Officer, Hamlet B School for. Retarded Children, Johannesburg. '... silly children, with no understanding .. -'. Jeremiah 4:22. Tt has been observed' that mentally retarded children have.

  5. Fire and smoke retardants

    Science.gov (United States)

    Drews, M. J.

    Despite a reduction in Federal regulatory activity, research concerned with flame retardancy and smoke suppression in the private sector appears to be increasing. This trend seem related to the increased utilization of plastics for end uses which traditionally have employed metal or wood products. As a result, new markets have appeared for thermally stable and fire resistance thermoplastic materials, and this in turn has spurred research and development activity. In addition, public awareness of the dangers associated with fire has increased as a result of several highly publicized hotel and restaurant fires within the past two years. The consumers recognition of flammability characteristics as important materials property considerations has increased. The current status of fire and smoke retardant chemistry and research are summarized.

  6. Intracellular protein breakdown. 8

    International Nuclear Information System (INIS)

    Bohley, P.; Kirschke, H.; Langner, J.; Wiederanders, B.; Ansorge, S.

    1976-01-01

    Double-labelled proteins from rat liver cytosol ( 14 C in long-lived, 3 H in short-lived proteins after in-vivo-labelling) are used as substrates for unlabelled proteinases in vitro. Differences in the degradation rates of short-lived and long-lived proteins in vitro by different proteinases and after addition of different effectors allow conclusions concerning their importance for the in-vivo-turnover of substrate proteins. The main activity (>90%) of soluble lysosomal proteinases at pH 6.1 and pH 6.9 is caused by thiolproteinases, which degrade preferentially short-lived cytosol proteins. These proteinases are inhibited by leupeptin. Autolysis of double-labelled cell fractions shows a remarkably faster breakdown of short-lived substrate proteins only in the soluble part of lysosomes. Microsomal fractions degrade in vitro preferentially long-lived substrate proteins. (author)

  7. Fire-retardant foams

    Science.gov (United States)

    Gagliani, J.

    1978-01-01

    Family of polyimide resins are being developed as foams with exceptional fire-retardant properties. Foams are potentially useful for seat cushions in aircraft and ground vehicles and for applications such as home furnishings and building-construction materials. Basic formulations can be modified with reinforcing fibers or fillers to produce celular materials for variety of applications. By selecting reactants, polymer structure can be modified to give foams with properties ranging from high resiliency and flexibility to brittleness and rigidity.

  8. Breakdown concepts for contingency tables

    NARCIS (Netherlands)

    Kuhnt, S.

    2010-01-01

    Loglinear Poisson models are commonly used to analyse contingency tables. So far, robustness of parameter estimators as well as outlier detection have rarely been treated in this context. We start with finite-sample breakdown points. We yield that the breakdown point of mean value estimators

  9. Cave breakdown by vadose weathering.

    Directory of Open Access Journals (Sweden)

    Osborne R. Armstrong L.

    2002-01-01

    Full Text Available Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coated, rather than having fresh broken faces, and blocks continue to disintegrate after separating from the bedrock. Not only gypsum, but also hydromagnesite and aragonite are responsible for crystal wedging. It is impossible to study or identify potential breakdown foci by surface surveys alone, in-cave observation and mapping are essential.

  10. Retardo mental Mental retardation

    Directory of Open Access Journals (Sweden)

    Marcio M. Vasconcelos

    2004-04-01

    Full Text Available OBJETIVO: Esta revisão aborda as recentes descobertas da neurobiologia do retardo mental, enfatizando os novos recursos da citogenética, das técnicas moleculares e da neurorradiologia para esclarecer o diagnóstico. FONTES DE DADOS: O autor pesquisou o banco de dados MEDLINE da National Library of Medicine utilizando as palavras-chave "mental retardation", "developmental disability", "child" e "adolescent" em diferentes combinações, abrangendo o período de janeiro de 2000 a outubro de 2003. Também foram utilizados os bancos de dados das revistas científicas Pediatrics e New England Journal of Medicine através da palavra-chave "mental retardation". No total, o autor consultou cerca de 1.500 títulos de artigos e 500 resumos, e teve acesso direto a 150 artigos completos pertinentes. Quando oportuno, algumas referências dos artigos consultados também foram consideradas. O site Online Mendelian Inheritance in Man foi utilizado como fonte de informações em genética clínica. SÍNTESE DOS DADOS: Em outubro de 2003, o total de síndromes genéticas associadas a retardo mental chegou a 1.149. Considerando-se o conjunto das causas genéticas ou ambientais e congênitas ou adquiridas de retardo mental, a avaliação diagnóstica atual é capaz de esclarecer a etiologia em 50 a 70% dos casos. CONCLUSÕES: O autor sugere uma avaliação diagnóstica do retardo mental em etapas lógicas, visando ao uso racional dos dispendiosos recursos da citogenética, biologia molecular e neuroimagem.OBJECTIVE: This paper describes recent advances in the neurobiology of mental retardation, emphasizing new diagnostic resources provided by cytogenetics, molecular testing, and neuroimaging. SOURCES OF DATA: MEDLINE (January 2000 through October 2003, using the following key words: mental retardation, developmental disability, child, and adolescent. Search of the Pediatrics and New England Journal of Medicine websites using the key word mental retardation. The

  11. Retroreflective Phase Retardation Prisms.

    Science.gov (United States)

    1981-06-01

    resonant cavity of a 1.064 Mm laser. This report shows that it is possible to coat the reflecting surfaces of a porro prism so that incident plane...with controlled phase retardation can be made by coating each reflecting surface of a porro prism with a single dielectric film. The amount of phase...of angle of incidence (n, < n2) S. Phase change on reflection as a function of angle of incidence (n" n ) [RL-0202-’R 6. Porro prism 7. Phase change

  12. Radiation and mental retardation

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1988-01-01

    The editorial comments on a report published by the Radiation Effects Research Foundation in Hiroshima updating information on the induction of mental changes in the light of the revised and more detailed estimate of doses of radiation during pregnancies received by those exposed at Hiroshima and Nagasaki. The estimated risks are little changed. The likelihood of a threshold for exposure during the 16th to 25th week is confirmed-at 700 mGy (with a lower 95% confidence interval of 200 mGy). For the more sensitive time between the eighth to 15th weeks a linear model with no threshold still gives a statistically adequate fit to the data. Now, however, if linear models are tested without the constraint of postulating a threshold of zero, fits are obtained indicating substantial thresholds below which mental retardation would not result. When data on all children are included the maximum likelihood threshold value averages about 250 mGy on the different criteria tested (with mean 95% confidence intervals of 0 and 550 mGy). Or if the analyses exclude five children with conditions that themselves sometimes cause mental retardation a threshold of about 400 mGy is indicated (with mean 95% confidence intervals of 150 and 600 mGy). (author)

  13. Analyzing randomly occurring voltage breakdowns

    International Nuclear Information System (INIS)

    Wiltshire, C.W.

    1977-01-01

    During acceptance testing of high-vacuum neutron tubes, 40% of the tubes failed after experiencing high-voltage breakdowns during the aging process. Use of a digitizer in place of an oscilloscope revealed two types of breakdowns, only one of which affected acceptance testing. This information allowed redesign of the aging sequence to prevent tube damage and improve yield and quality of the final product

  14. The Right Brain: Surviving Retardation

    Science.gov (United States)

    Science News, 1977

    1977-01-01

    Describes two studies of brain hemisphere development which indicate children retarded in the functions of one hemisphere may not be retarded in the functions of the second hemisphere. Suggests that the left hemisphere functions may inhibit some right hemisphere functions. (SL)

  15. High gradient RF breakdown study

    International Nuclear Information System (INIS)

    Laurent, L.; Luhmann, N.C. Jr.; Scheitrum, G.; Hanna, S.; Pearson, C.; Phillips, R.

    1998-01-01

    Stanford Linear Accelerator Center and UC Davis have been investigating high gradient RF breakdown and its effects on pulse shortening in high energy microwave devices. RF breakdown is a critical issue in the development of high power microwave sources and next generation linear accelerators since it limits the output power of microwave sources and the accelerating gradient of linacs. The motivation of this research is to find methods to increase the breakdown threshold level in X-band structures by reducing dark current. Emphasis is focused on improved materials, surface finish, and cleanliness. The test platform for this research is a traveling wave resonant ring. A 30 MW klystron is employed to provide up to 300 MW of traveling wave power in the ring to trigger breakdown in the cavity. Five TM 01 cavities have previously been tested, each with a different combination of surface polish and/or coating. The onset of breakdown was extended up to 250 MV/m with a TiN surface finish, as compared to 210 MV/m for uncoated OFE copper. Although the TiN coating was helpful in depressing the field emission, the lowest dark current was obtained with a 1 microinch surface finish, single-point diamond-turned cavity

  16. Local Equilibrium and Retardation Revisited.

    Science.gov (United States)

    Hansen, Scott K; Vesselinov, Velimir V

    2018-01-01

    In modeling solute transport with mobile-immobile mass transfer (MIMT), it is common to use an advection-dispersion equation (ADE) with a retardation factor, or retarded ADE. This is commonly referred to as making the local equilibrium assumption (LEA). Assuming local equilibrium, Eulerian textbook treatments derive the retarded ADE, ostensibly exactly. However, other authors have presented rigorous mathematical derivations of the dispersive effect of MIMT, applicable even in the case of arbitrarily fast mass transfer. We resolve the apparent contradiction between these seemingly exact derivations by adopting a Lagrangian point of view. We show that local equilibrium constrains the expected time immobile, whereas the retarded ADE actually embeds a stronger, nonphysical, constraint: that all particles spend the same amount of every time increment immobile. Eulerian derivations of the retarded ADE thus silently commit the gambler's fallacy, leading them to ignore dispersion due to mass transfer that is correctly modeled by other approaches. We then present a particle tracking simulation illustrating how poor an approximation the retarded ADE may be, even when mobile and immobile plumes are continually near local equilibrium. We note that classic "LEA" (actually, retarded ADE validity) criteria test for insignificance of MIMT-driven dispersion relative to hydrodynamic dispersion, rather than for local equilibrium. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  17. Vortex breakdown incipience: Theoretical considerations

    Science.gov (United States)

    Berger, Stanley A.; Erlebacher, Gordon

    1992-01-01

    The sensitivity of the onset and the location of vortex breakdowns in concentrated vortex cores, and the pronounced tendency of the breakdowns to migrate upstream have been characteristic observations of experimental investigations; they have also been features of numerical simulations and led to questions about the validity of these simulations. This behavior seems to be inconsistent with the strong time-like axial evolution of the flow, as expressed explicitly, for example, by the quasi-cylindrical approximate equations for this flow. An order-of-magnitude analysis of the equations of motion near breakdown leads to a modified set of governing equations, analysis of which demonstrates that the interplay between radial inertial, pressure, and viscous forces gives an elliptic character to these concentrated swirling flows. Analytical, asymptotic, and numerical solutions of a simplified non-linear equation are presented; these qualitatively exhibit the features of vortex onset and location noted above.

  18. Neurotoxicity of brominated flame retardants

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) have been commonly used as commercial flame retardants in a variety of products including plastics and textiles. Despite their decreasing usage worldwide, congeners continue to accumulate in the environment, including soil, dust, food, anima...

  19. Can earthworms survive fire retardants?

    Science.gov (United States)

    Beyer, W.N.; Olson, A.

    1996-01-01

    Most common fire retardants are foams or are similar to common agricultural fertilizers, such as ammonium sulfate and ammonium phosphate. Although fire retardants are widely applied to soils, we lack basic information about their toxicities to soil organisms. We measured the toxicity of five fire retardants (Firetrol LCG-R, Firetrol GTS-R, Silv-Ex Foam Concentrate, Phos-chek D-75, and Phos-chek WD-881) to earthworms using the pesticide toxicity test developed for earthworms by the European Economic Community. None was lethal at 1,000 ppm in the soil, which was suggested as a relatively high exposure under normal applications. We concluded that the fire retardants tested are relatively nontoxic to soil organisms compared with other environmental chemicals and that they probably do not reduce earthworm populations when applied under usual firefighting conditions.

  20. Investigations of dc breakdown fields

    CERN Document Server

    Ramsvik, Trond; Reginelli, Alessandra; Taborelli, Mauro

    2006-01-01

    The need for high accelerating gradients for the future 30 GHz multi-TeV e+e- Compact Linear Collider (CLIC) at CERN has triggered a comprehensive study of DC breakdown fields of metals in UHV. The study shows that molybdenum (Mo), tungsten (W), titanium (Ti) and TiVAl reach high breakdown fields, and are thus good candidates for the iris material of CLIC structures. A significant decrease in the saturated breakdown field (Esat) is observed for molybdenum and tungsten when exposed to air. Specifically, at air pressures of 10-5 mbar, the decrease in Esat is found to be 50% and 30% for molybdenum and tungsten, respectively. In addition, a 30% decrease is found when molybdenum is conditioned with a CO pressure of ~1-10-5 mbar. Surface analysis measurements and breakdown conditioning in O2 ambience imply that the origin of the decrease in Esat is closely linked to oxide formation on the cathode surface. "Ex-situ" treatments by ion bombardment of molybdenum effectively reduce the oxide layers, and improve the brea...

  1. Gauge theories as theories of spontaneous breakdown

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Ogievetsky, V.I.

    1976-01-01

    Any gauge theory is proved to arise from spontaneous breakdown of symmetry under certain infinite parameter group, the corresponding gauge field being the Goldstone field by which this breakdown is accompanied

  2. Individual breakdown of pension rights

    CERN Multimedia

    2016-01-01

    You should have recently received, via email, your “Individual breakdown of pension rights”.   Please note that: the calculation was based on data as at 1st July 2016, as at 1st September 2016, CERN will introduce a new career structure; the salary position will now be expressed as a percentage of a midpoint of a grade.   We would like to draw your attention to the fact that your pension rights will remain unchanged. Benefits Service CERN Pension Fund

  3. Voltage breakdown on niobium and copper surfaces

    International Nuclear Information System (INIS)

    Werner, G.R.; Padamsee, H.; Betzwieser, J.C.; Liu, Y.G.; Rubin, K.H.R.; Shipman, J.E.; Ying, L.T.

    2003-01-01

    Experiments have shown that voltage breakdown in superconducting niobium RF cavities is in many ways similar to voltage breakdown on niobium cathodes in DC voltage gaps; most striking are the distinctive starburst patterns and craters that mark the site of voltage breakdown in both superconducting cavities and DC vacuum gaps. Therefore, we can learn much about RF breakdown from simpler, faster DC experiments. We have direct evidence, in the form of before'' and ''after'' pictures, that breakdown events caused by high surface electric fields occur with high probability at contaminant particles on surfaces. Although the pre-breakdown behavior (field emission) seems to depend mostly on the contaminant particles present and little on the substrate, the breakdown event itself is greatly affected by the substrate-niobium, heavily oxidized niobium, electropolished copper, and diamond-machined copper cathodes lead to different kinds of breakdown events. By studying DC voltage breakdown we hope to learn more details about the processes involved in the transition from field emission to catastrophic arcing and the cratering of the surface; as well as learning how to prevent breakdown, we would like to learn how to cause breakdown, which could be important when ''processing'' cavities to reduce field emission. (author)

  4. Screening of 20 patients with X-linked mental retardation using chromosome X-specific array-MAPH.

    NARCIS (Netherlands)

    Kousoulidou, L.; Parkel, S.; Zilina, O.; Palta, P.; Puusepp, H.; Remm, M.; Turner, G.; Boyle, J.; Bokhoven, J.H.L.M. van; Brouwer, A.; Esch, H. van; Froyen, G.; Ropers, H.H.; Chelly, J.; Moraine, C.; Gecz, J.; Kurg, A.; Patsalis, P.C.

    2007-01-01

    The rapid advancement of high-resolution DNA copy number assessment methods revealed the significant contribution of submicroscopic genetic imbalances to abnormal phenotypes, including mental retardation. In order to detect submicroscopic genetic imbalances, we have screened 20 families with

  5. Research on flame retardation of wool fibers

    International Nuclear Information System (INIS)

    Enomoto, Ichiro; Ametani, Kazuo; Sawai, Takeshi

    1990-01-01

    Flame retardant, vinyl phosphonate oligomer, was uniformly impregnated in wool fibers, and by irradiating low energy electron beam or cobalt-60 gamma ray, the flame retardation of fabrics was attempted, as the results, the following knowledges were obtained. At the rate of sticking of flame retardant lower than that in cotton fabrics, sufficient flame retarding property can be given. The flame retarding property withstands 30 times of washing. The lowering of strength due to the processing hardly arose. For the flame retardation, gamma-ray was more effective than electron beam. Since the accidents of burning clothes have occurred frequently, their flame retardation has been demanded. So far the flame retardation of cotton fabrics has been advanced, but this time the research on the flame retardation of wool fabrics was carried out by the same method. The experimental method is explained. As for the performance of the processed fabrics, the rate of sticking of the flame retardant, the efficiency of utilization, the flame retarding property, the endurance in washing and the tensile and tearing strength were examined. As the oxygen index was higher, the flame retarding property was higher, and in the case of the index being more than 27, the flame retarding property is sufficient, that is, the rate of sticking of 6% in serge and 5% in muslin. (K.I.)

  6. Genetic Counseling in Mental Retardation.

    Science.gov (United States)

    Bowen, Peter

    The task of the genetic counselor who identifies genetic causes of mental retardation and assists families to understand risk of recurrence is described. Considered are chromosomal genetic disorders such as Down's syndrome, inherited disorders such as Tay-Sachs disease, identification by testing the amniotic fluid cells (amniocentresis) in time…

  7. Epilepsy and Comorbid Mental Retardation

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-08-01

    Full Text Available Preventable and unpreventable causes of childhood-onset epilepsy associated with mental retardation were determined in 692 patients with epilepsy onset between 1977 and 1985 in a Nova Scotia population-based cohort studied in the Department of Pediatrics, Dalhousie University, Halifax, Canada.

  8. Mental Retardation: Diagnosis and Treatment.

    Science.gov (United States)

    Poser, Charles M., Ed.

    A collection of writings by 17 authors, the text includes the following discussions: general principles of diagnosis and management of mental retardation, neurologic evaluation of the infant and child, psychological evaluation, educational information, and treatment of pseudoretardation, communicative disorders, and metabolic and endocrine causes.…

  9. Mental Retardation and Parenting Stress

    Directory of Open Access Journals (Sweden)

    Eleni Siamaga

    2011-01-01

    Full Text Available Backround: The presence, upbringing and looking after of a mentally retarded child in the family, can become a threat to the mental health of its parents and is the main predisposing factor of stress for the parents.Aim: The purpose of this systematic review is (a to document the contemporary research bibliography related to the stress of parents with mentally retarded children, (b to aggregate the factors and secondary parameters based on the contemporary research related to the influence of the (child’s mental retardation on the parents and (c to show an intercultural aspect regarding the presence of stress to parents with mentally retarded children.Methods: Systematic review of research articles published in scientific journals included in the international academic databases HEAL-LING, SAGE, ELSEVIER, WILSON, SCIENCEDIRECT, MEDLINE, PUBMED, PsycINFO, Cochrane, EMBASE, SCIRUS and CINAHL having as search criteria and key words the terms («parental stress and mental retardation» [MeSH], «parenting stress and persons with special needs» [MeSH], «mental retardation and family problems» [MeSH], «stress and parents» [MeSH], «parenting and stress» [MeSH], «mental delay and parents» [MeSH], «developmental disabilities and family stress» [MeSH], «intellectual handicap and parenting» [MeSH], «maternal stress and child with disabilities» [MeSH].Discussion: The review has proven that all forms of mental retardation have an important -from a statistic point of viewimpacton the parents’ mental health. Anxiety, stress and depression are common symptoms mentioned by the parents.Additionally, there are individual variables such as the husband-wife relationship, the parents’ approach to their child’s disability, the parental strategies used in order to cope with the daily life of the child’s disability and the behavioural problems of their child, all of which contribute to the increase of the level of parental stress

  10. Flame Retardants Used in Flexible Polyurethane Foam

    Science.gov (United States)

    The partnership project on flame retardants in furniture seeks to update the health and environmental profiles of flame-retardant chemicals that meet fire safety standards for upholstered consumer products with polyurethane foam

  11. The breakdown of COSMOS 1402

    International Nuclear Information System (INIS)

    Westerlund, E.A.

    1983-01-01

    Sections of the satellite COSMOS 1402 containing radioactive materials disintegrated in the atmosphere over the Indian and Atlantic oceans Janyary/February 1983. Having the COSMOS 954 incident in mind and taking account of the fact that several satellite orbits crossed Norwegian territory, some preparedness measures were implemented prior to the break-down. The report describes the functions and experiences of an ad hoc satellite counsil which was appointed to take care of data collection, informaton to the public and planning for emergency actions. (RF)

  12. Dielectric breakdown in liquid helium

    International Nuclear Information System (INIS)

    Miller, F.L. Jr.

    1975-01-01

    The experimental apparatus consists of a 130 kV dc 80 kV ac intermediate voltage unit and a 600 kV dc 700 kV high voltage unit under construction. The experimental devices consist of an insulated container, or dewar, in which two electrodes are placed, one above the other. A voltage is built up in one electrode until an arc occurs to the other electrode. A typical set of breakdown data is shown. A mathematical analysis is briefly described. (MOW)

  13. People with Mental Retardation Are Dying, Legally.

    Science.gov (United States)

    Keyes, Denis; And Others

    1997-01-01

    Criticizes the institution of the death penalty for convicted criminals with mental retardation. Examples are given of cases in which juries were not told of the defendant's mental retardation before sentencing, and a list of defendants with mental retardation that have been executed since 1976 is provided. (CR)

  14. ["Nervous breakdown": a diagnostic characterization study].

    Science.gov (United States)

    Salmán, E; Carrasco, J L; Liebowitz, M; Díaz Marsá, M; Prieto, R; Jusino, C; Cárdenas, D; Klein, D

    1997-01-01

    An evaluation was made of the influence of different psychiatric co-morbidities on the symptoms of the disorder popularly known as "ataque de nervios" (nervous breakdown) among the US Hispanic population. Using a self-completed instrument designed specially for both traditional nervous breakdown and for panic symptoms, and structured or semi-structured psychiatric interviews for Axis I disorders, and evaluation was made of Hispanic subjects who sought treatment for anxiety in a clinic (n = 156). This study centered on 102 subjects who presented symptoms of "nervous breakdown" and comorbidity with panic disorder, other anxiety disorders, or affective disorder. Variations in co-morbidity with "nervous breakdown" enabled the identification of different patterns of "nervous breakdown" presenting symptoms. Individuals with "nervous breakdown" and panic disorder characteristically expressed a greater sense of asphyxiation, fear of dying, and growing fear (panic-like) during their breakdowns. Subjects with "nervous breakdown" and affective disorder had a greater sensation of anger and more tendency toward screaming and aggressive behavior such as breaking things during the breakdown (emotional anger). Finally, subjects with "nervous breakdown" and co-morbidity with another anxiety disorder had fewer "paniclike" or "emotional anger" symptoms. These findings suggest that: a) the widely used term "nervous breakdown" is a popular label for different patterns of loss of emotional control; b) the type of loss of emotional control is influenced by the associated psychiatric disorder; and c) the symptoms characteristics of the "nervous breakdown" can be useful clinical markers for associated psychiatric disorders. Future research is needed to determine whether the known Hispanic entity "ataque de nervios" is simply a popular description for different aspects of well-known psychiatric disorders, or if it reflects specific demographic, environmental, personality and/or clinical

  15. Discharge breakdown in the EXTRAP configuration

    International Nuclear Information System (INIS)

    Drake, J.R.

    1982-02-01

    The breakdown of a discharge in a linear EXTRAP configuration has been studied experimentally. In this configuration the breakdown occurs along the zero B-field line, which is the axis of the linear octupole magnetic field, between the anode and cathode which constitute the ends of the linear device. Breakdown could be described by a modified Townsend criterion which included additional electron losses due to the presence of the B-field transverse to the discharge. (author)

  16. Electrode breakdown potentials in MHD plasmas

    International Nuclear Information System (INIS)

    Sodha, M.S.; Raju, G.V.R.; Kumar, A.S.; Gupta, Bhumesh

    1988-01-01

    Electrode breakdown potentials and current densities have been calculated for both the thermionically electron emitting and non-emitting cathodes. Calculated values have been compared with the available experimental results. It is found that the cathode potential drop for the breakdown is almost unaffected by the emission. However, both the total potential difference between the anode and the cathode and the current density at the breakdown are higher for electron-emitting cathodes than for non-emitting cathodes. (author)

  17. The Development of Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2007-01-01

    Full Text Available The conditions under which breakdown of composite liquid - solid insulation can be occurred, e.g. in transformer, play an important role in designing of such insulation. The initial state of breakdown development is explained based on development of streamers in cavitations. The whole breakdown development in transformer oil is represented by RLC circuit and it depends on the parameters of outer circuit.

  18. Multiple helical modes of vortex breakdown

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; Naumov, I. V.; Okulov, Valery

    2011-01-01

    Experimental observations of vortex breakdown in a rotating lid-driven cavity are presented. The results show that vortex breakdown for cavities with high aspect ratios is associated with the appearance of stable helical vortex multiplets. By using results from stability theory generalizing Kelvi......’s problem on vortex polygon stability, and systematically exploring the cavity flow, we succeeded in identifying two new stable vortex breakdown states consisting of triple and quadruple helical multiplets....

  19. Work Breakdown Structure (WBS) Handbook

    Science.gov (United States)

    2010-01-01

    The purpose of this document is to provide program/project teams necessary instruction and guidance in the best practices for Work Breakdown Structure (WBS) and WBS dictionary development and use for project implementation and management control. This handbook can be used for all types of NASA projects and work activities including research, development, construction, test and evaluation, and operations. The products of these work efforts may be hardware, software, data, or service elements (alone or in combination). The aim of this document is to assist project teams in the development of effective work breakdown structures that provide a framework of common reference for all project elements. The WBS and WBS dictionary are effective management processes for planning, organizing, and administering NASA programs and projects. The guidance contained in this document is applicable to both in-house, NASA-led effort and contracted effort. It assists management teams from both entities in fulfilling necessary responsibilities for successful accomplishment of project cost, schedule, and technical goals. Benefits resulting from the use of an effective WBS include, but are not limited to: providing a basis for assigned project responsibilities, providing a basis for project schedule development, simplifying a project by dividing the total work scope into manageable units, and providing a common reference for all project communication.

  20. The Multistability of Technological Breakdowns in Education

    DEFF Research Database (Denmark)

    Andersen, Bjarke Lindsø; Tafdrup, Oliver Alexander

    2017-01-01

    Introduction Everyone who is involved with modern technological artefacts such as computers, software and tablets has experienced situations where the artefacts suddenly cease to function properly. This is commonly known as a technological breakdown. Within education and the praxis of teaching...... technological breakdowns become a more and more ubiquitous phenomenon due to the rapid increase of technological artefacts utilized for educational purposes (Riis, 2012). The breakdowns impact the educational practice with consequences ranging from creating small obstacles to rendering it impossible to conduct...... successful teaching. Thus, knowing how to cope with technological breakdowns is a pivotal part of being a technological literate....

  1. Parental Attitude Towards Mental Retardation

    Directory of Open Access Journals (Sweden)

    LEOKADIA WIATROWSKA

    2017-10-01

    Full Text Available https://doaj.org/puChild's developmental retardation is an undoubted condition for the absence of educational attainment and its unpleasant mental state. Due to the nature of multidimensional state of that, parental attitudes become relevant, as they affect the acceleration or retardation of development. Positive parental attitudes are the strong weapon for the child and his struggles on the way to an equal start and equal development opportunities. For this reason you should emphasize those factors that build the structures supporting developmental progression.An ecosystem approach to human development emphasizes each factor as relevant component for growth and expansion, without denying its own human activity and his self-determination rightblisher/metadata

  2. The physics of ''vacuum'' breakdown

    International Nuclear Information System (INIS)

    Schwirzke, F.

    1993-01-01

    Many discharges form small cathode spots which provide such a high energy density that the cathode material explodes into a dense plasma cloud within a very short time. Despite the fundamental importance of cathode spots for the breakdown process and the formation of a discharge, the structure of the cathode spot plasma and the source of the high energy density were not yet well defined. One model, the whisker explosive emission model, assumes that joule heating by field emitted electrons provides the energy. Current densities of j FE = 10 12 - 10 13 A/m 2 would be required. However, the pre-breakdown j FE is self-limiting. The negative space charge caused by j FE in the cathode-anode gap reduces the effective electric field E on the cathode surface. The maximum current density j CL is space charge limited by Child-Langmuir's law. The field emitting spot cannot deliver j CL without turning itself off, since the negative space charge caused by j CL reduces E congruent 0 at the cathode surface. Hence, it must be that the vacuum j FE CL . The development of a current with j > j FE (vacuum) requires that ions exist in front of the electron emitting spot. Ions cannot be emitted from the surface of the field emitting spot, the enhanced electric field would hold them back. The initial ionization must occur in the cathode-anode gap near the electron emitting spot. Ionization of desorbed neutrals provides the mechanism. This ionization process requires considerably less current than the ionization of solid material by joule heating. Field emission and the impact of ions stimulate desorption of weakly bound adsorbates from the surface of the electron emitting spot. The cross section for ionization of the neutrals has a maximum for ∼ 100 eV electrons

  3. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-02

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

  4. Suppression of discharge breakdown of polyethylene insulation during electron beam irradiation to power cable

    International Nuclear Information System (INIS)

    Sasaki, T.; Hosoi, F.; Kasai, N.; Hagiwara, M.

    1981-01-01

    In an attempt to apply the electron beam process to the crosslinking procedure for polyethylene insulation of high tension power cables, the suppression of discharge breakdown during irradiation has been investigated in the presence of crosslinking agents. Alkylamines of strong basicity and secondary or tertiary alcoholamines were found to be effective additives to suppress the discharge breakdown. The retardation of crosslinking by amines was minimized by reducing the amount of an amine and adding an alcohol instead. Polyethylene compounds contaning crosslinking agents, amines and alcohols which gave properties suitable for insulating a cable were obtained. The feasibility of these results are ascertained by irradiating cable specimens of a 22 kV class. (author)

  5. Fast Breakdown as Coronal/Ionization Waves?

    Science.gov (United States)

    Krehbiel, P. R.; Petersen, D.; da Silva, C. L.

    2017-12-01

    Studies of high-power narrow bipolar events (NBEs) have shown they are produced by a newly-recognized breakdown process called fast positive breakdown (FPB, Rison et al., 2016, doi:10.1038/ncomms10721). The breakdown was inferred to be produced by a system of positive streamers that propagate at high speed ( ˜3-6 x 107 m/s) due to occurring in a localized region of strong electric field. The polarity of the breakdown was determined from broadband interferometer (INTF) observations of the propagation direction of its VHF radiation, which was downward into the main negative charge region of a normally-electrified storm. Subsequent INTF observations being conducted in at Kennedy Space Center in Florida have shown a much greater incidence of NBEs than in New Mexico. Among the larger dataset have been clear-cut instances of some NBEs being produced by upward breakdown that would be of negative polarity. The speed and behavior of the negative breakdown is the same as that of the fast positive, leading to it being termed fast negative breakdown (FNB). The similarity (not too mention its occurrence) is surprising, given the fact that negative streamers and breakdown develops much differently than that of positive breakdown. The question is how this happens. In this study, we compare fast breakdown characteristics to well-known streamer properties as inferred from laboratory experiments and theoretical analysis. Additionally, we begin to explore the possibility that both polarities of fast breakdown are produced by what may be called coronal or ionization waves, in which the enhanced electric field produced by streamer or coronal breakdown of either polarity propagates away from the advancing front at the speed of light into a medium that is in a metastable condition of being at the threshold of hydrometeor-mediated corona onset or other ionization processes. The wave would develop at a faster speed than the streamer breakdown that gives rise to it, and thus would be

  6. Breakdown properties of irradiated MOS capacitors

    International Nuclear Information System (INIS)

    Paccagnella, A.; Candelori, A.; Pellizzer, F.; Fuochi, P.G.; Lavale, M.

    1996-01-01

    The authors have studied the effects of ionizing and non-ionizing radiation on the breakdown properties of different types of MOS capacitors, with thick (200 nm) and thin (down to 8 nm) oxides. In general, no large variations of the average breakdown field, time-to-breakdown at constant voltage, or charge-to-breakdown at constant voltage, or charge-to-breakdown values have been observed after high dose irradiation (20 Mrad(Si) 9 MeV electrons on thin and thick oxides, 17(Si) Mrad Co 60 gamma and 10 14 neutrons/cm 2 only on thick oxides). However, some modifications of the cumulative failure distributions have been observed in few of the oxides tested

  7. Experiments concerning the theories of vortex breakdown

    Science.gov (United States)

    Panton, Ronald L.; Stifle, Kirk E.

    1991-01-01

    An experimental project was undertaken to investigate the character of vortex breakdown with particular regard to the stagnation and wave guide theories of vortex breakdown. Three different wings were used to produce a trailing vortex which convected downstream without undergoing breakdown. Disturbances were then introduced onto the vortex using a moving wire to 'cut' the vortex. The development of upstream and downstream propagating disturbance waves was observed and the propagation velocities measured. A downstream traveling wave was observed to produce a structure similar in appearance to a vortex breakdown. An upstream traveling wave produced a moving turbulent region. The upstream disturbance moved into an axial velocity profile that had a wake-like defect while the downstream moving vortex breakdown moved against a jet-like overshoot. The longitudinal and swirl velocity profiles were documented by LDV measurement. Wave velocities, swirl angles, and swirl parameters are reported.

  8. AC electrical breakdown phenomena of epoxy/layered silicate nanocomposite in needle-plate electrodes.

    Science.gov (United States)

    Park, Jae-Jun; Lee, Jae-Young

    2013-05-01

    Epoxy/layered silicate nanocomposite for the insulation of heavy electric equipments were prepared by dispersing 1 wt% of a layered silicate into an epoxy matrix with a homogenizing mixer and then AC electrical treeing and breakdown tests were carried out. Wide-angle X-ray diffraction (WAXD) analysis and transmission electron microscopy (TEM) observation showed that nano-sized monolayers were exfoliated from a multilayered silicate in the epoxy matrix. When the nano-sized silicate layers were incorporated into the epoxy matrix, the breakdown rate in needle-plate electrode geometry was 10.6 times lowered than that of the neat epoxy resin under the applied electrical field of 520.9 kV/mm at 30 degrees C, and electrical tree propagated with much more branches in the epoxy/layered silicate nanocomposite. These results showed that well-dispersed nano-sized silicate layers retarded the electrical tree growth rate. The effects of applied voltage and ambient temperature on the tree initiation, growth, and breakdown rate were also studied, and it was found that the breakdown rate was largely increased, as the applied voltage and ambient temperature increased.

  9. The Work Breakdown Structure in an Acquisition Reform Environment

    National Research Council Canada - National Science Library

    Albert, Neil

    1997-01-01

    These viewgraphs discuss acquisition reform, costs, provide a definition for work breakdown structure, development process of work breakdown, an overview of contract business management, a GAO review...

  10. Breakdown characteristics of xenon HID Lamps

    Science.gov (United States)

    Babaeva, Natalia; Sato, Ayumu; Brates, Nanu; Noro, Koji; Kushner, Mark

    2009-10-01

    The breakdown characteristics of mercury free xenon high intensity discharge (HID) lamps exhibit a large statistical time lag often having a large scatter in breakdown voltages. In this paper, we report on results from a computational investigation of the processes which determine the ignition voltages for positive and negative pulses in commercial HID lamps having fill pressures of up to 20 atm. Steep voltage rise results in higher avalanche electron densities and earlier breakdown times. Circuit characteristics also play a role. Large ballast resistors may limit current to the degree that breakdown is quenched. The breakdown voltage critically depends on cathode charge injection by electric field emission (or other mechanisms) which in large part controls the statistical time lag for breakdown. For symmetric lamps, ionization waves (IWs) simultaneously develop from the bottom and top electrodes. Breakdown typically occurs when the top and bottom IWs converge. Condensed salt layers having small conductivities on the inner walls of HID lamps and on the electrodes can influence the ignition behavior. With these layers, IWs tend to propagate along the inner wall and exhibit a different structure depending on the polarity.

  11. Alpha thalassaemia-mental retardation, X linked

    Directory of Open Access Journals (Sweden)

    Gibbons Richard

    2006-05-01

    Full Text Available Abstract X-linked alpha thalassaemia mental retardation (ATR-X syndrome in males is associated with profound developmental delay, facial dysmorphism, genital abnormalities and alpha thalassaemia. Female carriers are usually physically and intellectually normal. So far, 168 patients have been reported. Language is usually very limited. Seizures occur in about one third of the cases. While many patients are affectionate with their caregivers, some exhibit autistic-like behaviour. Patients present with facial hypotonia and a characteristic mouth. Genital abnormalities are observed in 80% of children and range from undescended testes to ambiguous genitalia. Alpha-thalassaemia is not always present. This syndrome is X-linked recessive and results from mutations in the ATRX gene. This gene encodes the widely expressed ATRX protein. ATRX mutations cause diverse changes in the pattern of DNA methylation at heterochromatic loci but it is not yet known whether this is responsible for the clinical phenotype. The diagnosis can be established by detection of alpha thalassaemia, identification of ATRX gene mutations, ATRX protein studies and X-inactivation studies. Genetic counselling can be offered to families. Management is multidisciplinary: young children must be carefully monitored for gastro-oesophageal reflux as it may cause death. A number of individuals with ATR-X are fit and well in their 30s and 40s.

  12. Breakdown Cause and Effect Analysis. Case Study

    Science.gov (United States)

    Biały, Witold; Ružbarský, Juraj

    2018-06-01

    Every company must ensure that the production process proceeds without interferences. Within this article, the author uses the term "interferences" in reference to unplanned stoppages caused by breakdowns. Unfortunately, usually due to machine operators' mistakes, machines break, which causes stoppages thus generating additional costs for the company. This article shows a cause and effect analysis of a breakdown in a production process. The FMEA as well as quality management tools: the Ishikawa diagram and Pareto chart were used for the analysis. Correction measures were presented which allowed for a significant reduction in the number of stoppages caused by breakdowns.

  13. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    Silicone elastomers have been heavily investigated as candidates for dielectric elastomers and are as such almost ideal candidates with their inherent softness and compliance but they suffer from low dielectric permittivity. This shortcoming has been sought optimized by many means during recent...... years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we investigate the electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers. Two types...... of silicone elastomers are investigated and different types of breakdown are discussed. Furthermore the use of voltage stabilizers in silicone-based dielectric elastomers is investigated and discussed....

  14. Fundamental studies of passivity and passivity breakdown

    International Nuclear Information System (INIS)

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed ''point defects models'' (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies

  15. Mental Retardation; Its Social Context and Social Consequences.

    Science.gov (United States)

    Farber, Bernard

    Concerned with mental retardation as a social product, the following topics are discussed: mental retardation as a social phenomenon, the concept of the retarded as surplus population, labeling and incompetence in relation to life chances, mental retardation as deviance and as incompetence, and findings on the prevalence of retardation in the…

  16. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  17. Surface breakdown igniter for mercury arc devices

    Science.gov (United States)

    Bayless, John R.

    1977-01-01

    Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.

  18. Obstacle-induced spiral vortex breakdown

    OpenAIRE

    Pasche, Simon; Gallaire, François; Dreyer, Matthieu; Farhat, Mohamed

    2014-01-01

    An experimental investigation on vortex breakdown dynamics is performed. An adverse pressure gradient is created along the axis of a wing-tip vortex by introducing a sphere downstream of an elliptical hydrofoil. The instrumentation involves high-speed visualizations with air bubbles used as tracers and 2D Laser Doppler Velocimeter (LDV). Two key parameters are identified and varied to control the onset of vortex breakdown: the swirl number, defined as the maximum azimuthal velocity divided by...

  19. Modeling Covariance Breakdowns in Multivariate GARCH

    OpenAIRE

    Jin, Xin; Maheu, John M

    2014-01-01

    This paper proposes a flexible way of modeling dynamic heterogeneous covariance breakdowns in multivariate GARCH (MGARCH) models. During periods of normal market activity, volatility dynamics are governed by an MGARCH specification. A covariance breakdown is any significant temporary deviation of the conditional covariance matrix from its implied MGARCH dynamics. This is captured through a flexible stochastic component that allows for changes in the conditional variances, covariances and impl...

  20. Intumescent Coatings as Fire Retardants

    Science.gov (United States)

    Parker, J. A.; Fohlen, G. M.; Sawko, P. M.; Fish, R. H.

    1970-01-01

    The development of fire-retardant coatings to protect surfaces which may be exposed to fire or extreme heat is a subject of intense interest to many industries. A fire-retardant paint has been developed which represents a new chemical approach for preparing intumescent coatings, and potentially, is very important to fire-prevention authorities. The requirements for a superior coating include ease of application, suitability to a wide variety of surfaces and finishes, and stability over an extended period of time within a broad range of ambient temperature and humidity conditions. These innovative coatings, when activated by the heat of a fire, react to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction. Two fire-protection mechanisms thus become available: (1) the char layer retards the flow of heat, due to the extremely low thermal conductivity; and (2) water vapor and sulfur dioxide are released, providing fire quenching properties. Still another mechanism functions in cases where the char, by virtue of its high oxidation resistance and low thermal conductivity, reaches a sufficiently high temperature to re-radiate much of the incident heat load. The coatings consist of dispersions of selective salts of a nitro-amino-arornatic compound. Specifically, para-nitroaniline bisulfate and the ammonium salt of para-nitroaniline-ortho sulphuric acid (2-amino-5-nitrobenzenesulphuric acid) are used. Suitable vehicles are cellulose nitrate of lacquer grade, a nitrite-phenolic modified rubber, or epoxy-polysulfide copolymer. Three separate formulations have been developed. A solvent is usually employed, such as methylethyl ketone, butyl acetate, or toluene, which renders the coatings suitably thin and which evaporates after the coatings are applied. Generally, the intumescent material is treated as insoluble in the vehicle, and is ground and dispersed in the vehicle and solvent like an

  1. Skin breakdown in acute care pediatrics.

    Science.gov (United States)

    Suddaby, Elizabeth C; Barnett, Scott D; Facteau, Lorna

    2006-04-01

    The purpose of this study was to develop a simple, single-page measurement tool that evaluates risk of skin breakdown in the peadiatric population and apply it to the acutely hospitalized child. Data were collected over a 15-month period from 347 patients on four in-patient units (PICU, medical-surgical, oncology, and adolescents) on skin breakdown using the AHCPR staging guidelines and compared to the total score on the Starkid SkinScale in order to determine its ability to predict skin breakdown. The inter-rater reliability of the Starkid Skin Scale was r2 = 0.85 with an internal reliablity of 0.71. The sensitivity of the total score was low (17.5%) but highly specific (98.5%). The prevalence of skin breakdown in the acutely hospitalized child was 23%, the majority (77.5%) occurring as erythema of the skin. Buttocks, perineum, and occiput were the most common locations of breakdown. Occiput breakdown was more common in critically ill (PICU) patients while diaper dermatitis was more common in the general medical-surgical population.

  2. Humidity effects on wire insulation breakdown strength.

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  3. Orthognathic surgery for mentally retarded patients

    NARCIS (Netherlands)

    Becking, A. G.; Tuinzing, D. B.

    1991-01-01

    The surgical treatment of mentally retarded children for esthetic reasons is discussed. In mentally retarded adults a facial deformity can give rise to functional problems; in some cases a facial deformity can stigmatize the mental state. In selected cases orthognathic surgery may offer a solution

  4. Body Awareness in Children with Mental Retardation

    Science.gov (United States)

    Simons, Johan; Dedroog, Inge

    2009-01-01

    The body awareness of 124 toddlers with mental retardation and of 124 children developing normally matched to them on age and gender was examined. Twenty-nine of the children with mental retardation were diagnosed as Down syndrome (DS). The "Pointing and Naming" Test of Berges and Lezine [Berges, J., & Lezine, I. (1978). "Test d'imitation de…

  5. Political Philosophy and the Mentally Retarded.

    Science.gov (United States)

    Stanovich, Keith E.

    The effects of Social Darwinism, eugenics, and contemporary political conservatism on the status of advocacy efforts for the mentally retarded are reviewed. Provided are historical sketches of Social Darwinism, which viewed the retarded as members of an inferior race, and eugenics, which argued for sterilization of the "genetically…

  6. Noncitizen: Plight of the Mentally Retarded

    Science.gov (United States)

    Skarnulis, Ed

    1974-01-01

    Mentally retarded citizens have been denied their human and civil rights, not only by the public, but by professionals--including social workers. The author claims that most programs for the mentally retarded are, at best, dehumanizing. Professionals have an ethical obligation to refuse to refer children to such programs. (Author)

  7. Sustained Attention of Adults with Mental Retardation.

    Science.gov (United States)

    Tomporowski, Phillip D.; Allison, Pamela

    1988-01-01

    The sustained attention of 23 young adults with mild mental retardation and nonretarded subjects was assessed. Findings suggested that the sustained attention of the retarded differs from that of the nonretarded on those vigilance tasks that place demands on memory abilities. (Author/DB)

  8. The Mentally Retarded Offender and Corrections.

    Science.gov (United States)

    Santamour, Miles; West, Bernadette

    The booklet provides an overview of the issues involved in correctional rehabilitation for the mentally retarded offender. Reviewed are clinical and legal definitions of criminal behavior and retardation, and discussed are such issues as law enforcement and court proceedings problems, pros and cons of special facilities, labeling, normalization,…

  9. AUTISTIC FEATURES IN CHILDREN WITH MENTAL RETARDATION

    Science.gov (United States)

    Kar, Nilamadhab; Khanna, Rakesh; Kar, Gopal Chandra

    1997-01-01

    Most of the autistic disorder patients are also mentally retarded and many mentally retarded persons exhibit autistic symptoms. By using a standard instrument (Ritvo-Freeman Real Life Rating Scale) the autistic features of the mentally retarded children were studied. The study also examined the influence of age, sex and level of mental retardation on the occurrence of autistic symptoms. Children who came for consultation to child psychiatric unit were compared with those at a school for children with mental retardation receiving stimulation. Male children from child psychiatric unit had significantly higher scores than those from the school. Social and language impairment could be reliably identified and grouped. It was possible to diagnose the syndrome of autism in children with mental retardation in a significant number (9.6%)as compared to that was possible only clinically (1.9%). More number of children with severe/ profound mental retardation could be diagnosed as autistic. The autistic syndrome in children with mental retardation can be picked up more effectively by the use of structured instrument. PMID:21584097

  10. DNA repair in proteus mirabilis. Pt. 4

    International Nuclear Information System (INIS)

    Hofemeister, J.

    1977-01-01

    Post-irradiation DNA degradation in P. mirabilis rec + strains after UV irradiation is found to be more extensive in starvation buffer than in growth medium. In growth medium restriction of protein synthesis, but not DNA synthesis, largely prevents the expression of 'breakdown limitation'. By the addition of chloramphenicol during post-irradiation incubation in growth medium the expression of breakdown limitation was followed and found to occur 20 to 40 min after UV irradiation. Pre-irradiation by a low dose of UV leads after a corresponding time of post-irradiation incubation to breakdown limitation even in starvation buffer after a second UV exposure. Post-irradiation DNA degradation is presumed to be initiated at the sites of DNA lesions which arise at replication points damaged by UV. While pre-starvation restricts the efficiency of postirradiation DNA degradation by the reduction of the number of replication points active at the time of irradiation, caffeine as well as 2.4-dinitrophenol inhibit DNA degradation even in rec - cells probably by the interference with nicking or exonucleoltytic events initiated at those sites in the absence of breakdown limitation. Breakdown limitation is postulated to be due to inducible derepression of REC-functions which lead to the protection and, probably, repair of DNA lesions arising at the replication points following UV exposure. (orig.) [de

  11. Measuring protein breakdown rate in individual proteins in vivo

    DEFF Research Database (Denmark)

    Holm, Lars; Kjaer, Michael

    2010-01-01

    To outline different approaches of how protein breakdown can be quantified and to present a new approach to determine the fractional breakdown rate of individual slow turnover proteins in vivo.......To outline different approaches of how protein breakdown can be quantified and to present a new approach to determine the fractional breakdown rate of individual slow turnover proteins in vivo....

  12. CT findings of mentally retarded patients

    International Nuclear Information System (INIS)

    Mikami, Akihiro; Watanabe, Hiroshi

    1984-01-01

    Cranial CT findings were compared according to the age group in 192 mentally retarded patients aged from 15 to 59 years and in 132 control subjects. Enlargement of the ventricles, cisterns or fissures was judged. The incidence of ''enlargement'' was higher, irrespective of age, in mentally retarded group than in the control group. When the mentally retarded patients were divided into the group with pathologic symptoms and the group without them, the incidence of ''enlargement'' was higher in the former group than in the control group, but there was no significant difference between the latter group and the control group. There was no consistent relationship between the degree of mental retardation and the incidence of ''enlargement''. Many of the mentally retarded patients with pathologic symptoms tended to have a wide range of enlargement, while many of the patients without them had narrowed lateral ventricle. (Namekawa, K.)

  13. CASE REPORT OF A MENTALLY RETARDED CHILD

    Directory of Open Access Journals (Sweden)

    Vasilka GALEVSKA

    2006-06-01

    Full Text Available Mental retardation is a complex individual and social problem. According to WHO, around 1-3 % of world population are mentally retarded people and the percentage between school children is around 2 %.The development of a mentally retarded child depends on factors related to the disability itself, all the limitations and characteristics which results from that. But, physical, psychical, educational and social development of a mentally retarded child, also, depend on other conditions, such as the family and the wider environment, their reactions, attitudes, awareness and sensitivity for special needs of the child, as well as their preparedness and possibilities to respond.At the same time, it is necessary that the mentally retarded child is detected and diagnosed in time, as well as the early start of an adequate treatment.

  14. A computational study of the topology of vortex breakdown

    Science.gov (United States)

    Spall, Robert E.; Gatski, Thomas B.

    1991-01-01

    A fully three-dimensional numerical simulation of vortex breakdown using the unsteady, incompressible Navier-Stokes equations has been performed. Solutions to four distinct types of breakdown are identified and compared with experimental results. The computed solutions include weak helical, double helix, spiral, and bubble-type breakdowns. The topological structure of the various breakdowns as well as their interrelationship are studied. The data reveal that the asymmetric modes of breakdown may be subject to additional breakdowns as the vortex core evolves in the streamwise direction. The solutions also show that the freestream axial velocity distribution has a significant effect on the position and type of vortex breakdown.

  15. dc breakdown conditioning and breakdown rate of metals and metallic alloys under ultrahigh vacuum

    Directory of Open Access Journals (Sweden)

    A. Descoeudres

    2009-03-01

    Full Text Available The rf accelerating structures of the Compact Linear Collider (CLIC require a material capable of sustaining high electric field with a low breakdown rate and low induced damage. Because of the similarity of many aspects of dc and rf breakdown, a dc breakdown study is underway at CERN in order to test candidate materials and surface preparations, and have a better understanding of the breakdown mechanism under ultrahigh vacuum in a simple setup. Conditioning speeds and breakdown fields of several metals and alloys have been measured. The average breakdown field after conditioning ranges from 100  MV/m for Al to 850  MV/m for stainless steel, and is around 170  MV/m for Cu which is the present base-line material for CLIC structures. The results indicate clearly that the breakdown field is limited by the cathode. The presence of a thin cuprous oxide film at the surface of copper electrodes significantly increases the breakdown field. On the other hand, the conditioning speed of Mo is improved by removing oxides at the surface with a vacuum heat treatment, typically at 875°C for 2 hours. Surface finishing treatments of Cu samples only affect the very first breakdowns. More generally, surface treatments have an effect on the conditioning process itself, but not on the average breakdown field reached after the conditioning phase. In analogy to rf, the breakdown probability has been measured in dc with Cu and Mo electrodes. The dc data show similar behavior as rf as a function of the applied electric field.

  16. dc breakdown conditioning and breakdown rate of metals and metallic alloys under ultrahigh vacuum

    CERN Document Server

    Descoeudres, A; Calatroni, S; Taborelli, M; Wuensch, W

    2009-01-01

    RF accelerating structures of the Compact Linear Collider (CLIC) require a material capable of sustaining high electric field with a low breakdown rate and low induced damage. Because of the similarity of many aspects of DC and RF breakdown, a DC breakdown study is underway at CERN in order to test candidate materials and surface preparations, and have a better understanding of the breakdown mechanism under ultra-high vacuum in a simple setup. Conditioning speeds and breakdown fields of several metals and alloys have been measured. The average breakdown field after conditioning ranges from 100 MV/m for Al to 850 MV/m for stainless steel, and is around 170 MV/m for Cu which is the present base-line material for CLIC structures. The results indicate clearly that the breakdown field is limited by the cathode. The presence of a thin cuprous oxide film at the surface of copper electrodes significantly increases the breakdown field. On the other hand, the conditioning speed of Mo is improved by removing oxides at t...

  17. The measurement of retardation in depression.

    Science.gov (United States)

    Dantchev, N; Widlöcher, D J

    1998-01-01

    The description of clinical features helps to distinguish between depressive illness and nondepressive psychic pain and enables the clinician to decide whether prescription of an antidepressant is beneficial. Psychomotor retardation is probably a central feature of depression, and this review discusses the methods available for measuring it. The Salpêtrière Retardation Rating Scale (SRRS) specifically measures psychomotor retardation; the scale and applications are described. Means of measuring motor and speech activity and an experimental approach for understanding the process underlying psychomotor retardation are reviewed. Comparison of the SRRS and other rating scale scores demonstrates that retardation is related to depression severity and therapeutic change and is a good criterion for prediction of therapeutic effect. The SRRS has been used to show that selective antidepressants target specific clinical dimensions of depression depending on the patient subgroup treated. Measures of motor and speech activity are sensitive to therapeutic response. Choice Reaction Time and Simple Reaction Time tasks are particularly suited for examining psychomotor retardation because they test the decision process while avoiding motivation and attention interference. Psychomotor retardation is a constant and probably central feature of depression. Means available for measuring it can be used to assess the effects of antidepressants on specific clinical dimensions.

  18. Three-dimensional supersonic vortex breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1993-01-01

    Three-dimensional supersonic vortex-breakdown problems in bound and unbound domains are solved. The solutions are obtained using the time-accurate integration of the unsteady, compressible, full Navier-Stokes (NS) equations. The computational scheme is an implicit, upwind, flux-difference splitting, finite-volume scheme. Two vortex-breakdown applications are considered in the present paper. The first is for a supersonic swirling jet which is issued from a nozzle into a supersonic uniform flow at a lower Mach number than that of the swirling jet. The second is for a supersonic swirling flow in a configured circular duct. In the first application, an extensive study of the effects of grid fineness, shape and grid-point distribution on the vortex breakdown is presented. Four grids are used in this study and they show a substantial dependence of the breakdown bubble and shock wave on the grid used. In the second application, the bubble-type and helix-type vortex breakdown have been captured.

  19. Planned waveguide electric field breakdown studies

    International Nuclear Information System (INIS)

    Wang Faya; Li Zenghai

    2012-01-01

    This paper presents an experimental setup for X-band rf breakdown studies. The setup is composed of a section of WR90 waveguide with a tapered pin located at the middle of the waveguide E-plane. Another pin is used to rf match the waveguide so it operates in a travelling wave mode. By adjusting the penetration depth of the tapered pin, different surface electric field enhancements can be obtained. The setup will be used to study the rf breakdown rate dependence on power flow in the waveguide for a constant maximum surface electric field on the pin. Two groups of pins have been designed. The Q of one group is different and very low. The other has a similar Q. With the test of the two groups of pins, we should be able to discern how the net power flow and Q affect the breakdown. Furthermore, we will apply an electron beam treatment to the pins to study its effect on breakdown. Overall, these experiments should be very helpful in understanding rf breakdown phenomena and could significantly benefit the design of high gradient accelerator structures.

  20. Electrical breakdown of water in microgaps

    International Nuclear Information System (INIS)

    Schoenbach, Karl; Kolb, Juergen; Xiao Shu; Katsuki, Sunao; Minamitani, Yasushi; Joshi, Ravindra

    2008-01-01

    Experimental and modeling studies on electrical breakdown in water in submillimeter gaps between pin and plane electrodes have been performed. Prebreakdown, breakdown and recovery of the water gaps were studied experimentally by using optical and electrical diagnostics with a temporal resolution on the order of one nanosecond. By using Mach-Zehnder interferometry, the electric field distribution in the prebreakdown phase was determined by means of the Kerr effect. Electric fields values in excess of the computed electric fields, which reach >4 MV cm -1 for applied electrical pulses of 20 ns duration, were recorded at the tip of the pin electrode, an effect which can be explained by a reduced permittivity of water at high electric fields. Breakdown of the gaps, streamer-to-arc transition, was recorded by means of high-speed electrical diagnostics, and through high-speed photography. It was shown, through simulations, that breakdown is initiated by field emission at the interface of preexisting microbubbles. Impact ionization within the micro-bubble's gas then contributes to plasma development. Experiments using pulse-probe methods and Schlieren diagnostics allowed us to follow the development of the disturbance caused by the breakdown over a time of more than milliseconds and to determine the recovery time of a water switch. In order to trigger water switches a trigger electrode with a triple point has been utilized. The results of this research have found application in the construction of compact pulse power generators for bioelectric applications.

  1. SLEEP DISORDERS IN MENTALLY RETARDED CHILDREN

    Directory of Open Access Journals (Sweden)

    I. A. Kelmanson

    2014-01-01

    Full Text Available The paper presents the study of the association between sleep disturbances and mental retardation in children. Attention is paid to the instant connection between sleep neurophysiology and intellectual progress, as well as between sleep disorders and the pathogenesis of mental retardation in children. The data on characteristic forms of sleep disturbances, including bed-time resistance, frequent night awakenings, parasomnias, abnormal sleep structure, and notably reduced REM-sleep proportion are provided. The potential role of abnormal melatonin production in the origins of sleep disturbances in children with mental retardation is discussed. Certain approaches to pharmacological and non-pharmacological corrections of sleep disorders are outlined.

  2. Impact of Machine Breakdowns on Productivity

    Directory of Open Access Journals (Sweden)

    Anwaruddin Tanwari

    2011-10-01

    Full Text Available This paper reports the machine breakdowns and their impact on the total productivity for the FMCGs (Fast Moving Consumer Goods industry because higher productivity rate is important factor on which the customer services largely depend in this competitive business world. This paper also suggests that the machine breakdowns and other related problems within the plant are due to improper care, keeping the plant operative for twenty four hours a day, seven days a week without any break and lack of management\\'s concentration towards these issues. These break-downs results in un-timely closure of the plant and very poor production performance is achieved in the plant that affects the service level at great level. Realising the importance of maintenance in improving productivity and service, an attempt has been made in this paper to study the scope of maintenance with the help of a case study.

  3. The Electrical Breakdown of Thin Dielectric Elastomers

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed

    2014-01-01

    Dielectric elastomers are being developed for use in actuators, sensors and generators to be used in various applications, such as artificial eye lids, pressure sensors and human motion energy generators. In order to obtain maximum efficiency, the devices are operated at high electrical fields....... This increases the likelihood for electrical breakdown significantly. Hence, for many applications the performance of the dielectric elastomers is limited by this risk of failure, which is triggered by several factors. Amongst others thermal effects may strongly influence the electrical breakdown strength....... In this study, we model the electrothermal breakdown in thin PDMS based dielectric elastomers in order to evaluate the thermal mechanisms behind the electrical failures. The objective is to predict the operation range of PDMS based dielectric elastomers with respect to the temperature at given electric field...

  4. Education of Mentally Retarded Adults

    Directory of Open Access Journals (Sweden)

    Dora Jelenc

    2000-12-01

    Full Text Available Adult education of people with severe, modest and profound mental retardation got only recently an important place in the special education theory and practice. It could be established that in this area both in the intentional as well as in the contentual field the meaningfull shift has been achieved. Today we are talking about authonomy and rights of these people to taking part in a decission-making about the way of their living, but on the other  side the fast development and changes in society are again and again compelling this people to the decisions which they are not able to put into effect and which are burdening them and making them dependent of others. This could partly be prevented by continuing education as it is also true for them that in the stage of initial education they cannot subdue everything what they would need later in their life. Next to the findings of the foreign experts this has been confirmed as well in the first our investigations in this area. Some of the findings will be presented in our paper.

  5. A, a Brominated Flame Retardant

    Directory of Open Access Journals (Sweden)

    Tomomi Takeshita

    2013-01-01

    Full Text Available Tetrabromobisphenol A (TBBPA, a brominated flame retardant, has been found to exacerbate pneumonia in respiratory syncytial virus- (RSV- infected mice. We examined the effect of Brazilian propolis (AF-08 on the exacerbation of RSV infection by TBBPA exposure in mice. Mice were fed a powdered diet mixed with 1% TBBPA alone, 0.02% AF-08 alone, or 1% TBBPA and 0.02% AF-08 for four weeks and then intranasally infected with RSV. TBBPA exposure increased the pulmonary virus titer and level of IFN-γ, a representative marker of pneumonia due to RSV infection, in the lungs of infected mice without toxicity. AF-08 was significantly effective in reducing the virus titers and IFN-γ level increased by TBBPA exposure. Also, AF-08 significantly reduced proinflammatory cytokine (TNF-α and IL-6 levels in the lungs of RSV-infected mice with TBBPA exposure, but Th2 cytokine (IL-4 and IL-10 levels were not evidently increased. Neither TBBPA exposure nor AF-08 treatment affected the anti-RSV antibody production in RSV-infected mice. In flow cytometry analysis, AF-08 seemed to be effective in reducing the ratio of pulmonary CD8a+ cells in RSV-infected mice with TBBPA exposure. TBBPA and AF-08 did not exhibit anti-RSV activity in vitro. Thus, AF-08 probably ameliorated pneumonia exacerbated by TBBPA exposure in RSV-infected mice by limiting excess cellular immune responses.

  6. NASA Work Breakdown Structure (WBS) Handbook

    Science.gov (United States)

    Terrell, Stefanie M.

    2018-01-01

    The purpose of this document is to provide program/project teams necessary instruction and guidance in the best practices for Work Breakdown Structure (WBS) and WBS dictionary development and use for project implementation and management control. This handbook can be used for all types of NASA projects and work activities including research, development, construction, test and evaluation, and operations. The products of these work efforts may be hardware, software, data, or service elements (alone or in combination). The aim of this document is to assist project teams in the development of effective work breakdown structures that provide a framework of common reference for all project elements.

  7. Project management strategies for prototyping breakdowns

    DEFF Research Database (Denmark)

    Granlien, Maren Sander; Pries-Heje, Jan; Baskerville, Richard

    2009-01-01

    , managing the explorative and iterative aspects of prototyping projects is not a trivial task. We examine the managerial challenges in a small scale prototyping project in the Danish healthcare sector where a prototype breakdown and project escalation occurs. From this study we derive a framework...... of strategies for coping with escalation in troubled prototyping projects; the framework is based on project management triangle theory and is useful when considering how to manage prototype breakdown and escalation. All strategies were applied in the project case at different points in time. The strategies led...

  8. Vortex breakdown in a supersonic jet

    Science.gov (United States)

    Cutler, Andrew D.; Levey, Brian S.

    1991-01-01

    This paper reports a study of a vortex breakdown in a supersonic jet. A supersonic vortical jets were created by tangential injection and acceleration through a convergent-divergent nozzle. Vortex circulation was varied, and the nature of the flow in vortical jets was investigated using several types of flow visualization, including focusing schlieren and imaging of Rayleigh scattering from a laser light sheet. Results show that the vortical jet mixed much more rapidly with the ambient air than a comparable straight jet. When overexpanded, the vortical jet exhibited considerable unsteadiness and showed signs of vortex breakdown.

  9. Breakdowns in Coordination Between Air Traffic Controllers

    Science.gov (United States)

    Bearman, Chris; Orasanu, Judith; Miller, Ronald C.

    2011-01-01

    This talk outlines the complexity of coordination in air traffic control, introduces the NextGen technologies, identifies common causes for coordination breakdowns in air traffic control and examines whether these causes are likely to be reduced with the introduction of NextGen technologies. While some of the common causes of breakdowns will be reduced in a NextGen environment this conclusion should be drawn carefully given the current stage of development of the technologies and the observation that new technologies often shift problems rather than reduce them.

  10. The Political Values of Mentally Retarded Citizens.

    Science.gov (United States)

    Green, Barbara B.; Klein, Nancy K.

    1980-01-01

    The findings indicated that the retarded are affected by the process of political socialization much like their nonretarded peers. In forming a ranking of goal-values, age and socioeconomic status outweighed differences in cognitive ability. (Author/DLS)

  11. Nanocellular foam with solid flame retardant

    Science.gov (United States)

    Chen, Liang; Kelly-Rowley, Anne M.; Bunker, Shana P.; Costeux, Stephane

    2017-11-21

    Prepare nanofoam by (a) providing an aqueous solution of a flame retardant dissolved in an aqueous solvent, wherein the flame retardant is a solid at 23.degree. C. and 101 kiloPascals pressure when in neat form; (b) providing a fluid polymer composition selected from a solution of polymer dissolved in a water-miscible solvent or a latex of polymer particles in a continuous aqueous phase; (c) mixing the aqueous solution of flame retardant with the fluid polymer composition to form a mixture; (d) removing water and, if present, solvent from the mixture to produce a polymeric composition having less than 74 weight-percent flame retardant based on total polymeric composition weight; (e) compound the polymeric composition with a matrix polymer to form a matrix polymer composition; and (f) foam the matrix polymer composition into nanofoam having a porosity of at least 60 percent.

  12. Mental Retardation, Poverty and Community Based Rehabilitation

    Directory of Open Access Journals (Sweden)

    Einar Helander

    2009-10-01

    Full Text Available A person with moderate mental retardation would, in a western country, be "diagnosed" early on in life. Consequently, such a child is likely to be sent for special education. Given the high level of job requirements, such a person is unlikely to be employed in the open market later in life. Mental retardation is one of the most frequent disabilities in most studies, mental retardation is found in about three percent of the population. Persons even with mild mental retardation have very large difficulties finding employment and are for this reason often deprived of opportunities for suitable and productive income generation this is why most stay poor. But disability does not only cause poverty poverty itself causes disability. This study follows an analysis, based on a review of the Swedish programme for mental retardation during the period 1930-2000. It is concluded that in Sweden a very large proportion of mild and moderate mental retardation has been eliminated though the combination of poverty alleviation with a community-based rehabilitation programme. For these situations a pro-active programme analysing and meeting the needs of the target groups should be useful as a means to achieve poverty alleviation.

  13. A Model for the Onset of Vortex Breakdown

    Science.gov (United States)

    Mahesh, K.

    1996-01-01

    A large body of information exists on the breakdown of incompressible streamwise vortices. Less is known about vortex breakdown at high speeds. An interesting example of supersonic vortex breakdown is the breakdown induced by the interaction of vortices with shock waves. The flow in supersonic engine inlets and over high-speed delta wings constitute technologically important examples of this phenomenon, which is termed 'shock-induced vortex breakdown'. In this report, we propose a model to predict the onset of shock-induced vortex breakdown. The proposed model has no adjustable constants, and is compared to both experiment and computation. The model is then extended to consider two other problems: the breakdown of a free compressible vortex, and free incompressible vortex breakdown. The same breakdown criterion is used in all three problems to predict the onset of breakdown. Finally, a new breakdown map is proposed that allows the simultaneous comparison of data from flows ranging from incompressible breakdown to breakdown induced by a shock wave.

  14. Spontaneous symmetry breakdown in gauge theories

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1982-01-01

    The dynamical theory of spontaneous breakdown correctly predicts the bound states and relates the order parameters of electron-photon superconductivity and quark-gluon chiral symmetry. A similar statement cannot be made for the standard electro-weak gauge symmetry. (author)

  15. Vortex breakdown in a truncated conical bioreactor

    DEFF Research Database (Denmark)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.

    2015-01-01

    . It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as Hw varies. The changes are due to (a) competing effects of AMF (the air meridional...

  16. Investigation of multipactor breakdown in communication satellite

    Indian Academy of Sciences (India)

    Multipactor breakdown or multipactor discharge is a form of high frequency discharge that may occur in microwave components operating at very low pressures. Some RF components of multi-channel communication satellites have co-axial geometry and handle high RF power under near-vacuum conditions.

  17. Breakdown and bad luck in Biblis

    International Nuclear Information System (INIS)

    Randow, G. von.

    1994-01-01

    Five minor breakdowns within a month have heated up the dispute between the ministries of the environment of the Federation and the Land of Hesse. Biblis A is to be shut down at all costs. As yet, however, the Hessian Ministry of the Environment has not solved the question of how to compensate the power cut. (DG) [de

  18. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Mateiu, Ramona Valentina; Skov, Anne Ladegaard

    2017-01-01

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al[2] and we investigate the electrical...

  19. Fear of breakdown and the unlived life.

    Science.gov (United States)

    Ogden, Thomas H

    2014-04-01

    Winnicott's Fear of breakdown is an unfinished work that requires that the reader be not only a reader, but also a writer of this work which often gestures toward meaning as opposed to presenting fully developed ideas. The author's understanding of the often confusing, sometimes opaque, argument of Winnicott's paper is as follows. In infancy there occurs a breakdown in the mother-infant tie that forces the infant to take on, by himself, emotional events that he is unable to manage. He short-circuits his experience of primitive agony by generating defense organizations that are psychotic in nature, i.e., they substitute self-created inner reality for external reality, thus foreclosing his actually experiencing critical life events. By not experiencing the breakdown of the mother-infant tie when it occurred in infancy, the individual creates a psychological state in which he lives in fear of a breakdown that has already happened, but which he did not experience. The author extends Winnicott's thinking by suggesting that the driving force of the patient's need to find the source of his fear is his feeling that parts of himself are missing and that he must find them if he is to become whole. What remains of his life feels to him like a life that is mostly an unlived life. Copyright © 2014 Institute of Psychoanalysis.

  20. Numerical Borehole Breakdown Investigations using XFEM

    Science.gov (United States)

    Beckhuis, Sven; Leonhart, Dirk; Meschke, Günther

    2016-04-01

    During pressurization of a wellbore a typical downhole pressure record shows the following regimes: first the applied wellbore pressure balances the reservoir pressure, then after the compressive circumferential hole stresses are overcome, tensile stresses are induced on the inside surface of the hole. When the magnitude of these stresses reach the tensile failure stress of the surrounding rock medium, a fracture is initiated and propagates into the reservoir. [1] In standard theories this pressure, the so called breakdown pressure, is the peak pressure in the down-hole pressure record. However experimental investigations [2] show that the breakdown did not occur even if a fracture was initiated at the borehole wall. Drilling muds had the tendency to seal and stabilize fractures and prevent fracture propagation. Also fracture mechanics analysis of breakdown process in mini-frac or leak off tests [3] show that the breakdown pressure could be either equal or larger than the fracture initiation pressure. In order to gain a deeper understanding of the breakdown process in reservoir rock, numerical investigations using the extended finite element method (XFEM) for hydraulic fracturing of porous materials [4] are discussed. The reservoir rock is assumed to be pre-fractured. During pressurization of the borehole, the injection pressure, the pressure distribution and the position of the highest flux along the fracture for different fracturing fluid viscosities are recorded and the influence of the aforementioned values on the stability of fracture propagation is discussed. [1] YEW, C. H. (1997), "Mechanics of Hydraulic Fracturing", Gulf Publishing Company [2] MORITA, N.; BLACK, A. D.; FUH, G.-F. (1996), "Borehole Breakdown Pressure with Drilling Fluids". International Journal of Rock Mechanics and Mining Sciences 33, pp. 39-51 [3] DETOURNAY, E.; CARBONELL, R. (1996), "Fracture Mechanics Analysis of the Breakdown Process in Minifrac or Leakoff Test", Society of Petroleum

  1. Intrauterine radiation exposures and mental retardation

    International Nuclear Information System (INIS)

    Miller, R.W.

    1988-01-01

    Small head size and mental retardation have been known as effects of intrauterine exposure to ionizing radiation since the 1920s. In the 1950s, studies of Japanese atomic-bomb survivors revealed that at 4-17 wk of gestation, the greater the dose, the smaller the brain (and head size), and that beginning at 0.5 Gy (50 rad) in Hiroshima, mental retardation increased in frequency with increasing dose. No other excess of birth defects was observed. Otake and Schull (1984) pointed out that the period of susceptibility to mental retardation coincided with that for proliferation and migration of neuronal elements from near the cerebral ventricles to the cortex. Mental retardation could be the result of interference with this process. Their analysis indicated that exposures at 8-15 wk to 0.01-0.02 Gy (1-2 rad) doubled the frequency of severe mental retardation. This estimate was based on small numbers of mentally retarded atomic-bomb survivors. Although nuclear accidents have occurred recently, new cases will hopefully be too rare to provide further information about the risk of mental retardation. It may be possible, however, to learn about lesser impairment. New psychometric tests may be helpful in detecting subtle deficits in intelligence or neurodevelopmental function. One such test is PEERAMID, which is being used in schools to identify learning disabilities due, for example, to deficits in attention, short- or long-term memory, or in sequencing information. This and other tests could be applied in evaluating survivors of intrauterine exposure to various doses of ionizing radiation. The results could change our understanding of the safety of low-dose exposures

  2. A computational study of the taxonomy of vortex breakdown

    Science.gov (United States)

    Spall, Robert E.; Gatski, Thomas B.

    1990-01-01

    The results of a fully three-dimensional numerical simulation of vortex breakdown using the unsteady, incompressible Navier-Stokes equations are presented. The solutions show that the freestream axial velocity distribution has a significant effect on the position and type of vortex breakdown. Common features between bubble-type and spiral-type breakdown are identified and the role of flow stagnation and the critical state are discussed as complimentary ideas describing the initiation of breakdown.

  3. Differentiation of retarded integrals and the divergence theorem for retarded functions with discontinuities

    International Nuclear Information System (INIS)

    Cooperstock, F.I.; Lim, P.H.

    1986-01-01

    Theorems expressing the time derivatives of retarded volume and surface integrals are presented as well as the Gauss divergence theorem for retarded functions with discontinuities. These theorems greatly facilitate the analysis of gravitational radiation from the motion of disjoint matter distributions in general relativity and could find useful application in other branches of physics

  4. [Clinical features of strabismus in psychomotor retardation].

    Science.gov (United States)

    Arias-Cabello, Belina; Arroyo-Yllanes, María Estela; Pérez-Pérez, José Fernando; Fonte-Vázquez, Anselmo

    2016-01-01

    In psychomotor retardation there is an abnormal development of mental, sensory and motor skills associated with ocular manifestations. There are biological and psychosocial risk factors that predispose an individual to neurological damage. From 50% to 80% of patients with strabismus retardation have special features that differentiate it from the rest of strabismus in healthy patients. To determine the most common type of strabismus in patients with psychomotor retardation and their clinical features. Patients with psychomotor retardation and strabismus were included. An ophthalmological examination was performed, as well as an evaluation of the characteristics of strabismus, including perinatal and post-natal history. Esotropia was the most frequent squint with 65.3%, followed by exotropia with 32.7%. The variability in the squint magnitude was 60% in both types, and 6 patients had dissociated vertical deviation. Most of the patients started to present strabismus since they were born. The most frequent perinatal risk factors were threatened miscarriage, pre-eclampsia, foetal distress, and hypoxia. Esotropia is the most common type of strabismus in psychomotor retardation. The variability of squint magnitude is a characteristic in these patients. The moderate variability is the most frequent in both esotropia and exotropia. The most common refractive error is hyperopic astigmatism in esotropia and the myopic kind in exotropia. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  5. Flame-retardant carbon nanotube films

    Science.gov (United States)

    Janas, Dawid; Rdest, Monika; Koziol, Krzysztof K. K.

    2017-07-01

    We have demonstrated fire-retardancy properties of a polymer matrix-free CNT film for the first time. As compared with classical fire-retardant materials such as Kevlar, Twaron or Nomex, the CNT film showed a spectrum of advantages. The material is lightweight, flexible and well-adherent to even the most complicated shapes. The results have showed that by using CNTs for fire-retardancy we can extend the operational time almost two-fold, what makes CNTs a much better protection than the solutions employed nowadays. We believe that among other great properties of CNT, their macroscopic assemblies such as CNT films show significant potential for becoming a fire protective coating, which exhibits high performance in not sustaining fire.

  6. Electrical breakdown studies with Mycalex insulators

    International Nuclear Information System (INIS)

    Waldron, W.; Greenway, W.; Eylon, S.; Henestroza, E.; Yu, S.

    2003-01-01

    Insulating materials such as alumina and glass-bonded mica (Mycalex) are used in accelerator systems for high voltage feedthroughs, structural supports, and barriers between high voltage insulating oil and the vacuum beam pipe in induction accelerator cells. Electric fields in the triple points should be minimized to prevent voltage breakdown. Mechanical stress can compromise seals and result in oil contamination of the insulator surface. We have tested various insulator cleaning procedures including ultrasonic cleaning with a variety of aqueous-based detergents, and manual scrubbing with various detergents. Water sheeting tests were used to determine the initial results of the cleaning methods. Ultimately, voltage breakdown tests will be used to quantify the benefits of these cleaning procedures

  7. Prevention of breakdown behind railgun projectiles

    International Nuclear Information System (INIS)

    Hawke, R.S.

    1992-01-01

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF 6 . The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs

  8. Supersonic quasi-axisymmetric vortex breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1991-01-01

    An extensive computational study of supersonic quasi-axisymmetric vortex breakdown in a configured circular duct is presented. The unsteady, compressible, full Navier-Stokes (NS) equations are used. The NS equations are solved for the quasi-axisymmetric flows using an implicit, upwind, flux difference splitting, finite volume scheme. The quasi-axisymmetric solutions are time accurate and are obtained by forcing the components of the flowfield vector to be equal on two axial planes, which are in close proximity of each other. The effect of Reynolds number, for laminar flows, on the evolution and persistence of vortex breakdown, is studied. Finally, the effect of swirl ration at the duct inlet is investigated.

  9. Breakdown Studies for the CLIC Accelerating

    CERN Document Server

    Calatroni, S; Kovermann, J; Taborelli, M; Timko, H; Wuensch, W; Durabekova, F; Nordlund, K; Pohjonen, A; Kuronen, A

    2010-01-01

    Optimizing the design and the manufacturing of the CLIC RF accelerating structures for achieving the target value of breakdown rate at the nominal accelerating gradient of 100 MV/m requires a detailed understanding of all the steps involved in the mechanism of breakdown. These include surface modification under RF fields, electron emission and neutral evaporation in the vacuum, arc ignition and consequent surface modification due to plasma bombardment. Together with RF tests, experiments are conducted in a simple DC test set-up instrumented with electrical diagnostics and optical spectroscopy. The results are also used for validating simulations which are performed using a wide range of numerical tools (MD coupled to electrostatic codes, PIC plasma simulations) able to include all the above phenomena. Some recent results are presented in this paper

  10. Bioavailability of glucosinolates and their breakdown products

    DEFF Research Database (Denmark)

    Barba Orellana, Francisco Jose; Nikmaram, Nooshin; Roohinejad, Shahin

    2016-01-01

    Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized ...... the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability....

  11. Topology hidden behind the breakdown of adiabaticity

    International Nuclear Information System (INIS)

    Fu, L.-B.; Chen, S.-G.

    2005-01-01

    For classical Hamiltonian systems, the adiabatic condition may fail at some critical points. However, the breakdown of the adiabatic condition does not always cause the adiabatic evolution to be destroyed. In this paper, we suggest a supplemental condition of the adiabatic evolution for the fixed points of classical Hamiltonian systems when the adiabatic condition breaks down at the critical points. As an example, we investigate the adiabatic evolution of the fixed points of a classical Hamiltonian system which has a number of applications

  12. Three-dimensional simulation of vortex breakdown

    Science.gov (United States)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  13. Electrical Breakdown Phenomena Involving Material Interfaces

    Science.gov (United States)

    2013-06-01

    create ozone through chemical reactions involving reactive species created by the electrical discharge [3]. The glow discharge breakdown in such...2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Investigation Of Pre-Ionization And Atmospheric Pulsed Discharge Plasma 5a...growth of the air discharge in the form of a conductive filament consisting of electrons and ions. This filament is created by temporal pulse that

  14. Breakdown localization in the fixed gap system

    CERN Document Server

    Rajamaki, Robin; Wuensch, Walter

    2014-01-01

    Accurate localization of breakdowns in vacuum could help shed light on breakdown related processes that are not yet fully understood. At the DC spark lab at CERN, an instrument called the Fixed Gap System (FGS) has been developed partially for this purpose. Among other things, the FGS has four built-in antennas, which are intended for breakdown localization. The capability of this aspect of the FGS was explored in this report. Specifically, the feasibility of using a method similar to that which is used in cavity Beam Position Monitors (BPMs) was investigated. The usable frequency range of the current experimental setup was also studied. Firstly, a modal analysis of the inner geometry of the FGS was done in HFSS. This showed that the two first modes to be expected in the spark gap quite differ from those of the ideal pillbox – both in field pattern and in frequency ( 4 and 6 GHz vs. 0.2 and 3 GHz). Secondly, S-parameters of the system were measured. These showed that the coupling between antennas is weak...

  15. Kinetic Simulations of Dense Plasma Focus Breakdown

    Science.gov (United States)

    Schmidt, A.; Higginson, D. P.; Jiang, S.; Link, A.; Povilus, A.; Sears, J.; Bennett, N.; Rose, D. V.; Welch, D. R.

    2015-11-01

    A dense plasma focus (DPF) device is a type of plasma gun that drives current through a set of coaxial electrodes to assemble gas inside the device and then implode that gas on axis to form a Z-pinch. This implosion drives hydrodynamic and kinetic instabilities that generate strong electric fields, which produces a short intense pulse of x-rays, high-energy (>100 keV) electrons and ions, and (in deuterium gas) neutrons. A strong factor in pinch performance is the initial breakdown and ionization of the gas along the insulator surface separating the two electrodes. The smoothness and isotropy of this ionized sheath are imprinted on the current sheath that travels along the electrodes, thus making it an important portion of the DPF to both understand and optimize. Here we use kinetic simulations in the Particle-in-cell code LSP to model the breakdown. Simulations are initiated with neutral gas and the breakdown modeled self-consistently as driven by a charged capacitor system. We also investigate novel geometries for the insulator and electrodes to attempt to control the electric field profile. The initial ionization fraction of gas is explored computationally to gauge possible advantages of pre-ionization which could be created experimentally via lasers or a glow-discharge. Prepared by LLNL under Contract DE-AC52-07NA27344.

  16. Runaway breakdown and electrical discharges in thunderstorms

    Science.gov (United States)

    Milikh, Gennady; Roussel-Dupré, Robert

    2010-12-01

    This review considers the precise role played by runaway breakdown (RB) in the initiation and development of lightning discharges. RB remains a fundamental research topic under intense investigation. The question of how lightning is initiated and subsequently evolves in the thunderstorm environment rests in part on a fundamental understanding of RB and cosmic rays and the potential coupling to thermal runaway (as a seed to RB) and conventional breakdown (as a source of thermal runaways). In this paper, we describe the basic mechanism of RB and the conditions required to initiate an observable avalanche. Feedback processes that fundamentally enhance RB are discussed, as are both conventional breakdown and thermal runaway. Observations that provide clear evidence for the presence of energetic particles in thunderstorms/lightning include γ-ray and X-ray flux intensifications over thunderstorms, γ-ray and X-ray bursts in conjunction with stepped leaders, terrestrial γ-ray flashes, and neutron production by lightning. Intense radio impulses termed narrow bipolar pulses (or NBPs) provide indirect evidence for RB particularly when measured in association with cosmic ray showers. Our present understanding of these phenomena and their enduring enigmatic character are touched upon briefly.

  17. Dispersion of breakdown voltage of liquid helium

    International Nuclear Information System (INIS)

    Ishii, Itaru; Noguchi, Takuya

    1978-01-01

    As for the electrical insulation characteristics of liquid helium, the discrepancy among the measured values by each person is very large even in the fundamental DC breakdown voltage in uniform electric field. The dispersion of experimental values obtained in the experiments by the same person is also large. Hereafter, the difference among the mean values obtained by each experimenter will be referred to as ''deviation of mean values'', and the dispersion of measured values around the mean value obtained by the same person as ''deviation around the man value''. The authors have mainly investigated on the latter experimentally. The cryostat was made of stainless steel, and the innermost helium chamber was of 500 mm I.D. and approximately 1200 mm deep. The high voltage electrode was of brass sphere of 25 mm diameter, and the low voltage electrode was of brass plate. The experiment was conducted for liquid helium boiling at 4.2 K and 1 atm, and the breakdown voltage and time lag were measured by applying the approximately square wave impulses of fast rise and long tail, ramp and DC voltages. The cause of the deviation of mean values may be the presence of impurity particles or the effect of electrode shape. As for the deviation around the mean value, the dispersion is large, and its standard deviation may amount to 10 to 20% of the man value. The dispersion is not due to the statistical time lag, but is due to parameters that vary with breakdown. (Wakatsuki, Y.)

  18. Flexible PVC flame retarded with expandable graphite

    CSIR Research Space (South Africa)

    Focke, WW

    2014-02-01

    Full Text Available this outstanding fire resistance. Thus flame-retardant (FR) and smoke-suppressant (SS) additives must be incorporated in order to meet product test specifications such as oxygen index, heat release rate, smoke evolution, or the extent of burning [1]. Levchik... plot for the composites fabricated in this work. For a material to be effectively flame retarded both the fire load and the fire growth index should assume low values. Figure 11 shows a dramatic decrease for all the EG composites relative to the neat...

  19. Shock/vortex interaction and vortex-breakdown modes

    Science.gov (United States)

    Kandil, Osama A.; Kandil, H. A.; Liu, C. H.

    1992-01-01

    Computational simulation and study of shock/vortex interaction and vortex-breakdown modes are considered for bound (internal) and unbound (external) flow domains. The problem is formulated using the unsteady, compressible, full Navier-Stokes (NS) equations which are solved using an implicit, flux-difference splitting, finite-volume scheme. For the bound flow domain, a supersonic swirling flow is considered in a configured circular duct and the problem is solved for quasi-axisymmetric and three-dimensional flows. For the unbound domain, a supersonic swirling flow issued from a nozzle into a uniform supersonic flow of lower Mach number is considered for quasi-axisymmetric and three-dimensional flows. The results show several modes of breakdown; e.g., no-breakdown, transient single-bubble breakdown, transient multi-bubble breakdown, periodic multi-bubble multi-frequency breakdown and helical breakdown.

  20. Comparative Studies of High-Gradient Rf and Dc Breakdowns

    CERN Document Server

    Kovermann, Jan Wilhelm; Wuensch, Walter

    2010-01-01

    The CLIC project is based on normal-conducting high-gradient accelerating structures with an average accelerating gradient of 100 MV/m. The maximum achievable gradient in these structures is limited by the breakdown phenomenon. The physics of breakdowns is not yet fully understood quantitatively. A full knowledge could have strong impact on the design, material choice and construction of rf structures. Therefore, understanding breakdowns has great importance to reaching a gradient of 100MV/m with an acceptable breakdown probability. This thesis addresses the physics underlying the breakdown effect, focusing on a comparison of breakdowns in rf structures and in a dc spark setup. The dc system is simpler, easier to benchmark against simulations, with a faster turnaround time, but the relationship to rf breakdown must be established. To do so, an experimental approach based on optical diagnostics and electrical measurements methods was made. Following an introduction into the CLIC project, a general theoretical ...

  1. The effect of eicosapentaenoic and docosahexaenoic acid on protein synthesis and breakdown in murine C2C12 myotubes

    International Nuclear Information System (INIS)

    Kamolrat, Torkamol; Gray, Stuart R.

    2013-01-01

    Highlights: ► EPA can enhance protein synthesis and retard protein breakdown in muscle cells. ► These effects were concurrent with increases in p70s6k and FOXO3a phosphorylation. ► EPA may be a useful tool in the treatment of muscle wasting conditions. -- Abstract: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been found to stimulate protein synthesis with little information regarding their effects on protein breakdown. Furthermore whether there are distinct effects of EPA and DHA remains to be established. The aim of the current study was to determine the distinct effects of EPA and DHA on protein synthesis, protein breakdown and signalling pathways in C2C12 myotubes. Fully differentiated C2C12 cells were incubated for 24 h with 0.1% ethanol (control), 50 μM EPA or 50 μM DHA prior to experimentation. After serum (4 h) and amino acid (1 h) starvation cells were stimulated with 2 mM L-leucine and protein synthesis measured using 3 H-labelled phenylalanine. Protein breakdown was measured using 3 H-labelled phenylalanine and signalling pathways (Akt, mTOR, p70S6k, 4EBP1, rps6 and FOXO3a) via Western blots. Data revealed that after incubation with EPA protein synthesis was 25% greater (P < 0.05) compared to control cells, with no effect of DHA. Protein breakdown was 22% (P < 0.05) lower, compared to control cells, after incubation with EPA, with no effect of DHA. Analysis of signalling pathways revealed that both EPA and DHA incubation increased (P < 0.05) p70s6k phosphorylation, EPA increased (P < 0.05) FOXO3a phosphorylation, with no alteration in other signalling proteins. The current study has demonstrated distinct effects of EPA and DHA on protein metabolism with EPA showing a greater ability to result in skeletal muscle protein accretion

  2. The effect of eicosapentaenoic and docosahexaenoic acid on protein synthesis and breakdown in murine C2C12 myotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kamolrat, Torkamol [Musculoskeletal Research Programme, Institute of Medical Sciences, University of Aberdeen, AB25 2ZD (United Kingdom); Gray, Stuart R., E-mail: s.r.gray@abdn.ac.uk [Musculoskeletal Research Programme, Institute of Medical Sciences, University of Aberdeen, AB25 2ZD (United Kingdom)

    2013-03-22

    Highlights: ► EPA can enhance protein synthesis and retard protein breakdown in muscle cells. ► These effects were concurrent with increases in p70s6k and FOXO3a phosphorylation. ► EPA may be a useful tool in the treatment of muscle wasting conditions. -- Abstract: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been found to stimulate protein synthesis with little information regarding their effects on protein breakdown. Furthermore whether there are distinct effects of EPA and DHA remains to be established. The aim of the current study was to determine the distinct effects of EPA and DHA on protein synthesis, protein breakdown and signalling pathways in C2C12 myotubes. Fully differentiated C2C12 cells were incubated for 24 h with 0.1% ethanol (control), 50 μM EPA or 50 μM DHA prior to experimentation. After serum (4 h) and amino acid (1 h) starvation cells were stimulated with 2 mM L-leucine and protein synthesis measured using {sup 3}H-labelled phenylalanine. Protein breakdown was measured using {sup 3}H-labelled phenylalanine and signalling pathways (Akt, mTOR, p70S6k, 4EBP1, rps6 and FOXO3a) via Western blots. Data revealed that after incubation with EPA protein synthesis was 25% greater (P < 0.05) compared to control cells, with no effect of DHA. Protein breakdown was 22% (P < 0.05) lower, compared to control cells, after incubation with EPA, with no effect of DHA. Analysis of signalling pathways revealed that both EPA and DHA incubation increased (P < 0.05) p70s6k phosphorylation, EPA increased (P < 0.05) FOXO3a phosphorylation, with no alteration in other signalling proteins. The current study has demonstrated distinct effects of EPA and DHA on protein metabolism with EPA showing a greater ability to result in skeletal muscle protein accretion.

  3. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A

  4. Brominated flame retardants and endocrine disruption

    NARCIS (Netherlands)

    Vos, J.G.; Becher, G.; Berg, van den M.; Boer, de J.; Leonards, P.E.G.

    2003-01-01

    From an environmental point of view, an increasing important group of organohalogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production volume

  5. Brominated flame retardants and endocrine disruption

    NARCIS (Netherlands)

    Vos, Joseph G.; Becher, Georg; Van Den Berg, Martin; Leonards, Pim E G

    2003-01-01

    From an environmental point of view, an increasing important group of organo-halogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production

  6. Retarded hippocampal development following prenatal exposure to ...

    African Journals Online (AJOL)

    Results: Rats in Group A showed no implantation, rats in Group B had abortion on the 7th day after administration, and rats in Group C gave birth with their litters showing retarded hippocampus development and neural degeneration and rats in Group D (control) showed normal development. Conclusion: Ethanolic extract of ...

  7. International Directory of Mental Retardation Resources.

    Science.gov (United States)

    Dybwad, Rosemary F., Ed.

    The directory lists and describes governmental and voluntary agencies, research, and other resources in the field of mental retardation in foreign countries. The first section, on international organizations, gives names, addresses, names of directors, and one or more paragraphs of description for the United Nations and its specialized agencies,…

  8. Improving Outcomes for Workers with Mental Retardation

    Science.gov (United States)

    Fornes, Sandra; Rocco, Tonette S.; Rosenberg, Howard

    2008-01-01

    This research presents an analysis of factors predicting job retention, job satisfaction, and job performance of workers with mental retardation. The findings highlight self-determination as a critical skill in predicting the three important employee outcomes. The study examined a hypothesized job retention model and the outcome of the three…

  9. Euthanasia and Mental Retardation: Suggesting the Unthinkable.

    Science.gov (United States)

    Hollander, Russell

    1989-01-01

    The article examines current opinions toward euthanasia of persons with mental retardation in light of the history of public and professional attitudes. It also discusses the rejection of euthanasia on moral and religious grounds, and notes the use of lifelong incarceration, based on eugenics principles, to accomplish similar ends. (DB)

  10. Opitz C syndrome: Trigonocephaly, mental retardation and ...

    African Journals Online (AJOL)

    We describe a 4-year-old female child with a dysmorphic and neurological syndrome of trigonocephaly, mental and psychomotor retardation and dysmorphic facial ... The patient had important cerebral anomalies with diffuse alterations in white matter that caused developmental delay with verbal and nonverbal disabilities ...

  11. Puberty in the Girl Who is Retarded.

    Science.gov (United States)

    Pattullo, Ann

    Designed to help mothers of mentally retarded girls deal with the problems and concerns of puberty, the booklet provides information on physical and emotional changes, menstruation, masturbation, heterosexual behavior, contraception, protection against sexual aggression, the possibilities of marriage, and additional sources of information.…

  12. Skin mastocytosis, hearing loss and mental retardation

    NARCIS (Netherlands)

    Hennekam, R. C.; Beemer, F. A.

    1992-01-01

    A girl with skin mastocytosis, hearing loss, microcephaly, mild dysmorphic features and severe mental retardation is described. The symptoms of the child resemble those reported in 1990 by Wolach et al. in another patient sufficiently to suspect the same entity in both. Inheritance may be autosomal

  13. Computer Needs of Severely Mentally Retarded Persons.

    Science.gov (United States)

    Flanagan, Kelly

    1982-01-01

    The article reviews technology applicable for use by severely mentally retarded learners. Descriptions are given of assistive devices (including communication aids), controls and interfaces (such as single switch access to standard software), and software (including games to teach cause and effect and simple matching and counting). (CL)

  14. Preparation of Flame Retardant Modified with Titanate for Asphalt Binder

    Directory of Open Access Journals (Sweden)

    Bo Li

    2014-01-01

    Full Text Available Improving the compatibility between flame retardant and asphalt is a difficult task due to the complex nature of the materials. This study explores a low dosage compound flame retardant and seeks to improve the compatibility between flame retardants and asphalt. An orthogonal experiment was designed taking magnesium hydroxide, ammonium polyphosphate, and melamine as factors. The oil absorption and activation index were tested to determine the effect of titanate on the flame retardant additive. The pavement performance test was conducted to evaluate the effect of the flame retardant additive. Oxygen index test was conducted to confirm the effect of flame retardant on flame ability of asphalt binder. The results of this study showed that the new composite flame retardant is more effective in improving the compatibility between flame retardant and asphalt and reducing the limiting oxygen index of asphalt binder tested in this study.

  15. Nonretarded and Mentally Retarded Children's Control over Syntax Structures.

    Science.gov (United States)

    McLeavey, Breda C.; And Others

    1982-01-01

    Ten nonretarded preschoolers and 10 mildly mentally retarded children (mean age 8 years) were compared for control over various syntactic structures. The retarded children evidenced difficulties similar to those of younger nonretarded children. (Author/SB)

  16. Effectiveness of Flame Retardants in TufFoam.

    Energy Technology Data Exchange (ETDEWEB)

    Abelow, Alexis Elizabeth [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Nissen, April [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Massey, Lee Taylor [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-12-01

    An investigation of polyurethane foam filled with known flame retardant fillers including hydroxides, melamine, phosphate-containing compounds, and melamine phosphates was carried out to produce a low-cost material with high flame retardant efficiency. The impact of flame retardant fillers on the physical properties such a s composite foam density, glass transition temperature, storage modulus, and thermal expansion of composite foams was investigated with the goal of synthesizing a robust rigid foam with excellent flame retardant properties.

  17. Study of chelating agent as a surface modifier for retarding corrosion attack on ferrous metal

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Muhamad Daud; Siti Radiah Mohd Kamarudin; Zaifol Samsu; Azali Muhamad; Rusni Rejab; Mohd Saari Ripin; Mohd Shariff Sattar

    2010-01-01

    A different concentration of chelating agents in electrolyte of 3.5 % NaCl was applied to bare ferrous metal and tested for their effectiveness as a corrosion retardant. The performance of the samples was measured using corrosion measurement system. The results indicated that the contribution of chelating agent was expediting the reduction of the passive film. The anodic behavior was clearly found to be influenced by the concentration of the chelating agent. It was also found that some of the corrosion was apparently converted to protective layer over a period of time. Excessive moisture caused breakdown of film by removing the unreacted chelating agent and causing regrowth of the existing rust. (author)

  18. Flame retardancy and thermal degradation of cotton textiles based on UV-curable flame retardant coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Weiyi [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China); Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren' ai Road, Suzhou, Jiangsu 215123 (China); Jie, Ganxin [State Key Laboratory of Environmental Adaptability for Industrial Products, China National Electric Apparatus Research Institute, Guangzhou 510300 (China); Song, Lei; Hu, Shuang; Lv, Xiaoqi; Wang, Xin [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzai Road, Hefei, Anhui 230026 (China); Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren' ai Road, Suzhou, Jiangsu 215123 (China)

    2011-01-20

    The flame retardant coatings were prepared through UV-curable technique using tri(acryloyloxyethyl) phosphate (TAEP) and triglycidyl isocyanurate acrylate (TGICA). Results from FTIR-ATR spectroscopy and scanning electron microscopy (SEM) showed that flame retardant coatings were successfully coated onto the surface of cotton fabrics. The flame retardancy of the treated fabrics was studied by Micro-scale Combustion Calorimeter (MCC) and limited oxygen index (LOI). The cottons coated flame retardant coatings had the lower peak heat release rate (PHRR), heat release capacity (HRC), total heat of combustion (THC) and higher LOI value compared with untreated cotton. The results from TGA test showed that the flame retardant coatings lowered the decomposition temperature of treated fabric. The thermal decomposition of cottons was monitored by real time FTIR analysis and thermogravimetric analysis/infrared spectrometry (TGA-IR). The enhanced flame retardant action might be caused by thermal decomposition of TAEP structure, producing acidic intermediates, which could react with fabrics to alter its thermal decomposition process.

  19. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  20. Caring for children with mental retardation: The experiences of ...

    African Journals Online (AJOL)

    Caring for children with mental retardation at home requires great patience and understanding. Mothers often experience difficulties adjusting to the fact that their children are mentally retarded and that it cannot be cured. This study investigated the experiences of mothers caring for children with mental retardation.

  1. Anxious-retarded depression: relation to family history of depression

    NARCIS (Netherlands)

    de Winter, Remco F. P.; Zwinderman, Koos H.; Goekoop, Jaap G.

    2004-01-01

    Anxious-retarded depression is a two-dimensionally defined subcategory of depression based on high scores for both anxiety and retardation. The anxious-retarded subcategory is related to melancholia as defined by DSM-IV. Patients with this diagnosis exhibit elevated plasma arginine vasopressin (AVP)

  2. Need for spontaneous breakdown of chiral symmetry

    International Nuclear Information System (INIS)

    Salomone, A.; Schechter, J.; Tudron, T.

    1981-01-01

    The question of whether the chiral symmetry of the theory of strong interactions (with massless quarks) is required to be spontaneously broken is examined in the framework of a previously discussed effective Lagrangian for quantum chromodynamics. The assumption that physical masses of the theory be finite leads in a very direct way to the necessity of spontaneous breakdown. This result holds for all N/sub F/> or =2, where N/sub F/ is the number of different flavors of light quarks. The atypical cases N/sub F/ = 1,2 are discussed separately

  3. Criteria for vacuum breakdown in rf cavities

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  4. On spontaneous breakdown in Σ-models

    International Nuclear Information System (INIS)

    Ivanov, E.A.

    1975-01-01

    The group theory aspects of spontaneous breakdown in linear Σ-models are discussed. General conditions are formulated under which multiplet of group G (compact or noncompact) is suitable for constructing the Σ-model with a given subgroup of stability of vacuum. It is shown that the Σ-models of spontaneously broken space-time symmetries can be constructed in general only if some extra coordinates are introduced in addition to an ordinary 4-coordinate xsub(μ). The connection between Σ-models of internal symmetries and appropriate nonlinear realizations has also been investigated

  5. Ergodicity breakdown and scaling from single sequences

    Energy Technology Data Exchange (ETDEWEB)

    Kalashyan, Armen K. [Center for Nonlinear Science, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); Buiatti, Marco [Laboratoire de Neurophysique et Physiologie, CNRS UMR 8119 Universite Rene Descartes - Paris 5 45, rue des Saints Peres, 75270 Paris Cedex 06 (France); Cognitive Neuroimaging Unit - INSERM U562, Service Hospitalier Frederic Joliot, CEA/DRM/DSV, 4 Place du general Leclerc, 91401 Orsay Cedex (France); Grigolini, Paolo [Center for Nonlinear Science, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); Dipartimento di Fisica ' E.Fermi' - Universita di Pisa and INFM, Largo Pontecorvo 3, 56127 Pisa (Italy); Istituto dei Processi Chimico, Fisici del CNR Area della Ricerca di Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy)], E-mail: grigo@df.unipi.it

    2009-01-30

    In the ergodic regime, several methods efficiently estimate the temporal scaling of time series characterized by long-range power-law correlations by converting them into diffusion processes. However, in the condition of ergodicity breakdown, the same methods give ambiguous results. We show that in such regime, two different scaling behaviors emerge depending on the age of the windows used for the estimation. We explain the ambiguity of the estimation methods by the different influence of the two scaling behaviors on each method. Our results suggest that aging drastically alters the scaling properties of non-ergodic processes.

  6. Ergodicity breakdown and scaling from single sequences

    International Nuclear Information System (INIS)

    Kalashyan, Armen K.; Buiatti, Marco; Grigolini, Paolo

    2009-01-01

    In the ergodic regime, several methods efficiently estimate the temporal scaling of time series characterized by long-range power-law correlations by converting them into diffusion processes. However, in the condition of ergodicity breakdown, the same methods give ambiguous results. We show that in such regime, two different scaling behaviors emerge depending on the age of the windows used for the estimation. We explain the ambiguity of the estimation methods by the different influence of the two scaling behaviors on each method. Our results suggest that aging drastically alters the scaling properties of non-ergodic processes.

  7. Numerical simulation and physical aspects of supersonic vortex breakdown

    Science.gov (United States)

    Liu, C. H.; Kandil, O. A.; Kandil, H. A.

    1993-01-01

    Existing numerical simulations and physical aspects of subsonic and supersonic vortex-breakdown modes are reviewed. The solution to the problem of supersonic vortex breakdown is emphasized in this paper and carried out with the full Navier-Stokes equations for compressible flows. Numerical simulations of vortex-breakdown modes are presented in bounded and unbounded domains. The effects of different types of downstream-exit boundary conditions are studied and discussed.

  8. Pressurized-helium breakdown at very low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Metas, R J

    1972-06-01

    An investigation of the electrical-breakdown behavior of helium at very low temperatures has been carried out to assist the design and development of superconducting power cables. At very high densities, both liquid and gaseous helium showed an enhancement in electric strength when pressurized to a few atmospheres; conditioned values of breakdown fields then varied between 30 and 45 MV/m. Breakdown processes occurring over a wide range of helium densities are discussed. 24 references.

  9. Measurement of skeletal muscle collagen breakdown by microdialysis

    DEFF Research Database (Denmark)

    Miller, B F; Ellis, D; Robinson, M M

    2011-01-01

    Exercise increases the synthesis of collagen in the extracellular matrix of skeletal muscle. Breakdown of skeletal muscle collagen has not yet been determined because of technical limitations. The purpose of the present study was to use local sampling to determine skeletal muscle collagen breakdown...... collagen breakdown 17–21 h post-exercise, and our measurement of OHP using GC–MS was in agreement with traditional assays....

  10. Analysis on X-band structure breakdown at GLCTA

    International Nuclear Information System (INIS)

    Suehara, T.; Sanuki, T.; Komamiya, S.; Higo, T.; Hayano, H.; Terunuma, N.; Saeki, T.; Watanabe, K.; Hayakawa, A.; Tsukada, Y.

    2004-01-01

    We have built a new monitoring system for accelerator structure breakdown in the X-band high-gradient test facility at KEK (GLCTA: Global Linear Collider Test Accelerator). An X-band test structure KX01 (made by KEK) has been processed at GLCTA and we have been collecting data for about 3 months using this breakdown monitoring system. We describe overview of the monitoring system and preliminary result of breakdown analysis of the structure. (author)

  11. Breakdown of highly excited oxygen in a DC electric field

    International Nuclear Information System (INIS)

    Vagin, N.P.; Ionin, A.A.; Klimachev, Yu.M.; Sinitsin, D.V.; Yuryshev, N.N.; Deryugin, A.A.; Kochetov, I.V.; Napartovich, A.P.

    2000-01-01

    The breakdown of oxygen in a dc electric field is studied. A high concentration of oxygen molecules in the a 1 Δ g excited state is obtained in a purely chemical reactor. A decrease in the breakdown voltage at degrees of excitation exceeding 50% is observed. The theoretical decrement in the breakdown voltage obtained by solving the Boltzmann equation is in good agreement with the experimental data

  12. Studies of RF Breakdown of Metals in Dense Gases

    CERN Document Server

    Hanlet, Pierrick M; Ankenbrandt, Charles; Johnson, Rolland P; Kaplan, Daniel; Kuchnir, Moyses; Moretti, Alfred; Paul, Kevin; Popovic, Milorad; Yarba, Victor; Yonehara, Katsuya

    2005-01-01

    A study of RF breakdown of metals in gases has begun as part of a program to develop RF cavities filled with dense hydrogen gas to be used for muon ionization cooling. A pressurized 800 MHz test cell has been used at Fermilab to compare the conditioning and breakdown behavior of copper, molybdenum, chromium, and beryllium electrodes as functions of hydrogen and helium gas density. These results are compared to the predicted or known RF breakdown behavior of these metals in vacuum.

  13. Numerical simulation of a precessing vortex breakdown

    International Nuclear Information System (INIS)

    Jochmann, P.; Sinigersky, A.; Hehle, M.; Schaefer, O.; Koch, R.; Bauer, H.-J.

    2006-01-01

    The objective of this work is to present the results of time-dependent numerical predictions of a turbulent symmetry breaking vortex breakdown in a realistic gas turbine combustor. The unsteady Reynolds-averaged Navier-Stokes (URANS) equations are solved by using the k-ε two-equation model as well as by a full second-order closure using the Reynolds stress model of Speziale, Sarkar and Gatski (SSG). The results for a Reynolds number of 5.2 x 10 4 , a swirl number of 0.52 and an expansion ratio of 5 show that the flow is emerging from the swirler as a spiral gyrating around a zone of strong recirculation which is also asymmetric and precessing. These flow structures which are typical for the spiral type (S-type) vortex breakdown have been confirmed by PIV and local LDA measurements in a corresponding experimental setup. Provided that high resolution meshes are employed the calculations with both turbulence models are capable to reproduce the spatial and temporal dynamics of the flow

  14. Microemulsion systems applied to breakdown petroleum emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Neuma de Castro Dantas, Tereza; Avelino Dantas Neto, Afonso; Ferreira Moura, Everlane [Deptos de Quimica e Eng. Quimica, Universidade Federal do Rio Grande do Norte, Campus Universitario s/n, 59072.970, Natal/RN Campinas (Brazil)

    2001-12-29

    Microemulsion systems obtained using commercial surfactants with demulsifier and emulsion prevention properties have been employed to break down Brazilian crude water-in-oil (W/O) emulsions. These crude oils were supplied by the Brazilian oil company-PETROBRAS-and were characterized by the different Balance sheet of Sediment and Water (BSW) values of 48%, 36%, and 32%. The microemulsion systems formed in this study were composed of an aqueous phase (HCl 5.2% solution); an oil phase (toluene); a cosurfactant/surfactant (C/S) phase (isopropyl alcohol (C)/surfactants (S) with a ratio C/S of 9.0). The microemulsion efficiency to break down oil emulsions was evaluated by a direct contact method between the microemulsions and crude (W/O) emulsions. The Scheffe net statistical planning for mixtures was used to relate the component mass fractions to the relative breakdown of petroleum emulsions. The best composition of the microemulsion system for the complete breakdown of oil emulsions with high BSW values had the lowest C/S phase percentage.

  15. Second harmonic electron cyclotron breakdown in stellarators

    International Nuclear Information System (INIS)

    Carter, M.D.; Batchelor, D.B.; England, A.C.

    1987-01-01

    In linear wave-particle interaction models, the coupling between cold electrons and microwaves with frequency equal to twice the electron gyrofrequency is so weak that the ionization of a significant number of neutral hydrogen atoms would seem impossible in practical applications. However, the non-linear interaction of a cold electron with the wave is very large if the electron becomes trapped near resonance in a shallow, static magnetic well. A model has been developed to describe the breakdown of a neutral gas when these non-linear interactions are considered, and it is in reasonable agreement with the limited amount of available experimental data. For gas pressures that are too large, electron-neutral collisions inhibit the non-linear interaction and prevent breakdown. For gas pressures that are too low, the growth rate of the free electron population is limited because electrons capable of causing ionization are lost before suffering a collision with a neutral. Quantitative growth rate predictions are presented for stellarators, and formulae for rough estimates are given. (author)

  16. Electrical strength of vacuum gap at repetitive breakdown

    International Nuclear Information System (INIS)

    Dubinin, N.P.; Chistyakov, N.P.

    1983-01-01

    The investigation of repetitive pulse breakdown of vacuum space, which electrodes have been subjected to various treatment in vacuum and inert gas, is carried out. In case of electrode warm-up in vacuum up to 400 deg C as well as electronic heating up to 900 deg C the voltage in case of repetitive breakdown hasncreased approximately twice and in case of a through treatment, which is accomplished by a high-current glow discharge in inert gas, the maximum high voltage in case of the first breakdown at repetitive breakdown has decreased by 30...40%, remaining 2-3 times higher than in the first case

  17. Interpersonal Communication of Children with Mental Retardation

    Directory of Open Access Journals (Sweden)

    Aliyah Nur'aini Hanun

    2013-11-01

    Full Text Available Tunagrahita were a terminology to called the children with mentally retarded conditions. This conditions caused these children having difficulties at least on four areas, related with attention, memory, language, and academics. The research problem is how interpersonal communication tunagrahita in Dormitory Extraordinary Education Foundation (YPLB Cipaganti Bandung. This research’s aim is to seek the interpersonal communication phenomenon of children with mentally retarded in YPLB Cipaganti Dormitory. The research method which were used is the qualitative method with communication Ethnography approach and Symbolic Interactionism theory to have comprehensive descriptions about life reality of mentally retarded’s children in YPLB Cipaganti Dormitory. Data obtained by participation observer, unstructured interviews, and documentary study. The result showed that interpersonal interactions are done with each child boarding and with the management of the hostel, is a series of unique events and interpersonal communication with a distinctive circular process that takes place continuously.

  18. Psychomotor Retardation in untreated depressed elderly

    Directory of Open Access Journals (Sweden)

    Lieve Lia Beheydt

    2015-01-01

    Full Text Available Background: Psychomotor retardation (PR is one of the core features in depression according to 17 DSM V1, but also aging in itself causes cognitive and psychomotor slowing. This is the first study 18 investigating psychomotor retardation in relation to cognitive functioning and to the concomitant 19 effect of depression and aging in a geriatric population ruling out contending effects of psychotropic 20 medication. Methods: A group of 28 non-demented depressed elderly is compared to a matched 21 control group of 20 healthy elderly. All participants underwent a test battery containing clinical 22 depression measures, cognitive measures of processing speed, executive function and memory, 23 clinical ratings of psychomotor retardation and objective computerized fine motor skill-tests. 24 Statistical analysis consisted of a General Linear Method (GLM multivariate analysis of variance to 25 compare the clinical, cognitive and psychomotor outcomes of the two groups. Results: Patients 26 performed worse on all clinical, cognitive and psychomotor retardation measures. Both groups 27 showed an effect of cognitive load on fine motor function but the influence was significantly larger 28 for patients than for healthy elderly except for the initiation time. Limitations: due to the restrictive 29 inclusion criteria, only a relatively limited sample size could be obtained. Conclusion: With a 30 medication free sample, an additive effect of depression and aging on cognition and PR in geriatric 31 patients was found,. As this effect was independent of demand of effort (by varying the cognitive 32 load, it was apparently not a motivational slowing effect of depression.

  19. Oral Rehabilitation and Management of Mentally Retarded

    OpenAIRE

    Solanki, Jitender; Khetan, Jitendra; Gupta, Sarika; Tomar, Deepak; Singh, Meenakshi

    2015-01-01

    High level of periodontal problems of dental caries are frequently observed in mentally handicapped children. This group of patients presents various problems when they face dental treatments. Identification of such population and providing them affordable oral health care is the new concept. A systematic method for identification and screening of persons with mental retardation has been developed and is being followed. Cost and fear are the most commonly cited barriers to dental care. Physic...

  20. Inherited retarded eruption in the permanent dentition.

    Science.gov (United States)

    Rasmussen, P; Kotsaki, A

    1997-01-01

    The term retarded eruption, may be used in cases where eruption is inhibited, causing an interruption in the coordination of tooth formation and tooth eruption. The phenomenon may be local or general, and several etiological factors for retarded eruption have been listed, comprising a lack of space, ankylosis, cysts, supernumerary teeth, hormone and vitamin deficiencies and several developmental disturbances and syndromes. The present paper describes several cases of retarded eruption where no factors other than inheritance have been evident. So far 14 cases have been evaluated, 9 boys and 5 girls. In addition several cases have been registered among parents and grandparents of the probands. Typical features are: retarded eruption, defined as more than 3 SD beyond mean eruption figures, comprises all teeth in the permanent dentition, and in 5 cases also second primary molars. The chronology of tooth formation are within normal limits. Consequently the teeth finish development still laying deeply buried in the jaws, often in aberrant positions and with curves or hooks on the roots. When the teeth finally get the "signal" for eruption, 5-15 years beyond normal eruption time, they move rather quickly into right positions, despite the long eruption paths and the hooked roots. Permanent teeth without, as well as with predecessors, are affected. Extraction of predecessors does not seem to provoke eruption. The main features in management are to take care of the primary teeth, to improve-esthetics, and offer surgery and orthodontics when needed. Analyses of pedigrees indicates that the genetic transmittance may be autosomal dominant as both sexes are affected, about half of the siblings show the trait, and the trait shows continuity through generations.

  1. Preparation and properties studies of halogen-free flame retardant form-stable phase change materials based on paraffin/high density polyethylene composites

    International Nuclear Information System (INIS)

    Cai Yibing; Wei Qufu; Huang Fenglin; Gao Weidong

    2008-01-01

    The halogen-free flame retardant form-stable phase change materials (PCM) based on paraffin/high density polyethylene (HDPE) composites were prepared by using twin-screw extruder technique. The structures and properties of the form-stable PCM composites based on intumescent flame retardant system with expandable graphite (EG) and different synergistic additives, such as ammonium polyphosphate (APP) and zinc borate (ZB) were characterized by scanning electronic microscope (SEM), thermogravimetric analyses (TGA), dynamic Fourier-transform infrared (FTIR) spectra, differential scanning calorimeter (DSC) and Cone calorimeter test. The TGA results showed that the halogen-free flame retardant form-stable PCM composites produced a larger amount of charred residue at 700 deg. C, although the onset of weight loss of the halogen-free flame retardant form-stable PCM composites occurred at a lower temperature due to the thermal decomposition of flame retardant. The DSC measurements indicated that the additives of flame retardant had little effect on the thermal energy storage property, and the temperatures of phase change peaks and the latent heat of the paraffin showed better occurrence during the freezing process. The dynamic FTIR monitoring results revealed that the breakdowns of main chains (HDPE and paraffin) and formations of various residues increased with increasing thermo-oxidation temperature. It was also found from the Cone calorimeter tests that the peak of heat release rate (PHRR) decreased significantly. Both the decrease of the PHRR and the structure of charred residue after combustion indicated that there was a synergistic effect between the EG and APP, contributing to the improved flammability of the halogen-free flame retardant form-stable PCM composites

  2. Fears of institutionalized mentally retarded adults.

    Science.gov (United States)

    Sternlicht, M

    1979-01-01

    The patterns of fears of institutionalized mentally retarded adults were studied in a sample of i2 moderately retarded men and women between the ages of 21-49. The direct questioning method was employed. Two interviews were held, two weeks apart; the first interview elicited the Ss' fears, while the second concerned the fears of their friends. A total of 146 responses were obtained, and these were categorized according to the types of fears: supernatural-natural events, animals, physical injury, psychological stress, egocentric responses, and no fears. The Ss displayed a higher percentage of fears in the preoperational stage than in the concrete operational stage. In a comparison of male to female fears, only one category, that of fears of animals, reached significance. The study suggested that the same developmental trend of fears that appears in normal children appears in the retarded as well, and these fears follow Piaget's level of cognitive development, proceeding from egocentric perceptions of causality to realistic cause and effect thinking.

  3. Flame Retardant Polyamide Fibres: The Challenge of Minimising Flame Retardant Additive Contents with Added Nanoclays

    Directory of Open Access Journals (Sweden)

    Richard Horrocks

    2016-08-01

    Full Text Available This work shows that halogen-free, flame retarded polyamide 6 (PA6, fabrics may be produced in which component fibres still have acceptable tensile properties and low levels (preferably ≤10 wt % of additives by incorporating a nanoclay along with two types of flame retardant formulations. The latter include (i aluminium diethyl phosphinate (AlPi at 10 wt %, known to work principally in the vapour phase and (ii ammonium sulphamate (AS/dipentaerythritol (DP system present at 2.5 and 1 wt % respectively, believed to be condense phase active. The nanoclay chosen is an organically modified montmorillonite clay, Cloisite 25A. The effect of each additive system is analysed in terms of its ability to maximise both filament tensile properties relative to 100% PA6 and flame retardant behaviour of knitted fabrics in a vertical orientation. None of the AlPi-containing formulations achieved self-extinguishability, although the presence of nanoclay promoted lower burning and melt dripping rates. The AS/DP-containing formulations with total flame retardant levels of 5.5 wt % or less showed far superior properties and with nanoclay, showed fabric extinction times ≤ 39 s and reduced melt dripping. The tensile and flammability results, supported by thermogravimetric analysis, have been interpreted in terms of the mechanism of action of each flame retardant/nanoclay type.

  4. Robust AIC with High Breakdown Scale Estimate

    Directory of Open Access Journals (Sweden)

    Shokrya Saleh

    2014-01-01

    Full Text Available Akaike Information Criterion (AIC based on least squares (LS regression minimizes the sum of the squared residuals; LS is sensitive to outlier observations. Alternative criterion, which is less sensitive to outlying observation, has been proposed; examples are robust AIC (RAIC, robust Mallows Cp (RCp, and robust Bayesian information criterion (RBIC. In this paper, we propose a robust AIC by replacing the scale estimate with a high breakdown point estimate of scale. The robustness of the proposed methods is studied through its influence function. We show that, the proposed robust AIC is effective in selecting accurate models in the presence of outliers and high leverage points, through simulated and real data examples.

  5. Vortex breakdown in simple pipe bends

    Science.gov (United States)

    Ault, Jesse; Shin, Sangwoo; Stone, Howard

    2016-11-01

    Pipe bends and elbows are one of the most common fluid mechanics elements that exists. However, despite their ubiquity and the extensive amount of research related to these common, simple geometries, unexpected complexities still remain. We show that for a range of geometries and flow conditions, these simple flows experience unexpected fluid dynamical bifurcations resembling the bubble-type vortex breakdown phenomenon. Specifically, we show with simulations and experiments that recirculation zones develop within the bends under certain conditions. As a consequence, fluid and particles can remain trapped within these structures for unexpectedly-long time scales. We also present simple techniques to mitigate this recirculation effect which can potentially have impact across industries ranging from biomedical and chemical processing to food and health sciences.

  6. Runaway breakdown and hydrometeors in lightning initiation.

    Science.gov (United States)

    Gurevich, A V; Karashtin, A N

    2013-05-03

    The particular electric pulse discharges are observed in thunderclouds during the initiation stage of negative cloud-to-ground lightning. The discharges are quite different from conventional streamers or leaders. A detailed analysis reveals that the shape of the pulses is determined by the runaway breakdown of air in the thundercloud electric field initiated by extensive atmospheric showers (RB-EAS). The high amplitude of the pulse electric current is due to the multiple microdischarges at hydrometeors stimulated and synchronized by the low-energy electrons generated in the RB-EAS process. The series of specific pulse discharges leads to charge reset from hydrometeors to the free ions and creates numerous stretched ion clusters, both positive and negative. As a result, a wide region in the thundercloud with a sufficiently high fractal ion conductivity is formed. The charge transport by ions plays a decisive role in the lightning leader preconditioning.

  7. Development of Electrical Breakdown in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Jozef Kudelcik

    2006-01-01

    Full Text Available Power transformers are key equipment for transfer and distribution of the electric power. Considering the significance of the power transformers in the electric system, their price and possible damages occurred by accidents, it is necessary to pay attention to their higher prevention. To prevent failure states of transformers, we perform different types ofmeasurements. They shall illustrate a momentary state of the measured equipment and if necessary to draw attention in advance to changes of parameters, which have specific relationship to no-failure operation of the equipment. The conditions under which breakdown of composite liquid/ solid insulation can occur, e.g. in transformer, play an important role in designing such insulation. The liquid, mainly mineral oil, generally constitutes the weakest part of insulation and a great amount of work has been devoted to the study of streamers, which appear in the gaseous phase, and most often are triggering the failure of insulation.

  8. Junction depth dependence of breakdown in silicon detector diodes

    International Nuclear Information System (INIS)

    Beck, G.A.; Carter, A.A.; Carter, J.R.; Greenwood, N.M.; Lucas, A.D.; Munday, D.J.; Pritchard, T.W.; Robinson, D.; Wilburn, C.D.; Wyllie, K.

    1996-01-01

    The high voltage capability of detector diodes fabricated in the planar process is limited by the high field generated at the edge of the junction.We have fabricated diodes with increased junction depth with respect to our standard process and find a significantly higher breakdown voltage,in reasonable agreement with previous studies of junction breakdown. (orig.)

  9. Breakdown Breakthrough: NREL Finds Easier Ways to Deconstruct Biomass |

    Science.gov (United States)

    News | NREL Breakdown Breakthrough: NREL Finds Easier Ways to Deconstruct Biomass Breakdown Breakthrough: NREL Finds Easier Ways to Deconstruct Biomass May 22, 2018 Roman Brunecky (left), Yannick Bomble soften biomass. Photo by Dennis Schroeder, NREL If there's an easier, more efficient method, science will

  10. Simulation of a three-dimensional vortex breakdown

    Science.gov (United States)

    Liu, C. H.; Menne, Stefan

    1989-01-01

    The breakdown of a vortex flow in a tube is studied for a slightly diverging tube by means of a numerical solution of the Navier-Stokes equations for a quasi-stationary, incompressible, laminar flow. Numerical results are compared to experiments of Faler and Leibovich. The numerical data display features similar to the experimental results concerning breakdown conditions, location, and structure.

  11. Formation of vortex breakdown in conical–cylindrical cavities

    International Nuclear Information System (INIS)

    Martins, Diego Alves de Moro; Souza, Francisco José de; Salvo, Ricardo de Vasconcelos

    2014-01-01

    Highlights: • Rotating flows in conical–cylindrical cavities were simulated via an in-house code using unstructured meshes. • The vortex breakdown phenomenon was verified in the geometries analyzed. • The influence of Stewartson and Bödewadt layers was observed in the vortex breakdown formation. • A curve of stability and number of breakdowns was obtained as a function of Reynolds number. • Spiral vortex breakdown was observed in some situations. - Abstract: Numerical simulations in confined rotating flows were performed in this work, in order to verify and characterize the formation of the vortex breakdown phenomenon. Cylindrical and conical–cylindrical geometries, both closed, were used in the simulations. The rotating flow is induced by the bottom wall, which rotates at constant angular velocity. Firstly the numerical results were compared to experimental results available in references, with the purpose to verify the capacity of the computational code to predict the vortex breakdown phenomenon. Further, several simulations varying the parameters which govern the characteristics of the flows analyzed in this work, i.e., the Reynolds number and the aspect ratio, were performed. In these simulations, the limits for the transitional regime and the vortex breakdown formation were verified. Steady and transient cases, with and without turbulence modeling, were simulated. In general, some aspects of the process of vortex breakdown in conical–cylindrical geometries were observed to be different from that in cylinders

  12. Electric field measurements in moving ionization fronts during plasma breakdown

    NARCIS (Netherlands)

    Wagenaars, E.; Bowden, M.D.; Kroesen, G.M.W.

    2006-01-01

    We have performed time-resolved, direct measurements of electric field strengths in moving ionization fronts during the breakdown phase of a pulsed plasma. Plasma breakdown, or plasma ignition, is a highly transient process marking the transition from a gas to a plasma. Some aspects of plasma

  13. Quasiparticle Breakdown in a Quantum Spin Liquid

    International Nuclear Information System (INIS)

    Stone, Matthew B.; Zalinznyak, I.; Hong, T.; Broholm, C.L.; Reich, D.H.

    2006-01-01

    Much of modern condensed matter physics is understood in terms of elementary excitations, or quasiparticles -- fundamental quanta of energy and momentum. Various strongly interacting atomic systems are successfully treated as a collection of quasiparticles with weak or no interactions. However, there are interesting limitations to this description: in some systems the very existence of quasiparticles cannot be taken for granted. Like unstable elementary particles, quasiparticles cannot survive beyond a threshold where certain decay channels become allowed by conservation laws; their spectrum terminates at this threshold. Such quasiparticle breakdown was first predicted for an exotic state of matter -- super-fluid 4 He at temperatures close to absolute zero, a quantum Bose liquid where zero-point atomic motion precludes crystallization. Here we show, using neutron scattering, that quasiparticle breakdown can also occur in a quantum magnet and, by implication, in other systems with Bose quasiparticles. We have measured spin excitations in a two-dimensional quantum magnet, piperazinium hexachlorodicuprate (PHCC), in which spin-1/2 copper ions form a non-magnetic quantum spin liquid, and find remarkable similarities with excitations in superfluid 4 He. We observe a threshold momentum beyond which the quasiparticle peak merges with the two-quasiparticle continuum. It then acquires a finite energy width and becomes indistinguishable from a leading-edge singularity, so that excited states are no longer quasiparticles but occupy a wide band of energy. Our findings have important ramifications for understanding excitations with gapped spectra in many condensed matter systems, ranging from band insulators to high-transition-temperature superconductors.

  14. Determining the mode of high voltage breakdowns in vacuum devices

    International Nuclear Information System (INIS)

    Miller, H.C.; Furno, E.J.; Sturtz, J.P.

    1980-01-01

    Devices were constructed which were essentially vacuum diodes equipped with windows allowing observation of high voltage breakdowns. The waveform of the applied voltage was photographed, and the x-ray output was monitored to investigate electrical breakdown in these vacuum diodes. Results indicate that breakdowns may be divided into two types: (1) vacuum (interelectrode) breakdown - characterized by a diffuse moderately bright discharge, a relative slow and smooth voltage collapse, and a large burst of x-rays, and (2) surface (insulator) flashover - characterized by a bright discharge with a very bright filamentary core, a relatively fast and noisy voltage collapse and no x-ray burst. Useful information concerning the type of breakdown in a vacuum device can be obtained by monitoring the voltage (current) waveform and the x-ray output

  15. Development of Hybrid Product Breakdown Structure for NASA Ground Systems

    Science.gov (United States)

    Monaghan, Mark W.; Henry, Robert J.

    2013-01-01

    The Product Breakdown Structure is traditionally a method of identification of the products of a project in a tree structure. It is a tool used to assess, plan, document, and display the equipment requirements for a project. It is part of a product based planning technique, and attempts to break down all components of a project in as much detail as possible, so that nothing is overlooked. The PBS for ground systems at the Kennedy Space Center is being developed to encompass the traditional requirements including the alignment of facility, systems, and components to the organizational hierarchy. The Ground Operations Product Breakdown Structure is a hybrid in nature in that some aspects of a work breakdown structure will be incorporated and merged with the Architecture Concept of Operations, Master Subsystem List, customer interface, and assigned management responsibility. The Ground Operations Product Breakdown Structure needs to be able to identify the flexibility of support differing customers (internal and external) usage of ground support equipment within the Kennedy Space Center launch and processing complex. The development of the Product Breakdown Structure is an iterative activity Initially documenting the organization hierarchy structure and relationships. The Product Breakdown Structure identifies the linkage between the customer program requirements, allocation of system resources, development of design goals, and identification logistics products. As the Product Breakdown Structure progresses the incorporation of the results of requirement planning for the customer occurs identifying facility needs and systems. The mature Product Breakdown Structure is baselined with a hierarchical drawing, the Product Breakdown Structure database, and an associated document identifying the verification of the data through the life cycle of the program/product line. This paper will document, demonstrate, and identify key aspects of the life cycle of a Hybrid Product

  16. Retardo del crecimiento intrauterino Intrauterine growth retardation

    Directory of Open Access Journals (Sweden)

    Adriana Cuartas Calle

    1995-01-01

    Full Text Available

    El crecimiento fetal anormal es un aspecto de gran interés en la obstetricia actual y un dilema clínico relativamente frecuente. La falla del crecimiento sigue siendo un enigma a pesar de los adelantos que ha habido en su conocimiento: el diagnóstico temprano y preciso del retardo del crecimiento puede aminorar la incidencia de complicaciones y muerte en fetos con este problema. Por ello es necesario mejorar las técnicas para identificar esta entidad y asegurar una atención apropiada durante el embarazo y el parto. En este artículo se resumen datos acerca de la definición del retardo del crecimiento fetal, su fisiopatología, clasificación, etiología, diagnóstico y manejo.

    Abnormal fetal growth is a very important aspect In present-day obstetrics and a frequent clinical dilemma. Fetal failure to grow continues to be puzzling, despite advances in its knowledge; early and precise diagnosis of growth retardation can diminish the incidence of complications and death of fetuses with this problem. It becomes therefore necessary, in the presence of growth retardation, to improve diagnostic techniques and assure proper attention during pregnancy and delivery. Information is summarized in this review on the definition, pathophysiology, classification, etiology, diagnosis and handling of fetal growth retardation.

  17. Fire-retardant decorative inks for aircraft interiors

    Science.gov (United States)

    Kourtides, D. A.; Nir, Z.; Mikroyannidis, J. A.

    1985-01-01

    Commercial and experimental fire retardants were screened as potential fire retardants for acrylic printing inks used on aircraft interior sandwich panels. The fire retardants are selected according to their physical properties and their thermostabilities. A criterion for selecting a more stable fire retardant is established. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to determine thermostabilities. Results show that the fire retardant formulations are more thermally stable than the acrylic ink control. It is determined that an ink formulation containing a brominated phenol and carboxy-terminated butadiene acrylonitrile which has been modified with a brominated polymeric additive (BPA), yields the highest limiting oxygen index (LOI) of all the compounds tested. All of the fire-retardant formulations have a higher oxygen index than the baseline acrylic ink.

  18. Investigation of pressure retarded osmosis power production

    Directory of Open Access Journals (Sweden)

    Taousanidis Nikolaos

    2017-01-01

    Full Text Available A major source of energy exists where there is mixing between aqueous solutions of different salinities. This energy source is particularly concentrated where fresh water rivers flow on to the ocean. The power, represented by the osmotic pressure difference between fresh water and salt water, may be called salinity gradient power. In this study the pressure retarded osmosis method for the extraction of salinity gradients’ energy is investigated, main problems and difficulties are pointed out and finally the whole subject is justified with experimental results.

  19. Characteristics of Those Persons with Mental Retardation Registered with the Mental Retardation Division.

    Science.gov (United States)

    Cocks, Errol; Ng, Pin Chee

    1983-01-01

    The paper discusses an analysis of a computerized data bank on the mentally retarded population in Victoria, Australia. Prevalence rates, severity of handicap, age, sex, and residence type are reviewed and implications for community vocational and residential services for adults are noted. (CL)

  20. Distal joint contractures, mental retardation, characteristic face and growth retardation: Chitayat syndrome revisited.

    NARCIS (Netherlands)

    Wortmann, S.B.; Rodenburg, R.J.T.; Schwahn, B.; Smeitink, J.A.M.; Morava, E.

    2007-01-01

    We report on a patient with congenital distal limb contractures, characteristic face, prominent metopic sutures, narrow forehead, severe psychomotor and growth retardation, white matter lesions and failure to thrive. The child has many overlapping features with those reported previously by Chitayat.

  1. Dysmorphology and mental retardation: molecular cytogenetic studies in dysmorphic mentally retarded patients.

    NARCIS (Netherlands)

    Buggenhout, G.J.C.M. van; Ravenswaaij-Arts, C.M.A. van; Mieloo, H.; Syrrou, M.; Hamel, B.C.J.; Brunner, H.G.; Fryns, J.P.

    2001-01-01

    In an institutionalised population of 471 mentally retarded adult residents (436 males and 35 females), 18 patients (16 males and 2 females) with dysmorphic features were selected to perform FISH studies by using subtelomeric probes to discover cryptic terminal deletions or duplications,

  2. Crack retardation by load reduction during fatigue crack propagation

    International Nuclear Information System (INIS)

    Kim, Hyun Soo; Nam, Ki Woo; Ahn, Seok Hwan; Do, Jae Yoon

    2003-01-01

    Fracture life and crack retardation behavior were examined experimentally using CT specimens of aluminum alloy 5083. Crack retardation life and fracture life were a wide difference between 0.8 and 0.6 in proportion to ratio of load reduction. The wheeler model retardation parameter was used successfully to predict crack growth behavior. By using a crack propagation rule, prediction of fracture life can be evaluated quantitatively. A statistical approach based on Weibull distribution was applied to the test data to evaluate the dispersion in the retardation life and fracture life by the change of load reduction

  3. Experimental Study on High Electrical Breakdown of Water Dielectric

    International Nuclear Information System (INIS)

    Zhang Zicheng; Zhang Jiande; Yang Jianhua

    2005-01-01

    By means of a coaxial apparatus, pressurized water breakdown experiments with microsecond charging have been carried out with different surface roughness of electrodes and different ethylene glycol concentrations of ethylene glycol/water mixture. The experimental results about the breakdown stress and the effective time are presented. The breakdown stress is normalized to the situation that the effective time is transformed to 1 μs and analyzed. The conclusions are as follows: (1) the breakdown stress formula is modified to E = 0.561M A -1/10 t eff -1/N P 1/8 ; (2) the coefficient M is significantly increased by surface polishing and ethylene glycol additive; (3) it is accumulative for the capacity of improving electrical breakdown strength for surface polishing, ethylene glycol additive, and pressurization, of which pressurization is the most effective method; (4) the highest stress of 235.5 kV/cm is observed in ethylene glycol/water mixture with an ethylene glycol concentration of 80% at a hydrostatic pressure of 1215.9 kPa and is about one time greater than that in pure water at constant pressure; (5) for pressurization and surface polishing, the primary mechanism to improve the breakdown strength of water dielectric is the increase in the breakdown time delay. Research results indicate great potential in the application of the high power pulse conditioning system of water dielectric

  4. POLYAMIDE 6 WITH A FLAME RETARDANT ENCAPSULATED BY POLYAMIDE 66: FLAME RETARDATION, THERMO-DECOMPOSITION AND THE POTENTIAL MECHANISM

    Institute of Scientific and Technical Information of China (English)

    Wei-cheng Xiong; Li Chen; Bin Zhao; De-yi Wang; Yu-zhong Wang

    2012-01-01

    A novel encapsulated flame retardant containing phosphorus-nitrogen (MSMM-Al-P) was prepared by encapsulating with polyamide 66 (PA66-MSMM-Al-P) for the flame retardation of polyamide 6 (PA6).The structure and thermal properties of PA66-MSMM-Al-P were characterized by Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy and thermogravimetric analysis.The flammability of PA6 containing' flame retardants (MSMMAl-P and PA66-MSMM-Al-P) was investigated by the limiting oxygen index test,vertical burning test and cone calorimeter.The flame retardancy and cone calorimetric analyses suggested a synergistic effect between PA66 and MSMM-Al-P in the flame-retardant PA6.Thermal stability of the flame-retardant PA6 was also investigated.

  5. Social support of mentally retarded persons

    Directory of Open Access Journals (Sweden)

    Danuta Zwolinska

    2015-01-01

    Full Text Available Purpose: The aim of this work is to assess the relationship between the environment and mentally retarded persons. Material and methods: Information referring to social support of mentally retarded persons is a source material collected on the base of the data included in the Polish and foreign literature. The issues under discussion related to the following problems: social integration of persons with intellectual disabilities in a family and local environment, social functioning of people with mild intellectual disability, social rehabilitation of people with moderate, severe and profound intellectual disability and specific contact with people with disabilities. Results: For a person with an intellectual disability, the family is the source of acquisition of basic social skills that give him the opportunity for further development and performing certain social roles in a sense of safety. Full acceptance of the intellectually disabled, may dismiss their sense of shame and fear, and instill the satisfaction of belonging to a social community. Conclusions: Full social acceptance of people with intellectual disabilities is the basis for their assimilation and social functioning.

  6. Work Breakdown Structures The Foundation for Project Management Excellence

    CERN Document Server

    Norman, Eric S; Fried, Robert T

    2011-01-01

    Understand and apply new concepts regarding Work Breakdown Structures The Work Breakdown Structure (WBS) has emerged as a foundational concept and tool in Project Management. It is an enabler that ensures clear definition and communication of project scope while performing a critical role as a monitoring and controlling tool. Created by the three experts who led the development of PMI's Practice Standard for Work Breakdown Structures, Second Edition, this much-needed text expands on what the standard covers and describes how to go about successfully implementing the WBS within the project life

  7. A model of breakdown in parallel-plate detectors

    International Nuclear Information System (INIS)

    Fonte, P.

    1996-01-01

    Parallel-plate avalanche chambers (PPAC's) have many desirable properties, such as a fast, large area particle detector. However, the maximum gain is limited by a form of violent breakdown that limits the usefulness of this detector, despite its other evident qualities. The exact nature of this phenomenon is not yet sufficiently clear to sustain possible improvements. A previous experimental study is complemented in the present work by a quantitative model of the breakdown phenomenon in PPAC's, based on the streamer theory. The model reproduces well the peculiar behavior of the external current observed in PPAC's and resistive-plate chambers. Other breakdown properties measured in PPAC's are also well reproduced

  8. Vortex breakdown in a truncated conical bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Balci, Adnan; Brøns, Morten [DTU Compute, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Herrada, Miguel A [E.S.I, Universidad de Sevilla, Camino de los Descubrimientos s/n, E-41092 (Spain); Shtern, Vladimir N, E-mail: mobr@dtu.dk [Shtern Research and Consulting, Houston, TX 77096 (United States)

    2015-12-15

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air–water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, H{sub w}, and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as H{sub w} varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small H{sub w}, the AMF effect dominates. As H{sub w} increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors. (paper)

  9. Subnanosecond breakdown in high-pressure gases

    Science.gov (United States)

    Naidis, George V.; Tarasenko, Victor F.; Babaeva, Natalia Yu; Lomaev, Mikhail I.

    2018-01-01

    Pulsed discharges in high-pressure gases are of considerable interest as sources of nonequilibrium plasma for various technological applications: pollution control, pumping of laser media, plasma-assisted combustion, etc. Recently, attention has been attracted to the use of subnanosecond voltage fronts, producing diffuse discharges with radii of several millimeters. Such plasma structures, similar to pulsed glow discharges, are of special interest for applications due to quasi-uniformity of plasma parameters in relatively large gas volumes. This review presents the results of experimental and computational study of subnanosecond diffuse discharge formation. A description of generators of short high-voltage pulses with subnanosecond fronts and of discharge setups is given. Diagnostic methods for the measurement of various discharge parameters with high temporal and spatial resolution are described. Obtained experimental data on plasma properties for a wide range of governing factors are discussed. A review of various theoretical approaches used for computational study of the dynamics and structure of fast ionization waves is given; the applicability of conventional fluid streamer models for simulation of subnanosecond ionization waves is discussed. Calculated spatial-temporal profiles of plasma parameters during streamer propagation are presented. The efficiency of subnanosecond discharges for the production of reactive species is evaluated. On the basis of the comparison of simulation results and experimental data the effects of various factors (voltage rise time, polarity, etc.) on discharge characteristics are revealed. The major physical phenomena governing the properties of subnanosecond breakdown are analyzed.

  10. Vortex breakdown in a truncated conical bioreactor

    International Nuclear Information System (INIS)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A; Shtern, Vladimir N

    2015-01-01

    This numerical study explains the eddy formation and disappearance in a slow steady axisymmetric air–water flow in a vertical truncated conical container, driven by the rotating top disk. Numerous topological metamorphoses occur as the water height, H w , and the bottom-sidewall angle, α, vary. It is found that the sidewall convergence (divergence) from the top to the bottom stimulates (suppresses) the development of vortex breakdown (VB) in both water and air. At α = 60°, the flow topology changes eighteen times as H w varies. The changes are due to (a) competing effects of AMF (the air meridional flow) and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow on AMF. For small H w , the AMF effect dominates. As H w increases, the swirl effect dominates and causes VB. The water flow feedback produces and modifies air eddies. The results are of fundamental interest and can be relevant for aerial bioreactors. (paper)

  11. Medical Applications of Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Pathak, A K; Rai, N K; Singh, Ankita; Rai, A K; Rai, Pradeep K; Rai, Pramod K

    2014-01-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail

  12. The legal aspects of the power breakdown in August 2003

    International Nuclear Information System (INIS)

    Dunberry, E.

    2004-01-01

    The power breakdown on August 14, 2003 could re-occur. There are legal liabilities over interruptions of power without notice and honouring of contract terms. This risk must be managed with prudence and diligence. (author)

  13. Low-pressure gas breakdown in longitudinal combined electric fields

    International Nuclear Information System (INIS)

    Lisovskiy, V A; Kharchenko, N D; Yegorenkov, V D

    2010-01-01

    This paper contains the complete experimental and analytical picture of gas breakdown in combined electric fields for arbitrary values of rf and dc fields. To obtain it, we continued the study of the discharge ignition modes in nitrogen with simultaneous application of dc and rf electric fields presented in Lisovskiy et al (2008 J. Phys. D: Appl. Phys. 41 125207). To this end, we studied the effect of rf voltage on dc discharge ignition. When we applied an rf voltage exceeding the one corresponding to the minimum breakdown voltage of a self-sustained rf discharge, the curve of dependence of the dc breakdown voltage of a combined discharge on gas pressure was found to consist of two sections. We got the generalized gas breakdown criterion in the combined field valid for arbitrary values of rf and dc electric fields. The calculation results agree with experimental data satisfactorily.

  14. Surface of Alumina Films after Prolonged Breakdowns in Galvanostatic Anodization

    Directory of Open Access Journals (Sweden)

    Christian Girginov

    2011-01-01

    Full Text Available Breakdown phenomena are investigated at continuous isothermal (20∘C and galvanostatic (0.2–5 mA cm−2 anodizing of aluminum in ammonium salicylate in dimethylformamide (1 M AS/DMF electrolyte. From the kinetic (-curves, the breakdown voltage ( values are estimated, as well as the frequency and amplitude of oscillations of formation voltage ( at different current densities. The surface of the aluminum specimens was studied using atomic force microscopy (AFM. Data on topography and surface roughness parameters of the electrode after electric breakdowns are obtained as a function of anodization time. The electrode surface of anodic films, formed with different current densities until the same charge density has passed (2.5 C cm−2, was assessed. Results are discussed on the basis of perceptions of avalanche mechanism of the breakdown phenomena, due to the injection of electrons and their multiplication in the volume of the film.

  15. Review of Vortex Methods for Simulation of Vortex Breakdown

    National Research Council Canada - National Science Library

    Levinski, Oleg

    2001-01-01

    The aim of this work is to identify current developments in the field of vortex breakdown modelling in order to initiate the development of a numerical model for the simulation of F/A-18 empennage buffet...

  16. Vortex breakdown in closed containers with polygonal cross sections

    International Nuclear Information System (INIS)

    Naumov, I. V.; Dvoynishnikov, S. V.; Kabardin, I. K.; Tsoy, M. A.

    2015-01-01

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results

  17. Streamwise Fluctuations of Vortex Breakdown at High Reynolds Numbers

    National Research Council Canada - National Science Library

    Connelly, Jonathan S

    2006-01-01

    This thesis deals with the characterization of the dependence on the flow geometry of the stream wise fluctuations of the stagnation point of vortex breakdown in axisymmetric tubes and over delta wing aircraft...

  18. Optimal Rules for Single Machine Scheduling with Stochastic Breakdowns

    Directory of Open Access Journals (Sweden)

    Jinwei Gu

    2014-01-01

    Full Text Available This paper studies the problem of scheduling a set of jobs on a single machine subject to stochastic breakdowns, where jobs have to be restarted if preemptions occur because of breakdowns. The breakdown process of the machine is independent of the jobs processed on the machine. The processing times required to complete the jobs are constants if no breakdown occurs. The machine uptimes are independently and identically distributed (i.i.d. and are subject to a uniform distribution. It is proved that the Longest Processing Time first (LPT rule minimizes the expected makespan. For the large-scale problem, it is also showed that the Shortest Processing Time first (SPT rule is optimal to minimize the expected total completion times of all jobs.

  19. Breakdown processes in wire chambers, prevention and rate capability

    International Nuclear Information System (INIS)

    Atac, M.

    1983-01-01

    Breakdowns were optically and electronically observed in drift tubes and drift chambers. They occur at a critical gain for given intensity in a gas mixture when ultraviolet photons are not completely quenched. It was observed that the breakdowns depended critically on average current for a given gas mixture independent of the size of the drift tubes used. Using 4.6% ethyl alcohol vapor mixed into 50/50 argon ethane gas, breakdown are eliminated up to 7 /sub μ/A average current drawn by pulses on a 1 cm section of an anode wire under an intense source. Pulses with an avalanche size of 10 6 electron rates above 10 6 pulses per centimeter per wire may be obtained with the elimination of breakdowns

  20. Breakdown processes in wire chambers, prevention and rate capability

    International Nuclear Information System (INIS)

    Atac, M.

    1982-01-01

    Breakdowns were optically and electronically observed in drift tubes and drift chambers. They occur at a critical gain for given intensity in a gas mixture when ultraviolet photons are not completely quenched. It was observed that the breakdowns depended critically on average current for a given gas mixture independent of the size of the drift tubes used. Using 4.6% ethyl alcohol vapor mixed into 50/50 argon ethane gas, breakdowns are eliminated up to 7 μA average current drawn by pulses on a 1 cm section of an anode wire under an intense source. Pulses with an avalanche size of 10 6 electron rates above 10 6 pulses per centimeter per wire may be obtained with the elimination of breakdowns

  1. Kertész line of thermally activated breakdown phenomena

    KAUST Repository

    Yoshioka, Naoki; Kun, Ferenc; Ito, Nobuyasu

    2010-01-01

    Based on a fiber bundle model we substantially extend the phase-transition analogy of thermally activated breakdown of homogeneous materials. We show that the competition of breaking due to stress enhancement and due to thermal fluctuations leads

  2. 38 CFR 4.127 - Mental retardation and personality disorders.

    Science.gov (United States)

    2010-07-01

    ... AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings Mental Disorders § 4.127 Mental retardation and personality disorders. Mental retardation and personality disorders are not diseases or injuries... from them may not be service-connected. However, disability resulting from a mental disorder that is...

  3. Fatigue crack growth retardation in spot heated mild steel sheet

    Indian Academy of Sciences (India)

    A fatigue crack can be effectively retarded by heating a spot near the crack tip under nil remote stress condition. The subcritical spot heating at a proper position modifies the crack growth behaviour in a way, more or less, similar to specimen subjected to overload spike. It is observed that the extent of crack growth retardation ...

  4. Piagetian Object Permanence in Severely Mentally Retarded Adults.

    Science.gov (United States)

    Brekke, Beverly; And Others

    The measurability of sensorimotor development in 60 severely retarded, institutionalized adults was studied, using the Piagetian concept of object permanence in a delayed recall paradigm that involved special apparatus. Results suggested, among other things, that severely retarded, institutionalized adults learn most efficiently when trained with…

  5. Sex between persons with 'mental retardation': an ethical evaluation

    NARCIS (Netherlands)

    Spiecker, B.; Steutel, J.W.

    2002-01-01

    Is sex between people with "mental retardation" morally permissible and, if at all, under what conditions? This paper tries to answer this question, but only with regard to sex between biologically mature individuals with mild or moderate mental retardation. First, the concepts of "sexual activity"

  6. Growth retardation in children injected with 224Ra

    International Nuclear Information System (INIS)

    Spiess, H.; Mays, C.W.; Spiess-Paulus, E.

    1986-01-01

    We have obtained the adult heights of 133 patients formerly injected with 224 Ra as juveniles. 224 Ra induced growth retardation was greatest in children injected at young ages and increased with dose. The growth retardation was well represented as a 2% decrease in potential growth post irradiation per 100 rads of calculated average skeletal dose. (orig.)

  7. Decision Making in Leisure. Empowerment for People with Mental Retardation.

    Science.gov (United States)

    Bullock, Charles C.; Mahon, Michael J.

    1992-01-01

    People with mental retardation have been overlooked in recreation/leisure and decision making, which are integral to full community participation. They must be provided with leisure education and decision-making skills. The article describes the Decision Making in Leisure model, explaining its use with individuals with mental retardation. (SM)

  8. Brominated flame retardants: occurrence, dietary intake and risk assessment

    NARCIS (Netherlands)

    Winter-Sorkina R de; Bakker MI; Wolterink G; Zeijlmaker MJ; SIR

    2006-01-01

    Brominated flame retardants have entered the human food chain. For the time being the occurrence of these chemicals in Dutch food does not pose a human health risk. However, this might easily change at increasing contents of flame retardants in Dutch food. The monitoring of brominated flame

  9. Psychiatric Illness in Mentally Retarded Adolescents: Clinical Features.

    Science.gov (United States)

    Masi, Gabriele

    1998-01-01

    Describes the clinical features of the most important psychiatric disorders in mentally retarded adolescents: mood disorders, psychotic disorders, severe behavioral disorders, personality disorders, anxiety disorders, and attention-deficit The impact of mental retardation on personality development is confirmed by the high psychopathological…

  10. Flame retardants: Dust - and not food - might be the risk

    NARCIS (Netherlands)

    de Boer, J.; Ballesteros-Gomez, A.M.; Leslie, H.A.; Brandsma, S.H.; Leonards, P.E.G.

    2016-01-01

    Flame retardants (FRs) are used to delay ignition of materials such as furniture and electric and electronic instruments. Many FRs are persistent and end up in the environment. Environmental studies on flame retardants (FRs) took off in the late 1990s. Polybrominated diphenylethers (PBDEs) appeared

  11. Fire-retardant-treated strandboard : properties and fire performance

    Science.gov (United States)

    Jerrold Winandy; Qingwen Wang; Robert H. White

    2008-01-01

    This study evaluated a series of single-layer, randomly oriented strandboard panels made with one resin type, a single resin loading level, and four fire-retardant-treatment levels. The fire retardant (FR) evaluated was a pH-buffered combination of boric acid and organic phosphate. Siberian larch strands were separated into five batches. One batch of strands served as...

  12. Perceptual-Motor Attributes of Mentally Retarded Youth.

    Science.gov (United States)

    Cratty, Bryant J.

    To evaluate six perceptual-motor attributes of trainable and educable mentally retarded children, a battery of tests was constructed which included body perception, gross agility, balance, locomotor ability, throwing, and tracking; 83 retarded subjects provided reliability data, and their scores, with those of 120 additional subjects, provided…

  13. Labeling, Rehearsal, and Short-Term Memory in Retarded Children

    Science.gov (United States)

    Hagen, John W.; And Others

    1974-01-01

    A short-term memory task was used to explore the effects of verbal labeling and rehearsal on serial-position recall in mildly retarded 9-to 11-year-old children. Results support the view that verbal skills affect recall in mildly retarded children similarly to normal children. (Author/SDH)

  14. Theories on Criminality and Mental Retardation Project CAMIO, Volume 2.

    Science.gov (United States)

    Haskins, Jimmy R.; Friel, Charles M.

    This historical review of theories on criminality and mental retardation is part of Project CAMIO (Correctional Administration and the Mentally Incompetent Offender), a Texas study to determine the incidence of criminal incarceration of the mentally retarded (MR) and to identify laws, procedures, and practices which affect the prosecution and…

  15. Muscle Fatigue during Intermittent Exercise in Individuals with Mental Retardation

    Science.gov (United States)

    Zafeiridis, Andreas; Giagazoglou, Paraskevi; Dipla, Konstantina; Salonikidis, Konstantinos; Karra, Chrisanthi; Kellis, Eleftherios

    2010-01-01

    This study examined fatigue profile during intermittent exercise in 10 men with mild to moderate mental retardation (MR) and 10 men without mental retardation (C). They performed 4 x 30 s maximal knee extensions and flexions with 1-min rest on an isokinetic dynamometer. Peak torque of flexors (PTFL) and extensors (PTEX), total work (TW), and…

  16. Life cycle assessment of flame retardants in an electronics application

    NARCIS (Netherlands)

    Jonkers, Niels; Krop, Hildo; van Ewijk, Harry; Leonards, Pim E.G.

    2016-01-01

    Purpose: Flame retardants are added to plastics and textiles to save lives. However, certain brominated flame retardants (BFRs) form an environmental hazard and should be replaced by less harmful alternatives. In the recently completed European research project ENFIRO, we examined which alternatives

  17. Trace element analysis of hair of mentally retarded children

    International Nuclear Information System (INIS)

    Bhandari, H.P.S.; Lal, G.; Sidhu, N.P.S.; Mittal, V.K.; Sahota, H.S.

    1987-01-01

    Unlike previously reported, Zn and Se levels were found to be the same in the hair of mentally retarded children and controls. Non-essential toxic Ag concentration was low whereas that of Hg, Au and Sc rather high in mentally retarded children. (author) 4 refs

  18. Iconic Memory Deficit of Mildly Mentally Retarded Individuals.

    Science.gov (United States)

    Hornstein, Henry A.; Mosley, James L.

    1987-01-01

    Ten mildly retarded young adult males and nonretarded subjects matched for chronological age or mental age were required to recognize both verbal and nonverbal stimuli presented tachistoscopically. Results of a backward visual masking paradigm varying stimulus onset asynchrony (SOA) indicated the retarded subjects performed poorer at the longest…

  19. Cognitive Representation of Motion in Individuals with Mental Retardation.

    Science.gov (United States)

    Conners, Frances A.; Wyatt, Beverly S.; Dulaney, Cynthia L.

    1998-01-01

    Fifteen adolescents with and 15 without mental retardation were compared on their tendency to show the representational momentum effect when viewing a stimulus array that implied motion. Participants with mental retardation showed the representational momentum effects as did the others, although the magnitude of the memory shift was smaller.…

  20. Adoptive and Birth Family Adjustment to Rearing Retarded Children.

    Science.gov (United States)

    Glidden, Laraine Masters; Bush, Beverly A.

    The study identified 81 families who adopted children with mental retardation or at risk for mental retardation, and compared them with 61 matched families with similar birth children. For birth families, the initial diagnosis was a time of crisis, with high depression scores, while scores at follow-up (an average of 5.3 years later) indicated no…

  1. Enhancement of dielectric breakdown strengths in polymer film capacitors

    International Nuclear Information System (INIS)

    Binder, M.; Mammone, R.J.; Lavene, B.; Rondeau, E.

    1992-01-01

    This paper reports that breakdown voltages of wound, polymer film/metal foil capacitors have been dramatically increased by briefly exposing them (after they had been spirally wound) to a low pressure, low temperature gas plasma. Exposure of wound, polycarbonate-based capacitors to a 96%CF 4 /4%O 2 gas plasma for 4 minutes, for example, produced a 200% increase in breakdown voltage

  2. Communication Breakdown: Unraveling the Islamic States Media Efforts

    Science.gov (United States)

    2016-10-01

    Communication Breakdown: Unraveling the Islamic State’s Media Efforts Daniel Milton Communication Breakdown: Unraveling the Islamic State’s Media ...production arm of central media office).28 The high level of communication between the central media office and the satellite offices illustrates the tension...and discussed by the mass media . Those products are likely important to the group’s recruitment efforts, but clearly it is trying to portray itself

  3. Method of making dielectric capacitors with increased dielectric breakdown strength

    Science.gov (United States)

    Ma, Beihai; Balachandran, Uthamalingam; Liu, Shanshan

    2017-05-09

    The invention is directed to a process for making a dielectric ceramic film capacitor and the ceramic dielectric laminated capacitor formed therefrom, the dielectric ceramic film capacitors having increased dielectric breakdown strength. The invention increases breakdown strength by embedding a conductive oxide layer between electrode layers within the dielectric layer of the capacitors. The conductive oxide layer redistributes and dissipates charge, thus mitigating charge concentration and micro fractures formed within the dielectric by electric fields.

  4. Dynamical symmetry breakdown in SU(5) and SO(10)

    International Nuclear Information System (INIS)

    Shellard, R.C.

    1983-09-01

    Some restrictions imposed upon Grand Unified Theories by dynamical symmetry breakdown are examined. It is observed in particular, that theories with SU(5) as symmetry group, with 3 or more fermion families undergo dynamical symmetry breakdown, and some of the fermions will acquire mass at the Grand Unified scale. On the other hand, the SO(10) group, with 3 families is free from this problem. (Author) [pt

  5. Ionizing potential waves and high-voltage breakdown streamers.

    Science.gov (United States)

    Albright, N. W.; Tidman, D. A.

    1972-01-01

    The structure of ionizing potential waves driven by a strong electric field in a dense gas is discussed. Negative breakdown waves are found to propagate with a velocity proportional to the electric field normal to the wavefront. This causes a curved ionizing potential wavefront to focus down into a filamentary structure, and may provide the reason why breakdown in dense gases propagates in the form of a narrow leader streamer instead of a broad wavefront.

  6. A mentally retarded patient with schizophrenia.

    Science.gov (United States)

    Rabia, K; Khoo, Em

    2008-01-01

    Schizophrenia is one of the most incapacitating forms of mental disorder that runs a chronic and relapsing course. It typically starts in adolescence or early adulthood and can be life-long. It is more common in people with learning disabilities than in the general population. Its prodromal features include depression, anxiety, suspiciousness, social isolation and bizarre behaviour. It may result in significant functional, social and economic impairments. The care of patients with schizophrenia places a considerable burden on all carers including patient's family, health and social services. Treatment includes pharmacotherapy and psychosocial interventions. In this case report we describe a thirteen-year-old patient with schizophrenia who has a background history of mental retardation.

  7. A MENTALLY RETARDED PATIENT WITH SCHIZOPHRENIA

    Directory of Open Access Journals (Sweden)

    KHOO EM

    2008-01-01

    Full Text Available Schizophrenia is one of the most incapacitating forms of mental disorder that runs a chronic and relapsing course. It typically starts in adolescence or early adulthood and can be life-long. It is more common in people with learning disabilities than in the general population. Its prodromal features include depression, anxiety, suspiciousness, social isolation and bizarre behaviour. It may result in significant functional, social and economic impairments. The care of patients with schizophrenia places a considerable burden on all carers including patient’s family, health and social services. Treatment includes pharmacotherapy and psychosocial interventions. In this case report we describe a thirteen-year-old patient with schizophrenia who has a background history of mental retardation.

  8. Relativistic quarkonium model with retardation effect, 1

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1990-01-01

    A new relativistic two-body equation is proposed which has the charge-conjugation symmetry. The renormalization of the wave function at the origin (WFO) is done by incorporating the corresponding vertex equation. By using this model, the heavy-quarkonium phenomenology is developed putting emphasis on the short-distance interaction. The typical scale of the distance restricting the applicability of the ladder model for the mass spectra is found to be 0.13 fm: By assuming the equivalent high-momentum cutoff for the gluonic correction, good results are obtained for the charmonium masses. The improved fine-splittings of the bb-bar states are obtained by inclusion of the retardation. Leptonic decay rates are predicted by assuming the renormalized WFO reduced by another high-momentum cutoff. (author)

  9. Adsorption and Retardation of PFASs in Soil

    Science.gov (United States)

    Chen, W.; Yan, N.; Fu, X.; Carroll, K. C.; Holguin, F. O. O.; Brusseau, M. L.

    2017-12-01

    Per- and poly-fluorinated alkyl substances (PFASs) are emerging contaminants of concern that are present in the subsurface at numerous military and industrial facilities. Knowledge of the retention behavior of these compounds in the subsurface environment is critical for effective risk characterization and remediation. The objective of this research is to investigate the role of adsorption at the air-water interface on PFAS retention in vadose-zone systems. Surface tensions were measured for select PFAS to determine interfacial adsorption coefficients. Column experiments were conducted to characterize retardation and transport under saturated and unsaturated flow conditions. The impact of soil properties and groundwater constituents on surface tension, solid-phase adsorption, and interfacial adsorption was investigated.

  10. Breakdown of predictability in gravitational collapse

    International Nuclear Information System (INIS)

    Hawking, S.W.

    1976-01-01

    In this paper it is claimed that the breakdown of classical concepts of space and time is not merely a result of our ignorance of the correct theory but that it represents a fundamental limitation to our ability to predict the future, a limitation that is analogous but additional to the limitation imposed by the normal quantum-mechanical uncertainty principle. The new limitation arises because general relativity allows the causal structure of space-time to be very different from that of Minkowski space. The interaction region can be bounded not only by an initial surface on which data are given and a final surface on which measurements are made but also a ''hidden surface'' about which the observer has only limited information such as the mass, angular momentum, and charge. Concerning this hidden surface one has a ''principle of ignorance'': The surface emits with equal probability all configurations of particles compatible with the observerslimited knowledge. It is shown that the ignorance principle holds for the quantum-mechanical evaporation of black holes: The black hole creates particles in pairs, with one particle always falling into the hole and the other possibly escaping to infinity. Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state. This means there is no S matrix for the process of black-hole formation and evaporation. Instead one has to introduce a new operator, called the superscattering operator, which maps density matrices describing the initial situation to density matrices describing the final situation

  11. Stress-induced breakdown during galvanostatic anodising of zirconium

    International Nuclear Information System (INIS)

    Van Overmeere, Q.; Proost, J.

    2010-01-01

    Although internal stress is frequently being suggested as a plausible reason for oxide breakdown during valve metal anodising, no direct quantitative evidence has been made available yet. In this work, we anodized sputtered zirconium thin films galvanostatically at room temperature in sulphuric acid until breakdown was observed, and simultaneously measured the internal stress evolution in the oxide in situ, using a high-resolution curvature setup. It was found that the higher the magnitude of the observed internal compressive stress in the oxide, the smaller the oxide thickness at which breakdown occurred. The moment of breakdown was identified from a slope change in the cell voltage evolution, indicative for a decrease in anodising efficiency. The latter presumably occurs as a result of oxygen evolution, initiated by the relative increase of the cubic or tetragonal zirconia phase content relative to the monoclinic one. This was evidenced in turn by comparing electron diffractograms, taken in a transmission electron microscope, before and after breakdown. The critical role of internal stress on oxide breakdown during zirconium anodising can therefore be associated with its promoting effect on the densifying phase transformation of monoclinic oxide.

  12. Breakdown coefficients and scaling properties of rain fields

    Directory of Open Access Journals (Sweden)

    D. Harris

    1998-01-01

    Full Text Available The theory of scale similarity and breakdown coefficients is applied here to intermittent rainfall data consisting of time series and spatial rain fields. The probability distributions (pdf of the logarithm of the breakdown coefficients are the principal descriptor used. Rain fields are distinguished as being either multiscaling or multiaffine depending on whether the pdfs of breakdown coefficients are scale similar or scale dependent, respectively. Parameter  estimation techniques are developed which are applicable to both multiscaling and multiaffine fields. The scale parameter (width, σ, of the pdfs of the log-breakdown coefficients is a measure of the intermittency of a field. For multiaffine fields, this scale parameter is found to increase with scale in a power-law fashion consistent with a bounded-cascade picture of rainfall modelling. The resulting power-law exponent, H, is indicative of the smoothness of the field. Some details of breakdown coefficient analysis are addressed and a theoretical link between this analysis and moment scaling analysis is also presented. Breakdown coefficient properties of cascades are also investigated in the context of parameter estimation for modelling purposes.

  13. AVLIS Production Plant work breakdown structure and Dictionary

    International Nuclear Information System (INIS)

    1984-01-01

    The work breakdown structure has been prepared for the AVLIS Production Plant to define, organize, and identify the work efforts and is summarized in Fig. 1-1 for the top three project levels. The work breakdown structure itself is intended to be the primary organizational tool of the AVLIS Production Plant and is consistent with the overall AVLIS Program Work Breakdown Structure. It is designed to provide a framework for definition and accounting of all of the elements that are required for the eventual design, procurement, and construction of the AVLIS Production Plant. During the present phase of the AVLIS Project, the conceptual engineering phase, the work breakdown structure is intended to be the master structure and project organizer of documents, designs, and cost estimates. As the master project organizer, the key role of the work breakdown structure is to provide the mechanism for developing completeness in AVLIS cost estimates and design development of all hardware and systems. The work breakdown structure provides the framework for tracking, on a one-to-one basis, the component design criteria, systems requirements, design concepts, design drawings, performance projections, and conceptual cost estimates. It also serves as a vehicle for contract reporting. 12 figures, 2 tables

  14. Plasma breakdown in a capacitively-coupled radiofrequency argon discharge

    Science.gov (United States)

    Smith, H. B.; Charles, C.; Boswell, R. W.

    1998-10-01

    Low pressure, capacitively-coupled rf discharges are widely used in research and commercial ventures. Understanding of the non-equilibrium processes which occur in these discharges during breakdown is of interest, both for industrial applications and for a deeper understanding of fundamental plasma behaviour. The voltage required to breakdown the discharge V_brk has long been known to be a strong function of the product of the neutral gas pressure and the electrode seperation (pd). This paper investigates the dependence of V_brk on pd in rf systems using experimental, computational and analytic techniques. Experimental measurements of V_brk are made for pressures in the range 1 -- 500 mTorr and electrode separations of 2 -- 20 cm. A Paschen-style curve for breakdown in rf systems is developed which has the minimum breakdown voltage at a much smaller pd value, and breakdown voltages which are significantly lower overall, than for Paschen curves obtained from dc discharges. The differences between the two systems are explained using a simple analytic model. A Particle-in-Cell simulation is used to investigate a similar pd range and examine the effect of the secondary emission coefficient on the rf breakdown curve, particularly at low pd values. Analytic curves are fitted to both experimental and simulation results.

  15. Referential first mention in narratives by mildly mentally retarded adults.

    Science.gov (United States)

    Kernan, K T; Sabsay, S

    1987-01-01

    Referential first mentions in narrative reports of a short film by 40 mildly mentally retarded adults and 20 nonretarded adults were compared. The mentally retarded sample included equal numbers of male and female, and black and white speakers. The mentally retarded speakers made significantly fewer first mentions and significantly more errors in the form of the first mentions than did nonretarded speakers. A pattern of better performance by black males than by other mentally retarded speakers was found. It is suggested that task difficulty and incomplete mastery of the use of definite and indefinite forms for encoding old and new information, rather than some global type of egocentrism, accounted for the poorer performance by mentally retarded speakers.

  16. BAF is a cytosolic DNA sensor that leads to exogenous DNA avoiding autophagy.

    Science.gov (United States)

    Kobayashi, Shouhei; Koujin, Takako; Kojidani, Tomoko; Osakada, Hiroko; Mori, Chie; Hiraoka, Yasushi; Haraguchi, Tokuko

    2015-06-02

    Knowledge of the mechanisms by which a cell detects exogenous DNA is important for controlling pathogen infection, because most pathogens entail the presence of exogenous DNA in the cytosol, as well as for understanding the cell's response to artificially transfected DNA. The cellular response to pathogen invasion has been well studied. However, spatiotemporal information of the cellular response immediately after exogenous double-stranded DNA (dsDNA) appears in the cytosol is lacking, in part because of difficulties in monitoring when exogenous dsDNA enters the cytosol of the cell. We have recently developed a method to monitor endosome breakdown around exogenous materials using transfection reagent-coated polystyrene beads incorporated into living human cells as the objective for microscopic observations. In the present study, using dsDNA-coated polystyrene beads (DNA-beads) incorporated into living cells, we show that barrier-to-autointegration factor (BAF) bound to exogenous dsDNA immediately after its appearance in the cytosol at endosome breakdown. The BAF(+) DNA-beads then assembled a nuclear envelope (NE)-like membrane and avoided autophagy that targeted the remnants of the endosome membranes. Knockdown of BAF caused a significant decrease in the assembly of NE-like membranes and increased the formation of autophagic membranes around the DNA-beads, suggesting that BAF-mediated assembly of NE-like membranes was required for the DNA-beads to evade autophagy. Importantly, BAF-bound beads without dsDNA also assembled NE-like membranes and avoided autophagy. We propose a new role for BAF: remodeling intracellular membranes upon detection of dsDNA in mammalian cells.

  17. Numerical study on physical mechanism of vortex breakdown occurrence in spin-up process

    OpenAIRE

    "小出, 輝明"; Teruaki", "Koide

    2008-01-01

    "A Numerical study presented on a vortex breakdown in spin-up process in an enclosed cylindrical container. In a transitional state, momentary vortex breakdowns can occur for particular parameter values ofthe Reynolds number and aspect ratio where no vortex breakdown appears in a steady state. This transient vortex breakdown flow is convenient to consider a mechanism for the occurrence of a vortex breakdown. It isdiscussed that periodical increase and decrease of angular momentum in upstream ...

  18. Evaluation of Inheritance Pattern in Mentally Retarded Children

    Directory of Open Access Journals (Sweden)

    F Behnaz

    2011-07-01

    Full Text Available Introduction: Mental retardation is one of the most important problems of general health. The purpose of this study was to evaluate inheritance pattern of mentally retarded patients in Yazd city. Methods: In a descriptive cross- sectional study, all medical records and pedigrees of 320 mentally retarded children whose parents had referred for genetic consultation to the Welfare center of Yazd city were reviewed. Results: Of the total, 62.8% of the parents had consanguineous marriage. Mean inbreeding coefficient of offsprings was 0.0713 in third degree related parents versus 0.0156 in non-related parents. Mental retardation was seen in 43.4% of first– degree relatives of children (6.6% of parents and 36.8% of siblings, respectively. Frequency of mental retardation did not differ significantly in both sexes. Pedigree showed inheritance pattern in 43.4% of patients (autosomal recessive, autosomal dominant and x-linked inheritance pattern were seen in 33.75%, 6.9% and 2.8%, respectively, while 37% of patients had no definite inheritance pattern. Abnormal karyotype were seen in 19.4% of patients, 28 of whom(8.75% of all patients had Down syndrome. The prevalence of autosomal recessive inheritance in patients with consanguineous marriages and non family marriages was 62.8 % and 10%, respectively (P=0. 002. Conclusion: Since multiple cases of mental retardation were seen in families and rate of consanguineous marriage was more in parents of mentally retarded children, genetic counseling in consanguinity marriages and families of mentally retarded children can prevent incidence of mental retardation in these families.

  19. Breakdown-prone volume in terahertz wave beams

    Energy Technology Data Exchange (ETDEWEB)

    Nusinovich, G. S.; Qiao, F.; Kashyn, D. G.; Pu, R. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742-3511 (United States); Dolin, L. S. [Institute of Applied Physics, Nizhny Novgorod 603600 (Russian Federation)

    2013-06-21

    This study was motivated by the recently proposed concept of remote detection of concealed radioactive materials by a focused terahertz (THz) radiation [V. L. Granatstein and G. S. Nusinovich, J. Appl. Phys. 108, 063304 (2010)]. According to this concept, a high-power THz radiation should be focused in a small spot where the field intensity exceeds the breakdown threshold. In the presence of free electrons in such a breakdown-prone volume, a THz discharge will occur there. However, this volume should be so small that in the absence of ionizing sources in its vicinity the probability to have there any free electrons is low. Then, the increased breakdown rate in a series of THz pulses would indicate the presence of hidden radioactive materials in the vicinity of the focused spot. For this concept, it is important to accurately determine the breakdown-prone volume created by a focused THz radiation. This problem is analyzed in this paper, first, for the case of a single wave beam and, then, for the case of crossing wave beams of different polarizations. The problem is studied first ignoring the diffraction spread of wave beams in the vicinity of the focal plane and, then, with the account for the diffraction spreading. Then, relations between the THz wave power, the range of such a system and the breakdown-prone volume are analyzed. Finally, the effect of the atmospheric turbulence on propagation and focusing of THz wave beams in air is considered.

  20. Dramatically enhanced electrical breakdown strength in cellulose nanopaper

    Directory of Open Access Journals (Sweden)

    Jianwen Huang

    2016-09-01

    Full Text Available Electrical breakdown behaviors of nanopaper prepared from nanofibrillated cellulose (NFC were investigated. Compared to conventional insulating paper made from micro softwood fibers, nanopaper has a dramatically enhanced breakdown strength. Breakdown field of nanopaper is 67.7 kV/mm, whereas that of conventional paper is only 20 kV/mm. Air voids in the surface of conventional paper are observed by scanning electron microscope (SEM. Further analyses using mercury intrusion show that pore diameter of conventional paper is around 1.7 μm, while that of nanopaper is below 3 nm. Specific pore size of nanopaper is determined to be approximately 2.8 nm by the gas adsorption technique. In addition, theoretical breakdown strengths of nanopaper and conventional paper are also calculated to evaluate the effect of pore size. It turns out that theoretical values agree well with experimental data, indicating that the improved strength in nanopaper is mainly attributed to the decreased pore size. Due to its outstanding breakdown strength, this study indicates the suitability of nanopaper for electrical insulation in ultra-high voltage convert transformers and other electrical devices.

  1. Accoustic Localization of Breakdown in Radio Frequency Accelerating Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Peter Gwin [IIT, Chicago

    2016-07-01

    Current designs for muon accelerators require high-gradient radio frequency (RF) cavities to be placed in solenoidal magnetic fields. These fields help contain and efficiently reduce the phase space volume of source muons in order to create a usable muon beam for collider and neutrino experiments. In this context and in general, the use of RF cavities in strong magnetic fields has its challenges. It has been found that placing normal conducting RF cavities in strong magnetic fields reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields, it would be helpful to have a diagnostic tool which can localize the source of breakdown sparks inside the cavity. These sparks generate thermal shocks to small regions of the inner cavity wall that can be detected and localized using microphones attached to the outer cavity surface. Details on RF cavity sound sources as well as the hardware, software, and algorithms used to localize the source of sound emitted from breakdown thermal shocks are presented. In addition, results from simulations and experiments on three RF cavities, namely the Aluminum Mock Cavity, the High-Pressure Cavity, and the Modular Cavity, are also given. These results demonstrate the validity and effectiveness of the described technique for acoustic localization of breakdown.

  2. Breakdown resistance of refractory metals compared to copper

    CERN Document Server

    Taborelli, M; Kildemo, M

    2004-01-01

    The behaviour of Mo, W and Cu with respect to electrical breakdown in ultra high vacuum has been investigated by means of a capacitor discharge method. The maximum stable electric field without breakdown and the field enhancement factor, beta have been measured between electrodes of the same material in a sphere/plane geometry for anode and cathode, respectively. The maximum stable field increases as a function of the number of breakdown events for W and Mo. In contrast, no systematic increase is observed for Cu. The highest values obtained are typically 500 MV/m for W, 350 MV/m for Mo and only 180 MV/m for Cu. This conditioning, found for the refractory metals, corresponds to a simultaneous decrease of beta and is therefore related to the field emission properties of the surface and their modification upon sparking. Accordingly, high beta values and no applicable field increase occur for Cu even after repeated breakdown. The results are compared with RF breakdown experiments [1] performed on prototype 30 GHz...

  3. Abnormal breakdown characteristic in a two-phase mixture

    International Nuclear Information System (INIS)

    Ye Qizheng; Li Jin; Lu Fei

    2006-01-01

    A two-phase mixture (TPM) is a mixture of gas and macroparticles of high concentration. Based on Townsend's theory, a new cell-iterative model in analytical form for the breakdown mechanism in TPM is presented. Compared with the original cell-iterative model in our previous paper, the obstructive factor of the macroparticles that influences the electron avalanche propagation is considered, except for the macroparticles distorting the electrical field and capture of the electrons. The cell attractive parameter k is presented according to the classical continuum theory for field charging. The modified Paschen law for a TPM is presented to calculate the breakdown voltage. The breakdown voltage of the TPM, U TPM , increases gradually with an increase in the macroparticle number density (m). The voltage U TPM is lower than that of the pure gas at low m values and larger at high m values. With a decrease of the macroparticle volume fraction and the dielectric mismatch, the voltage U TPM increases gradually at low m values and decreases gradually at high m values. The voltage U TPM at pd 200 cm Torr is lower than that at pd = 760 cm Torr for low m values and larger for high m values. This kind of abnormal breakdown characteristic in the TPM occurs in the case of high macroparticle volume fraction. On the other hand, the minimum of the TPM's Paschen curve increases with increase in m. It provides the possibility and the conditions of greatly increasing the breakdown voltage in a nearly uniform field

  4. Breakdown-prone volume in terahertz wave beams

    International Nuclear Information System (INIS)

    Nusinovich, G. S.; Qiao, F.; Kashyn, D. G.; Pu, R.; Dolin, L. S.

    2013-01-01

    This study was motivated by the recently proposed concept of remote detection of concealed radioactive materials by a focused terahertz (THz) radiation [V. L. Granatstein and G. S. Nusinovich, J. Appl. Phys. 108, 063304 (2010)]. According to this concept, a high-power THz radiation should be focused in a small spot where the field intensity exceeds the breakdown threshold. In the presence of free electrons in such a breakdown-prone volume, a THz discharge will occur there. However, this volume should be so small that in the absence of ionizing sources in its vicinity the probability to have there any free electrons is low. Then, the increased breakdown rate in a series of THz pulses would indicate the presence of hidden radioactive materials in the vicinity of the focused spot. For this concept, it is important to accurately determine the breakdown-prone volume created by a focused THz radiation. This problem is analyzed in this paper, first, for the case of a single wave beam and, then, for the case of crossing wave beams of different polarizations. The problem is studied first ignoring the diffraction spread of wave beams in the vicinity of the focal plane and, then, with the account for the diffraction spreading. Then, relations between the THz wave power, the range of such a system and the breakdown-prone volume are analyzed. Finally, the effect of the atmospheric turbulence on propagation and focusing of THz wave beams in air is considered.

  5. Laser-induced breakdown spectroscopy analysis of asbestos

    International Nuclear Information System (INIS)

    Caneve, L.; Colao, F.; Fabbri, F.; Fantoni, R.; Spizzichino, V.; Striber, J.

    2005-01-01

    Laser-induced breakdown spectroscopy was applied to test the possibility of detecting and identifying asbestos in different samples in view of the perspective at field operation without sample preparation which is peculiar to this technique. Several like-resin materials were first investigated by laser-induced breakdown spectroscopy, in order to find an asbestos container assuring safe laboratory operation during the material characterization aimed to identify indicators suitable for a quick identification on field. Successively, spectra of asbestos samples of both in serpentine and amphibole forms were measured and the variability in elemental composition was calculated from the emission spectra. Ratios of intensities of characteristic elements were tested as indicators for asbestos recognition. Laser-induced breakdown spectroscopy results were compared with those obtained by analyzing the same asbestos samples with a scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, a good correlation was found for Mg/Si and Fe/Si, thus showing the capability of laser-induced breakdown spectroscopy as a diagnostic tool for this category of materials. In particular, it was demonstrated that the method based on two indicators derived from laser-induced breakdown spectroscopy intensity ratios allows to discriminate between asbestos and cements in single shot measurements suitable to field operation

  6. Synergistic Effect of Nanosilica Aerogel with Phosphorus Flame Retardants on Improving Flame Retardancy and Leaching Resistance of Wood

    Directory of Open Access Journals (Sweden)

    Xiaodan Zhu

    2014-01-01

    Full Text Available Nanosilica (Nano-SiO2 sol fabricated by a sol-gel process was introduced into wood modification with phosphorus flame retardants to improve the flame retardancy and leaching resistance of wood. The obtained materials were characterized by scanning electron microscopy and energy dispersive spectrometer (SEM-EDS, thermogravimetric analysis (TGA, cone calorimetric (CONE, and infrared spectroscopy (FT-IR. The residual rate of flame retardants before and after leaching was determinated by a leaching resistance. The results showed that the phosphorus flame retardants and SiO2 sol could reside in the poplar wood and are widely distributed in the vessels, pits, wood timber, and the spaces between wood cells of poplar substrate. TGA and CONE results indicated that the introduction of nano-SiO2 aerogel with phosphorus flame retardants had a significantly synergistic effect on improving the flame retardancy and inhibiting the release of smoke and toxic gases. In addition, the leaching resistance test, combined with infrared analysis and EDS analysis, confirmed that the phosphorus flame retardants were able to be fixed by SiO2 aerogel in the wood.

  7. Plasma diagnostics with a retarding potential analyzer

    International Nuclear Information System (INIS)

    Jack, T.M.

    1996-01-01

    The plasma rocket is located at NASA Johnson Space Center. To produce a thrust in space, an inert gas is ionized into a plasma and heated in the linear section of a tokamak fusion device. The magnetic field used to contain the plasma has a magnitude of 2--10 kGauss. The plasma plume has a variable thrust and specific impulse. A high temperature retarding potential analyzer (RPA) is being developed to characterize the plasma in the plume and at the edge of the magnetically contained plasma. The RPA measures the energy and density of ions or electrons entering into its solid angle of collection. An oscilloscope displays the ion flux versus the collected current. All measurements are made relative to the facility ground. Testing of this device involves the determination of its output parameters, sensitivity, and responses to a wide range of energies and densities. Each grid will be tested individually by changing only its voltage and observing the output from the RPA. To verify that the RPA is providing proper output, it is compared to the output from a Langmuir or Faraday probe

  8. The needs of the retarded adult.

    Science.gov (United States)

    Armour, W E

    1979-11-01

    This article deals primarily with the needs of people with a degree of mental retardation, from mild to moderately severe, who are able to live approximately normal lives with assistance by counselling, advice and family help.It has been found that they do much better living in the community, mixing with normal people, but also with access to the company of persons similarly affected. With adequate advice and counselling, they can become self-sustaining in a number of ways, such as self care, living in their own homes or in small groups, and working either in sheltered employment or in the labor force. Their needs, like those of all others, range from the material such as shelter, food, clothing, possessions, transportation, health care, through the pyschological such as self fulfillment, recreation and enjoyment, love, affection and sex, and social such as legal protection and responsibility. With appropriate arrangements, these needs can be better met in community living, probably at less cost than if they were living in the traditional large institutions. Continued training and rehabilitative measures can often improve their abilities to an astonishing degree. They are rarely unteachable.

  9. Oral rehabilitation and management of mentally retarded.

    Science.gov (United States)

    Solanki, Jitender; Khetan, Jitendra; Gupta, Sarika; Tomar, Deepak; Singh, Meenakshi

    2015-01-01

    High level of periodontal problems of dental caries are frequently observed in mentally handicapped children. This group of patients presents various problems when they face dental treatments. Identification of such population and providing them affordable oral health care is the new concept. A systematic method for identification and screening of persons with mental retardation has been developed and is being followed. Cost and fear are the most commonly cited barriers to dental care. Physical or mental may lead to deterioration in self-care, and oral care state have a low priority. Risk factors are inter-related and are often barriers to oral health. With advancements in today's world sufficient information and support is available for each and every individual to lead a healthy life which include the access to the oral health care. Factors such as fear, anxiety and dental phobia plays a vital role in acceptance of dental care and also the delaying of dental care. Lack of knowledge of oral and dental disease, awareness or oral need, oral side-effects of medication and organization of dental services are highlighted in the literature. All health personnel should receive training to support the concept of primary oral health care. Training about dealing with such mentally handicapped people should be addressed urgently among the health professionals.

  10. Radionuclide transport and retardation in tuff

    International Nuclear Information System (INIS)

    Vine, E.N.; Bayhurst, B.P.; Daniels, W.R.; DeVilliers, S.J.; Erdal, B.R.; Lawrence, F.O.; Wolfsberg, K.

    1980-01-01

    Batch measurements provide an understanding of which experimental variables are important. For example, sorption ratios vary little with particle size (and surface area); however, groundwater composition and rock composition are quite important. A general correlation has been identified between mineralogy (major phases) and degree of sorption for strontium, cesium, and barium. Although these are approximate, a more detailed analysis may be possible as more samples are studied and the data base increased. Data from crushed tuff columns indicate that, except in simple cases where sorption coefficients are relatively low, and ion-exchange equilibria not only exist but are the dominant mechanism for removal of radioisotopes from solution, the simple relation between the sorption ratio R/sub d/ (or K/sub d/) and the relative velocity of radionuclides with respect to groundwater velocity may be insufficient to permit accurate modeling of the retardation of radionuclides. Additional work on whole core columns and larger blocks of intact material is required to better understand radionuclide sorption and transport through rock

  11. Some plant extracts retarde nitrification in soil

    Directory of Open Access Journals (Sweden)

    Abdul–Mehdi S. AL-ANSARI

    2015-12-01

    Full Text Available An incubation experiment was conducted to evaluate the effect of aqueous extracts of 17 plant materials on nitrification inhibition of urea- N in soil as compared with chemical inhibitor Dicyandiamide (DCD. Plant materials used in study were collected from different areas of Basrah province, south of Iraq. Aqueous extracts were prepared at ratio of 1:10 (plant material: water and added at conc. of 0.05, 0.10 and 0.20 ml g– 1 soil to loamy sand soil. DCD was added to soil at rate of 50 µg g-1 soil . Soil received urea at rate of 1000 µg N g-1 soil. Treated soils were incubated at 30 OC for 40 days. Results showed that application of all plant extracts, except those of casuarina, date palm and eucalyptus to soil retarded nitrification in soil. Caper, Sowthistle ,bladygrass and pomegranate extracts showed highest inhibition percentage (51, 42, 40 and 40 %, respectively and were found to be more effective than DCD (33 %. Highest inhibition was achieved by using those extracts at conc. of 0.1 ml g-1 soil after 10 days of incubation . Data also revealed that treated soil with these plant extracts significantly increased amount of NH4+–N and decreased amount of NO3-–N accumulation in soil compared with DCD and control treatments. Results of the study suggested a possibility of using aqueous extracts of some studied plants as potent nitrification inhibitor in soil.

  12. RF Breakdown in Normal Conducting Single-cell Structures

    CERN Document Server

    Dolgashev, Valery A; Higo, Toshiyasu; Nantista, Christopher D; Tantawi, Sami G

    2005-01-01

    Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape and material. Experimental and theoretical study of the effects of these parameters on the breakdown limit in full scale structures is difficult and costly. We use 11.4 GHz single-cell traveling wave and standing wave accelerating structures for experiments and modeling of rf breakdown behavior. These test structures are designed so that the electromagnetic fields in one cell mimic the fields in prototype multicell structures for the X-band linear collider. Fields elsewhere in the test structures are significantly lower than that of the single cell. The setup uses matched mode converters that launch the circular TM01 mode into short test structures. The test structures are connected to the mode launchers with vacuum rf flanges. This setup allows economic testing of different cell geometries, cell materials an...

  13. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  14. The structure and dynamics of bubble-type vortex breakdown

    Science.gov (United States)

    Spall, R. E.; Ash, R. L.; Gatski, T. B.

    1990-01-01

    A unique discrete form of the Navier-Stokes equations for unsteady, three-dimensional, incompressible flow has been used to study vortex breakdown numerically. A Burgers-type vortex was introduced along the central axis of the computational domain, and allowed to evolve in space and time. By varying the strength of the vortex and the free stream axial velocity distribution, using a previously developed Rossby number criterion as a guide, the location and size of the vortex breakdown region was controlled. While the boundaries of the vortex breakdown bubble appear to be nominally symmetric, the internal flow field is not. Consequently, the mechanisms for mixing and entrainment required to sustain the bubble region are different from those suggested by earlier axisymmetric models. Results presented in this study, for a Reynolds number of 200, are in good qualitative agreement with higher Reynolds number experimental observations, and a variety of plots have been presented to help illuminate the fluid physics.

  15. New method for determining avalanche breakdown voltage of silicon photomultipliers

    International Nuclear Information System (INIS)

    Chirikov-Zorin, I.

    2017-01-01

    The avalanche breakdown and Geiger mode of the silicon p-n junction is considered. A precise physically motivated method is proposed for determining the avalanche breakdown voltage of silicon photomultipliers (SiPM). The method is based on measuring the dependence of the relative photon detection efficiency (PDE rel ) on the bias voltage when one type of carriers (electron or hole) is injected into the avalanche multiplication zone of the p-n junction. The injection of electrons or holes from the base region of the SiPM semiconductor structure is performed using short-wave or long-wave light. At a low overvoltage (1-2 V) the detection efficiency is linearly dependent on the bias voltage; therefore, extrapolation to zero PDE rel value determines the SiPM avalanche breakdown voltage with an accuracy within a few millivolts. [ru

  16. Gas breakdown at cyclotron resonance with a submillimeter laser

    International Nuclear Information System (INIS)

    Hacker, M.P.; Temkin, R.J.; Lax, B.

    1976-01-01

    A pulsed 496-μm CH 3 F laser is used to produce gas breakdown in He at pressures between 1 and 300 Torr in an intense longitudinal magnetic field. Breakdown is detected by the observation of visible light when the electron cyclotron frequency (eB/m) equals the laser frequency, which occurs at B=216 kG for lambda=496 μm. At the lowest helium pressures and near cyclotron resonance, the focused laser intensity of 40 kW/cm 2 gives rise to very large electron heating rates, well beyond the limit of validity of conventional equilibrium breakdown theory. The observed result is an intensity-dependent resonant linewidth, much larger than predicted by equilibrium theories

  17. Assessing and Increasing Descriptive Communication Skills in Retarded Children

    Science.gov (United States)

    Longhurst, Thomas M.

    1972-01-01

    The purpose of the paper was to review the impact of recent developments in research methodology with specific reference to the assessment and habilitation of communication problems in retarded children. (Author)

  18. Horticultural Careers for Persons with Mental Retardation. Expanding Opportunities.

    Science.gov (United States)

    Dehart-Bennett, Mary E.; Relf, Diane

    1990-01-01

    Horticulture careers provide therapeutic, rewarding employment for persons with mental retardation. Rehabilitation experts should become aware of the potential employment opportunities in horticulture so that individuals with disabilities can receive the training and job placement support they need. (Author)

  19. Persistence, bioaccumulation and toxicity of halogen-free flame retardants.

    NARCIS (Netherlands)

    Waaijers, S.L.; Kong, D; Hendriks, H.S.; de Wit, C.A.; Cousins, I.T.; Westerink, R.H.S.; Leonards, P.E.G.; Kraak, M.H.S.; Admiraal, W.; de Voogt, P.; Parsons, J.R.

    2013-01-01

    Polymers are synthetic organic materials that have a high carbon and hydrogen content, which renders them readily combustible. When used in buildings, electrical appliances, furniture, textiles, transportation, mining, and in many other applications, polymers have to fulfill flame retardancy

  20. Organophosphorous flame retardants in biota from Svalbard, Norway

    NARCIS (Netherlands)

    Hallanger, I.G.; Sagerup, K.; Evenset, A.; Kovacs, K.M.; Leonards, P.E.G.; Fuglei, E.; Routti, H.; Aars, J.; Strom, H.; Lydersen, C.; Gabrielsen, G. W.

    2015-01-01

    Eight arctic species, including fish, birds and mammals, from diverse habitats (marine and terrestrial) within the Svalbard Archipelago, Norway, were screened for 14 organophosphorus flame retardant (PFR) compounds. Ten PFRs were detected: tris(2-chloroethyl)phosphate (TCEP),

  1. Psychosocial Impacts of Mentally Retarded Children on Parents in ...

    African Journals Online (AJOL)

    Psychosocial Impacts of Mentally Retarded Children on Parents in Sudan. ... the age, number of handicapped children in the family as well as the degree of mental ... Results and discussion: The parents reported different psychological effects ...

  2. Etiological Study of Mental Retardation in Budapest, Hungary.

    Science.gov (United States)

    Czeizel, A.; And Others

    1980-01-01

    The first complex etiological study of mental retardation in Budapest was carried out with 1,364 children ages 7 to 14 years. Results are compared with findings from previous surveys in the United States and the United Kingdom. (Author)

  3. [Associated factors in newborns with intrauterine growth retardation].

    Science.gov (United States)

    Thompson-Chagoyán, Oscar C; Vega-Franco, Leopoldo

    2008-01-01

    To identify the risk factors implicated in the intrauterine growth retardation (IUGR) of neonates born in a social security institution. Case controls design study in 376 neonates: 188 with IUGR (weight RCIU in the population.

  4. Tourette syndrome, growth retardation, and platyspondyly: an entity?

    NARCIS (Netherlands)

    Scheper, Frederike Y.; Hennekam, Raoul C. M.

    2002-01-01

    A 14-year-old male is described with Tourette syndrome, platyspondyly, a marked delay in bone age, growth retardation that is more expressed in the limbs and talipes equinovarus. This appears to be a new entity

  5. Fatigue crack growth retardation in spot heated mild steel sheet

    Indian Academy of Sciences (India)

    Unknown

    Department of Metallurgical Engineering, *Department of Applied Mechanics and Hydraulics, ... growth retardation increases with increasing level of overload as well as with ..... Suresh S 1996 Fatigue of materials (Cambridge: Cambridge.

  6. Crusted piloleiomyoma with mental retardation: A rare association

    Directory of Open Access Journals (Sweden)

    Kamboj Sangeeta

    2009-01-01

    Full Text Available Piloleiomyoma is an uncommon benign smooth muscle neoplasm arising from arrector pili muscle. It is clinically defined by the presence of solitary or multiple reddish brown, dome-shaped, smooth papules or nodules, ranging in size from a few millimeters to a centimeter. The patients are otherwise healthy; but mental retardation developing in some patients with multiple Piloleiomyomas has been emerging as an intriguing matter for analysis by the scientists. In this case report, a mentally retarded patient with Piloleiomyoma is described, who, besides the characteristic smooth and dome-shaped lesions on the anterolateral aspect of the dorsum of the right foot, had developed crusting on one of the largest lesions. The histopathological features were consistent with Piloleiomyoma. The occurrence of Piloleiomyoma in a mentally retarded child and its unusual crusted nature has been rarely reported. The association between Piloleiomyoma and mental retardation is further stressed in this case report.

  7. The Overjustification Effect in Retarded Children: Durability and Generalizability.

    Science.gov (United States)

    Ogilvie, Lee; Prior, Margot

    1982-01-01

    Generalizability and durability of the overjustification effect (on decline in intrinsic motivation due to the lack of rewards in behavior modification programs) were examined in 35 normal preschool children and 17 mental age-matched retarded children. (Author/SW)

  8. Aryl Polyphosphonates: Useful Halogen-Free Flame Retardants for Polymers

    Directory of Open Access Journals (Sweden)

    Li Chen

    2010-10-01

    Full Text Available Aryl polyphosphonates (ArPPN have been demonstrated to function in wide applications as flame retardants for different polymer materials, including thermosets, polycarbonate, polyesters and polyamides, particularly due to their satisfactory thermal stability compared to aliphatic flame retardants, and to their desirable flow behavior observed during the processing of polymeric materials. This paper provides a brief overview of the main developments in ArPPN and their derivatives for flame-retarding polymeric materials, primarily based on the authors’ research work and the literature published over the last two decades. The synthetic chemistry of these compounds is discussed along with their thermal stabilities and flame-retardant properties. The possible mechanisms of ArPPN and their derivatives containing hetero elements, which exhibit a synergistic effect with phosphorus, are also discussed.

  9. Acquired alopecia, mental retardation, short stature, microcephaly, and optic atrophy

    NARCIS (Netherlands)

    Hennekam, R. C.; Renckens-Wennen, E. G.

    1990-01-01

    We report on a female patient who had acquired total alopecia, short stature, microcephaly, optic atrophy, severe myopia, and mental retardation. A survey of published reports failed to show an identical patient, despite various similar cases

  10. Halogenated flame retardants in the Great Lakes environment.

    Science.gov (United States)

    Venier, Marta; Salamova, Amina; Hites, Ronald A

    2015-07-21

    Flame retardants are widely used industrial chemicals that are added to polymers, such as polyurethane foam, to prevent them from rapidly burning if exposed to a small flame or a smoldering cigarette. Flame retardants, especially brominated flame retardants, are added to many polymeric products at percent levels and are present in most upholstered furniture and mattresses. Most of these chemicals are so-called "additive" flame retardants and are not chemically bound to the polymer; thus, they migrate from the polymeric materials into the environment and into people. As a result, some of these chemicals have become widespread pollutants, which is a concern given their possible adverse health effects. Perhaps because of their environmental ubiquity, the most heavily used group of brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), was withdrawn from production and use during the 2004-2013 period. This led to an increasing demand for other flame retardants, including other brominated aromatics and organophosphate esters. Although little is known about the use or production volumes of these newer flame retardants, it is evident that some of these chemicals are also becoming pervasive in the environment and in humans. In this Account, we describe our research on the occurrence of halogenated and organophosphate flame retardants in the environment, with a specific focus on the Great Lakes region. This Account starts with a short introduction to the first generation of brominated flame retardants, the polybrominated biphenyls, and then presents our measurements of their replacement, the PBDEs. We summarize our data on PBDE levels in babies, bald eagles, and in air. Once these compounds came off the market, we began to measure several of the newer flame retardants in air collected on the shores of the Great Lakes once every 12 days. These new measurements focus on a tetrabrominated benzoate, a tetrabrominated phthalate, a hexabrominated diphenoxyethane

  11. New phenomenology of gas breakdown in DC and RF fields

    Science.gov (United States)

    Petrović, Zoran Lj; Sivoš, Jelena; Savić, Marija; Škoro, Nikola; Radmilović Radenović, Marija; Malović, Gordana; Gocić, Saša; Marić, Dragana

    2014-05-01

    This paper follows a review lecture on the new developments in the field of gas breakdown and low current discharges, usually covered by a form of Townsend's theory and phenomenology. It gives an overview of a new approach to identifying which feedback agents provide breakdown, how to model gas discharge conditions and reconcile the results with binary experiments and how to employ that knowledge in modelling gas discharges. The next step is an illustration on how to record volt-ampere characteristics and use them on one hand to obtain the breakdown voltage and, on the other, to identify the regime of operation and model the secondary electron yields. The second aspect of this section concerns understanding the different regimes, their anatomy, how those are generated and how free running oscillations occur. While temporal development is the most useful and interesting part of the new developments, the difficulty of presenting the data in a written form precludes an easy publication and discussion. Thus, we shall only mention some of the results that stem from these measurements. Most micro discharges operate in DC albeit with complex geometries. Thus, parallel plate micro discharge measurements were needed to establish that Townsend's theory, with all its recent extensions, is still valid until some very small gaps. We have shown, for example, how a long-path breakdown puts in jeopardy many experimental observations and why a flat left-hand side of the Paschen curve often does not represent good physics. We will also summarize a kinetic representation of the RF breakdown revealing a somewhat more complex picture than the standard model. Finally, we will address briefly the breakdown in radially inhomogeneous conditions and how that affects the measured properties of the discharge. This review has the goal of summarizing (rather than developing details of) the current status of the low-current DC discharges formation and operation as a discipline which, in spite of

  12. Development of highly fire-retardant irradiated polyolefin cables

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Keiji; Inui, Toshifumi; Uda, Ikujiro (Sumitomo Electric Industries Ltd., Osaka (Japan))

    1982-12-01

    In recent years, motors, automobiles, heaters, etc., have been made into light weight and compact form in view of labour-saving and energy-saving. For this purpose, the wires for the electrical appliances used for these equipment are required to reduce insulation thickness and to improve heat resistance. On the other hand, the requirement for fire-retardant property has become severer than before from the viewpoint of safety. As an insulation for the wires which meets such requirement, the polyolefin cross-linked by irradiation was investigated, and the heat-resistant, highly fire-retardant, polyolefin-insulated wires have been developed, which have passed vertical combustion test (VW-1) and have the insulation thickness of 0.4 mm (voltage rating 300V) and UL standard 125 deg C and 150 deg C grades. Fire-retardant polyolefin resin is normally obtained by adding halogen series flame retarders. The selection of flame retarders requires the investigation on high thermal stability, high flame retardation, no impedance to cross-linking, and good dispersion into polymers. The evaluation of heat resistance performed on two points, thermal aging and thermal deformation. The use of oxidation inhibitors is indispensable to improve the anti-thermal aging capability, but it is important to balance the requirements well by combining oxidation inhibitors, considering thermal deformation, colouring and discolouration. By comparative test with silicone rubber, cross-linked polyethylene and cross-linked PVC-insulated wires, the characteristics of highly fire-retardant wires, insulated with polyethylene cross-linked by irradiation, are described about the fire retardation, thermal deformation, thermal aging resistance, electrical characteristics and oil resistance.

  13. Studies on flame retardancy of radiation crosslinked PE foam

    International Nuclear Information System (INIS)

    Yang Huili; Yao Zhanhai; Xu Jun

    1996-01-01

    CPE, DBDPO and Sb 2 O 3 were used as flame-retardant of PE foam. Effect of CPE on PE foam under radiation and it's flame-retardancy were studied. The result showed that CPE can enhance radiation cross-linking of PE, and trinary of addition being made of CPE, DBDPO and Sb 2 O 3 made oxygen index of PE foam achieve over 30, and self-extinguish, it did not influence manufacture and mechanical properties of PE foam

  14. Determining trace element in hair of children with mental retardation

    International Nuclear Information System (INIS)

    Wang Zhilan; Gu Bomei; Jia Meixiang

    1992-01-01

    Seven trace elements in the hair come from 29 mental retardation children and 29 normal children have been analysed by INAA and XRF. There are significant differences for Fe and Sc between the two groups. The average value of Pb in the hair of the mental retardation children is higher than that of the normal children. Although Zn is very important for children growing, there is no significant difference between two children groups

  15. A Case with Mental Retardation, Gynecomastia and Dysmorphic Features

    Directory of Open Access Journals (Sweden)

    Ozge Ozalp Yuregir

    2012-03-01

    Full Text Available The 17 years old boy was diagnosed as Borjeson Forsmann Lehmann Syndrome who was referred to our Genetic Diagnosis Center for his dysmorphic features, obesity, gynecomasty and mental retardation . There are so many diseases in differantial diagnosis of obesity and mental retardation that BFLS is a rare one of them. We aimed to discuss the findings of the patient clinically diagnosed as BFLS within the scope of literature. [Cukurova Med J 2012; 37(1: 60-63

  16. A Case with Mental Retardation, Gynecomastia and Dysmorphic Features

    Directory of Open Access Journals (Sweden)

    Ozge Ozalp Yuregir

    2012-02-01

    Full Text Available The 17 years old boy was diagnosed as Borjeson Forsmann Lehmann Syndrome who was referred to our Genetic Diagnosis Center for his dysmorphic features, obesity, gynecomasty and mental retardation . There are so many diseases in differantial diagnosis of obesity and mental retardation that BFLS is a rare one of them. We aimed to discuss the findings of the patient clinically diagnosed as BFLS within the scope of literature. [Cukurova Med J 2012; 37(1.000: 60-63

  17. Retarded Boson–Fermion interaction in atomic systems

    Indian Academy of Sciences (India)

    WINTEC

    The retardation effect arises from the finite speed of light, and the fact that a virtual photon is always in transit. By separating the center of mass motion, a wave equa- tion that looks like the effective equation for only one spin-1/2 fermion is derived in §3. The retardation ef- fect can now be calculated to all orders. Separation ...

  18. Blackbody Emission from Laser Breakdown in High-Pressure Gases

    Science.gov (United States)

    Bataller, A.; Plateau, G. R.; Kappus, B.; Putterman, S.

    2014-08-01

    Laser induced breakdown of pressurized gases is used to generate plasmas under conditions where the atomic density and temperature are similar to those found in sonoluminescing bubbles. Calibrated streak spectroscopy reveals that a blackbody persists well after the exciting femtosecond laser pulse has turned off. Deviation from Saha's equation of state and an accompanying large reduction in ionization potential are observed at unexpectedly low atomic densities—in parallel with sonoluminescence. In laser breakdown, energy input proceeds via excitation of electrons whereas in sonoluminescence it is initiated via the atoms. The similar responses indicate that these systems are revealing the thermodynamics and transport of a strongly coupled plasma.

  19. A Coaxial Vortex Ring Model for Vortex Breakdown

    OpenAIRE

    Blackmore, Denis; Brons, Morten; Goullet, Arnaud

    2008-01-01

    A simple - yet plausible - model for B-type vortex breakdown flows is postulated; one that is based on the immersion of a pair of slender coaxial vortex rings in a swirling flow of an ideal fluid rotating around the axis of symmetry of the rings. It is shown that this model exhibits in the advection of passive fluid particles (kinematics) just about all of the characteristics that have been observed in what is now a substantial body of published research on the phenomenon of vortex breakdown....

  20. Nanosecond air breakdown parameters for electron and microwave beam propagation

    International Nuclear Information System (INIS)

    Ali, A.W.

    1988-01-01

    Air breakdown by avalanche ionization plays an important role in the electron beam and microwave propagations. For high electric fields and short pulse applications one needs avalanche ionization parameters for modeling and scaling of experimental devices. However, the breakdown parameters, i.e., the ionization frequency vs E/p (volt. cm -1 . Torr -1 ) in air is uncertain for very high values of E/P. A review is given of the experimental data for the electron drift velocity, the Townsend ionization coefficient in N 2 and O 2 and the ionization frequency and the collision frequency for momentum transfer in air are developed. (author)

  1. Electrical Breakdown and Mechanical Ageing in Dielectric Elastomers

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin

    Dielectric elastomers (DE) are used in various applications, such as artificial eye lids, pressure sensors and human motion energy generators. For many applications, one of the major factors that limits the DE performance is premature electrical breakdown. There are many approaches that have been......, the lifetime of elastomer materials needs further investigation. Therefore, in the second strategy, several DE parameters such as Young’s moduli, breakdown strengths and dielectric permittivities of PDMS elastomers filled with hard filler particles were investigated after being subjected to pre...

  2. Development of flame retardant, radiation resistant insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M.

    1984-01-01

    On the cables used for nuclear power stations, in particular those ranked as IE class, flame retardation test, simulated LOCA environment test, radiation resistance test and so on are imposed. The results of the evaluation of performance by these tests largely depend on the insulating materials mainly made of polymers. Ethylene propylene copolymer rubber has been widely used as cable insulator because of its electrical characteristics, workability, economy and relatively good radiation resistance, but it is combustible, therefore, in the practical use, it is necessary to make it fire resistant. The author et al. have advanced the research on the molecular design of new fire retarding materials, and successfully developed acenaphthylene bromide condensate, which is not only fire resistant but also effective for improving radiation resistance. The condition of flame retardant, radiation resistant auxiliary agents is explained, and there are additive type and reaction type in fire retarding materials. The synthesis of acenaphthylene bromide condensate and its effect of giving flame retardant and radiation resistant properties are reported. The characteristics of the cables insulated with the flame retardant ethylene propylene rubber containing acenaphthylene bromide condensate were tested, and the results are shown. (Kako, I.).

  3. Autism and Mental Retardation of Young Children in China

    Institute of Scientific and Technical Information of China (English)

    XIN ZHANG; CHENG-YE JI

    2005-01-01

    Objective To understand the prevalence and rehabilitation status of autism and mental retardation in China. Methods Screening test and clinical assessment were conducted for the diagnosis of autism and mental retardation. The assessment included investigation of the histories of medical conditions and development of these two disorders, utilization and needs for the rehabilitation service, and related intellectual and behavioral appraisal. Results Among the 7345 children investigated, the prevalence of autism disorder was 1.10 cases per 1000 children aged 2-6 years (95% CI=0.34 to 2.54), and the prevalence of mental retardation was 10.76 cases per 1000 children (95% CI=8.40 to 13.12). All the children suffering from autistic disorder were intellectually disabled, whereas 31.0% of the non-autism mental retardates had other disabilities. The medical conditions prior to birth and perinatal period were important potential factors for autism. Half of the autistic children and 84% of the children with non-autism mental retardation had never received any rehabilitative service. Conclusions The prevalence of autistic disorder in children aged 2-6 years in Tianjin is rather high. It is urgent to improve the status of the autistic and intelligently disabled young children in China. In order to upgrade the level of early diagnostic and improve the intervention to autism and mental retardation, public awareness and training courses should be heightened.

  4. Unexplained mental retardation: is brain MRI useful?

    Energy Technology Data Exchange (ETDEWEB)

    Decobert, Fabrice; Merzoug, Valerie; Kalifa, Gabriel; Adamsbaum, Catherine [Saint Vincent de Paul Hospital, Department of Radiology, 75674 Paris Cedex 14 (France); Grabar, Sophie [Cochin Hospital, Department of Biostatistics and Medical Information, Paris (France); Ponsot, Gerard [Saint Vincent de Paul Hospital, Department of Neuropaediatrics, Paris (France); Des Portes, Vincent [Saint Vincent de Paul Hospital, Department of Neuropaediatrics, Paris (France); Debrousse Hospital, Department of Neuropaediatrics, Lyon (France)

    2005-06-01

    Mental retardation (MR), defined as an IQ below 70, is a frequent cause of consultation in paediatrics. To evaluate the yield of brain MRI in the diagnostic work-up of unexplained MR in children. Patients and methods: The MRI features and clinical data of 100 patients (age 1-18 years) affected with non-progressive MR of unknown origin were compared to an age-matched control group (n=100). Two radiologists conducted an independent review of the MRI scans. Univariate and multivariate analyses showed a higher incidence of brain anomalies in the MR group than in the control group (53 vs 17, OR=5.7 [2.9-11.1]), for signal abnormalities within the periventricular white matter (OR=20.3 [2.6-155.3]), lateral ventricular dilatation (OR=15.6 [2.0-124]), mild corpus callosum abnormalities (shortness, atrophy) (OR=6.8 [1.8-25.6]) and subtle cerebellar abnormalities, including fissure enlargement (OR=5.2 [1.1-26.2]). The diagnostic value of MRI abnormalities was considered good in 5% of patients (Alexander disease n=1, diffuse cortical malformation n=1, leukomalacia n=1, vermian agenesis n=1, commissural agenesis n=1), and weak in 48% of patients, in whom non-specific abnormalities did not lead to a diagnosis. Some clinical features resulted in a significantly higher percentage of abnormal MRI scans: abnormal neurological examination (82% vs 47%, P=0.008), abnormal skull circumference (66% vs 49%, P=0.04). Motor delay was associated with cerebellar abnormalities (P=0.01). (orig.)

  5. Unexplained mental retardation: is brain MRI useful?

    International Nuclear Information System (INIS)

    Decobert, Fabrice; Merzoug, Valerie; Kalifa, Gabriel; Adamsbaum, Catherine; Grabar, Sophie; Ponsot, Gerard; Des Portes, Vincent

    2005-01-01

    Mental retardation (MR), defined as an IQ below 70, is a frequent cause of consultation in paediatrics. To evaluate the yield of brain MRI in the diagnostic work-up of unexplained MR in children. Patients and methods: The MRI features and clinical data of 100 patients (age 1-18 years) affected with non-progressive MR of unknown origin were compared to an age-matched control group (n=100). Two radiologists conducted an independent review of the MRI scans. Univariate and multivariate analyses showed a higher incidence of brain anomalies in the MR group than in the control group (53 vs 17, OR=5.7 [2.9-11.1]), for signal abnormalities within the periventricular white matter (OR=20.3 [2.6-155.3]), lateral ventricular dilatation (OR=15.6 [2.0-124]), mild corpus callosum abnormalities (shortness, atrophy) (OR=6.8 [1.8-25.6]) and subtle cerebellar abnormalities, including fissure enlargement (OR=5.2 [1.1-26.2]). The diagnostic value of MRI abnormalities was considered good in 5% of patients (Alexander disease n=1, diffuse cortical malformation n=1, leukomalacia n=1, vermian agenesis n=1, commissural agenesis n=1), and weak in 48% of patients, in whom non-specific abnormalities did not lead to a diagnosis. Some clinical features resulted in a significantly higher percentage of abnormal MRI scans: abnormal neurological examination (82% vs 47%, P=0.008), abnormal skull circumference (66% vs 49%, P=0.04). Motor delay was associated with cerebellar abnormalities (P=0.01). (orig.)

  6. Mental retardation and prenatal methylmercury toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Trasande, L.; Schechter, C.B.; Haynes, K.A.; Landrigan, P.J. [CUNY Mt. Sinai School of Medicine, New York, NY (United States). Dept. of Community & Preventative Medicine

    2006-03-15

    Methylmercury (MeHg) is a developmental neurotoxicant; exposure results principally from consumption of seafood contaminated by mercury (Hg). In this analysis, the burden of mental retardation (MR) associated with methylmercury exposure in the 2000 U.S. birth cohort is estimated, and the portion of this burden attributable to mercury (Hg) emissions from coal-fired power plants is identified. The aggregate loss in cognition associated with MeHg exposure in the 2000 U.S. birth cohort was estimated using two previously published dose-response models that relate increases in cord blood Hg concentrations with decrements in IQ. MeHg exposure was assumed not to be correlated with native cognitive ability. Previously published estimates were used to estimate economic costs of MR caused by MeHg. Downward shifts in IQ resulting from prenatal exposure to MeHg of anthropogenic origin are associated with 1,566 excess cases of MR annually (range: 376-14,293). This represents 3.2% of MR cases in the US (range: 0.8%-29.2%). The MR costs associated with decreases in IQ in these children amount to $2.0 billion/year (range: $0.5-17.9 billion). Hg from American power plants accounts for 231 of the excess MR cases year (range: 28-2,109), or 0.5% (range: 0.06%-4.3%) of all MR. These cases cost $289 million (range: $35 million-2.6 billion). Toxic injury to the fetal brain caused by Hg emitted from coal-fired power plants exacts a significant human and economic toll on American children.

  7. A Combined Electro-Thermal Breakdown Model for Oil-Impregnated Paper

    Directory of Open Access Journals (Sweden)

    Meng Huang

    2017-12-01

    Full Text Available The breakdown property of oil-impregnated paper is a key factor for converter transformer design and operation, but it is not well understood. In this paper, breakdown voltages of oil-impregnated paper were measured at different temperatures. The results showed that with the increase of temperature, electrical, electro-thermal and thermal breakdown occurred successively. An electro-thermal breakdown model was proposed based on the heat equilibrium and space charge transport, and negative differential mobility was introduced to the model. It was shown that carrier mobility determined whether it was electrical or thermal breakdown, and the model can effectively explain the temperature-dependent breakdown.

  8. Measuring the Electronic Properties of DNA-Specific Schottky Diodes Towards Detecting and Identifying Basidiomycetes DNA

    Science.gov (United States)

    Periasamy, Vengadesh; Rizan, Nastaran; Al-Ta’ii, Hassan Maktuff Jaber; Tan, Yee Shin; Tajuddin, Hairul Annuar; Iwamoto, Mitsumasa

    2016-01-01

    The discovery of semiconducting behavior of deoxyribonucleic acid (DNA) has resulted in a large number of literatures in the study of DNA electronics. Sequence-specific electronic response provides a platform towards understanding charge transfer mechanism and therefore the electronic properties of DNA. It is possible to utilize these characteristic properties to identify/detect DNA. In this current work, we demonstrate a novel method of DNA-based identification of basidiomycetes using current-voltage (I-V) profiles obtained from DNA-specific Schottky barrier diodes. Electronic properties such as ideality factor, barrier height, shunt resistance, series resistance, turn-on voltage, knee-voltage, breakdown voltage and breakdown current were calculated and used to quantify the identification process as compared to morphological and molecular characterization techniques. The use of these techniques is necessary in order to study biodiversity, but sometimes it can be misleading and unreliable and is not sufficiently useful for the identification of fungi genera. Many of these methods have failed when it comes to identification of closely related species of certain genus like Pleurotus. Our electronics profiles, both in the negative and positive bias regions were however found to be highly characteristic according to the base-pair sequences. We believe that this simple, low-cost and practical method could be useful towards identifying and detecting DNA in biotechnology and pathology. PMID:27435636

  9. Melatonin Improves the Photosynthetic Apparatus in Pea Leaves Stressed by Paraquat via Chlorophyll Breakdown Regulation and Its Accelerated de novo Synthesis

    Directory of Open Access Journals (Sweden)

    Katarzyna Szafrańska

    2017-05-01

    Full Text Available The positive effect of melatonin on the function of the photosynthetic apparatus is known, but little is known about the specific mechanisms of melatonin's action in plants. The influence of melatonin on chlorophyll metabolism of 24-day-old Pisum sativum L. seedlings during paraquat (PQ-induced oxidative stress was investigated in this study. Seeds were hydro-primed with water (H, 50 and 200 μM melatonin/water solutions (H-MEL50, H-MEL200, while non-primed seeds were used as controls (C. Increases in chlorophyllase activity (key enzyme in chlorophyll degradation and 5-aminolevulinic acid contents (the first compound in the porphyrin synthesis pathway were observed in H-MEL50 and H-MEL200 leaf disks. This suggests that melatonin may accelerate damaged chlorophyll breakdown and its de novo synthesis during the first hours of PQ treatment. Elevated level of pheophytin in control leaf disks following 24 h of PQ incubation probably was associated with an enhanced rate of chlorophyll degradation through formation of pheophytin as a chlorophyll derivative. This validates the hypothesis that chlorophyllide, considered for many years, as a first intermediate of chlorophyll breakdown is not. This is indicated by the almost unchanged chlorophyll to chlorophyllide ratio after 24 h of PQ treatment. However, prolonged effects of PQ-induced stress (48 h revealed extensive discolouration of control and water-treated leaf disks, while melatonin treatment alleviated PQ-induced photobleaching. Also the ratio of chlorophyll to chlorophyllide and porphyrin contents were significantly higher in plants treated with melatonin, which may indicate that this indoleamine both retards chlorophyll breakdown and stimulates its de novo synthesis during extended stress. We concluded that melatonin added into the seeds enhances the ability of pea seedlings to accelerate chlorophyll breakdown and its de novo synthesis before stress appeared and for several hours after, while

  10. Collaborating functions of BLM and DNA topoisomerase I in regulating human rDNA transcription

    International Nuclear Information System (INIS)

    Grierson, Patrick M.; Acharya, Samir; Groden, Joanna

    2013-01-01

    Bloom's syndrome (BS) is an inherited disorder caused by loss of function of the recQ-like BLM helicase. It is characterized clinically by severe growth retardation and cancer predisposition. BLM localizes to PML nuclear bodies and to the nucleolus; its deficiency results in increased intra- and inter-chromosomal recombination, including hyper-recombination of rDNA repeats. Our previous work has shown that BLM facilitates RNA polymerase I-mediated rRNA transcription in the nucleolus (Grierson et al., 2012 [18]). This study uses protein co-immunoprecipitation and in vitro transcription/translation (IVTT) to identify a direct interaction of DNA topoisomerase I with the C-terminus of BLM in the nucleolus. In vitro helicase assays demonstrate that DNA topoisomerase I stimulates BLM helicase activity on a nucleolar-relevant RNA:DNA hybrid, but has an insignificant effect on BLM helicase activity on a control DNA:DNA duplex substrate. Reciprocally, BLM enhances the DNA relaxation activity of DNA topoisomerase I on supercoiled DNA substrates. Our study suggests that BLM and DNA topoisomerase I function coordinately to modulate RNA:DNA hybrid formation as well as relaxation of DNA supercoils in the context of nucleolar transcription

  11. Collaborating functions of BLM and DNA topoisomerase I in regulating human rDNA transcription

    Energy Technology Data Exchange (ETDEWEB)

    Grierson, Patrick M. [Department of Microbiology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States); Acharya, Samir, E-mail: samir.acharya@osumc.edu [Department of Microbiology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States); Groden, Joanna [Department of Microbiology, Immunology and Medical Genetics, The Ohio State University College of Medicine, Columbus, OH 43210 (United States)

    2013-03-15

    Bloom's syndrome (BS) is an inherited disorder caused by loss of function of the recQ-like BLM helicase. It is characterized clinically by severe growth retardation and cancer predisposition. BLM localizes to PML nuclear bodies and to the nucleolus; its deficiency results in increased intra- and inter-chromosomal recombination, including hyper-recombination of rDNA repeats. Our previous work has shown that BLM facilitates RNA polymerase I-mediated rRNA transcription in the nucleolus (Grierson et al., 2012 [18]). This study uses protein co-immunoprecipitation and in vitro transcription/translation (IVTT) to identify a direct interaction of DNA topoisomerase I with the C-terminus of BLM in the nucleolus. In vitro helicase assays demonstrate that DNA topoisomerase I stimulates BLM helicase activity on a nucleolar-relevant RNA:DNA hybrid, but has an insignificant effect on BLM helicase activity on a control DNA:DNA duplex substrate. Reciprocally, BLM enhances the DNA relaxation activity of DNA topoisomerase I on supercoiled DNA substrates. Our study suggests that BLM and DNA topoisomerase I function coordinately to modulate RNA:DNA hybrid formation as well as relaxation of DNA supercoils in the context of nucleolar transcription.

  12. Further Delineation of the Clinical Phenotype of Cerebellar Ataxia, Mental Retardation, and Disequilibrium Syndrome Type 4

    Directory of Open Access Journals (Sweden)

    Saud Alsahli

    2018-02-01

    Full Text Available Background: Cerebellar ataxia, mental retardation, and disequilibrium syndrome (CAMRQ is a heterogeneous group of genetic disorders that have been grouped by shared clinical features; all of these features are transmitted via an autosomal recessive mechanism. Four variants of this syndrome have been identified so far, and each one differs in terms of both clinical and genotypical features. CAMRQ4 is a rare genetic disorder characterized by mental retardation, ataxia or an inability to walk, dysarthria and, in some patients, quadrupedal gait. Methods: We investigated three Saudi families with CAMRQ4. Blood samples were collected from the affected patients, their parents, and healthy siblings. DNA was extracted from whole blood, and whole-exome sequencing was performed. Findings were confirmed by segregation analysis, which was performed on other family members. Results: Thus far, 17 patients have been affected by CAMRQ4. Genetic analysis of all patients, including our current patients, showed a mutation in the aminophospholipid transporter, class I, type 8A, member 2 gene ( ATP8A2 . A series of common phenotypical features have been reported in these patients, with few exceptions. Ataxia, mental retardation, and hypotonia were present in all patients, consanguinity in 90% and abnormal movements in 50%. Moreover, 40% achieved ambulation at least once in their lifetime, 40% had microcephaly, whereas 30% were mute. Magnetic resonance imaging (MRI of the brain was normal in 60% of patients. Conclusions: We described the largest cohort of patients with CAMRQ4 syndrome and identified three novel mutations. CAMRQ4 syndrome should be suspected in patients presenting with ataxia, intellectual disability, hypotonia, microcephaly, choreoathetoid movements, ophthalmoplegia, and global developmental delay, even if brain MRI appears normal.

  13. Further Delineation of the Clinical Phenotype of Cerebellar Ataxia, Mental Retardation, and Disequilibrium Syndrome Type 4.

    Science.gov (United States)

    Alsahli, Saud; Alrifai, Muhammad Talal; Al Tala, Saeed; Mutairi, Fuad Al; Alfadhel, Majid

    2018-01-01

    Cerebellar ataxia, mental retardation, and disequilibrium syndrome (CAMRQ) is a heterogeneous group of genetic disorders that have been grouped by shared clinical features; all of these features are transmitted via an autosomal recessive mechanism. Four variants of this syndrome have been identified so far, and each one differs in terms of both clinical and genotypical features. CAMRQ4 is a rare genetic disorder characterized by mental retardation, ataxia or an inability to walk, dysarthria and, in some patients, quadrupedal gait. We investigated three Saudi families with CAMRQ4. Blood samples were collected from the affected patients, their parents, and healthy siblings. DNA was extracted from whole blood, and whole-exome sequencing was performed. Findings were confirmed by segregation analysis, which was performed on other family members. Thus far, 17 patients have been affected by CAMRQ4. Genetic analysis of all patients, including our current patients, showed a mutation in the aminophospholipid transporter, class I, type 8A, member 2 gene ( ATP8A2 ). A series of common phenotypical features have been reported in these patients, with few exceptions. Ataxia, mental retardation, and hypotonia were present in all patients, consanguinity in 90% and abnormal movements in 50%. Moreover, 40% achieved ambulation at least once in their lifetime, 40% had microcephaly, whereas 30% were mute. Magnetic resonance imaging (MRI) of the brain was normal in 60% of patients. We described the largest cohort of patients with CAMRQ4 syndrome and identified three novel mutations. CAMRQ4 syndrome should be suspected in patients presenting with ataxia, intellectual disability, hypotonia, microcephaly, choreoathetoid movements, ophthalmoplegia, and global developmental delay, even if brain MRI appears normal.

  14. Pulsed and streamer discharges in air above breakdown electric field

    NARCIS (Netherlands)

    A.B. Sun (Anbang); H.J. Teunissen (Jannis); U. M. Ebert (Ute)

    2013-01-01

    htmlabstractA 3D particle model is developed to investigate the streamer formation in electric fields above the breakdown threshold, in atmospheric air (1bar, 300 Kelvin). Adaptive particle management, adaptive mesh refinement and parallel computing techniques are used in the code. Photoionization

  15. Localization of rf breakdowns in a standing wave cavity

    Directory of Open Access Journals (Sweden)

    Faya Wang

    2009-04-01

    Full Text Available At SLAC, a five-cell, normal-conducting, L-band (1.3 GHz, standing-wave (SW cavity was built as a prototype positron capture accelerator for the ILC. The structure met the ILC gradient goal but required extensive rf processing. When rf breakdowns occurred, a large variation was observed in the decay rate of the stored energy in the cavity after the input power was shut off. It appeared that the breakdowns were isolating sections of the cavity, and that the trapped energy in those sections was then partitioned among its natural modes, producing a distinct beating pattern during the decay. To explore this phenomenon further, an equivalent circuit model of cavity was created that reproduces well its normal operating characteristics. The model was then used to compute the spectra of trapped energy for different numbers of isolated cells. The resulting modal patterns agree well with those of the breakdown data, and thus such a comparison appears to provide a means of identifying the irises on which the breakdowns occurred.

  16. characteristics of structural breakdown in plastic concrete and their

    African Journals Online (AJOL)

    Dr Obe

    observed as shearing proceeded. ANALYSIS OF THIXOTROPIC BREAKDOWN OF. CONCRETE. As the cup rotates on application of rotational shear stress, the stator also tends to rotate due to the viscous drag transmitted by the mix. The stator continues to rotate until the resistance registered by the torque arm becomes ...

  17. Characteristics of Structural Breakdown in Plastic Concrete and ...

    African Journals Online (AJOL)

    Characteristics of Structural Breakdown in Plastic Concrete and Their Potentials for Quality Control. ... A typical trace has four such significant features which characterise the mix. The significance of these features are analysed in relation to the functional requirements of plastic concrete in practice. Finally, the potentials of ...

  18. The breakdown phase in a coaxial plasma gun

    International Nuclear Information System (INIS)

    Donges, A.; Herziger, G.; Krompholz, H.; Ruehl, F.; Schoenbach, K.

    1980-01-01

    The electrical breakdown in a coaxial plasma gun was investigated by means of optical and electrical measurements. The optimum start and operation conditions of the gun turned out to be strongly dependent on material and length of the cylindrical insulator. (orig.)

  19. Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Cremers, D.A.

    1987-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs

  20. Direct relationship between breakdown strength and tracking index of composites

    DEFF Research Database (Denmark)

    Madsen, Søren Find; Henriksen, Mogens; Holbøll, Joachim

    2006-01-01

    . The breakdown field strength of specimens cut from similar samples is determined by a new method capable of estimating the stressed volume. The results from the two tests are finally compared and incorporated in a single analytical formula. All test specimens are supplied by Danish manufacturers of wind turbine...

  1. Highly Efficient Estimators of Multivariate Location with High Breakdown Point

    NARCIS (Netherlands)

    Lopuhaa, H.P.

    1991-01-01

    We propose an affine equivariant estimator of multivariate location that combines a high breakdown point and a bounded influence function with high asymptotic efficiency. This proposal is basically a location $M$-estimator based on the observations obtained after scaling with an affine equivariant

  2. The masking breakdown point of multivariate outlier identification rules

    OpenAIRE

    Becker, Claudia; Gather, Ursula

    1997-01-01

    In this paper, we consider one-step outlier identifiation rules for multivariate data, generalizing the concept of so-called alpha outlier identifiers, as presented in Davies and Gather (1993) for the case of univariate samples. We investigate, how the finite-sample breakdown points of estimators used in these identification rules influence the masking behaviour of the rules.

  3. Phenomena of g-u symmetry-breakdown in HD

    NARCIS (Netherlands)

    de Lange, A.; Reinhold, E.M.; Ubachs, W.M.G.

    2002-01-01

    Phenomena associated with the breakdown of inversion symmetry in the HD molecule are reviewed and discussed. A distinction is made between three kinds of physical effects observed in HD spectra. The existence of a small electric dipole moment in the ground state gives rise to vibrational and pure

  4. On locally uniformly linearizable high breakdown location and scale functionals

    NARCIS (Netherlands)

    Davies, P.L.

    1998-01-01

    This article gives two constructions of a weighted mean which has a large domain, is affinely equivariant, has a locally high breakdown point and is locally uniformly linearizable. One construction is based on $M$-functionals with smooth defining $\\psi$- and $\\chi$ -functions which are used to

  5. Electric breakdown of high polymer insulating materials at cryogenic temperature

    International Nuclear Information System (INIS)

    Kim, Sanhyon; Yoshino, Katsumi

    1985-01-01

    Cryogenic properties : temperature dependence of E sub(b) and effects of media upon E sub(b) were investigated on several high polymers. Temperature conditions were provided by liquid He (4.2 K), liquid N 2 (77 K) and cryogen (dry ice-methyl alcohol, 194 K). Silicone oil was used also at ambient temperature and elevated temperature. Polymer film coated with gold by vacuum evaporation was placed in cryostat, and high tension from pulse generator was applied to the film. Dielectric breakdowns were detected by oscilloscope and observed visually. The results of experiment are summerized as follow. (1) E sub(b) of film in He is affected by medium remarkably, and covering with 3-methyl pentane is effective for increasing E sub(b). (2) Temperature dependence of E sub(b) was not recognized in cryogenic temperature below liquid N 2 . (3) Temperature characteristic of E sub(b) changes considerably at the critical temperature T sub(c), and T sub(c) is dependent on material. (4) Strength against dielectric breakdown under cryogenic temperature is not affected by bridging caused by irradiation of electron beam. (5) Dielectric breakdown is thought to be caused by electronic process such as electron avalanche. Consequently, for designing insulation for the temperature below liquid He, insulation design for liquid N 2 is thought to be sufficient. However, the degradation and breakdown by mechanical stress under cryogenic temperature must be taken into consideration. (Ishimitsu, A.)

  6. Breakdown of large-scale circulation in turbulent rotating convection

    NARCIS (Netherlands)

    Kunnen, R.P.J.; Clercx, H.J.H.; Geurts, Bernardus J.

    2008-01-01

    Turbulent rotating convection in a cylinder is investigated both numerically and experimentally at Rayleigh number Ra = $10^9$ and Prandtl number $\\sigma$ = 6.4. In this Letter we discuss two topics: the breakdown under rotation of the domain-filling large-scale circulation (LSC) typical for

  7. Prediction of vortex breakdown on a delta wing

    Science.gov (United States)

    Agrawal, S.; Robinson, B. A.; Barnett, R. M.

    1992-01-01

    Recent studies of leading-edge vortex flows with computational fluid dynamics codes using Euler or Navier-Stokes formulations have shown fair agreement with experimental data. These studies have concentrated on simulating the flowfields associated with a sharp-edged flat plate 70 deg delta wing at angles of attack where vortex breakdown or burst is observed over the wing. There are, however, a number of discrepancies between the experimental data and the computed flowfields. The location of vortex breakdown in the computational solutions is seen to differ from the experimental data and to vary with changes in the computational grid and freestream Mach number. There also remain issues as to the validity of steady-state computations for cases which contain regions of unsteady flow, such as in the post-breakdown regions. As a partial response to these questions, a number of laminar Navier-Stokes solutions were examined for the 70 deg delta wing. The computed solutions are compared with an experimental database obtained at low subsonic speeds. The convergence of forces, moments and vortex breakdown locations are also analyzed to determine if the computed flowfields actually reach steady-state conditions.

  8. Effects of continuum breakdown on hypersonic aerothermodynamics for reacting flow

    Science.gov (United States)

    Holman, Timothy D.; Boyd, Iain D.

    2011-02-01

    This study investigates the effects of continuum breakdown on the surface aerothermodynamic properties (pressure, stress, and heat transfer rate) of a sphere in a Mach 25 flow of reacting air in regimes varying from continuum to a rarefied gas. Results are generated using both continuum [computational fluid dynamics (CFD)] and particle [direct simulation Monte Carlo (DSMC)] approaches. The DSMC method utilizes a chemistry model that calculates the backward rates from an equilibrium constant. A preferential dissociation model is modified in the CFD method to better compare with the vibrationally favored dissociation model that is utilized in the DSMC method. Tests of these models are performed to confirm their validity and to compare the chemistry models in both numerical methods. This study examines the effect of reacting air flow on continuum breakdown and the surface properties of the sphere. As the global Knudsen number increases, the amount of continuum breakdown in the flow and on the surface increases. This increase in continuum breakdown significantly affects the surface properties, causing an increase in the differences between CFD and DSMC. Explanations are provided for the trends observed.

  9. RF Breakdown in Normal Conducting Single-Cell Structures

    International Nuclear Information System (INIS)

    Dolgashev, V.A.; Nantista, C.D.; Tantawi, S.G.; Higashi, Y.; Higo, T.

    2006-01-01

    Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape and material. Experimental and theoretical study of the effects of these parameters on the breakdown limit in full scale structures is difficult and costly. We use 11.4 GHz single-cell traveling wave and standing wave accelerating structures for experiments and modeling of rf breakdown behavior. These test structures are designed so that the electromagnetic fields in one cell mimic the fields in prototype multicell structures for the X-band linear collider. Fields elsewhere in the test structures are significantly lower than that of the single cell. The setup uses matched mode converters that launch the circular TM 01 mode into short test structures. The test structures are connected to the mode launchers with vacuum rf flanges. This setup allows economic testing of different cell geometries, cell materials and preparation techniques with short turn-around time. Simple 2D geometry of the test structures simplifies modeling of the breakdown currents and their thermal effects

  10. Investigation of oral gels breakdown using image analysis

    NARCIS (Netherlands)

    Tournier, Carole; Devezeaux de Lavergne, Marine; Velde, van de Fred; Stieger, Markus; Salles, Christian; Bertrand, Dominique

    2017-01-01

    Characterizing the dynamics of food oral breakdown is of interest to understand the temporal perception of food products. The present work aimed at studying the possible contribution of artificial vision for studying bolus formation. Four emulsion-filled gels were prepared from two concentrations

  11. CANCER-PAthological breakdown of coherent energy states

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří; Pokorný, Jan; Kobilková, J.; Jandová, Anna; Vrba, J.; Vrba, J. jr.

    2014-01-01

    Roč. 9, č. 1 (2014), s. 115-133 ISSN 1793-0480 Institutional support: RVO:67985882 ; RVO:68378271 Keywords : breakdown of coherent states * Cancer electrodynamics * Warburg effect Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering; BO - Biophysics (FZU-D)

  12. Novel dielectric reduces corona breakdown in ac capacitors

    Science.gov (United States)

    Loehner, J. L.

    1972-01-01

    Dielectric system was developed which consists of two layers of 25-gage paper separated by one layer of 50-gage polypropylene to reduce corona breakdown in ac capacitors. System can be used in any alternating current application where constant voltage does not exceed 400 V rms. With a little research it could probably be increased to 700 to 800 V rms.

  13. Effects of streamwise vortex breakdown on supersonic combustion.

    Science.gov (United States)

    Hiejima, Toshihiko

    2016-04-01

    This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1.

  14. Hyperammonemic encephalopathy due to suture line breakdown after bladder operation.

    Science.gov (United States)

    Boogerd, W; Zoetmulder, F A; Moffie, D

    1990-01-01

    A patient is described with a severe encephalopathy and hyperammonemia in absence of liver dysfunction, attributed to urine absorption into the systemic circulation due to suture line breakdown after bladder dome resection. At autopsy characteristic Alzheimer type II astrocytes were found in the basal ganglia.

  15. Novel Voltage limiting concept for avalance breakdown protection

    NARCIS (Netherlands)

    Ruijs, L.C.H.; Bezooijen, van A.; Mahmoudi, R.; Roermund, van A.H.M.

    2006-01-01

    Destructive over-voltage breakdown of cellular phone power transistors is prevented by using a new voltage-limiting concept. The output voltage is detected by an avalanche-based detector, and limited by decreasing the output power when needed. The voltage detector contains a low voltage bipolar NPN

  16. Influence of ultrasound on the electrical breakdown of transformer oil

    Science.gov (United States)

    Isakaev, E. Kh; Tyuftyaev, A. S.; Gadzhiev, M. Kh; Demirov, N. A.; Akimov, P. L.

    2018-01-01

    When the transformer oil is exposed to low power ultrasonic waves (cavitation bubbles. With the increase of sonication time the breakdown voltage also increases, nonlinearly. The experimental data indicate the possibility of using ultrasonic waves of low power for degassing of transformer oil.

  17. Inhibitory effects of ethanol on phosphatidylinositol breakdown in pancreatic acini

    International Nuclear Information System (INIS)

    Towner, S.J.; Peppin, J.F.; Tsukamoto, H.

    1986-01-01

    Recently the physiological relationship between the phospholipid effect and secretagogue-induced cellular function has begun to be understood. In this study, the authors investigated acute and chronic effects of ethanol on phosphatidylinositol (PI) synthesis and breakdown in pancreatic acini. Five pairs of male Wistar rats were intragastrically infused for 30 days with high fat diet (25% total calories) plus ethanol or isocaloric dextrose. After intoxication, isolated in HEPES media, followed by 30 min incubation with CCK-8 (0, 100, 300 or 600 pM) and ethanol (0 or 100 mM). Acinar lipids were extracted and counted for labeled PI. Incorporation of 3 H-inositol into alcoholic acinar PI was reduced to 38.2% of that in controls. A percent maximal PI break down by CCK-8 was similar in the two groups (13-24% of basal). However, the magnitude of PI breakdown was markedly lower in alcoholic acini (482 vs 1081 dpm) due to the decreased PI synthesis rate. The presence of 100 mM ethanol in the media further inhibited the breakdown by 50% in this group. These results strongly indicate that chronic ethanol intoxication inhibits PI synthesis and breakdown in pancreatic acini, and that this inhibition can be potentiated by acute ethanol administration

  18. Experimental study of vortex breakdown in a cylindrical, swirling flow

    Science.gov (United States)

    Stevens, J. L.; Celik, Z. Z.; Cantwell, B. J.; Lopez, J. M.

    1996-01-01

    The stability of a steady, vortical flow in a cylindrical container with one rotating endwall has been experimentally examined to gain insight into the process of vortex breakdowwn. The dynamics of the flow are governed by the Reynolds number (Re) and the aspect ratio of the cylinder. Re is given by Omega R(sup 2)/nu, where Omega is the speed of rotation of the endwall, R is the cylinder radius, and nu is the kinematic viscosity of the fluid filling the cylinder. The aspect ratio is H/R, where H is the height of the cylinder. Numerical simulation studies disagree whether or not the steady breakdown is stable beyond a critical Reynolds number, Re(sub c). Previous experimental researches have considered the steady and unsteady flows near Re(sub c), but have not explored the stability of the steady breakdown structures beyond this value. In this investigation, laser induced fluorescence was utilized to observe both steady and unsteady vortex breakdown at a fixed H/R of 2.5 with Re varying around Re(sub c). When the Re of a steady flow was slowly increased beyond Re(sub c), the breakdown structure remained steady even though unsteadiness was possible. In addition, a number of hysteresis events involving the oscillation periods of the unsteady flow were noted. The results show that both steady and unsteady vortex breakdown occur for a limited range of Re above Re(sub c). Also, with increasing Re, complex flow transformations take place that alter the period at which the unsteady flow oscillates.

  19. Abnormal breakdown characteristic in a two-phase mixture

    Energy Technology Data Exchange (ETDEWEB)

    Ye Qizheng; Li Jin; Lu Fei [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2006-05-21

    A two-phase mixture (TPM) is a mixture of gas and macroparticles of high concentration. Based on Townsend's theory, a new cell-iterative model in analytical form for the breakdown mechanism in TPM is presented. Compared with the original cell-iterative model in our previous paper, the obstructive factor of the macroparticles that influences the electron avalanche propagation is considered, except for the macroparticles distorting the electrical field and capture of the electrons. The cell attractive parameter k is presented according to the classical continuum theory for field charging. The modified Paschen law for a TPM is presented to calculate the breakdown voltage. The breakdown voltage of the TPM, U{sub TPM}, increases gradually with an increase in the macroparticle number density (m). The voltage U{sub TPM} is lower than that of the pure gas at low m values and larger at high m values. With a decrease of the macroparticle volume fraction and the dielectric mismatch, the voltage U{sub TPM} increases gradually at low m values and decreases gradually at high m values. The voltage U{sub TPM} at pd 200 cm Torr is lower than that at pd = 760 cm Torr for low m values and larger for high m values. This kind of abnormal breakdown characteristic in the TPM occurs in the case of high macroparticle volume fraction. On the other hand, the minimum of the TPM's Paschen curve increases with increase in m. It provides the possibility and the conditions of greatly increasing the breakdown voltage in a nearly uniform field.

  20. A Real-time Breakdown Prediction Method for Urban Expressway On-ramp Bottlenecks

    Science.gov (United States)

    Ye, Yingjun; Qin, Guoyang; Sun, Jian; Liu, Qiyuan

    2018-01-01

    Breakdown occurrence on expressway is considered to relate with various factors. Therefore, to investigate the association between breakdowns and these factors, a Bayesian network (BN) model is adopted in this paper. Based on the breakdown events identified at 10 urban expressways on-ramp in Shanghai, China, 23 parameters before breakdowns are extracted, including dynamic environment conditions aggregated with 5-minutes and static geometry features. Different time periods data are used to predict breakdown. Results indicate that the models using 5-10 min data prior to breakdown performs the best prediction, with the prediction accuracies higher than 73%. Moreover, one unified model for all bottlenecks is also built and shows reasonably good prediction performance with the classification accuracy of breakdowns about 75%, at best. Additionally, to simplify the model parameter input, the random forests (RF) model is adopted to identify the key variables. Modeling with the selected 7 parameters, the refined BN model can predict breakdown with adequate accuracy.

  1. The fragile X mental retardation protein has nucleic acid chaperone properties.

    Science.gov (United States)

    Gabus, Caroline; Mazroui, Rachid; Tremblay, Sandra; Khandjian, Edouard W; Darlix, Jean-Luc

    2004-01-01

    The fragile X syndrome is the most common cause of inherited mental retardation resulting from the absence of the fragile X mental retardation protein (FMRP). FMRP contains two K-homology (KH) domains and one RGG box that are landmarks characteristic of RNA-binding proteins. In agreement with this, FMRP associates with messenger ribonucleoparticles (mRNPs) within actively translating ribosomes, and is thought to regulate translation of target mRNAs, including its own transcript. To investigate whether FMRP might chaperone nucleic acid folding and hybridization, we analysed the annealing and strand exchange activities of DNA oligonucleotides and the enhancement of ribozyme-directed RNA substrate cleavage by FMRP and deleted variants relative to canonical nucleic acid chaperones, such as the cellular YB-1/p50 protein and the retroviral nucleocapsid protein HIV-1 NCp7. FMRP was found to possess all the properties of a potent nucleic acid chaperone, requiring the KH motifs and RGG box for optimal activity. These findings suggest that FMRP may regulate translation by acting on RNA-RNA interactions and thus on the structural status of mRNAs.

  2. DNA-membrane complex restoration in Micrococcus radiodurans after X-irradiation: relation to repair, DNA synthesis and DNA degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dardalhon-Samsonoff, M; Averbeck, D [Institut du Radium, 75 - Paris (France). Lab. Curie

    1980-07-01

    The DNA-membrane complex in Micrococcus radiodurans was shown to be essentially constituted of proteins, lipids and DNA. The complex was dissociated immediately after X-irradiation of cells and restored during post-incubation in complete medium. In X-irradiated protoplasts some DNA remained associated with the complex. Restoration of the complex during post-incubation was only seen in a medium favouring DNA polymerase and ligase activities. Under this condition no DNA synthesis occurred, suggesting that complex restoration may involve ligase activity. The complex restoration in the wild type and the X-ray sensitive mutant UV17 of M. radiodurans was strictly dependent on the X-ray dose. It was correlated with survival and DNA degradation but always preceded the onset of DNA synthesis after X-irradiation. At the same dose the complex restoration was about 2 fold lower in mutant than in wild type cells indicating that the restoration of the complex is related to repair capacity. The results are consistent with the idea that the complex protects X-irradiated DNA of M. radiodurans from further breakdown and, subsequently, permits DNA synthesis and repair to occur.

  3. The electrical breakdown strength of pre-stretched elastomers, with and without sample volume conservation

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed

    2015-01-01

    In practice, the electrical breakdown strength of dielectric electroactive polymers (DEAPs)determines the upper limit for transduction. During DEAP actuation, the thickness of the elastomer decreases, and thus the electrical field increases and the breakdown process is determined by a coupled...... electro-mechanical failure mechanism. A thorough understanding of the mechanisms behind the electro-mechanical breakdown process is required for developing reliable transducers. In this study, two experimental configurations were used to determine the stretch dependence of the electrical breakdown...

  4. Flame Retardant Effect of Nano Fillers on Polydimethylsiloxane Composites.

    Science.gov (United States)

    Jagdale, Pravin; Salimpour, Samera; Islam, Md Hujjatul; Cuttica, Fabio; Hernandez, Francisco C Robles; Tagliaferro, Alberto; Frache, Alberto

    2018-02-01

    Polydimethylsiloxane has exceptional fire retardancy characteristics, which make it a popular polymer in flame retardancy applications. Flame retardancy of polydimethylsiloxane with different nano fillers was studied. Polydimethylsiloxane composite fire property varies because of the shape, size, density, and chemical nature of nano fillers. In house made carbon and bismuth oxide nano fillers were used in polydimethylsiloxane composite. Carbon from biochar (carbonised bamboo) and a carbon by-product (carbon soot) were selected. For comparative study of nano fillers, standard commercial multiwall carbon nano tubes (functionalised, graphitised and pristine) as nano fillers were selected. Nano fillers in polydimethylsiloxane positively affects their fire retardant properties such as total smoke release, peak heat release rate, and time to ignition. Charring and surface ceramization are the main reasons for such improvement. Nano fillers in polydimethylsiloxane may affect the thermal mobility of polymer chains, which can directly affect the time to ignition. The study concludes that the addition of pristine multiwall carbon nano tubes and bismuth oxide nano particles as filler in polydimethylsiloxane composite improves the fire retardant property.

  5. The RRP Project: investigating radionuclide retardation in the host rock

    International Nuclear Information System (INIS)

    Alexander, W.R.; Frieg, B.; Ota, K.; Bossart, P.

    1996-01-01

    The Radionuclide Retardation Project (RRP), which is a joint Nagra/PNC (Power Reactor and Nuclear Fuel Development Corp.) project, has two components: the first (the Excavation Project, EP) looks at the behaviour of radionuclides which are so strongly retarded in the experimental shear zone that they cannot pass through the zones in experimentally reasonable times. In order to determine where radionuclide retardation has occurred in the pore space, as well as the flowpath geometry in the shear zone, the entire injection zone has to be excavated and taken back to the laboratory for analysis of the sites of retardation of the radionuclides. This approach has the advantage of allowing a detailed 3D description of the experimental shear zone. The aim of the second component of the project (Connected Porosities, CP) is to examine the fate of those radionuclides which diffuse out of the main water-conducting features in the shear zone and into the pore spaces of the rock matrix, where they become trapped. This represents a potentially significant retardation mechanism in a repository host rock. (author) 8 figs., refs

  6. Impulse breakdown of small air gap in electric field Part II: Statistical ...

    African Journals Online (AJOL)

    The patterns of shot distribution and maximum coverage at impulse breakdown voltage for positive point electr-odes (needle and cone electrodes) in small air gaps in non-uniform electric fields were investigated. During the breakdown test, a sheet of paper was placed on the plate electrode (-ve), and each breakdown shot ...

  7. 48 CFR 252.236-7000 - Modification proposals-price breakdown.

    Science.gov (United States)

    2010-10-01

    ...-price breakdown. 252.236-7000 Section 252.236-7000 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.236-7000 Modification proposals—price breakdown. As prescribed in 236.570(a), use the following clause: Modification Proposals—Price Breakdown (DEC 1991) (a) The...

  8. Differential saliva-induced breakdown of starch filled protein gels in relation to sensory perception

    NARCIS (Netherlands)

    Janssen, A.M.; Pijpekamp, A.M. van de; Labiausse, D.

    2009-01-01

    In this study, the differential breakdown of protein gels containing four types of high and low cross-linked starch granules were studied. Susceptibility to saliva-induced breakdown of starch granules and the consequences of these for overall breakdown of the gel matrix were captured using a

  9. Relations between rheological properties, saliva-induced structure breakdown and sensory texture attributes of custards

    NARCIS (Netherlands)

    Janssen, A.M.; Terpstra, M.E.J.; Wijk, R.A.de; Prinz, J.F.

    2007-01-01

    The relevance of initial rheological properties and mechanical and enzymatic structure breakdown in determining selected sensory texture attributes of custards was studied. The so-called structure breakdown cell was used to characterize saliva-induced breakdown, i.e., by monitoring digestion of

  10. Breakdown of teenage placements in Danish out-of-home care

    DEFF Research Database (Denmark)

    Egelund, Tine; Olsson, Martin; Høst, Anders

    2012-01-01

    to breakdown. However, while the logistic regression model was significant, it explained only 6% of the variance. Earlier studies have indicated that breakdown is a substantial problem of child welfare in several other western countries, Denmark is no exception. These corresponding breakdown rates point out...

  11. Modeling DNA

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Deoxyribonucleic acid (DNA) is life's most amazing molecule. It carries the genetic instructions that almost every organism needs to develop and reproduce. In the human genome alone, there are some three billion DNA base pairs. The most difficult part of teaching DNA structure, however, may be getting students to visualize something as small as a…

  12. Development of low-smoke, flame-retarding cables

    International Nuclear Information System (INIS)

    Kato, H.; Kanemitsuya, K.; Furukawa, K.; Mio, K.

    1983-01-01

    A great deal of attention has been given to the potential fire hazard of combustion gases from organic materials. Although cable industries have developed flame-retarding organic materials for the insulation and jacketing of wires and cables, there was insufficient prevention of toxic gas formation during combustion. To cope with these problems associated with conventional PVC cables, the authors have directed to develop low-smoke, flame-retarding plasticized PVC formulations retaining the original mechanical, electrical and aging properties. A series of basic investigations on smoke suppression followed by an evaluation on practical cables could indicate some effective means to end these problems. This paper describes the results and discussion on smoke suppressing study of plasticized PVC as well as behavior and characteristics of the low-smoke, flame-retarding PVC wires and cables using these materials. (author)

  13. Flame Retardant and Antimicrobial Jute Textile Using Sodium Metasilicate Nonahydrate

    Directory of Open Access Journals (Sweden)

    Basak S.

    2014-06-01

    Full Text Available Flame retardant and antimicrobial functionalities were imparted in jute textile using sodium metasilicate nonahydrate (SMSN, commonly known as “water glass”. Sodium metasilicate nonahydrate (SMSN was applied in jute fabric in different concentration by padding method followed by drying. Flame retardancy of the fabric was evaluated by Limiting Oxygen Index (LOI and burning behaviour under vertical flammability tester including the char length. Burning rate was found to decrease by almost 10 times after an application of 2% SMSN compared to the control sample. Thermogravimetry (TG and differential scanning calorimetry (DSC analysis of both the control and treated jute fabrics were utilized to understand the mechanism of developed flame retardance in jute fabric. It was observed that the SMSN treated samples showed excellent antimicrobial property against both gram positive and gram negative bacteria. Antimicrobial properties of both the control and treated jute fabrics were also measured quantitatively.

  14. Visual evoked potentials of mildly mentally retarded and control children.

    Science.gov (United States)

    Gasser, T; Pietz, J; Schellberg, D; Köhler, W

    1988-10-01

    Visual evoked potentials (VEPs) were recorded from 25 10- to 13-year-old mildly mentally retarded children and compared with those from 31 control children of the same age-range. Correlations of VEPs with age were weak, but a relationship between VEPs and IQ was demonstrated for the control group. The retarded group had significantly longer latencies and higher amplitude peaks than the control group, with the differences occurring primarily over non-specific cortex and for secondary components. Analysis also showed that the retarded group were neurophysiologically heterogeneous. Since the same children had been analyzed earlier by quantitative EEG methods, comparisons are made with respect to these two methods of investigating brain function.

  15. Improving free play skills of severely retarded children.

    Science.gov (United States)

    Wehman, P; Marchant, J A

    1978-02-01

    Severely and profoundly retarded children are usually deficient in play skills. Since play facilitates socialization, language, and motor development, it is a vitally improtant skill to acquire. This pilot study examined the effects of a behavioral training program on the autistic, independent, and social types of play of four severely and profoundly retarded children. The training program involved the use of instructions, modeling, physical guidance, and verbal reinforcement. Results indicated that a marked increase in independent and social play occurred with the introduction of the training program with all four children. Occupational therapists can play an increasingly important role in helping educators formulate relevant educational programs for severely retarded children, particularly in the areas of play and motor skill development.

  16. Nonstatic one-boson-exchange potential with retardation

    International Nuclear Information System (INIS)

    Obinata, Toshio; Wada, Masanobu

    1975-01-01

    A one-boson-exchange potential (OBEP) with retardation represented in coordinate space is proposed, that produces a good fit to the experimental data such as the nuclear phase shifts, the deuteron properties and two-nucleon low-energy parameters. In addition to the scalar sigma 0 and Δ mesons, the well-established π, eta, ω and rho mesons have been exchanged in our OBEP. In the core region the hard core, Gaussian soft core and velocity-dependent core potentials are adopted. The characteristics of the retardation are discussed in detail as compared with those given in momentum space calculations. The OBEP's with and without retardation reproduce essentially the same phase shifts in spite of very different potential shapes, in particular in the central-to-tensor ratio. (auth.)

  17. Obstetric interventions and perinatal asphyxia in growth retarded term infants

    DEFF Research Database (Denmark)

    Langhoff-Roos, J; Lindmark, G

    1997-01-01

    BACKGROUND: The monitoring of fetal growth during pregnancy is usually justified because of the increased perinatal risk of these babies. METHODS: In 1552 infants from the Scandinavian Small for Gestational Age Study the need for obstetric interventions, risk of fetal asphyxia and immediate...... neonatal outcome at term have been studied in relation to different types of fetal growth retardation, including sub-groups with low ponderal index or low amount of subcutaneous fat. RESULTS: The need for obstetric intervention indicated by suspected fetal asphyxia before or during labor was increased 3......-fold (6-8%) for growth retarded infants both in SGA infants in general and infants with asymmetric body proportions. The immediate perinatal outcome, however, was favorable with Apgar below 8 at 5 min in only 2% irrespective of the type of growth retardation, in spite of the fact that less than 25...

  18. Moral and cognitive development in retarded and nonretarded children.

    Science.gov (United States)

    Taylor, J J; Achenbach, T M

    1975-07-01

    Subjects were 30 cultural-familially retarded and 30 nonretarded children matched for MA within 3 MA levels. The subjects were administered measures of moral judgement and cognitive operations hypothesized by Kohlberg to constitute necessary but not sufficient conditions for attainment of specific moral stages. Moral and cognitive performance improved with MA, but there were no differences between the MA-matched retarded and nonretarded children. Moral judgement related more strongly to MA then to any of the specific cognitive operations tested. The findings failed to support Kohlberg and Gilligan's (1971) hypothesis that the moral judgment of older individuals should be more advanced than that of younger individuals matched for cognitive level, but they were in accord with Zigler's (1969) "developmental" concept of cultural-familial retardation.

  19. Risk Factors to Growth Retardation in Major Thalassemia

    Directory of Open Access Journals (Sweden)

    Riva Uda

    2011-03-01

    Full Text Available The increasing in the life span of patients with major thalassemia should be followed by increased quality of life. There are factors which can affect growth retardation in these patients. The aim of this study was to find out the risk factors for growth retardation in patients with major thalassemia. An analytical study with cross-sectional design was conducted at Pediatric Thalassemia Clinics of Dr.Hasan Sadikin Hospital, Bandung, in June to July 2006. The subjects of this study were patients with major thalassemia. Inclusion criteria’s were age under 14 years old, had no chronic diseases like tuberculosis, cerebral palsy with complete medical records. Risk factors were the timing of diagnosis, initial and dose of deferoxamine, volume of transfused blood, mean pretransfusion hemoglobin level, family income, and age. Antropometric measurement indices were used to assess the growth which expressed in Z score. Growth evaluated based on height/age (H/A and growth retardation if H/A <-2 SD. Risk factors for growth retardation were analyzed separately using chi-square test and odds ratio (OR with 95% confidence interval (CI. Then they were analyzed simultaneously with logistic regression method. Subjects consisted of 152 patients with major thalassemia. Seventy three thalassemia patients were stunted. Analysis showed that age (OR: 5.42, 95% CI:2.32–12.65, p <0.001, dosage of deferoxamine (OR: 4.0, 95% CI: 1.29–12.41, p: 0.016, and family income (OR: 2.32, 95% CI: 1.06–5.06, p: 0.036 were risks factors for growth retardation. Conclusion, risk factors for growth retardation in major thalassemia are age, dosage of deferoxamine, and family income.

  20. THERMAL DEGRADATION AND FLAME RETARDANCY OF CALCIUM ALGINATE FIBERS

    Institute of Scientific and Technical Information of China (English)

    于建; 夏延致

    2009-01-01

    Calcium alginate fibers were prepared by wet spinning of sodium alginate into a coagulating bath containing calcium chloride.The thermal degradation and flame retardancy of calcium alginate fibers were investigated with thermal gravimetry(TG),X-ray diffraction(XRD),limiting oxygen index(LOI) and cone calorimeter(CONE).The results show that calcium alginate fibers are inherently flame retardant with a LOI value of 34,and the heat release rate(HRR),total heat release(THR),CO and CO_2 concentrations during ...

  1. Fetishistic transvestism in a patient with mental retardation and psychosis.

    Science.gov (United States)

    Velayudhan, Rajmohan; Khaleel, Asfia; Sankar, Nideesh; Kumar, Manoj; Kazhungil, Firoz; Raghuram, Thazhe Mangool

    2014-04-01

    Fetishistic transvestism is a disorder of sexual preference associated with fantasies and sexual urges to dress in opposite gender clothing as a means of arousal and as an adjunct to masturbation and coitus. The disorder has been reported in people with learning disabilities. The disorder has been reported in a young male with dull normal intelligence. Transvestism though has been described in schizophrenia and psychosis and fetishism has been described in the course of simple schizophrenia, there are no reports of fetishistic transvestism in a patient with mental retardation and psychosis. A case of fetishistic transvestism in a patient with mental retardation and psychosis with treatment and relevant review of literature is reported.

  2. Point defect engineering strategies to retard phosphorous diffusion in germanium

    KAUST Repository

    Tahini, H. A.; Chroneos, Alexander I.; Grimes, Robin W.; Schwingenschlö gl, Udo; Bracht, Hartmut A.

    2013-01-01

    The diffusion of phosphorous in germanium is very fast, requiring point defect engineering strategies to retard it in support of technological application. Density functional theory corroborated with hybrid density functional calculations are used to investigate the influence of the isovalent codopants tin and hafnium in the migration of phosphorous via the vacancy-mediated diffusion process. The migration energy barriers for phosphorous are increased significantly in the presence of oversized isovalent codopants. Therefore, it is proposed that tin and in particular hafnium codoping are efficient point defect engineering strategies to retard phosphorous migration. © the Owner Societies 2013.

  3. Dynamic retardation corrections to the mass spectrum of heavy quarkonia

    International Nuclear Information System (INIS)

    Kopalejshvili, T.; Rusetskij, A.

    1996-01-01

    In the framework of the Logunov-Tavkhelidze quasipotential approach the first-order retardation corrections to the heavy quarkonia mass spectrum are calculated with the use of the stationary wave boundary condition in the covariant kernel of the Bethe-Salpeter equation. As has been expected, these corrections turn out to be small for all low-lying heavy meson states and vanish in the heavy quark limit (m Q →∞). The comparison of the suggested approach to the calculation of retardation corrections with others, known in literature, is carried out. 22 refs., 1 tab

  4. Boron nitride as two dimensional dielectric: Reliability and dielectric breakdown

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yanfeng; Pan, Chengbin; Hui, Fei; Shi, Yuanyuan; Lanza, Mario, E-mail: mlanza@suda.edu.cn [Institute of Functional Nano and Soft Materials, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, 199 Ren-Ai Road, Suzhou 215123 (China); Zhang, Meiyun; Long, Shibing [Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Lian, Xiaojuan; Miao, Feng [National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Larcher, Luca [DISMI, Università di Modena e Reggio Emilia, 42122 Reggio Emilia (Italy); Wu, Ernest [IBM Research Division, Essex Junction, Vermont 05452 (United States)

    2016-01-04

    Boron Nitride (BN) is a two dimensional insulator with excellent chemical, thermal, mechanical, and optical properties, which make it especially attractive for logic device applications. Nevertheless, its insulating properties and reliability as a dielectric material have never been analyzed in-depth. Here, we present the first thorough characterization of BN as dielectric film using nanoscale and device level experiments complementing with theoretical study. Our results reveal that BN is extremely stable against voltage stress, and it does not show the reliability problems related to conventional dielectrics like HfO{sub 2}, such as charge trapping and detrapping, stress induced leakage current, and untimely dielectric breakdown. Moreover, we observe a unique layer-by-layer dielectric breakdown, both at the nanoscale and device level. These findings may be of interest for many materials scientists and could open a new pathway towards two dimensional logic device applications.

  5. Development of microwave-enhanced spark-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Ikeda, Yuji; Moon, Ahsa; Kaneko, Masashi

    2010-01-01

    We propose microwave-enhanced spark-induced breakdown spectroscopy with the same measurement and analysis processes as in laser-induced breakdown spectroscopy, but with a different plasma generation mechanism. The size and lifetime of the plasma generated can contribute to increased measurement accuracy and expand its applicability to industrial measurement, such as an exhaust gas analyzer for automobile engine development and its regulation, which has been hard to operate by laser at an engineering evaluation site. The use of microwaves in this application helps lower the cost, reduce the system size, and increase the ease of operation to make it commercially viable. A microwave frequency of 2.45 GHz was used to enhance the volume and lifetime of the plasma at atmospheric condition even at elevated pressure.

  6. Factors that Influence RF Breakdown in Antenna Systems

    Science.gov (United States)

    Caughman, J. B. O.; Baity, F. W.; Rasmussen, D. A.; Aghazarian, M.; Castano Giraldo, C. H.; Ruzic, David

    2007-11-01

    One of the main power-limiting factors in antenna systems is the maximum voltage that the antenna or vacuum transmission line can sustain before breaking down. The factors that influence RF breakdown are being studied in a resonant 1/4-wavelength section of vacuum transmission line terminated with an open circuit electrode structure. Breakdown can be initiated via electron emission by high electric fields and by plasma formation in the structure, depending on the gas pressure. Recent experiments have shown that a 1 kG magnetic field can influence plasma formation at pressures as low as 8x10-5 Torr at moderate voltage levels (LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725. Work supported by USDOE with grant DE-FG02-04ER54765

  7. Laser-induced breakdown spectroscopy (LIBS): a new spectrochemical technique

    International Nuclear Information System (INIS)

    Radziemski, L.J.; Loree, T.R.; Cremers, D.A.

    1982-01-01

    We have used the breakdown spark from a focused laser beam to generate analytically useful emission spectra of minor constituents in air and other carrier gases. The medium was sampled directly. It was not necessary to reduce the sample to solution nor to introduce electrodes. The apparatus is particularly simple; a pulsed laser, spectrometer, and some method for time resolution. The latter is essential in laser-induced-breakdown spectroscopy (LIBS) because of the strong early continuum. High temperatures in the spark result in vaporization of small particles, dissociation of molecules, and excitation of atomic and ionic spectra, including species which are normally difficult to detect. In one application, we have monitored beryllium in air at conventrations below 1 μg/m 3 , which is below 1 ppB (w/w). In another we have monitored chlorine and fluorine atoms in real time. LIBS has the potential for real-time direct sampling of contaminants in situ

  8. Breakdown dynamics of electrically exploding thin metal wires in vacuum

    Science.gov (United States)

    Sarkisov, G. S.; Caplinger, J.; Parada, F.; Sotnikov, V. I.

    2016-10-01

    Using a two-frame intensified charge coupled device (iCCD) imaging system with a 2 ns exposure time, we observed the dynamics of voltage breakdown and corona generation in experiments of fast ns-time exploding fine Ni and stainless-steel (SS) wires in a vacuum. These experiments show that corona generation along the wire surface is subjected to temporal-spatial inhomogeneity. For both metal wires, we observed an initial generation of a bright cathode spot before the ionization of the entire wire length. This cathode spot does not expand with time. For 25.4 μm diameter Ni and SS wire explosions with positive polarity, breakdown starts from the ground anode and propagates to the high voltage cathode with speeds approaching 3500 km/s or approximately one percent of light speed.

  9. Analysis of organic vapors with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh

    2015-01-01

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

  10. Research of Dielectric Breakdown Micro fluidic Sampling Chip

    International Nuclear Information System (INIS)

    Jiang, F.; Lei, Y.; Yu, J.

    2013-01-01

    Micro fluidic chip is mainly driven electrically by external electrode and array electrode, but there are certain disadvantages in both of ways, which affect the promotion and application of micro fluidic technology. This paper discusses a scheme that uses the conductive solution in a microchannel made by PDMS, replacing electrodes and the way of dielectric breakdown to achieve microfluidic chip driver. It could reduce the driving voltage and simplify the chip production process. To prove the feasibility of this method, we produced a micro fluidic chip used in PDMS material with the lithography technology and experimented it. The results showed that using the dielectric breakdown to achieve microfluidic chip driver is feasible, and it has certain application prospect.

  11. Vortex-Breakdown-Induced Particle Capture in Branching Junctions.

    Science.gov (United States)

    Ault, Jesse T; Fani, Andrea; Chen, Kevin K; Shin, Sangwoo; Gallaire, François; Stone, Howard A

    2016-08-19

    We show experimentally that a flow-induced, Reynolds number-dependent particle-capture mechanism in branching junctions can be enhanced or eliminated by varying the junction angle. In addition, numerical simulations are used to show that the features responsible for this capture have the signatures of classical vortex breakdown, including an approach flow aligned with the vortex axis and a pocket of subcriticality. We show how these recirculation regions originate and evolve and suggest a physical mechanism for their formation. Furthermore, comparing experiments and numerical simulations, the presence of vortex breakdown is found to be an excellent predictor of particle capture. These results inform the design of systems in which suspended particle accumulation can be eliminated or maximized.

  12. Critical effects of downstream boundary conditions on vortex breakdown

    Science.gov (United States)

    Kandil, Osama; Kandil, Hamdy A.; Liu, C. H.

    1992-01-01

    The unsteady, compressible, full Navier-Stokes (NS) equations are used to study the critical effects of the downstream boundary conditions on the supersonic vortex breakdown. The present study is applied to two supersonic vortex breakdown cases. In the first case, quasi-axisymmetric supersonic swirling flow is considered in a configured circular duct, and in the second case, quasi-axisymmetric supersonic swirling jet, that is issued from a nozzle into a supersonic jet of lower Mach number, is considered. For the configured duct flow, four different types of downstream boundary conditions are used, and for the swirling jet flow from the nozzle, two types of downstream boundary conditions are used. The solutions are time accurate which are obtained using an implicit, upwind, flux-difference splitting, finite-volume scheme.

  13. Relativistic runaway breakdown in low-frequency radio

    DEFF Research Database (Denmark)

    Fullekrug, M.; Roussel-Dupre, R.; Symbalisty, E.M.D.

    2011-01-01

    at a distance of similar to 550 km. The measured broadband pulses occur similar to 4-9 ms after the sprite-producing lightning discharge, they exhibit electromagnetic radiation which mainly spans the frequency range from similar to 50 to 350 kHz, and they exhibit complex waveforms without the typical...... electromagnetic pulses and possibly generates sprites. The source location of the broadband pulses can be determined with an interferometric network of wideband low-frequency radio receivers to lend further experimental support to the relativistic runaway breakdown theory.......The electromagnetic radiation emitted by an electron avalanche beam resulting from relativistic runaway breakdown within the Earth's atmosphere is investigated. It is found from theoretical modeling with a computer simulation that the electron beam emits electromagnetic radiation which...

  14. Partial discharges and breakdown in C3F8

    International Nuclear Information System (INIS)

    Koch, M; Franck, C M

    2014-01-01

    Traditional search processes of gases or gas mixtures for replacing SF 6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF 6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C 3 F 8 ) that it is possible to transfer the model developed for SF 6 to this gas to describe the breakdown behaviour of C 3 F 8 . Thus the model can be beneficial in the screening process of new insulation gases. (paper)

  15. Partial discharges and breakdown in C3F8

    Science.gov (United States)

    Koch, M.; Franck, C. M.

    2014-10-01

    Traditional search processes of gases or gas mixtures for replacing SF6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C3F8) that it is possible to transfer the model developed for SF6 to this gas to describe the breakdown behaviour of C3F8. Thus the model can be beneficial in the screening process of new insulation gases.

  16. Grain-Scale Supercharging and Breakdown on Airless Regoliths

    Science.gov (United States)

    Zimmerman, M. I.; Farrell, W. M.; Hartzell, C.M.; Wang, X.; Horanyi, M.; Hurley, D. M.; Hibbitts, K.

    2016-01-01

    Interactions of the solar wind and emitted photoelectrons with airless bodies have been studied extensively. However, the details of how charged particles interact with the regolith at the scale of a single grain have remained largely uncharacterized. Recent efforts have focused upon determining total surface charge under photoemission and solar wind bombardment and the associated electric field and potential. In this work, theory and simulations are used to show that grain-grain charge differences can exceed classical sheath predictions by several orders of magnitude, sometimes reaching dielectric breakdown levels. Temperature-dependent electrical conductivity works against supercharging by allowing current to leak through individual grains; the balance between internal conduction and surface charging controls the maximum possible grain-to-grain electric field. Understanding the finer details of regolith grain charging, conductive equilibrium, and dielectric breakdown will improve future numerical studies of space weathering and dust levitation on airless bodies.

  17. Analysis of organic vapors with laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nozari, Hadi; Tavassoli, Seyed Hassan [Laser and Plasma Research Institute, Shahid Beheshti University, G. C, 1983963113 Evin, Tehran (Iran, Islamic Republic of); Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir [Department of Physics, K. N. Toosi University of Technology, 15875-4416 Shariati, Tehran (Iran, Islamic Republic of)

    2015-09-15

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  18. Breakdown in traffic networks fundamentals of transportation science

    CERN Document Server

    Kerner, Boris S

    2017-01-01

    This book offers a detailed investigation of breakdowns in traffic and transportation networks. It shows empirically that transitions from free flow to so-called synchronized flow, initiated by local disturbances at network bottlenecks, display a nucleation-type behavior: while small disturbances in free flow decay, larger ones grow further and lead to breakdowns at the bottlenecks. Further, it discusses in detail the significance of this nucleation effect for traffic and transportation theories, and the consequences this has for future automatic driving, traffic control, dynamic traffic assignment, and optimization in traffic and transportation networks. Starting from a large volume of field traffic data collected from various sources obtained solely through measurements in real world traffic, the author develops his insights, with an emphasis less on reviewing existing methodologies, models and theories, and more on providing a detailed analysis of empirical traffic data and drawing consequences regarding t...

  19. The validity of the general similarity law for electrical breakdown of gases

    International Nuclear Information System (INIS)

    Osmokrovic, Predrag; Zivic, Tamara; Loncar, Boris; Vasic, Aleksandra

    2006-01-01

    This paper investigates the validity of the similarity law in cases of dc and pulse breakdown of gases. Geometrically similar systems insulated with SF 6 gas were used during experiments. It is shown that the similarity law is valid for dc breakdown voltage if the electron mean free path is included in geometrical parameters of the system, but not for pulse breakdown voltages. The explanation for this is the mechanism of the pulse discharge. The similarity law was expanded to take into account mechanisms of pulse breakdown initiation. Thus, the general similarity law is obtained, the validity of which in case of a pulse breakdown is established experimentally

  20. Effects of polarization and absorption on laser induced optical breakdown threshold for skin rejuvenation

    Science.gov (United States)

    Varghese, Babu; Bonito, Valentina; Turco, Simona; Verhagen, Rieko

    2016-03-01

    Laser induced optical breakdown (LIOB) is a non-linear absorption process leading to plasma formation at locations where the threshold irradiance for breakdown is surpassed. In this paper we experimentally demonstrate the influence of polarization and absorption on laser induced breakdown threshold in transparent, absorbing and scattering phantoms made from water suspensions of polystyrene microspheres. We demonstrate that radially polarized light yields a lower irradiance threshold for creating optical breakdown compared to linearly polarized light. We also demonstrate that the thermal initiation pathway used for generating seed electrons results in a lower irradiance threshold compared to multiphoton initiation pathway used for optical breakdown.

  1. Radiation effects on breakdown in silicon multiguarded diodes

    International Nuclear Information System (INIS)

    Bisello, D.; Da Rold, M.; Franzin, L.; Wheadon, R.

    1996-01-01

    The authors have investigated the current-voltage characteristics of silicon PIN diodes with a number of different multiguard structures. These structures were designed to increase the overall device breakdown voltage. The same measurements were carried out after gamma irradiation at different doses and neutron irradiation at fluences beyond type-inversion. This study is a first step towards defining guard structures optimized for operation in high-radiation environments such as those expected at the LHC

  2. Canadian Food Dollar: Breakdown between Farm and Marketing Costs

    OpenAIRE

    Kelly, Jessica; Weersink, Alfons; Cranfield, John

    2013-01-01

    This poster assesses the breakdown of the Canadian food dollar between farm and marketing costs. It uses input-output methods, comparable to those used by the Economic Research Service (ERS), in order to allow for Canadian-American comparison. The farm share and marketing bill provide a valuable snapshot of the dynamics of the agri-food supply chain, changing consumer demands, and the resultant value distribution of the retail food dollar.

  3. Breakdown, fractoemission, diffusion: role of defects in dielectrics

    International Nuclear Information System (INIS)

    Vigouroux, J.P.; Serruys, Y.

    1987-01-01

    During the surface analysis of dielectric materials, the impinging ionising particles induce point defects localised in the band gap and build an electrical charge. The electric field created by the charged defects modifies the physico-chemical properties of surface and bulk. We show that the fundamental study of defects allows a better understanding of technological phenomena such as dielectric breakdown, fracture and diffusion [fr

  4. Study of three-dimensional effects on vortex breakdown

    Science.gov (United States)

    Salas, M. D.; Kuruvila, G.

    1988-01-01

    The incompressible axisymmetric steady Navier-Stokes equations in primitive variables are used to simulate vortex breakdown. The equations, discretized using a second-order, central-difference scheme, are linearized and then solved using an exact LU decomposition, Gaussian elimination, and Newton iteration. Solutions are presented for Reynolds numbers, based on vortex-core radius, as high as 1500. An attempt to study the stability of the axisymmetric solutions against three-dimensional perturbations is discussed.

  5. Ionizing gas breakdown waves in strong electric fields.

    Science.gov (United States)

    Klingbeil, R.; Tidman, D. A.; Fernsler, R. F.

    1972-01-01

    A previous analysis by Albright and Tidman (1972) of the structure of an ionizing potential wave driven through a dense gas by a strong electric field is extended to include atomic structure details of the background atoms and radiative effects, especially, photoionization. It is found that photoionization plays an important role in avalanche propagation. Velocities, electron densities, and temperatures are presented as a function of electric field for both negative and positive breakdown waves in nitrogen.

  6. Quantum dynamics and breakdown of classical realism in nonlinear oscillators

    International Nuclear Information System (INIS)

    Gat, Omri

    2007-01-01

    The leading nonclassical term in the quantum dynamics of nonlinear oscillators is calculated in the Moyal quasi-trajectory representation. The irreducibility of the quantum dynamics to phase-space trajectories is quantified by the discrepancy of the canonical quasi-flow and the quasi-flow of a general observable. This discrepancy is shown to imply the breakdown of classical realism that can give rise to a dynamical violation of Bell's inequalities. (fast track communication)

  7. Optical breakdown of helium in Bessel laser radiation beams

    International Nuclear Information System (INIS)

    Andreev, N E; Pleshanov, I V; Margolin, L Ya; Pyatnitskii, Lev N

    1998-01-01

    Numerical simulation is used to investigate the dynamics of formation of a helium plasma in Bessel beams, shaped by an axicon and a phase converter from a laser radiation pulse with Gaussian temporal and radial intensity profiles. The beam intensities at the breakdown threshold are determined as a function of the pulse duration for various radial field distributions in a beam characterised by Bessel functions of order m (m = 0 - 5). It is shown that in the investigated range of parameters the threshold intensity is independent of m. The temporal and spatial evolution of the resultant plasma, and the dependence of the plasma characteristics on the pulse parameters are considered. Conditions are found for the formation of tubular plasma channels in beams of orders m≥1. The adopted model of the optical breakdown of helium is shown to be satisfactory because of a good agreement between the results of calculations of the moment of breakdown in a zeroth-order Bessel beam and experimental results. (interaction of laser radiation with matter. laser plasma)

  8. Magnetic breakdown in an array of overlapping Fermi surfaces

    International Nuclear Information System (INIS)

    Kadigrobov, A.M.; Radić, D.; Bjeliš, A.

    2015-01-01

    We develop a theoretical framework for a magnetic breakdown in an array of circular two-dimensional bands with a finite overlap of neighboring Fermi surfaces due to the presence of a presumably weak periodic potential, and apply the obtained results to the electron bands in carbon honeycomb structures of doped graphene and intercalated graphite compounds. In contrast to the standard treatment, inaugurated more than fifty years ago by Slutskin and Kadigrobov, with electron semiclassical trajectories encircling significantly overlapping Fermi surfaces, we examine a configuration in which bands are related in a way that the Fermi surfaces only slightly overlap, forming internal band pockets with areas of the size comparable to the area of the quantum magnetic flux for a given external magnetic field. Such band configuration has to be treated quantum mechanically. The calculation leads to the results for magnetic breakdown coefficients comprising an additional large factor with respect to the standard results, proportional to the ratio of the Fermi energy and the cyclotron energy. Also, these coefficients show oscillating dependence on energy, as well as on the wave number of periodic potential. Both mentioned elements enable the adjustment of the preferred wave vector of possible magnetic breakdown induced density wave instability at the highest possible critical temperature

  9. Improvement of powertrain efficiency through energy breakdown analysis

    International Nuclear Information System (INIS)

    Damiani, Lorenzo; Repetto, Matteo; Prato, Alessandro Pini

    2014-01-01

    Highlights: • Energy breakdown analysis for the vehicular powertrain. • Model for road vehicles simulation in different missions. • Implemented powertrain management strategies: intelligent gearbox, Stop and Start, free wheel. • Innovative hybrid powertrain turned to engine thermodynamic cycles minimization. • Evaluation of fuel savings associated to each management strategy. - Abstract: A vehicular powertrain can be thought as an energy conversion chain, each component being characterized by its efficiency. Significant global efficiency improvements can be achieved once is identified the system energy breakdown, individuating the losses connected to each powertrain component; it is then possible to carry out the most appropriate interventions. This paper presents a simulation study of a diesel-fuelled commercial vehicle powertrain based on the above summarized point of view. The work aims at individuating the energy flows involved in the system during different missions, proposing an intelligent combination of technical solutions which minimize fuel consumption. Through a validated Matlab–Simulink model, able to indicate the powertrain energy breakdown, simulations are carried out to evaluate the fuel saving associated to a series of powertrain management logics which lead to the minimization of engine losses, the recovery of reverse power in deceleration and braking, the elimination of useless engine cycles. Tests were performed for different real missions (urban, extra-urban and highway). The results obtained point out a –23% fuel consumption (average value for urban, extra-urban and highway missions) compared to the traditional powertrain. Clearly, such result affects positively the CO 2 emission

  10. Vortex breakdown of compressible swirling flows in a pipe

    Science.gov (United States)

    Lee, Harry; Rusak, Zvi; Wang, Shixiao

    2017-11-01

    The manifold of branches of steady and axisymmetric states of compressible subsonic swirling flows in a finite-length straight circular pipe are developed. The analysis is based on Rusak et al. (2015) nonlinear partial differential equation for the solution of the flow stream function in terms of the inlet flow total enthalpy, entropy and circulation functions. This equation reflects the complicated thermo-physical interactions in the flows. The flow problem is solved numerically using a finite difference approach with a penalty procedure for identifying vortex breakdown and wall-separation states. Several types of solutions are found and used to form the bifurcation diagram of steady compressible flows with swirl as the inlet swirl level is increased at a fixed inlet Mach number. Results are compared with predictions from the global analysis approach of Rusak et al. (2015). The computed results provide theoretical predictions of the critical swirl levels for the first appearance of vortex breakdown states as a function of the inlet Mach number. The shows the delay in the appearance of breakdown with increase of the inlet axial flow Mach number in the subsonic range of operation.

  11. Relativistic runaway breakdown in low-frequency radio

    Science.gov (United States)

    Füllekrug, Martin; Roussel-Dupré, Robert; Symbalisty, Eugene M. D.; Chanrion, Olivier; Odzimek, Anna; van der Velde, Oscar; Neubert, Torsten

    2010-01-01

    The electromagnetic radiation emitted by an electron avalanche beam resulting from relativistic runaway breakdown within the Earth's atmosphere is investigated. It is found from theoretical modeling with a computer simulation that the electron beam emits electromagnetic radiation which is characterized by consecutive broadband pulses in the low-frequency radio range from ˜10 to 300 kHz at a distance of ˜800 km. Experimental evidence for the existence of consecutive broadband pulses is provided by low-frequency radio observations of sprite-producing lightning discharges at a distance of ˜550 km. The measured broadband pulses occur ˜4-9 ms after the sprite-producing lightning discharge, they exhibit electromagnetic radiation which mainly spans the frequency range from ˜50 to 350 kHz, and they exhibit complex waveforms without the typical ionospheric reflection of the first hop sky wave. Two consecutive pulses occur ˜4.5 ms and ˜3 ms after the causative lightning discharge and coincide with the sprite luminosity. It is concluded that relativistic runaway breakdown within the Earth's atmosphere can emit broadband electromagnetic pulses and possibly generates sprites. The source location of the broadband pulses can be determined with an interferometric network of wideband low-frequency radio receivers to lend further experimental support to the relativistic runaway breakdown theory.

  12. Breakdown of coupling dielectrics for Si microstrip detectors

    International Nuclear Information System (INIS)

    Candelori, A.; Paccagnella, A.; Padova Univ.; Saglimbeni, G.

    1999-01-01

    Double-layer coupling dielectrics for AC-coupled Si microstrip detectors have been electrically characterized in order to determine their performance in a radiation-harsh environment, with a focus on the dielectric breakdown. Two different dielectric technologies have been investigated: SiO 2 /TEOS and SiO 2 /Si 3 N 4 . Dielectrics have been tested by using a negative gate voltage ramp of 0.2 MV/(cm·s). The metal/insulator/Si I-V characteristics show different behaviours depending on the technology. The extrapolated values of the breakdown field for unirradiated devices are significantly higher for SiO 2 /Si 3 N 4 dielectrics, but the data dispersion is lower for SiO 2 /TEOS devices. No significant variation of the breakdown field has been measured after a 10 Mrad (Si) γ irradiation for SiO 2 /Si 3 N 4 dielectrics. Finally, the SiO 2 /Si 3 N 4 DC conduction is enhanced if a positive gate voltage ramp is applied with respect to the negative one, due to the asymmetric conduction of the double-layer dielectric

  13. Evaluation of methods for increasing vacuum breakdown strength

    International Nuclear Information System (INIS)

    Evans, R.D.; Cooke, C.M.; Berman, E.R.

    1977-01-01

    Research to determine the effectiveness of coated and gas shielded cathodes as a means of increasing vacuum breakdown strength under short pulse conditions is reported. A technique for rapidly evaluating large numbers of coatings on small electrodes at relatively low pulse voltage (120 kV or less) and methods for testing larger electrodes and fewer coatings at higher total voltage were developed. Experiments with gas shielded cathodes were also conducted. Results suggest that it may be possible to eliminate prebreakdown current and to double breakdown strength by applying a suitable coating to the cathode. Breakdown stresses in excess of 2 MV/cm were obtained in a 0.5 mm gap with sputtered coatings of alumina, Cr 2 O 3 , and several readily available epoxies. Electrodes two orders of magnitude greater in area were tested, and stresses approaching 1 MV/cm were measured in 5 mm gaps for several epoxies and for alumina. It has further been shown that, because similar trends occurred in the data from large and small experiments, it should be possible to screen potential coatings rapidly and effectively with minimum expenditure using a method similar to that employed for small electrodes at low pulse voltage

  14. Specificity of binding to four-way junctions in DNA by bacteriophage T7 endonuclease I.

    OpenAIRE

    Parsons, C A; West, S C

    1990-01-01

    T7 endonuclease I binds specifically to four-way junctions in duplex DNA and promotes their resolution into linear duplexes. Under conditions in which the nuclease activity is blocked by the absence of divalent cations, the enzyme forms a distinct protein-DNA complex with the junction, as detected by gel retardation and filter binding assays. The formation of this complex is structure-specific and contrasts with the short-lived binding complexes formed on linear duplex DNA. The binding comple...

  15. Pre-breakdown light emission phenomena in low-pressure argon between parabolic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wagenaars, E [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Perriens, N W B [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Brok, W J M [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Bowden, M D [Department of Physics and Astronomy, The Open University, Milton Keynes, MK7 6AA (United Kingdom); Veldhuizen, E M van [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Kroesen, G M W [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2006-09-07

    An experimental study on pre-breakdown light emission in low-pressure argon gas was performed. In a pulsed discharge, pre-breakdown phenomena were observed for repetition rates between 100 and 2000 Hz and pulse duration of 100 {mu}s. These phenomena were studied with time-resolved emission imaging using an intensified charge coupled device camera. The origin of the pre-breakdown emission was identified as diffusion of volume charges left over from previous discharges. These charges were accelerated towards the anode in small electron avalanches causing excitation of argon atoms. Different spatial distributions of the pre-breakdown light emission for different times between discharges were measured and the effects of the pre-breakdown phenomena on the main breakdown phase were studied using a double voltage pulse. The observed effects were attributed to the distribution of volume charges, left over from previous discharges, in the discharge gap during the pre-breakdown phase.

  16. Radiation-grafting of flame retardants on flax fabrics - A comparison between different flame retardant structures

    Science.gov (United States)

    Teixeira, Marie; Sonnier, Rodolphe; Otazaghine, Belkacem; Ferry, Laurent; Aubert, Mélanie; Tirri, Teija; Wilén, Carl-Eric; Rouif, Sophie

    2018-04-01

    Three unsaturated compounds bearing respectively phosphate, aryl bromide and sulfenamide moieties were used as flame retardants (FR) for flax fabrics. Due to the presence of carbon-carbon double bonds, radiation-grafting was considered to covalently bond these FR onto fiber structure. Grafting efficiency and location of FR molecules were investigated by weight measurements and SEM-EDX observations. Flammability and especially self-extinguishment were assessed by thermogravimetric analysis, pyrolysis-combustion flow calorimetry and a non-standardized fire test already used in previous studies. All FRs were able to diffuse into elementary fiber bulk. Nevertheless only the phosphonated monomer (noted FR-P) was significantly grafted onto flax. Self-extinguishment was obtained for fabrics containing at least around 0.5 wt% of phosphorus. On the contrary the FR content of flax fibers after radiation-grafting procedure and washing was negligible for FR-S and FR-Br, evidencing that these molecules have not been grafted upon irradiation. Moreover, the combination of these molecules prevents the radiation-grafting of other molecules which showed good grafting rate when used alone.

  17. Predicting Adaptive Functioning of Mentally Retarded Persons in Community Settings.

    Science.gov (United States)

    Hull, John T.; Thompson, Joy C.

    1980-01-01

    The impact of a variety of individual, residential, and community variables on adaptive functioning of 369 retarded persons (18 to 73 years old) was examined using a multiple regression analysis. Individual characteristics (especially IQ) accounted for 21 percent of the variance, while environmental variables, primarily those related to…

  18. Formulation and In Vitro Evaluation of Release Retardant Diclofenac ...

    African Journals Online (AJOL)

    Development of release retardant matrix tablets of diclofenac sodium for 24 h by wet granulation technique using different combinations and ratios of hydroxypropylmethylcellulose (HPMC), sodium carboxymethylcellulose (sodium CMC), sodium alginate and cetostearyl alcohol was carried out. The tablets were evaluated ...

  19. The Opinions and Attitudes of Mothers to Mental Retardation in ...

    African Journals Online (AJOL)

    Conclusion There is an increased pervasive attitude to children with mental retardation. Therefore, efforts aimed at changing parental and by extension societal attitudes toward these children are necessary for their care and survival. There is also need for government and charitable organizations to reach-out to parents of ...

  20. Music Training for Severely and Profoundly Retarded Individuals.

    Science.gov (United States)

    Kesler, Buford; Richmond, Bert O.

    Investigated were the effects of sex, ability and training method on the musical instrument playing ability of 16 institutionalized severely and profoundly retarded persons ages 7 to 20 years. Ss were randomly assigned to one of four treatment groups, and the time required to reach criterion playing a familiar tune was recorded. Data indicated…

  1. Reducing Barriers to Sex Education for Adults with Mental Retardation.

    Science.gov (United States)

    Huntley, Cristy F.; Benner, Susan M.

    1993-01-01

    Opinions of professionals from 16 agencies were obtained to identify techniques that agencies serving adults or adolescents with mental retardation could utilize to provide systematic sex education and counseling. Recommendations are offered in five areas: self-advocacy and self-determination, individual design, staff training and support,…

  2. Ecotoxicity and biodegradability of new brominated flame retardants: A review

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Covino, Stefano; Cajthaml, Tomáš

    2014-01-01

    Roč. 110, č. 2 (2014), s. 153-167 ISSN 0147-6513 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Ecotoxicity * brominated flame retardants * biodegradation * review Subject RIV: EE - Microbiology, Virology Impact factor: 2.762, year: 2014

  3. Pressure retarded osmosis from hypersaline sources - A review

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Hélix-Nielsen, Claus; Madsen, Henrik T.

    2017-01-01

    for commercialization. The scope of this paper is to review the existing knowledge on the use of hypersaline waters in the salinity gradient process, pressure retarded osmosis. Although only few papers have had the specific aim of investigating hypersaline waters, concentrated solutions have been used in many papers...

  4. Acceleration of Object Permanence with Severely and Profoundly Retarded Children.

    Science.gov (United States)

    Kahn, James V.

    Examined was the effectiveness of training four severely and profoundly retarded children (3-6 years old) to improve their level of functioning on a measure of object permanence and to demonstrate generalization to other areas of sensorimotor intelligence. Ss were given a pretest and posttest on the I. Uzgiris and J. Hunt instrument which consists…

  5. A Prelanguage Program for Five Severely Retarded Children.

    Science.gov (United States)

    McAlonie, Mary Lynne; Wolf, Judith M.

    Five severely retarded emotionally disturbed children (2-7 years old) were exposed to a prelanguage sensorimotor program for 20 weeks. The program emphasized the use of exploratory behavior and gesture imitation. Results suggested that object permanence could be encouraged using these activities but that the approach used in training imitative…

  6. Career Development and Adults with Moderate to Severe Mental Retardation.

    Science.gov (United States)

    Wadsworth, John; Cocco, Karen

    Lifelong career development activities may assist persons with more severe forms of mental retardation in achieving occupational tenure. Occupational tenure is important if individuals are to move away from a succession of entry-level employment. Adaptive career development strategies and techniques may prevent job dissatisfaction and poor…

  7. Validation of a Weight Reduction Treatment Package for the Retarded.

    Science.gov (United States)

    Rotatori, Anthony F.; And Others

    Five studies are reviewed which indicated the effectiveness on weight loss by mentally retarded persons of a treatment program stressing self control. The intervention included procedures which increased the dieter's self awareness of overeating behavior patterns and body weight, reduced food cues, reduced eating rates, increased activity level…

  8. Factors which Motivate Job Acceptance and Profoundly Mentally Retarded Children.

    Science.gov (United States)

    Marozas, Donald S.; May, Deborah C.

    1980-01-01

    The study involving 360 Pennsylvania teachers was designed to identify factors which motivate job acceptance among teachers of severely and profoundly mentally retarded children. The responses of 235 teachers indicated that challenge and practicum experiences were the two most prevalent motivational factors underlying job acceptance. (Author)

  9. Isospin sum rule for nuclear photoabsorption: Effect of retardation

    International Nuclear Information System (INIS)

    Maize, M.A.; Fallieros, S.

    1987-01-01

    Motivated by the close similarity between a sum rule originally derived by Cabibbo and Radicati and a simplified version based on nonrelativistic nuclear physics in the long-wavelength limit, we have investigated the effect of retardation corrections. An account of the contributions due to higher multipolarities is presented, together with a physical interpretation of the results

  10. A near-infrared zero-order achromatic retarder

    Indian Academy of Sciences (India)

    The present investigation deals with a technique to design and study the characteristics of an achromatic combination of birefringent plates in 800–2000 nm range. The retarder has been designed using calcite, crystalline quartz and ADP. The thicknesses of the plates are 19.38 μm,. 446.14 μm and 12.57 μm respectively.

  11. PHENYLKETONURIA, AN INHERITED METABOLIC DISORDER ASSOCIATED WITH MENTAL RETARDATION.

    Science.gov (United States)

    CENTERWALL, WILLARD R.; CENTERWALL, SIEGRIED A.

    ADDRESSED TO PUBLIC HEALTH WORKERS AND PHYSICIANS IN GENERAL PRACTICE, THE PAMPHLET INTRODUCES METHODS OF DETECTING AND MANAGING PHENYLKETONURIA, AN INHERITED METABOLIC DISORDER ASSOCIATED WITH MENTAL RETARDATION. INFORMATION, UPDATED FROM THE 1961 EDITION, IS INCLUDED ON THE INCIDENCE AND GENETICS, BIOCHEMISTRY, AND CLINICAL COURSE OF THE…

  12. Pre-Language Activities for the Profoundly Mentally Retarded.

    Science.gov (United States)

    Poole, Marilyn R.; And Others

    Provided are sample lesson plans for a program to develop pre-language skills in profoundly retarded children and adults. Characteristic of the suggested activities is the stimulation of all sensory channels through structured infant-like play activities in five general areas: oral stimulation, sensory arousal, motor stimulation, vocal play, and…

  13. Enhancing Free-Recall Rates of Individuals with Mental Retardation.

    Science.gov (United States)

    Carlin, Michael T.; Soraci, Sal A.; Dennis, Nancy A.; Chechile, Nicholas A.; Loiselle, Raquel C.

    2001-01-01

    This study with 16 adolescents with mental retardation compared free-recall rates under two encoding conditions: (1) fade-in, initially presenting pictures out of focus then slowly fading them into focus; and (2) fade-out, slowly blurring originally clear pictures. Results indicated that free-recall rates were greater for the fade-in items for…

  14. Case Management for Individuals with Mental Retardation. ARC Facts.

    Science.gov (United States)

    Association for Retarded Citizens, Arlington, TX.

    A question-and-answer format is used in this fact sheet to provide information on case management for individuals with mental retardation. The fact sheet describes the major components of a case management system, the role of the case manager, the individual's or family's role in case management, providers of case management services and systems…

  15. C syndrome with skeletal anomalies, mental retardation, eyelid ...

    African Journals Online (AJOL)

    C syndrome with skeletal anomalies, mental retardation, eyelid chalazion, Bitot's spots and agenesis of the corpus callosum in an Egyptian child. ... broad nose, high arched palate, microretrognathia, low set ears, short neck, scoliosis, hypertrichosis over the back, talipes equinovarus as well as interatrial septal defect.

  16. Psychological Aspects of Sleep Disorders in Children with Mental Retardation.

    Science.gov (United States)

    Smith, David T.

    This paper reviews literature and clinical experiences on the neurobiological and psychological aspects of sleep in children with mental retardation. The lack of a universal, operational definition of sleep disorders is noted, and a study is cited in which 61% of a group of 20 children (ages 2-13) with developmental disabilities were found to have…

  17. Genetic Issues in Mental Retardation, 1996-1997.

    Science.gov (United States)

    Genetic Issues in Mental Retardation, 1996

    1996-01-01

    This document consists of the first six issues of a newsletter, which discusses current knowledge about and concerns related to genetics and mental retardation. The second issue addresses the problem of genetic discrimination. The third issue considers genetic testing, screening, and counseling. The fourth issue addresses genetic privacy issues.…

  18. The Mentally Retarded and the Educational System in Denmark.

    Science.gov (United States)

    Finkelstein, Harry

    The history of educational services for mentally retarded persons in Denmark is traced, along with the evolution of attitudes toward the population from a protectionist philosophy which promoted segregation to current thinking about normalization. The role of the national parents' association in influencing service review and reform is stressed.…

  19. Neglected and Abused Children of Mentally Retarded Parents.

    Science.gov (United States)

    Seagull, Elizabeth A. W.; Scheurer, Susan L.

    1986-01-01

    Follow-up of 64 neglected and abused children, seen one to seven years earlier, with mentally retarded parent revealed that six children had been relinquished voluntarily for adoption; that courts had terminated parental rights for 34 children; and that nine had been placed in foster care. Cognitive limitations prevented parents from utilizing…

  20. Occupational Interests and Mentally Retarded People: Review and Recommendations.

    Science.gov (United States)

    Stodden, Robert A.; And Others

    1979-01-01

    The article reviews several studies regarding the choice of occupational interests for the mentally retarded adolescent. Several concerns about current evaluation practices are discussed. Recommendations are offered for a client centered, developmental model, making the evaluation of occupational interests a viable part of the client's…

  1. Colour learning in retarded children | Karseboom | South African ...

    African Journals Online (AJOL)

    South African Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 45, No 2 (1971) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Colour learning in retarded children. E Karseboom. Abstract.

  2. Task Monotony and Performance Efficacy of Mentally Retarded Young Adults.

    Science.gov (United States)

    Locke, Bill J.; And Others

    1982-01-01

    Thirty-six mildly mentally retarded young adults were exposed to one of three training arrangements for vigilance performance, a monitoring task that some professionals consider uniquely appropriate for such persons because they are assumed to be less susceptible to boredom. (Author)

  3. by recycled subirrigational supply of plant growth retardants

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... an ebb and flow system on the growth and flowering of kalanchoe cultivar 'Gold Strike' was examined. Plants potted in 10 cm .... photoperiod during the first six weeks after pinching. .... stage and adverse influences on overall growth of the plants. ..... retardants on the growth and flowering in poinsettia. RDA.

  4. Increasing Wearing of Prescription Glasses in Individuals with Mental Retardation

    Science.gov (United States)

    DeLeon, Iser G.; Hagopian, Louis P.; Rodriguez-Catter, Vanessa; Bowman, Lynn G.; Long, Ethan S.; Boelter, Eric W.

    2008-01-01

    This study evaluated an intervention for promoting wearing of prescription glasses in 4 individuals with mental retardation who had refused to wear their glasses previously. Distraction through noncontingent reinforcement (NCR) increased independent glasses wearing for 1 of the 4 participants. An intervention consisting of NCR, response cost, and…

  5. Colemanite: a fire retardant candidate for wood plastic composites

    Science.gov (United States)

    Evren Terzi; Saip Nami Kartal; Sabriye Piskin; Nicole Stark; Aysel Kanturk Figen; Robert H. White

    2018-01-01

    The use of raw boron minerals (i.e. tincalconite, colemanite, and ulexite) was evaluated to increase the fire performance of wood plastic composites (WPCs) in comparison with commercially available fire retardants (FRs). Cone calorimetry and limited oxygen index tests were performed to evaluate the fire properties of WPC specimens. Artificial weathering and 3-point...

  6. A Job Retention Model for Individuals with Mental Retardation

    Science.gov (United States)

    Fornes, Sandra

    2006-01-01

    This structured literature review examines the literature and addresses issues of job retention for adult workers with moderate to mild mental retardation (MR), investigating the relationships between work-related social behaviors, self-determination, person-job congruency of individuals with MR, and their job performance and job satisfaction with…

  7. HIV and AIDS Awareness among Children with Mental Retardation ...

    African Journals Online (AJOL)

    Openness to the subject of sexuality and HIV and AIDS is considered as taboo in many African cultures. To persons with disabilities, let alone individuals with mental retardation, sexuality and HIV are still areas of grave concern, which still require further study and investigation, hence the interest in the present study.

  8. Long-Term Retardation of Uranium in the KURT Environment

    International Nuclear Information System (INIS)

    Baik, Min Hoon; Shin, Joo Do; Park, Tae Jin

    2016-01-01

    One of possibilities resolving this issue is to study the migration and retardation processes of radionuclides in the subsurface environments by using naturally occurring radionuclides as analogues of radioactive waste. To date, however, the long-term behavior of radionuclides in a granitic groundwater system is not yet fully understood. The ubiquitous presence of uranium (U) in rocks makes it an ideal natural analogue for studying the behaviors of radionuclides in a deep geological repository for the final disposal of HLW. In this study, long-term retardation behavior of natural uranium was investigated using granite rock samples taken from the KURT (KAERI Underground Research Tunnel), located in Daejeon city. The distribution of uranium and its binding mechanism in granite samples were investigated using the sequential chemical extraction (SCE) technique combined with X-ray diffraction (XRD) and ICP-MS methods. In this study, the long-term retardation of uranium in the KURT environment was investigated using SCE and EPMA techniques combined with ICP-MS and XRD. Results showed that long-term interaction of rock with groundwater can change U species and mineralize dissolved U, which can consequently contribute to the retardation of U in the fractured granitic rock environment. This study will help us to understand the long-term behavior of radionuclides migrating through the fractured granite rock and then enhance the reliability of the safety assessment for a HLW repository

  9. Haspeslagh syndrome without severe mental retardation and pterygia?

    NARCIS (Netherlands)

    van Bever, Y.; Hennekam, R. C.

    1995-01-01

    An adult female is described with mild developmental delay, typical facies, dental anomalies, arachnodactyly and camptodactyly. In many respects she resembles four other patients described earlier, but differs in not having multiple pterygia, nor severe mental retardation. We suggest that this

  10. "School Retardation" in Mexico from 1920 to 1960: Conceptual Passages

    Science.gov (United States)

    Castro, Josefina Granja

    2012-01-01

    Educational concepts, such as enrolment, attendance, passing or failing students, school retardation, and school desertion, which made it possible to describe the course of children through the school system, went through a gradual process, beginning in the second half of the nineteenth century and throughout the first decades of the twentieth. In…

  11. A Behavioral Weight Reduction Model for Moderately Mentally Retarded Adolescents.

    Science.gov (United States)

    Rotatori, Anthony F.; And Others

    1980-01-01

    A behavioral weight reduction treatment and maintenance program for moderately mentally retarded adolescents which involves six phases from background information collection to followup relies on stimulus control procedures to modify eating behaviors. Data from pilot studies show an average weekly weight loss of .5 to 1 pound per S. (CL)

  12. Sugar cane juice as a retarding admixture in concrete production ...

    African Journals Online (AJOL)

    Sugar cane juice (SCJ) was investigated as a retarding agent in concrete production. Slump values and compressive strength of concrete with partial replacement of water by sugar cane juice was also investigated. The concrete cubes were prepared by replacing water with SCJ in the following proportions 0, 3, 5, 10 and ...

  13. Characterization of Mental Retardation and Autism in Children's Books.

    Science.gov (United States)

    Dyches, Tina Taylor; Prater, Mary Anne; Cramer, Sharon F.

    2001-01-01

    A study involving 12 books, six picture books and six chapter books, examined how individuals with mental retardation and autism are depicted in children's literature. Results indicate characters were portrayed as making more choices in their lives and were educated in more inclusive environments than in an earlier study. (Contains references.)…

  14. Retardation of muscle growth in castrated male mice: further ...

    African Journals Online (AJOL)

    Retardation of muscle growth in castrated male mice was studied as an evidence for the influence of hormones on the development of muscle mass. Male albino mice were castrated at 28days of age by open castration method. The weights and the muscle mass indices (mg muscle weight per gram body weight) of the ...

  15. Second Order Impulsive Retarded Differential Inclusions with Nonlocal Conditions

    Directory of Open Access Journals (Sweden)

    Hernán R. Henríquez

    2014-01-01

    Full Text Available In this work we establish some existence results for abstract second order Cauchy problems modeled by a retarded differential inclusion involving nonlocal and impulsive conditions. Our results are obtained by using fixed point theory for the measure of noncompactness.

  16. Prognosis and risk factors for intrauterine growth retardation

    DEFF Research Database (Denmark)

    Sehested, Line Thousig; Pedersen, Pernille

    2014-01-01

    INTRODUCTION: Intrauterine growth retardation (IUGR) is the term describing a foetus that has not reached its genetic growth potential. There is no international consensus on the definition of IUGR. The aim of this study was to describe a cohort of weight-restricted neonates and their mothers...

  17. [Behavioral disorders and substance abuse in adolescents with mental retardation].

    Science.gov (United States)

    Papachristou, Ec; Anagnostopoulos, Dk

    2014-01-01

    The percentage of people with mental retardation in the general population is estimated at about 2.3%, with adolescence (15-20 years) constituting the development period during which a peak in rates of mental retardation is observed. The increased prevalence of adolescence may be explained from the fact that the specified requirements of the school initially, and society later, inevitably lead to comparative evaluation of the teen with mental retardation in relation to peers, thus making mental retardation more apparent. Adolescents with mental retardation face a number of physical and psychological needs which are not often distinguishable and as a consequence undergo the deterioration of their already burdened quality of life. In particular, mental health problems occur 3 to 4 times more often in adolescents with mental retardation compared with adolescents of the general population. This review presents the most recent epidemiological findings regarding the correlation between behavioral disorders, substance use and the possible comorbidity in adolescents with intellectual disability, both at community level and residential care level. Epidemiological data indicate that behavioral disorders are among the most common types of psychopathology in mentally retarded adolescents with the severity and symptoms varying depending on the personal characteristics of each adolescent. Regarding substance use, the available data show that the rates of substance use (alcohol, smoking, illicit drugs) are lower in this specific population group but the differences over the last years tend to be eliminated. Finally, according to the few surveys that were examined referring to the comorbidity of behavioral disorders and substance use in adolescents with intellectual disability, the results were contradictory. Specifically, while behavioral disorders continued to be one of the most common types of psychopathology, the related substances disorders indicated lower rates compared to

  18. Some Thoughts on Counseling Parents of the Mentally Retarded. Final Report.

    Science.gov (United States)

    Phelps, William R.

    Discussed are techniques in counseling parents of retarded children. Suggested are ways to structure the interview as well as methods to help the parents deal with such problems as overprotection and initial reactions to the diagnosis of retardation. (CL)

  19. DNA Camouflage

    Science.gov (United States)

    2016-01-08

    1 DNA Camouflage Supplementary Information Bijan Zakeri1,2*, Timothy K. Lu1,2*, Peter A. Carr2,3* 1Department of Electrical Engineering and...ll.mit.edu). Distribution A: Public Release   2 Supplementary Figure 1 DNA camouflage with the 2-state device. (a) In the presence of Cre, DSD-2[α...10 1 + Cre 1 500 1,000 length (bp) chromatogram alignment template − Cre   4 Supplementary Figure 3 DNA camouflage with a switchable

  20. Workability enhancement of geopolymer concrete through the use of retarder

    Science.gov (United States)

    Umniati, B. Sri; Risdanareni, Puput; Zein, Fahmi Tarmizi Zulfikar

    2017-09-01

    Geopolymer concrete is a type of concrete manufactured without the addition of cement. In geopolymer concrete, along with an activator, cement as the concrete binder can be replaced by the fly ash. This will reduce global demand on cement, and therefore will reduce CO2 emission due to cement production. Thus, geopolymer concrete is commonly known as an eco-friendly concrete. Geopolymer concrete also offers a solution concerning with the utilization of the fly ash waste. However, despite of its environmental advantages, geopolymer concrete has a drawback, namelygeopolymer concrete set quickly, thus reducing its workability. This research aimed to increase the workability of geopolymer concrete by using retarder admixture (Plastocrete RT6 Plus). Retarder used varies within 0.2%, 0.4% and 0.6% of fly ash mass. As a control, geopolymer concrete without retarder (0%) were also made. Activator used in this research was Na2SiO3 mixed with NaOH 10 M solution, with ratio of 1:5. The results showed an optimum composition of geopolymer concrete with 0.6% retarder, where initial setting time occured after 6.75 hours, and the final setting time reached after 9.5 hours. Moreover, the slump of the geopolymer concrete was 8.8 cm, and the slump flow was 24 cm. The compressive strength of the geopolymer concrete at 28 days was 47.21 MPa. The experiment showed that the more retarder added, the setting time of the geopolymer concrete will be increased, thus increasing its workability.

  1. NSP-Dependent Simple Nitrile Formation Dominates upon Breakdown of Major Aliphatic Glucosinolates in Roots, Seeds, and Seedlings of Arabidopsis thaliana Columbia-0.

    Science.gov (United States)

    Wittstock, Ute; Meier, Kathrin; Dörr, Friederike; Ravindran, Beena M

    2016-01-01

    One of the best-studied plant defense systems, the glucosinolate-myrosinase system of the Brassicales, is composed of thioglucosides known as glucosinolates and their hydrolytic enzymes, the myrosinases. Tissue disruption brings these components together, and bioactive products are formed as a consequence of myrosinase-catalyzed glucosinolate hydrolysis. Among these products, isothiocyanates have attracted most interest as chemical plant defenses against herbivores and pathogens and health-promoting compounds in the human diet. Previous research has identified specifier proteins whose presence results in the formation of alternative product types, e.g., nitriles, at the expense of isothiocyanates. The biological roles of specifier proteins and alternative breakdown products are poorly understood. Here, we assessed glucosinolate breakdown product profiles obtained upon maceration of roots, seedlings and seeds of Arabidopsis thaliana Columbia-0. We identified simple nitriles as the predominant breakdown products of the major endogenous aliphatic glucosinolates in root, seed, and seedling homogenates. In agreement with this finding, genes encoding nitrile-specifier proteins (NSPs) are expressed in roots, seeds, and seedlings. Analysis of glucosinolate breakdown in mutants with T-DNA insertions in any of the five NSP genes demonstrated, that simple nitrile formation upon tissue disruption depended almost entirely on NSP2 in seeds and mainly on NSP1 in seedlings. In roots, about 70-80% of the nitrile-forming activity was due to NSP1 and NSP3 . Thus, glucosinolate breakdown product profiles are organ-specifically regulated in A. thaliana Col-0, and high proportions of simple nitriles are formed in some parts of the plant. This should be considered in future studies on biological roles of the glucosinolate-myrosinase system.

  2. NSP-dependent simple nitrile formation dominates upon breakdown of major aliphatic glucosinolates in roots, seeds, and seedlings of Arabidopsis thaliana Columbia-0

    Directory of Open Access Journals (Sweden)

    Ute Wittstock

    2016-12-01

    Full Text Available One of the best-studied plant defense systems, the glucosinolate-myrosinase system of the Brassicales, is composed of thioglucosides known as glucosinolates and their hydrolytic enzymes, the myrosinases. Tissue disruption brings these components together, and bioactive products are formed as a consequence of myrosinase-catalyzed glucosinolate hydrolysis. Among these products, isothiocyanates have attracted most interest as chemical plant defenses against herbivores and pathogens and health-promoting compounds in the human diet. Previous research has identified specifier proteins whose presence results in the formation of alternative product types, e.g. nitriles, at the expense of isothiocyanates. The biological roles of specifier proteins and alternative breakdown products are poorly understood. Here, we assessed glucosinolate breakdown product profiles obtained upon maceration of roots, seedlings and seeds of Arabidopsis thaliana Columbia-0. We identified simple nitriles as the predominant breakdown products of the major endogenous aliphatic glucosinolates in root, seed, and seedling homogenates. In agreement with this finding, genes encoding nitrile-specifier proteins (NSPs are expressed in roots, seeds, and seedlings. Analysis of glucosinolate breakdown in mutants with T-DNA insertions in any of the five NSP genes demonstrated, that simple nitrile formation upon tissue disruption depended almost entirely on NSP2 in seeds and mainly on NSP1 in seedlings. In roots, about 70-80 % of the nitrile-forming activity was due to NSP1 and NSP3. Thus, glucosinolate breakdown product profiles are organ-specifically regulated in A. thaliana Col 0, and high proportions of simple nitriles are formed in some parts of the plant. This should be considered in future studies on biological roles of the glucosinolate-myrosinase system.

  3. Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana

    International Nuclear Information System (INIS)

    Won, Eun-Ji; Lee, Jae-Seong

    2014-01-01

    Highlights: • Mortality was increased with a dose dependent manner in ovigerous females of Paracyclopina nana. • Developmental impairments were observed in gamma irradiated nauplii. • Ovigerous females exposed to more than 50 Gy could not have normal two bilateral egg sacs. • Oxidative levels increased with antioxidant enzyme activities in the gamma irradiated P. nana. • The molecular indices (antioxidant enzymes and heat shock protein) were also increased. - Abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 – 96 h = 172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction

  4. Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana

    Energy Technology Data Exchange (ETDEWEB)

    Won, Eun-Ji; Lee, Jae-Seong, E-mail: jslee2@skku.edu

    2014-05-01

    Highlights: • Mortality was increased with a dose dependent manner in ovigerous females of Paracyclopina nana. • Developmental impairments were observed in gamma irradiated nauplii. • Ovigerous females exposed to more than 50 Gy could not have normal two bilateral egg sacs. • Oxidative levels increased with antioxidant enzyme activities in the gamma irradiated P. nana. • The molecular indices (antioxidant enzymes and heat shock protein) were also increased. - Abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 – 96 h = 172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction.

  5. Short-Term Memory for Movement Duration in Mentally Retarded and Nonretarded Adults.

    Science.gov (United States)

    Elliott, Digby; Grundy, Stephen B.

    1984-01-01

    Both retarded and nonretarded adults (N=26) failed to benefit from opportunities to mentally rehearse their criterion movement over the retention interval, suggesting that strategic differences between the groups cannot explain the poorer performances of the retarded Ss. The retarded Ss appeared to have problems remembering the sensory…

  6. Diagnostic test for prenatal identification of Down's syndrome and mental retardation and gene therapy therefor

    Science.gov (United States)

    Smith, Desmond J.; Rubin, Edward M.

    2000-01-01

    A a diagnostic test useful for prenatal identification of Down syndrome and mental retardation. A method for gene therapy for correction and treatment of Down syndrome. DYRK gene involved in the ability to learn. A method for diagnosing Down's syndrome and mental retardation and an assay therefor. A pharmaceutical composition for treatment of Down's syndrome mental retardation.

  7. The toxic effects of flame retardants: a gene expression study in elucidating their carcinogenicity

    Science.gov (United States)

    Vagula, Mary; Al-Dhumani, Ali; Al-Dhumani, Sajaad; Mastro, Alexandra

    2013-05-01

    Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used in many commercial products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams, and textiles. Although the specific toxic action of these chemicals is not clear, it is reported that they can cause serious damage to the nervous, reproductive, and endocrine systems. These chemicals are branded as "probable carcinogens" by Environmental Protection Agency (EPA). Therefore, this study is taken up to investigate the expression of genes namely, TP-53, RAD1, CRADD, and ATM, which are involved in apoptosis, DNA repair and cell cycle regulation. For this study human umbilical vein endothelial cells (HUVEC) are exposed to 5 μM of BDE-85 (a penta-BDE) and BDE-209 (deca-BDE). The results of this report reveal significant alteration in all the genes under investigation in BDE-85 and BDE-209 exposed cells. The BDE-85 induced responses are significantly more than BDE-209. These results emphasize the congener specific action of PBDEs on the expression of genes relevant to DNA repair and cell division of HUVEC cells.

  8. DNA glue

    DEFF Research Database (Denmark)

    Filichev, Vyacheslav V; Astakhova, Irina V.; Malakhov, Andrei D.

    2008-01-01

    Significant alterations in thermal stability of parallel DNA triplexes and antiparallel duplexes were observed upon changing the attachment of ethynylpyrenes from para to ortho in the structure of phenylmethylglycerol inserted as a bulge into DNA (TINA). Insertions of two ortho-TINAs as a pseudo...

  9. Hyperstretching DNA

    NARCIS (Netherlands)

    Schakenraad, Koen; Biebricher, Andreas S.; Sebregts, Maarten; Ten Bensel, Brian; Peterman, Erwin J.G.; Wuite, Gijs J L; Heller, Iddo; Storm, Cornelis; Van Der Schoot, Paul

    2017-01-01

    The three-dimensional structure of DNA is highly susceptible to changes by mechanical and biochemical cues in vivo and in vitro. In particular, large increases in base pair spacing compared to regular B-DNA are effected by mechanical (over)stretching and by intercalation of compounds that are widely

  10. Breakdown study of dc silicon micro-discharge devices

    International Nuclear Information System (INIS)

    Schwaederlé, L; Kulsreshath, M K; Lefaucheux, P; Tillocher, T; Dussart, R; Overzet, L J

    2012-01-01

    The influence of geometrical and operating parameters on the electrical characteristics of dc microcavity discharges provides insight into their controlling physics. We present here results of such a study on silicon-based microcavity discharge devices carried out in helium at pressure ranging from 100 to 1000 Torr. Different micro-reactor configurations were measured. The differences include isolated single cavities versus arrays of closely spaced cavities, various cavity geometries (un-etched as well as isotropically and anisotropically etched), various dimensions (100 or 150 µm cavity diameter and 0-150 µm depth). The electrode gap was kept constant in all cases at approximately 6 µm. The applied electric field reaches 5 × 10 7 V m -1 which results in current and power densities up to 2 A cm -2 and 200 kW cm -3 , respectively. The number of microcavities and the microcavity depth are shown to be the most important geometrical parameters for predicting breakdown and operation of microcavity devices. The probability of initiatory electron generation which is volume dependent and the electric field strength which is depth dependent are, respectively, considered to be responsible. The cavity shape (isotropic/anisotropic) and diameter had no significant influence. The number of micro-discharges that could be ignited depends on the rate of voltage rise and pressure. Larger numbers ignite at lower frequency and pressure. In addition, the voltage polarity has the largest influence on the electrical characteristics of the micro-discharge of all parameters, which is due to both the asymmetric role of electrodes as electron emitter and the non-uniformity of the electric field resulting in different ionization efficiencies. The qualitative shape of all breakdown voltage versus pressure curves can be explained in terms of the distance over which the discharge breakdown effectively occurs as long as one understand that this distance can depend on pressure. (paper)

  11. PHENIX Work Breakdown Structure. Cost and schedule review copy

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds are shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M&S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M&S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry.

  12. Laser induced breakdown spectroscopy library for the Martian environment

    International Nuclear Information System (INIS)

    Cousin, A.; Forni, O.; Maurice, S.; Gasnault, O.

    2011-01-01

    The NASA Mars Science Laboratory rover will carry the first Laser Induced Breakdown Spectroscopy experiment in space: ChemCam. We have developed a laboratory model which mimics ChemCam's main characteristics. We used a set of target samples relevant to Mars geochemistry, and we recorded individual spectra. We propose a data reduction scheme for Laser Induced Breakdown Spectroscopy data incorporating de-noising, continuum removal, and peak fitting. Known effects of the Martian atmosphere are confirmed with our experiment: better Signal-to-Noise Ratio on Mars compared to Earth, narrower peak width, and essentially no self-absorption. The wavelength shift of emission lines from air to Mars pressure is discussed. The National Institute of Standards and Technology vacuum database is used for wavelength calibration and to identify the elemental lines. Our Martian database contains 1336 lines for 32 elements: H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ar, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Rb, Sr, Cs, Ba, and Pb. It is a subset of the National Institute of Standards and Technology database to be used for Martian geochemistry. Finally, synthetic spectra can be built from the Martian database. Correlation calculations help to distinguish between elements in case of uncertainty. This work is used to create tools and support data for the interpretation of ChemCam results. - Highlights: ► Chemcam: first Laser Induced Breakdown Spectroscopy technique on Mars. ► Creation of a LIBS specific database to ChemCam on Mars. ► Data reduction scheme is proposed. ► Best signal under Martian conditions. ► LIBS emission lines database: subset of NIST database for Martian geochemistry.

  13. Plasma-enhanced synthesis of green flame retardant cellulosic materials

    Science.gov (United States)

    Totolin, Vladimir

    The natural fiber-containing fabrics and composites are more environmentally friendly, and are used in transportation (automobiles, aerospace), military applications, construction industries (ceiling paneling, partition boards), consumer products, etc. Therefore, the flammability characteristics of the composites based on polymers and natural fibers play an important role. This dissertation presents the development of plasma assisted - green flame retardant coatings for cellulosic substrates. The overall objective of this work was to generate durable flame retardant treatment on cellulosic materials. In the first approach sodium silicate layers were pre-deposited onto clean cotton substrates and cross linked using low pressure, non-equilibrium oxygen plasma. A statistical design of experiments was used to optimize the plasma parameters. The modified cotton samples were tested for flammability using an automatic 45° angle flammability test chamber. Aging tests were conducted to evaluate the coating resistance during the accelerated laundry technique. The samples revealed a high flame retardant behavior and good thermal stability proved by thermo-gravimetric analysis. In the second approach flame retardant cellulosic materials have been produced using a silicon dioxide (SiO2) network coating. SiO 2 network armor was prepared through hydrolysis and condensation of the precursor tetraethyl orthosilicate (TEOS), prior coating the substrates, and was cross linked on the surface of the substrates using atmospheric pressure plasma (APP) technique. Due to protection effects of the SiO2 network armor, the cellulosic based fibers exhibit enhanced thermal properties and improved flame retardancy. In the third approach, the TEOS/APP treatments were extended to linen fabrics. The thermal analysis showed a higher char content and a strong endothermic process of the treated samples compared with control ones, indicating a good thermal stability. Also, the surface analysis proved

  14. Optical breakdown threshold investigation of 1064 nm laser induced air plasmas

    International Nuclear Information System (INIS)

    Thiyagarajan, Magesh; Thompson, Shane

    2012-01-01

    We present the theoretical and experimental measurements and analysis of the optical breakdown threshold for dry air by 1064 nm infrared laser radiation and the significance of the multiphoton and collisional cascade ionization process on the breakdown threshold measurements over pressures range from 10 to 2000 Torr. Theoretical estimates of the breakdown threshold laser intensities and electric fields are obtained using two distinct theories namely multiphoton and collisional cascade ionization theories. The theoretical estimates are validated by experimental measurements and analysis of laser induced breakdown processes in dry air at a wavelength of 1064 nm by focusing 450 mJ max, 6 ns, 75 MW max high-power 1064 nm IR laser radiation onto a 20 μm radius spot size that produces laser intensities up to 3 - 6 TW/cm 2 , sufficient for air ionization over the pressures of interest ranging from 10 to 2000 Torr. Analysis of the measured breakdown threshold laser intensities and electric fields are carried out in relation with classical and quantum theoretical ionization processes, operating pressures. Comparative analysis of the laser air breakdown results at 1064 nm with corresponding results of a shorter laser wavelength (193 nm) [M. Thiyagarajan and J. E. Scharer, IEEE Trans. Plasma Sci. 36, 2512 (2008)] and a longer microwave wavelength (10 8 nm) [A. D. MacDonald, Microwave Breakdown in Gases (Wiley, New York, 1966)]. A universal scaling analysis of the breakdown threshold measurements provided a direct comparison of breakdown threshold values over a wide range of frequencies ranging from microwave to ultraviolet frequencies. Comparison of 1064 nm laser induced effective field intensities for air breakdown measurements with data calculated based on the collisional cascade and multiphoton breakdown theories is used successfully to determine the scaled collisional microwave portion. The measured breakdown threshold of 1064 nm laser intensities are then scaled to

  15. Individual breakdown of pension rights and end of contract

    CERN Multimedia

    2015-01-01

    As in previous years, members of the CERN Pension Fund will shortly receive their “Individual breakdown of pension rights” by e-mail.   In this respect, we would like to remind members that according to Articles II 1.11 - II 1.12 (calculation and payment of the transfer value) and II 2.02 (retirement pension), several options are possible at the end of their contract (depending on their length of service in the Fund): payment of the transfer value into a personal bank account, payment of the transfer value into a new pension scheme, pension (deferred, anticipated or retirement). Benefits Service CERN Pension Fund

  16. Autism Spectrum Disorder in Children Adopted After Early Care Breakdown

    OpenAIRE

    Green, Jonathan; Leadbitter, Kathy; Kay, Catherine; Sharma, Kishan

    2016-01-01

    Syndromic autism has been described in children adopted after orphanage rearing. We investigated whether the same existed in children adopted after family breakdown. Families of 54/60 adopted children aged 6?11?years (mean 102?months; SD 20; 45?% male) returned screening questionnaires for autism spectrum disorder (ASD); 21/54 (39?%) screened positive. Detailed in-person phenotyping of screen positive cases showed ASD in 6/54 (11?%), Broad ASD (sub threshold traits) in 10/54 (18.5?%); 5/54 (9...

  17. Dynamical breakdown of chiral symmetry and abnormal perturbation expansion

    International Nuclear Information System (INIS)

    Ebert, D.; Pervushin, V.N.

    1976-01-01

    Dynamical breakdown of γ 5 -symmetry is studied in the Abelian gauge theory of massless ''quarks'' interacting with massless vector ''gluons''. For this purpose the path-integral approach with bilocal fields as dynamical variables is used. The classical field equation defined by the stationary point of the generating functional turns out to be identical with the Schwinger-Dyson equation for the quark propagator. After a short discussion of the possible solutions of this equation an abnormal perturbation theory has been worked out

  18. Chemical consequences of laser-induced breakdown in molecular gases

    Czech Academy of Sciences Publication Activity Database

    Babánková, Dagmar; Civiš, Svatopluk; Juha, Libor

    2006-01-01

    Roč. 30, č. 2-3 (2006), s. 75-88 ISSN 0079-6727 R&D Projects: GA ČR GA203/06/1278; GA MŠk LC510; GA MŠk LC528; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100523 Keywords : laser spark * laser-induced dielectric breakdown * laser-plasma chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.500, year: 2006

  19. Recovering from trust breakdowns in large system implementations

    DEFF Research Database (Denmark)

    Rerup Schlichter, Bjarne Rerup; Andersen, Povl Erik Rostgård

    2011-01-01

    On the basis of experiences from the Faroese large-scale implementation of integrated healthcare information systems and insights into dynamic aspects of trust, we offer the following lessons learned for the successful management and recovery of trust (breakdowns) in large system implementations......: restore relations by turning towards face-to-face events and procedures, assure a well-functioning and available support organization, demonstrate trust in actors to enhance their own self-confidence and celebrate successes, even the smallest or ones injected by yourself. The propositions are based on a 6...

  20. Determination of secondary electron yields from low pressure breakdown

    International Nuclear Information System (INIS)

    Maric, D; Zivanov, S.; Strinic, A.; Malovic, G.; Djuric, M.; Petrovic, Z. Lj.

    2000-01-01

    In order to model accurately the secondary yields in gas breakdown and collisional plasmas both the numerous processes discussed in related experiments must be included and also proper determination of γ (E/n) must be provided. In addition to the application of the correct ionization rate it is also essential to include the nonequilibrium region where electrons gain energy and achieve hydrodynamics equilibrium. For lower values of E/n, greater values of γ than those based on the literature data for αn(E/n) have been found, possibly due to existence of the photoelectric effects

  1. Mechanism of laser beam reentry into a laser breakdown plasma

    International Nuclear Information System (INIS)

    Savic, P.; Kekez, M.M.; Makomaski, A.H.

    1975-01-01

    It is shown that the focus-directed filament often observed in streak photographs of CO 2 -laser produced gas breakdown can be explained by the lateral expansion and consequent cooling of the plasma behind the radiation supported shock. A simple analysis and more detailed numerical calculations show a temperature maximum developing in the plasma, which travels either towards or away from the light source, depending on the nature of the gas. Thus, the locus of the cutoff temperature also travels along the beam, allowing it to reenter the plasma at a velocity which may attain the speed of light. (Auth.)

  2. STRUCTURE OF BODY DEFORMATIES AMONG PERSONS WITH MENTAL RETARDATION

    Directory of Open Access Journals (Sweden)

    Blagoja GESHOSKI

    2010-04-01

    Full Text Available The purpose of this research was to assess body structure deformities among people with mental retardation.Knowing the structure of people with mental retardation’s physical deformities is the starting basis of a quality program for preventive and corrective work. Also, it is a starting point in the process of special education and rehabilitation in regards to their removal and mitigation.The structure of the physical deformities among persons with mental retardation were analyzed in terms of age and degree of mental retardation in relation to everyday life activities.The inquiry covered 170 respondents with mental retardation in both sexes. All respondents were placed in an institution for treatment of persons with severe and profound mental retardation (Special Institute Deep River. On the basis of two criteria, participants are divided into groups. The first criterion forestablishing a group of level of mental retardation: Group I - severe mental retardation (TMR and Group II - profound mental retardation (DMR. A second criterion for establishing the age group of respondents: Group I - age 18 years; Group II- Age 19 - 30 years and Group III - over 31 years. The structure of the physical deformities was analyzed in terms of age and degree of mental retardation in relation to activities in everyday life.For the purposes of the planned research , an integral protocol is established for the evaluation of physical deformities among persons with disabilities, including: an application form for general information about the respondents, a questionnaire to assess somatic status, and a clinical sheet and test activities in everyday life (Test ASZH, Rusk, 1971. All data obtained by the research are expressed quantitatively and treated with the following statistical methods and procedures: number of repetitions, frequency and percentages, measure of central tendency, the arithmetic mean and standard deviation, χ2 and Fisher Exact - test

  3. Influence of water trees on breakdown voltage of polymeric cables insulations

    Energy Technology Data Exchange (ETDEWEB)

    Stancu, Cristina [INCDIE ICPE CA, Bucharest (Romania); Notingher, Petru V.; Plopeanu, Mihai Gabriel [Politehnica University of Bucharest, Bucharest (Romania)

    2011-07-01

    In a previous paper was shown that water trees development modifies considerably the electric field repartition, which increases significantly in the vicinity of treed areas. In order to find the water trees influence on the breakdown voltage, in the present paper, an experimental study on model cables insulated with low density polyethylene is done. In insulation samples, water trees with various dimensions and densities were developed. For the reduction of the test duration, an electric field with a higher frequency (3-5 kHz) was used. For breakdown voltage measurement an automatic setup was realized. For each value of the ageing time the dimensions and densities of water trees and breakdown voltage were measured and the dependency of the breakdown voltage with these quantities were analysed. The results show a significant reduction of the breakdown voltage of treed cables insulations compared to un-treed ones. Key words: polyethylene, water treeing, electric field, breakdown, power cables.

  4. Influence of temperature on current-induced domain wall motion and its Walker breakdown

    International Nuclear Information System (INIS)

    Fan, Lvchao; Hu, Jingguo; Su, Yuanchang; Zhu, Jinrong

    2016-01-01

    The current-driven domain wall propagation along a thin ferromagnetic strip with thermal field is studied by means of micromagnetic simulations. The results show that the velocity of domain wall is almost independent of temperature until Walker breakdown happened. However the thermal field can suppress Walker breakdown and makes domain wall move faster. Further analysis indicates that the thermal field tends to keep the out-of-plane magnetic moment of the domain wall stay in high value, which can promote domain wall motion and suppress the Walker breakdown by breaking the period of domain wall transformation. - Highlights: • Influences of temperature on the displacement and the velocity of DW are shown. • The suppression of Walker breakdown by temperature is given. • The reason for suppressing Walker breakdown is analyzed. • The breaking transformation period of Walker breakdown by temperature is given.

  5. Criterion for vortex breakdown on shock wave and streamwise vortex interactions.

    Science.gov (United States)

    Hiejima, Toshihiko

    2014-05-01

    The interactions between supersonic streamwise vortices and oblique shock waves are theoretically and numerically investigated by three-dimensional (3D) Navier-Stokes equations. Based on the two inequalities, a criterion for shock-induced breakdown of the streamwise vortex is proposed. The simple breakdown condition depends on the Mach number, the swirl number, the velocity deficit, and the shock angle. According to the proposed criterion, the breakdown region expands as the Mach number increases. In numerical simulations, vortex breakdown appeared under conditions of multiple pressure increases and the helicity disappeared behind the oblique shock wave along the line of the vortex center. The numerical results are consistent with the predicted breakdown condition at Mach numbers 2.0 and 3.0. This study also found that the axial velocity deficit is important for classifying the breakdown configuration.

  6. Noise Parameter Analysis of SiGe HBTs for Different Sizes in the Breakdown Region

    Directory of Open Access Journals (Sweden)

    Chie-In Lee

    2016-01-01

    Full Text Available Noise parameters of silicon germanium (SiGe heterojunction bipolar transistors (HBTs for different sizes are investigated in the breakdown region for the first time. When the emitter length of SiGe HBTs shortens, minimum noise figure at breakdown decreases. In addition, narrower emitter width also decreases noise figure of SiGe HBTs in the avalanche region. Reduction of noise performance for smaller emitter length and width of SiGe HBTs at breakdown resulted from the lower noise spectral density resulting from the breakdown mechanism. Good agreement between experimental and simulated noise performance at breakdown is achieved for different sized SiGe HBTs. The presented analysis can benefit the RF circuits operating in the breakdown region.

  7. Experimental study of DC vacuum breakdown and application to high-gradient accelerating structures for CLIC

    CERN Document Server

    Shipman, Nicholas; Jones, Roger

    2016-01-01

    The compact linear collider (CLIC) is a leading candidate for the next generation high energy linear collider. As any breakdown would result in a partial or full loss of luminosity for the pulse in which it occurs, obtaining a low breakdown rate in CLIC accelerating structures is a critical requirement for the successful operation of the proposed collider. This thesis presents investigations into the breakdown phenomenon primarily in the low breakdown rate regime of interest to CLIC, performed using the CERN DC spark systems between 2011 and 2014. The design, construction and commissioning of several new pieces of hardware, as well as the development of improved techniques to measuring the inter-electrode gap distance are detailed. These hardware improvements were fundamental in enabling the exciting new experiments mentioned below, which in turn have provided significant additional insight into the phenomenon of breakdown. Experiments were performed to measure fundamental parameters of individual breakdowns...

  8. Determination of Retardation Effects in the High Tc Cuprates from Sharvin Contact Measurements

    International Nuclear Information System (INIS)

    Deutscher, G.

    1995-01-01

    It is well known that retardation effects are essential to allow the attractive part of the electron-electron interaction (for instance, phonon mediated) to overcome the Coulomb repulsion. In new superconductors such as the cuprates for which the interaction is a priori unknown, it is therefore essential to determine the retarded and non retarded parts of the interaction. We show how this can be achieved by an analysis of Sharvin contact measurements between a noble metal tip and a cuprate. It turns out that both the retarded and non retarded parts are large, the former being however larger than the later

  9. A newly identified DNA ligase of Saccharomyces cerevisiae involved in RAD52-independent repair of DNA double-strand breaks

    Science.gov (United States)

    Schär, Primo; Herrmann, Gernot; Daly, Graham; Lindahl, Tomas

    1997-01-01

    Eukaryotic DNA ligases are ATP-dependent DNA strand-joining enzymes that participate in DNA replication, repair, and recombination. Whereas mammalian cells contain several different DNA ligases, encoded by at least three distinct genes, only one DNA ligase has been detected previously in either budding yeast or fission yeast. Here, we describe a newly identified nonessential Saccharomyces cerevisiae gene that encodes a DNA ligase distinct from the CDC9 gene product. This DNA ligase shares significant amino acid sequence homology with human DNA ligase IV; accordingly, we designate the yeast gene LIG4. Recombinant LIG4 protein forms a covalent enzyme-AMP complex and can join a DNA single-strand break in a DNA/RNA hybrid duplex, the preferred substrate in vitro. Disruption of the LIG4 gene causes only marginally increased cellular sensitivity to several DNA damaging agents, and does not further sensitize cdc9 or rad52 mutant cells. In contrast, lig4 mutant cells have a 1000-fold reduced capacity for correct recircularization of linearized plasmids by illegitimate end-joining after transformation. Moreover, homozygous lig4 mutant diploids sporulate less efficiently than isogenic wild-type cells, and show retarded progression through meiotic prophase I. Spore viability is normal, but lig4 mutants appear to produce a higher proportion of tetrads with only three viable spores. The mutant phenotypes are consistent with functions of LIG4 in an illegitimate DNA end-joining pathway and ensuring efficient meiosis. PMID:9271115

  10. Breakdown characteristics in DC spark experiments of copper focusing on purity and hardness

    CERN Document Server

    Yokoyama, Kazue; Higashi, Yasuo; Higo, Toshi; Matsumoto, Shuji; Santiago-Kern, Ana Rocia; Pasquino, Chiara; Calatroni, Sergio; Wuensch, Walter

    2010-01-01

    The breakdown characteristics related to the differences in purity and hardness were investigated for several types of copper using a DC spark test system. Three types of oxygen-free copper (OFC) materials, usual class 1 OFC 7-nine large-grain copper and 6-nine hot-isotropic-pressed (HIP) copper with/without diamond finish, were tested with the DC spark test system. The measurements of the beta, breakdown fields, and breakdown probability are presented and discussed in this paper.

  11. Efficient composite broadband polarization retarders and polarization filters

    Science.gov (United States)

    Dimova, E.; Ivanov, S. S.; Popkirov, G.; Vitanov, N. V.

    2014-12-01

    A new type of broadband polarization half-wave retarder and narrowband polarization filters are described and experimentally tested. Both, the retarders and the filters are designed as composite stacks of standard optical half-wave plates, each of them twisted at specific angles. The theoretical background of the proposed optical devices was obtained by analogy with the method of composite pulses, known from the nuclear and quantum physics. We show that combining two composite filters built from different numbers and types of waveplates, the transmission spectrum is reduced from about 700 nm to about 10 nm width.We experimentally demonstrate that this method can be applied to different types of waveplates (broadband, zero-order, multiple order, etc.).

  12. Improved fire retardancy of thermoset composites modified with carbon nanofibers

    International Nuclear Information System (INIS)

    Zhao Zhongfu; Gou Jan

    2009-01-01

    Multifunctional thermoset composites were made from polyester resin, glass fiber mats and carbon nanofiber sheets (CNS). Their flaming behavior was investigated with cone calorimeter under well-controlled combustion conditions. The heat release rate was lowered by pre-planting carbon nanofiber sheets on the sample surface with the total fiber content of only 0.38 wt.%. Electron microscopy showed that carbon nanofiber sheet was partly burned and charred materials were formed on the combusting surface. Both the nanofibers and charred materials acted as an excellent insulator and/or mass transport barrier, improving the fire retardancy of the composite. This behavior agrees well with the general mechanism of fire retardancy in various nanoparticle-thermoplastic composites.

  13. Environmental Impact of Flame Retardants (Persistence and Biodegradability

    Directory of Open Access Journals (Sweden)

    Asher Brenner

    2009-02-01

    Full Text Available Flame-retardants (FR are a group of anthropogenic environmental contaminants used at relatively high concentrations in many applications. Currently, the largest market group of FRs is the brominated flame retardants (BFRs. Many of the BFRs are considered toxic, persistent and bioaccumulative. Bioremediation of contaminated water, soil and sediments is a possible solution for the problem. However, the main problem with this approach is the lack of knowledge concerning appropriate microorganisms, biochemical pathways and operational conditions facilitating degradation of these chemicals at an acceptable rate. This paper reviews and discusses current knowledge and recent developments related to the environmental fate and impact of FRs in natural systems and in engineered treatment processes.

  14. Power-spectral-density relationship for retarded differential equations

    Science.gov (United States)

    Barker, L. K.

    1974-01-01

    The power spectral density (PSD) relationship between input and output of a set of linear differential-difference equations of the retarded type with real constant coefficients and delays is discussed. The form of the PSD relationship is identical with that applicable to unretarded equations. Since the PSD relationship is useful if and only if the system described by the equations is stable, the stability must be determined before applying the PSD relationship. Since it is sometimes difficult to determine the stability of retarded equations, such equations are often approximated by simpler forms. It is pointed out that some common approximations can lead to erroneous conclusions regarding the stability of a system and, therefore, to the possibility of obtaining PSD results which are not valid.

  15. Deceased loved ones in the dreams of mentally retarded adults.

    Science.gov (United States)

    Turner, J L; Graffam, J H

    1987-11-01

    Dream reports were collected over a 10-year period as part of an ethnographic study of mentally retarded employees in a sheltered workshop. Deceased loved ones, usually parents or other family members, figured prominently as characters in many of these dreams. Dreams about the dead were often recurring and elicited salient emotional reactions from the dreamers. The various forms that these dreams take and their characteristic thematic content were described for 154 dreams by 60 dreamers. Some of the percepts and feelings that reflect the dreamers' understanding of their dreams were also noted. Findings reveal that the dream life of retarded adults is much more rich and diverse than previous studies suggest. Clinical implications and the occurrence of similar dreams among nonretarded persons were discussed.

  16. Mental retardation after prenatal exposure. Re-analysis indicated

    International Nuclear Information System (INIS)

    Paile, W.

    2000-01-01

    The current risk assessment for severe mental retardation after prenatal exposure to the A-bomb radiation is based on 21 cases exposed to more than 0.005 Gy, of which 17 were exposed in the most sensitive period 8-15 weeks p.c. The latest analysis, applying the best fitting model, indicates a threshold with a lower 95% bound of 0.06-0.31 Gy, depending on whether 2 cases with Down's syndrome are included or not. The authors have interpreted this as suggesting a threshold in the low-dose region. In the dose group 0.10-0.49 Gy, except one case with Down's syndrome there is only one other case, exposed 8 weeks p.c. to 0.14 Gy. However, in a RERF report (TR 13-91) concerning brain abnormalities detected by MRI in retarded persons, the same case is described. According to this report he was actually exposed to 0.86 Gy. The distance was 1060 m, and his mother exhibited severe epilation. These details indicate that the higher dose is correct and the lower dose is erroneous. In a small material the misclassification of one case has a deep influence on the result of the data analysis. Reclassification of this case will lead to a considerable change in the estimated threshold, notably in the 95% lower bound of the threshold. There will be no indication of severe retardation after less than 0.5 Gy even in the most sensitive period. This does not preclude a milder effect on intelligence from lower doses. The fraction of severe retardation after exposure to 1 Sv in the period 8-15 weeks p.c. has been estimated at 40%. The effect on intelligence score has been estimated at 30 IQ units per Sv in the same period. These estimates have been combined in ICRP 60 to create a model, based on a presumed normal distribution of IQ scores, according to which the final outcome for an individual is determined by his expected IQ without exposure. Thus the dose required to make an otherwise normal individual retarded would be high, while a much lower dose would be enough to bring an individual

  17. Fabrication of cotton fabric with superhydrophobicity and flame retardancy.

    Science.gov (United States)

    Zhang, Ming; Wang, Chengyu

    2013-07-25

    A simple and facile method for fabricating the cotton fabric with superhydrophobicity and flame retardancy is described in the present work. The cotton fabric with the maximal WCA of 160° has been prepared by the covalent deposition of amino-silica nanospheres and the further graft with (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The geometric microstructure of silica spheres was measured by transmission electron microscopy (TEM). The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, diverse performances of superhydrophobic cotton textiles have been evaluated as well. The results exhibited the outstanding superhydrophobicity, excellent waterproofing durability and flame retardancy of the cotton fabric after treatment, offering a good opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Role of microRNA Pathway in Mental Retardation

    Science.gov (United States)

    Qurashi, Abrar; Chang, Shuang; Jin, Peng

    2007-01-01

    Deficits in cognitive functions lead to mental retardation (MR). Understanding the genetic basis of inherited MR has provided insights into the pathogenesis of MR. Fragile X syndrome is one of the most common forms of inherited MR, caused by the loss of functional Fragile X Mental Retardation Protein (FMRP). MicroRNAs (miRNAs) are endogenous, single-stranded RNAs between 18 and 25 nucleotides in length, which have been implicated in diversified biological pathways. Recent studies have linked the miRNA pathway to fragile X syndrome. Here we review the role of the miRNA pathway in fragile X syndrome and discuss its implication in MR in general. PMID:17982588

  19. DNA probes

    International Nuclear Information System (INIS)

    Castelino, J.

    1992-01-01

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  20. DNA probes

    Energy Technology Data Exchange (ETDEWEB)

    Castelino, J

    1993-12-31

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with {sup 32}P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism`s genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens 10 figs, 2 tabs

  1. Development of new radiation resistant, fire-retardant cables

    International Nuclear Information System (INIS)

    Hagiwara, Ko; Morita, Yosuke; Udagawa, Takashi; Fujimura, Shun-ichi; Oda, Eisuke.

    1982-01-01

    For the cables for nuclear facilities, radiation resistance and fire-retardation are severely required. The authors took note of the fact that even in the existing cables for nuclear power plants, their mechanical properties are greatly degraded by the exposure to large dose (for example, 200 Mrad in PWR testing conditions), and attempted the improvement. They employed a new additive, bromated acenaphthylene condensate (con-BACN), which effectively gives radiation resistance and also is a good flame retarder, to be compounded to an insulation material, and examined the characteristics. In this paper, the features of con-BACN and the investigation of fire-retardant EPDM composition are described. As an initial composition, a small amount of zinc white, sulphur, stearic acid, noclac 224 (Ouchi-Shinko Chemicals, Co.), and antimony trioxide, 100 parts of tale and 45 parts of con-BACN were added to 100 parts of EPDM (propylene content 34 %, Japan Synthetic Rubber Co.). As the antiaging agent, it was decided to use phenol series No. 3 as a result of test. The fire-retardant EP rubber-composed cable was produced for trial, its insulation being fabricated, using a Furukawa's pressurized salt bath continuous vulcanizer. The tests of γ-irradiation, simulated LOCA and combustion were carried out, and the test results are reported. It was indicated that the cable resisted against high dose several times as much as 200 Mrad, and was suitable for the applications, in which the mechanical properties such as bending are required to be maintained after radiation exposure. It was also found that con-BACN was safe, and its properties of decomposition, concentration and acute toxicity were all very low. (Wakatsuki, Y.)

  2. Highly retarded M2 transition in 90Nb

    International Nuclear Information System (INIS)

    Sergeev, V.O.

    2006-01-01

    One studied properties of 2.3 keV transition between 124.67 (4 - ) and 122.37 keV (6 + ) in 90 Nb. The mentioned M2-transition is shown to be retarded by approximately 10 4 times and provided explanations of the mentioned extraordinary high factor of deceleration. One evaluated impurity of E3 possible multipolarity constituent in the mentioned transition (δ 2 [ru

  3. SELF-HELP GROUPS FOR PARENTS WITH MENTALLY RETARDED CHILDREN

    Directory of Open Access Journals (Sweden)

    Vaska STANCHEVA-POPKOSTADINOVA

    1997-09-01

    Full Text Available This presentation concerns a group for parents of mentally retarded children.A group of these parents receives professional help and environmental support. The parents are encouraged to assume responsibility in the everyday life educational process of their children.As Baker / 1980 / states: “ If parents cope better on daily basis with the child who has mental retardation, not only the child but also the parents would benefit”.Taking part in the group gave the parents:· the opportunity to meet other parents with the same children;· to talk to other parents and feel less isolated;· to share information and experiences, skills and ideas;· the opportunity to listen to the needs and problems of other parents;· to change the ways of working to meet the child’s needs;· share information about the possibilities of education and services;· parents are encouraged to meet together to support one another;· parents need a special approach to many problems existing in their families.· the education in the group puts the beginning of the work with the parents.The idea is to gather the efforts of specialists from different fields and to establish multi-disciplinary group aiming to work with the parents and create a good collaboration and partnership between them in order to improve the living conditions and services to the retarded persons.This paper reports on the development, evaluation and dissemination of the program for education of parents with mentally retarded children. At the Symposium we will be able to present the results of the effectiveness of the education.

  4. Advanced-Retarded Differential Equations in Quantum Photonic Systems

    Science.gov (United States)

    Alvarez-Rodriguez, Unai; Perez-Leija, Armando; Egusquiza, Iñigo L.; Gräfe, Markus; Sanz, Mikel; Lamata, Lucas; Szameit, Alexander; Solano, Enrique

    2017-01-01

    We propose the realization of photonic circuits whose dynamics is governed by advanced-retarded differential equations. Beyond their mathematical interest, these photonic configurations enable the implementation of quantum feedback and feedforward without requiring any intermediate measurement. We show how this protocol can be applied to implement interesting delay effects in the quantum regime, as well as in the classical limit. Our results elucidate the potential of the protocol as a promising route towards integrated quantum control systems on a chip. PMID:28230090

  5. Psychopathology in Children and Adolescents with ASD without Mental Retardation

    Science.gov (United States)

    Caamaño, Marta; Boada, Leticia; Merchán-Naranjo, Jessica; Moreno, Carmen; Llorente, Cloe; Moreno, Dolores; Arango, Celso; Parellada, Mara

    2013-01-01

    This study analyzes subclinical psychopathology in children and adolescents with autism spectrum disorders (ASD) without mental retardation with no comorbid disorder, assessed by an extensive general psychopathology interview. The K-SADS-PL was administered to a group of 25 patients with ASD (mean age = 12.80 ± 2.86 years) and 25 healthy controls…

  6. Computer optimization of retarding lens systems for ESCA spectrometers

    International Nuclear Information System (INIS)

    Wannberg, B.; Skoellermo, A.

    1977-01-01

    The performance of four-element electrostatic lenses as retarding systems between source and analyzer in ESCA spectrometers is calculated. The potential distribution in the lens is defined by an axial potential of the type phi(z)=V 0 +Σ(Vsub(i)-Vsub(i-1))/2 - tanh (ω/asub(i)(z-zsub(i))). For a given general shape of the lens and a given retardation ratio, the potentials of the two middle electrodes are fitted to give a paraxial image with a prescribed magnification at the exit slit of the lens system. The equipotential surfaces forming the electrodes are found by calculating the potential in an off-axis point, using the series expansion. All third-order geometrical and first-order chromatic aberrations of the lenses are calculated and used together with the second-order aberrations of the analyzer to calculate optimum dimensions of the lens elements and of the emittance-defining slits. A computer program, of which one part calculates the lens properties and one the properties of the entire system lens-analyzer, is described. Two lens systems are presented in some detail. The first one is intended for use with a hemispherical electrostatic analyzer. The angular acceptance is here defined by an aperture stop inside the lens. In this system, the image position and magnification can be kept constant for retardation ratios at least between 1:2 and 60:1, with moderate potentials on the middle electrodes. The second lens system is designed for a magnetic spectrometer of the π√2-type. Here, the central trajectory in the lens is slightly curved by the magnetic field, and the angular acceptance is defined by a baffle after the lens. This system is optimized for a constant retardation ratio of 5:1. (Auth.)

  7. Modelling Viscoelasticity of Loudspeaker Suspensions using Retardation Spectra

    DEFF Research Database (Denmark)

    Ritter, Tobias; Agerkvist, Finn T.

    2010-01-01

    , the viscoelastic retardation spectrum, which provides a more fundamental description of the suspension viscoelasticity, is rst used to explain the accuracy of the empirical LOG creep model (Knudsen et al.). Then, two extensions to the LOG model are proposed which include the low and high frequency limit...... of the compliance, not accounted for in the original LOG model. The new creep models are veried by measurements on two 5.5 loudspeakers with different surrounds....

  8. Methods for determining radionuclide retardation factors: status report

    International Nuclear Information System (INIS)

    Relyea, J.F.; Serne, R.J.; Rai, D.

    1980-04-01

    This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

  9. Possible retardation effects of quark confinement on the meson spectrum

    International Nuclear Information System (INIS)

    Qiao, C.; Huang, H.; Chao, K.

    1996-01-01

    The reduced Bethe-Salpeter equation with scalar confinement and vector gluon exchange is applied to quark-antiquark bound states. The so-called intrinsic flaw of the Salpeter equation with static scalar confinement is investigated. The notorious problem of narrow level spacings is found to be remedied by taking into consideration the retardation effect of scalar confinement. A good fit for the mass spectrum of both heavy and light quarkonium states is then obtained. copyright 1996 The American Physical Society

  10. Moral reasoning of Piagetian-matched retarded and nonretarded children and adolescents.

    Science.gov (United States)

    Kahn, J V

    1983-09-01

    The moral reasoning of four IQ/etiology groups was investigated: 19 organically abnormal moderately retarded, 19 organically abnormal mildly retarded, 19 mildly retarded due to psychosocial disadvantage, and 19 nonretarded individuals. In each group 12 Ss were preoperational and seven concrete operational. Moral reasoning was assessed by an instrument using moral dilemmas based on Kohlberg's procedures. The Slosson Intelligence Test was used to determine the IQs and mental ages of each S. Piagetian stage was determined with the standard conservation of number tasks. The findings indicated no overall significant differences between the mildly retarded and the nonretarded Ss or between the mildly retarded and the moderately retarded Ss, but differences were found between the moderately retarded and the nonretarded Ss. A significant interaction was found between the two independent variables, IQ/etiology and cognitive level. The results were discussed as supporting Zigler's development position and as damaging to Kohlberg's position.

  11. Time domain simulations of preliminary breakdown pulses in natural lightning.

    Science.gov (United States)

    Carlson, B E; Liang, C; Bitzer, P; Christian, H

    2015-06-16

    Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations.

  12. Experimental breakdown of selected anodized aluminum samples in dilute plasmas

    Science.gov (United States)

    Grier, Norman T.; Domitz, Stanley

    1992-01-01

    Anodized aluminum samples representative of Space Station Freedom structural material were tested for electrical breakdown under space plasma conditions. In space, this potential arises across the insulating anodized coating when the spacecraft structure is driven to a negative bias relative to the external plasma potential due to plasma-surface interaction phenomena. For anodized materials used in the tests, it was found that breakdown voltage varied from 100 to 2000 volts depending on the sample. The current in the arcs depended on the sample, the capacitor, and the voltage. The level of the arc currents varied from 60 to 1000 amperes. The plasma number density varied from 3 x 10 exp 6 to 10 exp 3 ions per cc. The time between arcs increased as the number density was lowered. Corona testing of anodized samples revealed that samples with higher corona inception voltage had higher arcing inception voltages. From this it is concluded that corona testing may provide a method of screening the samples.

  13. Control of leading edge vortex breakdown by blowing

    Science.gov (United States)

    Visser, K. D.; Iwanski, K. P.; Nelson, R. C.; Ng, T. T.

    1988-01-01

    An investigation into the effects of using a jet of air to control the vortex breakdown position on a 70 degree delta wing is presented. The specific objectives focused on optimizing the blowing positions in terms of maximum lift increments obtained for minimum blowing rates. The tests were conducted at chord Reynolds numbers of 150,000, 200,000, and 250,000 at angles of incidence of 30 and 35 degrees. Visualization and force data is presented to show the effect of the jet on the wing aerodynamic characteristics. The results indicate a jet position located at and aligned parallel to the leading edge to be the optimum. Nearness to the apex and tangency to the upper surface were also crucial factors. The influence of the jet on the leading edge vortex structure was examined using laser Doppler anemometry. Velocity surveys through the vortex showed that at high blowing rates the parallel velocity in the outer swirling region of the vortex increased and the normal velocity decreased. This resulted in a decrease in the swirling angle in the outer region. The peak core velocity was reduced and the vortex breakdown was delayed.

  14. Preliminary Breakdown: Physical Mechanisms and Potential for Energetic Emissions

    Science.gov (United States)

    Petersen, D.; Beasley, W. H.

    2014-12-01

    Observations and analysis of the preliminary breakdown phase of virgin negative cloud-to-ground (-CG) lightning strokes will be presented. Of primary interest are the physical processes responsible for the fast electric field "characteristic" pulses that are often observed during this phase. The pulse widths of characteristic pulses are shown to occur as a superposed bimodal distribution, with the short and long modes having characteristic timescales on the order of 1 microsecond and 10 microseconds, respectively. Analysis of these pulses is based on comparison with laboratory observations of long spark discharge processes and with recently acquired high-speed video observations of a single -CG event. It will be argued that the fast electric field bimodal distribution is the result of conventional discharge processes operating in an extensive strong ambient electric field environment. An important related topic will also be discussed, where it will be argued that preliminary breakdown discharges are capable of generating energetic electrons and may therefore seed relativistic electron avalanches that go on to produce pulsed energetic photon emissions.

  15. Materials and Breakdown Phenomena: Heterogeneous Molybdenum Metallic Films

    Directory of Open Access Journals (Sweden)

    Augusto Marcelli

    2017-05-01

    Full Text Available Technological activities to design, manufacture, and test new accelerating devices using different materials and methods is under way all over the world. The main goal of these studies is to increase the accelerating gradients and reduce the probability of radio-frequency (RF breakdown. Indeed, it is still not clear why, by increasing the intensity of the applied field, intense surface damage is observed in copper structures, limiting the lifetime and, therefore, the practical applications. A possible solution is represented by a coating of a relatively thick layer of molybdenum in order to improve the breakdown rate. molybdenum can be reliably grown on different substrates with a negligible strain and, for thicknesses up to 600 nm, with a resistivity < 100–150·μΩ cm. Moreover, Mo coatings with controlled composition, internal stress, and roughness may allow improving thermo-mechanical properties reaching values not attainable by uncoated copper. Although the Mo conductivity remains lower compared to Cu, a Mo coating represents a very interesting option for high gradient accelerator components manufactured in copper.

  16. Mechanical breakdown in the nuclear multifragmentation phenomena. Thermodynamic analysis

    International Nuclear Information System (INIS)

    Bulavin, L.A.; Cherevko, K.V.; Sysoev, V.M.

    2012-01-01

    Based on a similarity of the Van der Waals and nucleon-nucleon interaction the known thermodynamic relations for ordinary liquids are used to analyze the possible decay channels in the proton induced nuclear multifragmentation phenomena. The main features of the different phase trajectories in the P-V plane are compared with the experimental data on multifragmentation. It allowed choosing the phase trajectories with the correct qualitative picture of the phenomena. Based on the thermodynamic analysis of the proton-induced multifragmentation phenomena the most appropriate decay channel corresponding to the realistic phase trajectory is chosen. Macroscopic analysis of the suggested decay channel is done in order to check the possibility of the mechanical breakdown of the heated system. Based on a simple thermodynamic model preliminary quantitative calculations of corresponding macroscopic parameters (energy, pressure) are done and therefore the model verification on macroscopic level is held. It is shown that on macroscopic level the chosen decay channel through the mechanical breakdown meets the necessary conditions for describing the proton-induced multifragmentation phenomena

  17. Breakdown of the few-level approximation in collective systems

    International Nuclear Information System (INIS)

    Kiffner, M.; Evers, J.; Keitel, C. H.

    2007-01-01

    The validity of the few-level approximation in dipole-dipole interacting collective systems is discussed. As an example system, we study the archetype case of two dipole-dipole interacting atoms, each modeled by two complete sets of angular momentum multiplets. We establish the breakdown of the few-level approximation by first proving the intuitive result that the dipole-dipole induced energy shifts between collective two-atom states depend on the length of the vector connecting the atoms, but not on its orientation, if complete and degenerate multiplets are considered. A careful analysis of our findings reveals that the simplification of the atomic level scheme by artificially omitting Zeeman sublevels in a few-level approximation generally leads to incorrect predictions. We find that this breakdown can be traced back to the dipole-dipole coupling of transitions with orthogonal dipole moments. Our interpretation enables us to identify special geometries in which partial few-level approximations to two- or three-level systems are valid

  18. Breakdown of air pockets in downwardly inclined sewerage pressure mains.

    Science.gov (United States)

    Lubbers, C L; Clemens, F H L R

    2006-01-01

    In the Netherlands, wastewater is collected in municipal areas and transported to centralised WWTPs by an extensive system of pressure mains. Over the last decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. One of the many causes that account for the reduction of the flow capacity is the occurrence of free gas in the pipeline. During dry weather periods with low flow velocities, gas may accumulate at high points in the system. Once the velocity increases during storm weather flow, the air pockets may be broken down and transported to the end of the system. A research study is started focussing on the description of the gas-water phenomena in wastewater pressure mains with respect to transportation of gas. An experimental facility is constructed for the study of multi-phase flow. This paper describes the preliminary results of experiments on breakdown rates of gas pockets as a function of inclination angle and water flow rate. The results show an increasing breakdown rate with increasing inclination angle.

  19. Magnetoresistance and magnetic breakdown phenomenon in amorphous magnetic alloys

    International Nuclear Information System (INIS)

    Chen Hui-yu; Gong Xiao-yu

    1988-01-01

    Transverse magnetoresistance in amorphous magnetic alloys (Fe/sub 1-//sub x/CO/sub x/) 82 Cu/sub 0.4/Si/sub 4.4/B/sub 13.2/ were measured at room temperature and in the magnetic field range 0--15 kOe. For large magnetic field, three different functional dependences of magnetoresistance on magnetic field strength have been found as follows: (1) Δrho/rho approaches saturation. (2) Δrho/rho increases proportionally to H 2 . (3) For x = 0.15, a sharp Δrho/rho peak appears at a certain magnetic field strength in spatial angular orientation of both magnetic field and electric currents. Case (3) is a magnetic breakdown phenomenon. Magnetic breakdown occurs at the gap between the spin-up and spin-down sheets of the Fermi surface. This gap is the spin-orbit gap and its magnitude is a sensitive function of magnetization. Hence the magnitude and width of the magnetoresistance peak and the magnetic field strength at the peak point are functions of angular orientation of both magnetic field and electric current

  20. Rf breakdown studies in room temperature electron linac structures

    International Nuclear Information System (INIS)

    Loew, G.A.; Wang, J.W.

    1988-05-01

    This paper is an overall review of studies carried out by the authors and some of their colleagues on RF breakdown, Field Emission and RF processing in room temperature electron linac structure. The motivation behind this work is twofold: in a fundamental way, to contribute to the understanding of the RF breakdown phenomenon, and as an application, to determine the maximum electric field gradient that can be obtained and used safely in future e/sup +-/ linear colliders. Indeed, the next generation of these machines will have to reach into the TeV (10 12 eV) energy range, and the accelerating gradient will be to be of the crucial parameters affecting their design, construction and cost. For a specified total energy, the gradient sets the accelerator length, and once the RF structure, frequency and pulse repetition rate are selected, it also determines the peak and average power consumption. These three quantities are at the heart of the ultimate realizability and cost of these accelerators. 24 refs., 19 figs., 4 tabs