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Sample records for decreases predicted material

  1. Induced optimism as mental rehearsal to decrease depressive predictive certainty.

    Science.gov (United States)

    Miranda, Regina; Weierich, Mariann; Khait, Valerie; Jurska, Justyna; Andersen, Susan M

    2017-03-01

    The present study examined whether practice in making optimistic future-event predictions would result in change in the hopelessness-related cognitions that characterize depression. Individuals (N = 170) with low, mild, and moderate-to-severe depressive symptoms were randomly assigned to a condition in which they practiced making optimistic future-event predictions or to a control condition in which they viewed the same stimuli but practiced determining whether a given phrase contained an adjective. Overall, individuals in the induced optimism condition showed increases in optimistic predictions, relative to the control condition, as a result of practice, but only individuals with moderate-to-severe symptoms of depression who practiced making optimistic future-event predictions showed decreases in depressive predictive certainty, relative to the control condition. In addition, they showed gains in efficiency in making optimistic predictions over the practice blocks, as assessed by response time. There was no difference in depressed mood by practice condition. Mental rehearsal might be one way of changing the hopelessness-related cognitions that characterize depression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    stresses in castings are also gaining increasing attention. State-of-the-art tools allow the prediction of residual stresses and iron casting distortion quantitatively. Cracks in castings can be assessed, as well as the reduction of casting stresses during heat treatment. As the property requirements for cast iron as a material in design strongly increase, new alloys and materials such as ADI might become more attractive, where latest software developments allow the modeling of the required heat treatment. Phases can be predicted and parametric studies can be performed to optimize the alloy dependent heat treatment conditions during austenitization, quenching and ausferritization. All this quantitative information about the material's performance is most valuable if it can be used during casting design. The transfer of local properties into the designer抯 world, to predict fatigue and durability as a function of the entire manufacturing route, will increase the trust in this old but highly innovative material and will open new opportunities for cast iron in the future. The paper will give an overview on current capabilities to quantitatively predict cast iron specific defects and casting performance and will highlight latest developments in modeling the manufacture of cast iron and ADI as well as the prediction of iron casting stresses.

  3. Decreased dopamine activity predicts relapse in methamphetamine abusers

    Energy Technology Data Exchange (ETDEWEB)

    Wang G. J.; Wang, G.-J.; Smith, L.; Volkow, N.D.; Telang, F.; Logan, J.; Tomasi, D.; Wong, C.T.; Hoffman, W.; Jayne, M.; Alia-Klein, N.; Thanos, P.; Fowler, J.S.

    2011-01-20

    Studies in methamphetamine (METH) abusers showed that the decreases in brain dopamine (DA) function might recover with protracted detoxification. However, the extent to which striatal DA function in METH predicts recovery has not been evaluated. Here we assessed whether striatal DA activity in METH abusers is associated with clinical outcomes. Brain DA D2 receptor (D2R) availability was measured with positron emission tomography and [{sup 11}C]raclopride in 16 METH abusers, both after placebo and after challenge with 60 mg oral methylphenidate (MPH) (to measure DA release) to assess whether it predicted clinical outcomes. For this purpose, METH abusers were tested within 6 months of last METH use and then followed up for 9 months of abstinence. In parallel, 15 healthy controls were tested. METH abusers had lower D2R availability in caudate than in controls. Both METH abusers and controls showed decreased striatal D2R availability after MPH and these decreases were smaller in METH than in controls in left putamen. The six METH abusers who relapsed during the follow-up period had lower D2R availability in dorsal striatum than in controls, and had no D2R changes after MPH challenge. The 10 METH abusers who completed detoxification did not differ from controls neither in striatal D2R availability nor in MPH-induced striatal DA changes. These results provide preliminary evidence that low striatal DA function in METH abusers is associated with a greater likelihood of relapse during treatment. Detection of the extent of DA dysfunction may be helpful in predicting therapeutic outcomes.

  4. Decreased dopamine activity predicts relapse in methamphetamine abusers

    International Nuclear Information System (INIS)

    Wang, G.J.; Smith, L.; Volkow, N.D.; Telang, F.; Logan, J.; Tomasi, D.; Wong, C.T.; Hoffman, W.; Jayne, M.; Alia-Klein, N.; Thanos, P.; Fowler, J.S.

    2011-01-01

    Studies in methamphetamine (METH) abusers showed that the decreases in brain dopamine (DA) function might recover with protracted detoxification. However, the extent to which striatal DA function in METH predicts recovery has not been evaluated. Here we assessed whether striatal DA activity in METH abusers is associated with clinical outcomes. Brain DA D2 receptor (D2R) availability was measured with positron emission tomography and ( 11 C)raclopride in 16 METH abusers, both after placebo and after challenge with 60 mg oral methylphenidate (MPH) (to measure DA release) to assess whether it predicted clinical outcomes. For this purpose, METH abusers were tested within 6 months of last METH use and then followed up for 9 months of abstinence. In parallel, 15 healthy controls were tested. METH abusers had lower D2R availability in caudate than in controls. Both METH abusers and controls showed decreased striatal D2R availability after MPH and these decreases were smaller in METH than in controls in left putamen. The six METH abusers who relapsed during the follow-up period had lower D2R availability in dorsal striatum than in controls, and had no D2R changes after MPH challenge. The 10 METH abusers who completed detoxification did not differ from controls neither in striatal D2R availability nor in MPH-induced striatal DA changes. These results provide preliminary evidence that low striatal DA function in METH abusers is associated with a greater likelihood of relapse during treatment. Detection of the extent of DA dysfunction may be helpful in predicting therapeutic outcomes.

  5. Why Education Predicts Decreased Belief in Conspiracy Theories

    NARCIS (Netherlands)

    van Prooijen, Jan Willem

    2017-01-01

    People with high education are less likely than people with low education to believe in conspiracy theories. It is yet unclear why these effects occur, however, as education predicts a range of cognitive, emotional, and social outcomes. The present research sought to identify mediators of the

  6. Decrease of Pseudomonas aeruginosa biofilm formation by food waste materials

    Czech Academy of Sciences Publication Activity Database

    Maděrová, Z.; Horská, K.; Kim, S.-R.; Lee, Ch.-H.; Pospíšková, K.; Šafaříková, Miroslava; Šafařík, Ivo

    2016-01-01

    Roč. 73, č. 9 (2016), s. 2143-2149 ISSN 0273-1223 Institutional support: RVO:60077344 Keywords : biofilm * food waste materials * magnetic spent grain * Pseudomonas aeruginosa Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.197, year: 2016

  7. Plant corrosion: prediction of materials performance

    International Nuclear Information System (INIS)

    Strutt, J.E.; Nicholls, J.R.

    1987-01-01

    Seventeen papers have been compiled forming a book on computer-based approaches to corrosion prediction in a wide range of industrial sectors, including the chemical, petrochemical and power generation industries. Two papers have been selected and indexed separately. The first describes a system operating within BNFL's Reprocessing Division to predict materials performance in corrosive conditions to aid future plant design. The second describes the truncation of the distribution function of pit depths during high temperature oxidation of a 20Cr austenitic steel in the fuel cladding in AGR systems. (U.K.)

  8. Materials mobilised by the French economy: a decrease stabilised since the crisis of 2008

    International Nuclear Information System (INIS)

    Calatayud, Philippe

    2016-05-01

    This publication proposes data illustrating the evolution of the use of natural resources, and more particularly materials mobilised by the French economy and population since 1990. The evolution of domestic material consumption is described through that of domestic extraction, and of imports and exports, through the apparent and global material consumption in 2013, and the evolution of apparent domestic material consumption, and of the quantity of materials extracted from the French territory, imported or exported. Tables indicate these evolutions since 1990 for the different materials (biomass, wood, metallic ores, minerals used in construction or industry, coal, oil, natural gas, products based on fossil fuels). The rate between hidden flows and apparent flows is shown to be steady. It is also outlined that the recession has intensified material productivity but decreased material consumption per inhabitant. This material consumption per inhabitant is compared with that of European and non-European countries

  9. Decreasing redox voltage of terephthalate-based electrode material for Li-ion battery using substituent effect

    Science.gov (United States)

    Lakraychi, A. E.; Dolhem, F.; Djedaïni-Pilard, F.; Thiam, A.; Frayret, C.; Becuwe, M.

    2017-08-01

    The preparation and assessment versus lithium of a functionalized terephthalate-based as a potential new negative electrode material for Li-ion battery is presented. Inspired from molecular modelling, a decrease in redox potential is achieved through the symmetrical adjunction of electron-donating fragments (-CH3) on the aromatic ring. While the electrochemical activity of this organic material was maximized when used as nanocomposite and without any binder, the potential is furthermore lowered by 110 mV upon functionalization, consistently with predicted value gained from DFT calculations.

  10. Test accuracy of metabolic indicators in predicting decreased fertility in dairy cows

    DEFF Research Database (Denmark)

    Lomander, H; Gustafsson, H; Svensson, C

    2012-01-01

    Negative energy balance is a known risk factor for decreased fertility in dairy cows. This study evaluated the accuracy of plasma concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and insulin-like growth factor 1 (IGF-1)—factors related to negative energy balance...... was low when metabolic indicators measured as single values in early lactation were used to predict fertility in dairy cows, but accuracy was influenced by cow-level factors such as parity. The prevalence of the target condition (in this case, decreased fertility) also influences test usefulness......—in predicting decreased fertility. One plasma sample per cow was collected from 480 cows in 12 herds during the period from d 4 to 21 in milk and analyzed for NEFA, BHBA, and IGF-1. For each cow, data on breed, parity, calving date, gynecological examinations, and insemination dates were obtained. Milk samples...

  11. Application of the backstepping method to the prediction of increase or decrease of infected population.

    Science.gov (United States)

    Kuniya, Toshikazu; Sano, Hideki

    2016-05-10

    In mathematical epidemiology, age-structured epidemic models have usually been formulated as the boundary-value problems of the partial differential equations. On the other hand, in engineering, the backstepping method has recently been developed and widely studied by many authors. Using the backstepping method, we obtained a boundary feedback control which plays the role of the threshold criteria for the prediction of increase or decrease of newly infected population. Under an assumption that the period of infectiousness is same for all infected individuals (that is, the recovery rate is given by the Dirac delta function multiplied by a sufficiently large positive constant), the prediction method is simplified to the comparison of the numbers of reported cases at the current and previous time steps. Our prediction method was applied to the reported cases per sentinel of influenza in Japan from 2006 to 2015 and its accuracy was 0.81 (404 correct predictions to the total 500 predictions). It was higher than that of the ARIMA models with different orders of the autoregressive part, differencing and moving-average process. In addition, a proposed method for the estimation of the number of reported cases, which is consistent with our prediction method, was better than that of the best-fitted ARIMA model ARIMA(1,1,0) in the sense of mean square error. Our prediction method based on the backstepping method can be simplified to the comparison of the numbers of reported cases of the current and previous time steps. In spite of its simplicity, it can provide a good prediction for the spread of influenza in Japan.

  12. Cost-benefit analysis of decreased ventilation rates and radon exhalation from building materials

    International Nuclear Information System (INIS)

    Ericson, S.O.

    1984-01-01

    Decreased ventilation, achieved by weather stripping and other tightening measures, is the most cost effective way to energy conservation. A very low investment can result in a considerable decrease in ventilation rate. For a typical detached house in Sweden this can be equivalent to a decrease in oil consumption of 0.5 m 3 . At present price this corresponds to a saving of SEK 1200, 150 US dollars per annum. The contribution of the building materials to the concentration of radon in indoor air is approximately the inverse to air exchange rate. For a small change in ventilation rate and cost, in SEK/man Sv or US dollar/man Sv, is a function of ventilation rate, exhalation from building materials, the ratio between surface of walls, floor and ceiling to the volume of air. Thus, it is possible to find the specific ventilation rate where the marginal cost for a small increase in ventilation rate and the marginal reduction in radon concentration will give a specific amount of money for each man Sv. Examples are given. Conclusions are that for most building materials in a climate like the Swedish, there are other factors than exhalation of radon from building materials that sets the lower limit of recommendable ventilation rate. (Author)

  13. Service life prediction for refractory materials

    Czech Academy of Sciences Publication Activity Database

    Boccaccini, D. N.; Cannio, M.; Volkov-Husović, T. D.; Kamseu, E.; Romagnoli, M.; Veronesi, P.; Leonelli, C.; Dlouhý, Ivo; Boccaccini, A. R.

    2008-01-01

    Roč. 43, č. 12 (2008), s. 4079-4090 ISSN 0022-2461 R&D Projects: GA ČR(CZ) GA106/05/0495 Institutional research plan: CEZ:AV0Z20410507 Keywords : refractory materials * ultrasonic velocity * fracture toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.181, year: 2008

  14. Life Prediction Methodologies for Aerospace Materials

    National Research Council Canada - National Science Library

    Ashbaugh, N

    2000-01-01

    .... For a gamma titanium aluminide alloy, the coarse and refined lamellar materials with colony sizes equal to 700 and 280 m, respectively, have substantially greater crack growth resistance than does...

  15. Life Prediction Methodologies for Aerospace Materials

    National Research Council Canada - National Science Library

    Ashbaugh, N

    2001-01-01

    The understanding of the effect of material defects, i.e., inclusions and grain size variances, on tensile and fatigue behavior, specifically initiation, in wrought gamma titanium aluminides was improved...

  16. Life prediction technology of structural materials

    International Nuclear Information System (INIS)

    Nagata, Norio

    1992-01-01

    There is empirically the time limit of use in all industrial plants and components. By defining the loss of functions as the expiration of life, if the forecast of life time or residual life of plants and components can be done, a very useful means becomes available for safety and economical efficiency. The life of plants is controlled by the occurrence and extension of defects in materials, and by the life of the material which is placed under most severe condition. Such severe condition is the environment of use itself with high temperature, corrosive environment, load, vibration and so on. The forecast of material life is to quantitatively grasp the damage behavior of materials under such condition, and to carry out the time control of the functions of plants by defect control. The time dependence of material damage such as fatigue damage, creep damage and corrosion damage is discussed. The forecast of material life by empirical knowledge and theoretical inference and the forecast of residual life are explained. Finally, the forecast of the life time of light water reactors is described as those constructed in initial period approach their design life. (K.I.)

  17. EXPERIMENTAL PREDICTION AND OPTIMIZATION OF MATERIAL ...

    African Journals Online (AJOL)

    It investigates the influence of machining process parameters such as cutting speed, feed rate and depth of cut on the material removal rate (output parameter) during hard turning of AISI 304L austenitic stainless steel (0.03 wt. % C (max)). A total of 27 experiments were conducted using a MORISEIKI SL-253B CNC machine ...

  18. Predicting Weight Change in Gari in Two Packaging Materials ...

    African Journals Online (AJOL)

    An equation for predicting moisture loss or gain by gari grain packed in two types of materials was developed. From this, it may be possible to establish the storability of gari in these two packaging material. The equation took into account the permeabilities of the materials, which were determined experimentally. The validity ...

  19. Episodic Memory Encoding Interferes with Reward Learning and Decreases Striatal Prediction Errors

    Science.gov (United States)

    Braun, Erin Kendall; Daw, Nathaniel D.

    2014-01-01

    Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. PMID:25378157

  20. Episodic memory encoding interferes with reward learning and decreases striatal prediction errors.

    Science.gov (United States)

    Wimmer, G Elliott; Braun, Erin Kendall; Daw, Nathaniel D; Shohamy, Daphna

    2014-11-05

    Learning is essential for adaptive decision making. The striatum and its dopaminergic inputs are known to support incremental reward-based learning, while the hippocampus is known to support encoding of single events (episodic memory). Although traditionally studied separately, in even simple experiences, these two types of learning are likely to co-occur and may interact. Here we sought to understand the nature of this interaction by examining how incremental reward learning is related to concurrent episodic memory encoding. During the experiment, human participants made choices between two options (colored squares), each associated with a drifting probability of reward, with the goal of earning as much money as possible. Incidental, trial-unique object pictures, unrelated to the choice, were overlaid on each option. The next day, participants were given a surprise memory test for these pictures. We found that better episodic memory was related to a decreased influence of recent reward experience on choice, both within and across participants. fMRI analyses further revealed that during learning the canonical striatal reward prediction error signal was significantly weaker when episodic memory was stronger. This decrease in reward prediction error signals in the striatum was associated with enhanced functional connectivity between the hippocampus and striatum at the time of choice. Our results suggest a mechanism by which memory encoding may compete for striatal processing and provide insight into how interactions between different forms of learning guide reward-based decision making. Copyright © 2014 the authors 0270-6474/14/3414901-12$15.00/0.

  1. Narrative Changes Predict a Decrease in Symptoms in CBT for Depression: An Exploratory Study.

    Science.gov (United States)

    Gonçalves, Miguel M; Silva, Joana Ribeiro; Mendes, Inês; Rosa, Catarina; Ribeiro, António P; Batista, João; Sousa, Inês; Fernandes, Carlos F

    2017-07-01

    Innovative moments (IMs) are new and more adjusted ways of thinking, acting, feeling and relating that emerge during psychotherapy. Previous research on IMs has provided sustainable evidence that IMs differentiate recovered from unchanged psychotherapy cases. However, studies with cognitive behavioural therapy (CBT) are so far absent. The present study tests whether IMs can be reliably identified in CBT and examines if IMs and symptoms' improvement are associated. The following variables were assessed in each session from a sample of six cases of CBT for depression (a total of 111 sessions): (a) symptomatology outcomes (Outcome Questionnaire-OQ-10) and (b) IMs. Two hierarchical linear models were used: one to test whether IMs predicted a symptom decrease in the next session and a second one to test whether symptoms in one session predicted the emergence of IMs in the next session. Innovative moments were better predictors of symptom decrease than the reverse. A higher proportion of a specific type of IMs-reflection 2-in one session predicted a decrease in symptoms in the next session. Thus, when clients further elaborated this type of IM (in which clients describe positive contrasts or elaborate on changes processes), a reduction in symptoms was observed in the next session. A higher expression and elaboration of reflection 2 IMs appear to have a facilitative function in the reduction of depressive symptoms in this sample of CBT. Copyright © 2016 John Wiley & Sons, Ltd. Elaborating innovative moments (IMs) that are new ways of thinking, feeling, behaving and relating, in the therapeutic dialogue, may facilitate change. IMs that are more predictive of amelioration of symptoms in CBT are the ones focused on contrasts between former problematic patterns and new adjusted ones; and the ones in which the clients elaborate on processes of change. Therapists may integrate these kinds of questions (centred on contrasts and centred on what allowed change from the client

  2. Helping Others Regulate Emotion Predicts Increased Regulation of One's Own Emotions and Decreased Symptoms of Depression.

    Science.gov (United States)

    Doré, Bruce P; Morris, Robert R; Burr, Daisy A; Picard, Rosalind W; Ochsner, Kevin N

    2017-05-01

    Although much research considers how individuals manage their own emotions, less is known about the emotional benefits of regulating the emotions of others. We examined this topic in a 3-week study of an online platform providing training and practice in the social regulation of emotion. We found that participants who engaged more by helping others (vs. sharing and receiving support for their own problems) showed greater decreases in depression, mediated by increased use of reappraisal in daily life. Moreover, social regulation messages with more other-focused language (i.e., second-person pronouns) were (a) more likely to elicit expressions of gratitude from recipients and (b) predictive of increased use of reappraisal over time for message composers, suggesting perspective-taking enhances the benefits of practicing social regulation. These findings unpack potential mechanisms of socially oriented training in emotion regulation and suggest that by helping others regulate, we may enhance our own regulatory skills and emotional well-being.

  3. Decreased activation and subsyndromal manic symptoms predict lower remission rates in bipolar depression.

    Science.gov (United States)

    Caldieraro, Marco Antonio; Walsh, Samantha; Deckersbach, Thilo; Bobo, William V; Gao, Keming; Ketter, Terence A; Shelton, Richard C; Reilly-Harrington, Noreen A; Tohen, Mauricio; Calabrese, Joseph R; Thase, Michael E; Kocsis, James H; Sylvia, Louisa G; Nierenberg, Andrew A

    2017-11-01

    Activation encompasses energy and activity and is a central feature of bipolar disorder. However, the impact of activation on treatment response of bipolar depression requires further exploration. The aims of this study were to assess the association of decreased activation and sustained remission in bipolar depression and test for factors that could affect this association. We assessed participants with Diagnostic and Statistical Manual of Mental Disorders (4th ed) bipolar depression ( n = 303) included in a comparative effectiveness study of lithium- and quetiapine-based treatments (the Bipolar CHOICE study). Activation was evaluated using items from the Bipolar Inventory of Symptoms Scale. The selection of these items was based on a dimension of energy and interest symptoms associated with poorer treatment response in major depression. Decreased activation was associated with lower remission rates in the raw analyses and in a logistic regression model adjusted for baseline severity and subsyndromal manic symptoms (odds ratio = 0.899; p = 0.015). The manic features also predicted lower remission (odds ratio = 0.934; p bipolar depression. Patients with these features may require specific treatment approaches, but new studies are necessary to identify treatments that could improve outcomes in this population.

  4. Evaluation of whole genome amplified DNA to decrease material expenditure and increase quality

    Directory of Open Access Journals (Sweden)

    Marie Bækvad-Hansen

    2017-06-01

    Discussion: Whole genome amplified DNA samples from dried blood spots is well suited for array genotyping and produces robust and reliable genotype data. However, the amplification process introduces additional noise to the data, making detection of structural variants such as copy number variants difficult. With this study, we explore ways of optimizing the amplification protocol in order to reduce noise and increase data quality. We found, that the amplification process was very robust, and that changes in amplification time or temperature did not alter the genotyping calls or quality of the array data. Adding additional replicates of each sample also lead to insignificant changes in the array data. Thus, the amount of noise introduced by the amplification process was consistent regardless of changes made to the amplification protocol. We also explored ways of decreasing material expenditure by reducing the spot size or the amplification reaction volume. The reduction did not affect the quality of the genotyping data.

  5. Prediction of degradation and fracture of structural materials

    International Nuclear Information System (INIS)

    Tomkins, B.

    1992-01-01

    Prediction of materials performance in an engineering integrity context requires the underpinning of predictive modelling tuned by inputs from design, fabrication, operating experience, and laboratory testing. In this regard, in addition to fracture resistance four important areas of time dependent degradation are considered - mechanical, environmental, irradiation and thermal. The status of prediction of materials performance is discussed in relation to a number of important components such as LWR reactor pressure vessels and steam generators, and Fast Reactor high temperature structures. In each case the role of materials modelling is examined and the balance of factors which contribute to the overall prediction of component integrity/reliability noted. Structural integrity arguments must follow a clear strategy if the required level of confidence is to be established. Various strategies and their evolution are discussed. (author)

  6. How to decrease the hydrophilicity of wood flour to process efficient composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Pouzet, M.; Gautier, D.; Charlet, K. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Dubois, M., E-mail: Marc.DUBOIS@univ-bpclermont.fr [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Béakou, A. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France)

    2015-10-30

    Graphical abstract: Evolution of the contact angle of a water drop on sample (θ{sub c}) according to the fluorinated material. - Highlights: • Fluorination was applied to wood flour. • Covalent attachment of fluorine atoms onto wood surface decreases its hydrophilicity. • Fluorinated wood flour was added into composites with polyester. • Fluorination enhances the interface between wood flour and polymer matrix. - Abstract: Dynamic fluorination and static fluorination were applied to wood flour to decrease its hydrophilic character, aiming at processing wood-polymer composites with good properties. Fourier-Transform infrared spectra and {sup 19}F solid state NMR (Nuclear Magnetic Resonance) results proved the successful covalent bonding of fluorine atoms onto the wood's chemical structure. It revealed that static fluorination brings about a less damaged and less hydrophilic fluorinated wood than with dynamic fluorination. Composites manufactured from this fluorinated wood presented a hydrophobic character directly related to the hydrophicity of these wood reinforcements. A composite made with fluorinated wood and polyester exhibited a higher hydrophobicity than the neat polyester and than the composite made with non-treated wood. Moreover, the further fluorination of a composite made of fluorinated wood led to a contact angle comparable to that of some metals (steel, gold) due to the etching of the composite surface during fluorination.

  7. Tumor Necrosis Factor Inhibitor Primary Failure Predicts Decreased Ustekinumab Efficacy in Psoriasis Patients.

    Science.gov (United States)

    Sorensen, Eric P; Fanucci, Kristina A; Saraiya, Ami; Volf, Eva; Au, Shiu-chung; Argobi, Yahya; Mansfield, Ryan; Gottlieb, Alice B

    2015-08-01

    Additional studies are needed to examine the efficacy of ustekinumab in psoriasis patients who have previously been exposed to tumor necrosis factor inhibitors (TNFi). To examine the predictive effect of TNFi primary failure and the number of TNFi exposures on the efficacy of ustekinumab in psoriasis treatment. This retrospective study examined 44 psoriasis patients treated at the Tufts Medical Center Department of Dermatology between January 2008 and July 2014. Patients were selected if they were treated with ustekinumab and had ≥ 1 previous TNFi exposure. The following subgroups were compared: patients with vs without a previous TNFi primary failure, and patients with one vs multiple previous TNFi exposures. The efficacy measure used was the previously validated Simple Measure for Assessing Psoriasis Activity (S-MAPA), which is calculated by the product of the body surface area and physician global assessment. The primary outcome was the percentage improvement S-MAPA from course baseline at week 12 of ustekinumab treatment. Secondary outcomes were the psoriasis clearance, primary failure, and secondary failure rates with ustekinumab treatment. Patients with a previous TNFi primary failure had a significantly lower percentage improvement in S-MAPA score at week 12 of ustekinumab treatment compared with patients without TNFi primary failure (36.2% vs 61.1%, P=.027). Multivariate analysis demonstrated that this relationship was independent of patient demographics and medical comorbidities. Patients with multiple TNFi exposures had a non-statistically significant lower percentage S-MAPA improvement at week 12 (40.5% vs 52.9%, P=.294) of ustekinumab treatment compared with patients with a single TNFi exposure. Among psoriasis patients previously exposed to TNFi, a history of a previous TNFi primary failure predicts a decreased response to ustekinumab independent of patient demographics and medical comorbidities.

  8. Decreases in daily physical activity predict acute decline in attention and executive function in heart failure.

    Science.gov (United States)

    Alosco, Michael L; Spitznagel, Mary Beth; Cohen, Ronald; Sweet, Lawrence H; Hayes, Scott M; Josephson, Richard; Hughes, Joel; Gunstad, John

    2015-04-01

    Reduced physical activity (PA) may be one factor that contributes to cognitive decline and dementia in heart failure (HF). Yet, the longitudinal relationship between PA and cognition in HF is poorly understood owing to limitations of past work, including single-time assessments of PA. This is the first study to examine changes in objectively measured PA and cognition over time in HF. At baseline and 12 weeks, 57 HF patients completed psychosocial self-report measures and a neuropsychological battery and wore an accelerometer for 7 days. At baseline, HF patients spent an average of 597.83 (SD 75.91) minutes per day sedentary. Steps per day declined from baseline to the 12-week follow-up; there was also a trend for declines in moderate-vigorous PA. Regression analyses controlling for sex, HF severity, and depressive symptoms showed that decreases in light (P = .08) and moderate-vigorous (P = .04) daily PA emerged as strong predictors of declines in attention/executive function over the 12-week period, but not of memory or language. Reductions in daily PA predicted acute decline in attention/executive function in HF, but not of memory or language. Modifications to daily PA may attenuate cognitive decline, and prospective studies are needed to test this possibility. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

    International Nuclear Information System (INIS)

    Gillen, K.T.; Clough, R.L.

    1991-06-01

    In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs

  10. Predicting sample lifetimes in creep fracture of heterogeneous materials

    Science.gov (United States)

    Koivisto, Juha; Ovaska, Markus; Miksic, Amandine; Laurson, Lasse; Alava, Mikko J.

    2016-08-01

    Materials flow—under creep or constant loads—and, finally, fail. The prediction of sample lifetimes is an important and highly challenging problem because of the inherently heterogeneous nature of most materials that results in large sample-to-sample lifetime fluctuations, even under the same conditions. We study creep deformation of paper sheets as one heterogeneous material and thus show how to predict lifetimes of individual samples by exploiting the "universal" features in the sample-inherent creep curves, particularly the passage to an accelerating creep rate. Using simulations of a viscoelastic fiber bundle model, we illustrate how deformation localization controls the shape of the creep curve and thus the degree of lifetime predictability.

  11. A decrease in total bilirubin predicted hyper-LDL cholesterolemia in a health screening population.

    Science.gov (United States)

    Oda, Eiji

    2014-08-01

    To investigate cross-sectional and longitudinal associations between serum total bilirubin (TB) and LDL cholesterol. It is a retrospective observational study. Cross-sectional and longitudinal associations between TB and hyper-LDL cholesterolemia were investigated in a health screening population. Odds ratios (ORs) of coexisting hyper-LDL cholesterolemia for TB were calculated in 3,866 subjects, Spearman's correlation coefficients between baseline TB and LDL cholesterol at baseline and after 4 years were calculated in 1,735 subjects who did not use antihyperlipidemic drugs and hazard ratios (HRs) of incident hyper-LDL cholesterolemia for TB were calculated in 1,992 followed subjects. The ORs (p values) of coexisting hyper-LDL cholesterolemia for each 1 SD increase in TB was 1.04 (0.998) adjusted for sex, age, smoking, LDL cholesterol and other confounders. Spearman's correlation coefficients (p values) between baseline TB and LDL cholesterol at baseline and after 4 years and changes in LDL cholesterol were -0.026 (0.271), -0.078 (0.001) and -0.062 (0.010), respectively. Among 1,992 followed subjects, 481 developed hyper-LDL cholesterolemia during 4 years (60.4 per 1,000 person-years). The HRs (95% confidence intervals; p values) of incident hyper-LDL cholesterolemia for each 1 SD increase in TB was 0.86 (0.77-0.96; 0.006) adjusted for sex, age, smoking, LDL cholesterol, body mass index, triglycerides, HDL cholesterol, fasting glucose and other confounders. The quintiles of TB were significantly associated with the incident hyper-LDL cholesterolemia adjusted for the above covariates (p for trend = 0.008). A decrease in TB predicted incident hyper-LDL cholesterolemia in a health screening population. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Ab Initio Prediction of Piezoelectricity in Two-Dimensional Materials.

    Science.gov (United States)

    Blonsky, Michael N; Zhuang, Houlong L; Singh, Arunima K; Hennig, Richard G

    2015-10-27

    Two-dimensional (2D) materials present many unique materials concepts, including material properties that sometimes differ dramatically from those of their bulk counterparts. One of these properties, piezoelectricity, is important for micro- and nanoelectromechanical systems applications. Using symmetry analysis, we determine the independent piezoelectric coefficients for four groups of predicted and synthesized 2D materials. We calculate with density-functional perturbation theory the stiffness and piezoelectric tensors of these materials. We determine the in-plane piezoelectric coefficient d11 for 37 materials within the families of 2D metal dichalcogenides, metal oxides, and III-V semiconductor materials. A majority of the structures, including CrSe2, CrTe2, CaO, CdO, ZnO, and InN, have d11 coefficients greater than 5 pm/V, a typical value for bulk piezoelectric materials. Our symmetry analysis shows that buckled 2D materials exhibit an out-of-plane coefficient d31. We find that d31 for 8 III-V semiconductors ranges from 0.02 to 0.6 pm/V. From statistical analysis, we identify correlations between the piezoelectric coefficients and the electronic and structural properties of the 2D materials that elucidate the origin of the piezoelectricity. Among the 37 2D materials, CdO, ZnO, and CrTe2 stand out for their combination of large piezoelectric coefficient and low formation energy and are recommended for experimental exploration.

  13. Cellular and Porous Materials Thermal Properties Simulation and Prediction

    CERN Document Server

    Öchsner, Andreas; de Lemos, Marcelo J S

    2008-01-01

    Providing the reader with a solid understanding of the fundamentals as well as an awareness of recent advances in properties and applications of cellular and porous materials, this handbook and ready reference covers all important analytical and numerical methods for characterizing and predicting thermal properties. In so doing it directly addresses the special characteristics of foam-like and hole-riddled materials, combining theoretical and experimental aspects for characterization purposes.

  14. Decreased expression of pyruvate dehydrogenase A1 predicts an unfavorable prognosis in ovarian carcinoma.

    Science.gov (United States)

    Li, Yaqing; Huang, Ruixia; Li, Xiaoli; Li, Xiaoran; Yu, Dandan; Zhang, Mingzhi; Wen, Jianguo; Goscinski, Mariusz Adam; Trope, Claes G; Nesland, Jahn M; Suo, Zhenhe

    2016-01-01

    Pyruvate dehydrogenase A1 (PDHA1) serves as a gate-keeper enzyme link between glycolysis and the mitochondrial citric acid cycle. The inhibition of PDHA1 in cancer cells can result in an increased Warburg effect and a more aggressive phenotype in cancer cells. This study was conducted to investigate the expression of PDHA1 in ovarian cancer and the correlation between PDHA1 expression and the prognosis of patients. The PDHA1 protein expression in 3 ovarian cancer cell lines (OVCAR-3, SKOV-3 and ES-2) and 248 surgically removed ovarian carcinoma samples was immunocytochemically examined. Statistical analyses were performed to evaluate the correlations between PDHA1 expression and the clinicopathological characteristics of the patients as well as the predictive value of PDHA1. The results showed the presence of variable expression of PDHA1 in the three ovarian cancer cell lines. Of the 248 ovarian cancer tissue specimens, 45 cases (18.1%) were negative in tumor cells for PDHA1, 162 cases (65.3%) displayed a low expression level, and 41 cases (16.5%) had a relatively high PDHA1 staining. The expression of PDHA1 was associated with the histological subtype ( P =0.004) and FIGO stage ( P =0.002). The median OS time in the PDHA1 negative group, low expression group and high expression group were 0.939 years, 1.443 years and 9.900 years, respectively. The median PFS time in the above three groups were 0.287 years, 0.586 years and 9.900 years, respectively. Furthermore, the high expression of PDHA1 in ovarian carcinoma cells was significantly associated with better OS and PFS by statistical analyses. Multivariate analyses showed that PDHA1 expression was also an independent prognostic factor for higher OS in ovarian cancer patients (HR=0.705, 95% CI 0.541-0.918, P =0.01). Our study indicated that the decreased expression of PDHA1 might be an independent prognostic factor in unfavorable outcomes.

  15. predicting weight change in gari in two packaging materials

    African Journals Online (AJOL)

    MIS

    1983-09-01

    Sep 1, 1983 ... involved the microbial deterioration of gari stored in hessian and polythene bags, showed that the polythene bag gave a better result when gari was stored at moisture content of 11.2% wet basis. Mizrahi et al (1970) using dehydrated cabbage packed in two types of packaging materials predicted value.

  16. Predicting the Appearance of Materials Using Lorenz-Mie Theory

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Christensen, Niels Jørgen; Jensen, Henrik Wann

    2012-01-01

    Computer graphics systems today are able to produce highly realistic images. The realism has reached a level where an observer has difficulties telling whether an image is real or synthetic. The exception is when we try to compute a picture of a scene that really exists and compare the result...... in the scene have few geometrical details, a graphics system will still have a hard time predicting the result of taking a picture with a digital camera. The problem here is to model the optical properties of the materials correctly. In this chapter, we show how Lorenz–Mie theory enables us to compute...... the optical properties of turbid materials such that we can predict their appearance. To describe the entire process of predicting the appearance of amaterial, we include a description of the mathematical models used in realistic image synthesis....

  17. Decreased bio-inhibition of building materials due to transport of biocides

    NARCIS (Netherlands)

    Erich, S.J.F.; Mendoza, S.M.; Floor, W.; Hermanns, S.P.M.; Homan, W.J.; Adan, O.C.G.

    2011-01-01

    Bio-inhibition of buildings and structures is an important issue. In many cases building materials have biocides added to prevent growth of micro-organisms. Growth of microorganisms on building materials has several negative effects; (1) Aesthetic damage, e.g. fungi, algae grow on the material,

  18. Shelf life prediction of radiation sterilized polymeric materials

    International Nuclear Information System (INIS)

    Sandford, Craig; Woo, Lecon

    1988-01-01

    The functional properties of many polymers employed in medical disposables are unaffected by sterilizing doses of ionizing radiation. However, some materials (PVC, polypropylene, cellulosics, etc.) undergo undesirable changes which continue to occur for the shelf life of the product. In many cases, conventional accelerated aging techniques do not accurately predict the real time properties of the materials. As real time aging is not generally practical, it has become necessary to develop accelerated aging techniques which can predict the functional properties of a material for the shelf life of the product. This presentation will address issues involved in developing these tests. Real time physical property data is compared to data generated by various acceleration methods. (author)

  19. Looking Maori predicts decreased rates of home ownership : Institutional racism in housing based on perceived appearance

    NARCIS (Netherlands)

    Houkamau, C.A.; Sibley, C.G.

    2015-01-01

    This study examined differences in rates of home ownership among Māori (the indigenous peoples of New Zealand). We identified systematic factors that predicted why some Māori were more likely to own their own home (partially or fully) relative to other Māori. Data were drawn from a large national

  20. Transportation of hazardous materials in Iran: A strategic approach for decreasing accidents

    Directory of Open Access Journals (Sweden)

    S. Ghazinoory

    2008-06-01

    Full Text Available .“Hazardous materials” refer to those substances that seriously endanger human lives and/or the environment. The transportation of these materials will be inevitable in the increasingly industrialized economy of Iran. Nonetheless, numerous deadly accidents caused by the movement of these materials necessitate the design and implementation of preventive plans on several levels. This article looks into the present condition of transportation of hazardous materials in Iran and the resulting accidents. Optimal condition for the general transportation system of hazardous materials is delineated with due focus on transportation risk as the main parameter. Strategies for reaching the optimal condition are laid out and the impacts of these strategies on the reduction of accidents are analyzed.

  1. Increased Flap Weight and Decreased Perforator Number Predict Fat Necrosis in DIEP Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Carolyn L. Mulvey, BS

    2013-05-01

    Conclusions: Flaps with increasing weight have increased risk of fat necrosis. These data suggest that inclusion of more than 1 perforator may decrease odds of fat necrosis in large flaps. Perforator flap breast reconstruction can be performed safely; however, considerations concerning race, body mass index, staging with tissue expanders, perforator number, and flap weight may optimize outcomes.

  2. Formability prediction for AHSS materials using damage models

    Science.gov (United States)

    Amaral, R.; Santos, Abel D.; José, César de Sá; Miranda, Sara

    2017-05-01

    Advanced high strength steels (AHSS) are seeing an increased use, mostly due to lightweight design in automobile industry and strict regulations on safety and greenhouse gases emissions. However, the use of these materials, characterized by a high strength to weight ratio, stiffness and high work hardening at early stages of plastic deformation, have imposed many challenges in sheet metal industry, mainly their low formability and different behaviour, when compared to traditional steels, which may represent a defying task, both to obtain a successful component and also when using numerical simulation to predict material behaviour and its fracture limits. Although numerical prediction of critical strains in sheet metal forming processes is still very often based on the classic forming limit diagrams, alternative approaches can use damage models, which are based on stress states to predict failure during the forming process and they can be classified as empirical, physics based and phenomenological models. In the present paper a comparative analysis of different ductile damage models is carried out, in order numerically evaluate two isotropic coupled damage models proposed by Johnson-Cook and Gurson-Tvergaard-Needleman (GTN), each of them corresponding to the first two previous group classification. Finite element analysis is used considering these damage mechanics approaches and the obtained results are compared with experimental Nakajima tests, thus being possible to evaluate and validate the ability to predict damage and formability limits for previous defined approaches.

  3. Formability prediction for AHSS materials using damage models

    International Nuclear Information System (INIS)

    Amaral, R.; Miranda, Sara; Santos, Abel D.; José, César de Sá

    2017-01-01

    Advanced high strength steels (AHSS) are seeing an increased use, mostly due to lightweight design in automobile industry and strict regulations on safety and greenhouse gases emissions. However, the use of these materials, characterized by a high strength to weight ratio, stiffness and high work hardening at early stages of plastic deformation, have imposed many challenges in sheet metal industry, mainly their low formability and different behaviour, when compared to traditional steels, which may represent a defying task, both to obtain a successful component and also when using numerical simulation to predict material behaviour and its fracture limits. Although numerical prediction of critical strains in sheet metal forming processes is still very often based on the classic forming limit diagrams, alternative approaches can use damage models, which are based on stress states to predict failure during the forming process and they can be classified as empirical, physics based and phenomenological models. In the present paper a comparative analysis of different ductile damage models is carried out, in order numerically evaluate two isotropic coupled damage models proposed by Johnson-Cook and Gurson-Tvergaard-Needleman (GTN), each of them corresponding to the first two previous group classification. Finite element analysis is used considering these damage mechanics approaches and the obtained results are compared with experimental Nakajima tests, thus being possible to evaluate and validate the ability to predict damage and formability limits for previous defined approaches. (paper)

  4. Multiscale modelling for better hygrothermal prediction of porous building materials

    Directory of Open Access Journals (Sweden)

    Belarbi Rafik

    2018-01-01

    Full Text Available The aim of this work is to understand the influence of the microstructuralgeometric parameters of porous building materials on the mechanisms of coupled heat, air and moisture transfers, in order to predict behavior of the building to control and improve it in its durability. For this a multi-scale approach is implemented. It consists of mastering the dominant physical phenomena and their interactions on the microscopic scale. Followed by a dual-scale modelling, microscopic-macroscopic, of coupled heat, air and moisture transfers that takes into account the intrinsic properties and microstructural topology of the material using X-ray tomography combined with the correlation of 3D images were undertaken. In fact, the hygromorphicbehavior under hydric solicitations was considered. In this context, a model of coupled heat, air and moisture transfer in porous building materials was developed using the periodic homogenization technique. These informations were subsequently implemented in a dynamic computation simulation that model the hygrothermalbehaviourof material at the scale of the envelopes and indoor air quality of building. Results reveals that is essential to consider the local behaviors of materials, but also to be able to measure and quantify the evolution of its properties on a macroscopic scale from the youngest age of the material. In addition, comparisons between experimental and numerical temperature and relative humidity profilesin multilayers wall and in building envelopes were undertaken. Good agreements were observed.

  5. Mathematical model predicts the elastic behavior of composite materials

    Directory of Open Access Journals (Sweden)

    Zoroastro de Miranda Boari

    2005-03-01

    Full Text Available Several studies have found that the non-uniform distribution of reinforcing elements in a composite material can markedly influence its characteristics of elastic and plastic deformation and that a composite's overall response is influenced by the physical and geometrical properties of its reinforcing phases. The finite element method, Eshelby's method and dislocation mechanisms are usually employed in formulating a composite's constitutive response. This paper discusses a composite material containing SiC particles in an aluminum matrix. The purpose of this study was to find the correlation between a composite material's particle distribution and its resistance, and to come up with a mathematical model to predict the material's elastic behavior. The proposed formulation was applied to establish the thermal stress field in the aluminum-SiC composite resulting from its fabrication process, whereby the mixture is prepared at 600 °C and the composite material is used at room temperature. The analytical results, which are presented as stress probabilities, were obtained from the mathematical model proposed herein. These results were compared with the numerical ones obtained by the FEM method. A comparison of the results of the two methods, analytical and numerical, reveals very similar average thermal stress values. It is also shown that Maxwell-Boltzmann's distribution law can be applied to identify the correlation between the material's particle distribution and its resistance, using Eshelby's thermal stresses.

  6. Prediction of strength of wood composite materials using ultrasonic

    International Nuclear Information System (INIS)

    Mahmoud, M.K.; Emam, A.

    2005-01-01

    Wood is a biological material integrating a very large variability of its mechanical properties (tensile and compressive), on the two directional longitudinal and transverse Ultrasonic method has been utilized to measure both wood physical and / or wood mechanical properties. The aim of this article is to show the development of ultrasonic technique for quality evaluation of trees, wood material and wood based composites. For quality assessment of these products we discuss the nondestructive evaluation of different factors such as: moisture content, temperature, biological degradation induced by bacterial attack and fungal attack. These techniques were adapted for trees, timber and wood based composites. The present study discusses the prediction of tensile and compressive strength of wood composite materials using ultrasonic testing. Empirical relationships between the tensile properties, compression strength and ultrasonic were proposed. The experimental results indicate the possibility of establishing a relationship between tensile strength and compression values. Moreover, the fractures in tensile and compressive are discussed by photographic

  7. Tuning and predicting the wetting of nanoengineered material surface

    Science.gov (United States)

    Ramiasa-MacGregor, M.; Mierczynska, A.; Sedev, R.; Vasilev, K.

    2016-02-01

    The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the wetting of surfaces with nanoscale roughness by considering the physical and chemical properties of the material. The fundamental insights presented here are important for the rational design of advanced materials having tailored surface nanotopography with predictable wettability.The wetting of a material can be tuned by changing the roughness on its surface. Recent advances in the field of nanotechnology open exciting opportunities to control macroscopic wetting behaviour. Yet, the benchmark theories used to describe the wettability of macroscopically rough surfaces fail to fully describe the wetting behaviour of systems with topographical features at the nanoscale. To shed light on the events occurring at the nanoscale we have utilised model gradient substrata where surface nanotopography was tailored in a controlled and robust manner. The intrinsic wettability of the coatings was varied from hydrophilic to hydrophobic. The measured water contact angle could not be described by the classical theories. We developed an empirical model that effectively captures the experimental data, and further enables us to predict the

  8. Modelling decreased food chain accumulation of HOCs due to strong sorption to carbonaceous materials and metabolic transformation

    NARCIS (Netherlands)

    Moermond, C.T.A.; Traas, T.P.; Roessink, I.; Veltman, K.; Hendriks, A.J.; Koelmans, A.A.

    2007-01-01

    The predictive power of bioaccumulation models may be limited when they do not account for strong sorption of organic contaminants to carbonaceous materials (CM) such as black carbon, and when they do not include metabolic transformation. We tested a food web accumulation model, including sorption

  9. Long-term results of preventive embolization of renal angiomyolipomas: evaluation of predictive factors of volume decrease

    Energy Technology Data Exchange (ETDEWEB)

    Hocquelet, A.; Cornelis, F.; Le Bras, Y.; Meyer, M.; Tricaud, E.; Lasserre, A.S.; Grenier, N. [Centre Hospitalier Universitaire Pellegrin, Diagnostic and Therapeutic Urology and Vascular Imaging, Bordeaux (France); Ferriere, J.M.; Robert, G. [Centre Hospitalier Universitaire Pellegrin, Urology Service, Bordeaux (France)

    2014-08-15

    To evaluate the efficacy of selective arterial embolization (SAE) of angiomyolipomas based on the percentage volume reduction after embolization and to identify predictive factors of volume decrease. Patients receiving prophylactic SAE of renal angiomyolipomas were included retrospectively over 3 years. The volume change after SAE and haemorrhagic or surgical events were recorded. Initial tumour volume, percentage tumour fat content, mean tumour density, embolic agent used, number of angiomyolipomas and tuberous sclerosis disease were evaluated as predictive factors of volume decrease. A total of 19 patients with 39 angiomyolipomas were included with median follow-up of 28 months (interquartile range 21-37 months). All treatments were technically successful (92 % primary and 8 % secondary). No distal bleeding or any increase in size or surgical nephrectomy after SAE was recorded. Mean volume reduction was 72 % (±24 %). Volumes before SAE (R{sup 2} = 0.276; p = 0.001), percentage fat content (R{sup 2} = 0.612; p < 0.0001) and mean angiomyolipoma density (R{sup 2} = 0.536; p < 0.0001) were identified as predictive factors of volume decrease. In multivariate regression, only percentage fat content influenced volume decreases. SAE is an efficient treatment for angiomyolipoma devascularisation and volume reduction. A significant reduction of volume is modulated by the initial volume and tissue composition of the tumour. (orig.)

  10. The efficacy of denaturing actinide elements as a means of decreasing materials attractiveness

    Energy Technology Data Exchange (ETDEWEB)

    Hase, K.R.; Bathke, C.G. [Los Alamos National Laboratory: P.O. Box 1663, Los Alamos, NM 87545 (United States); Ebbinghaus, B.B.; Sleaford, B.W.; Robel, M. [Lawrence Livermore National Laboratory: P.O. Box 808, Livermore, CA 94551 (United States); Collins, B.A.; Prichard, A.W. [Pacific Northwest National Laboratory: P.O. Box 999, Richland, WA 99352 (United States)

    2013-07-01

    This study considers the concept of denaturing as applied to the actinide elements present in spent fuel as a means to reduce materials attractiveness. Highly attractive materials generally have low values of bare critical mass, heat content, and dose. To denature an attractive element, its spent-fuel isotopic composition (isotopic vector) is intentionally modified by introducing sufficient quantities of a significantly less attractive isotope to dilute the concentration of a highly attractive isotope so that the overall attractiveness of the element is reduced. The authors used FOM (Figure of Merit) formula as the material attractiveness metric for their parametric determination of the attractiveness of the Pu and U. Materials attractiveness needs to be considered in three distinct phases in the process to construct a nuclear explosive device (NED): the acquisition phase, processing phase, and utilization phase. The results show that denaturing uranium with {sup 238}U is actually an effective means of reducing the attractiveness. For uranium with a large minority of {sup 235}U, a mixture of 80% {sup 238}U to 20% {sup 235}U is required to reduce the attractiveness to low. For uranium with a large concentration of {sup 233}U, a mixture of 88% {sup 238}U to 12% {sup 233}U is required to reduce the attractiveness to low. The results also show that denaturing plutonium with {sup 238}Pu is less effective than denaturing uranium with {sup 238}U. Using {sup 238}Pu as the denaturing agent would require 80% or more by mass in order to reduce the attractiveness to low. No amount of {sup 240}Pu is enough to reduce the plutonium attractiveness below medium. The combination of {sup 238}Pu and {sup 240}Pu would require approximately 70% {sup 238}Pu and 25% {sup 240}Pu by mass to reduce the plutonium attractiveness to low.

  11. The efficacy of denaturing actinide elements as a means of decreasing materials attractiveness

    International Nuclear Information System (INIS)

    Hase, K.R.; Bathke, C.G.; Ebbinghaus, B.B.; Sleaford, B.W.; Robel, M.; Collins, B.A.; Prichard, A.W.

    2013-01-01

    This study considers the concept of denaturing as applied to the actinide elements present in spent fuel as a means to reduce materials attractiveness. Highly attractive materials generally have low values of bare critical mass, heat content, and dose. To denature an attractive element, its spent-fuel isotopic composition (isotopic vector) is intentionally modified by introducing sufficient quantities of a significantly less attractive isotope to dilute the concentration of a highly attractive isotope so that the overall attractiveness of the element is reduced. The authors used FOM (Figure of Merit) formula as the material attractiveness metric for their parametric determination of the attractiveness of the Pu and U. Materials attractiveness needs to be considered in three distinct phases in the process to construct a nuclear explosive device (NED): the acquisition phase, processing phase, and utilization phase. The results show that denaturing uranium with 238 U is actually an effective means of reducing the attractiveness. For uranium with a large minority of 235 U, a mixture of 80% 238 U to 20% 235 U is required to reduce the attractiveness to low. For uranium with a large concentration of 233 U, a mixture of 88% 238 U to 12% 233 U is required to reduce the attractiveness to low. The results also show that denaturing plutonium with 238 Pu is less effective than denaturing uranium with 238 U. Using 238 Pu as the denaturing agent would require 80% or more by mass in order to reduce the attractiveness to low. No amount of 240 Pu is enough to reduce the plutonium attractiveness below medium. The combination of 238 Pu and 240 Pu would require approximately 70% 238 Pu and 25% 240 Pu by mass to reduce the plutonium attractiveness to low

  12. The life prediction study of Rokkasho reprocessing plant materials

    International Nuclear Information System (INIS)

    Kiuchi, K.; Yano, M.; Takizawa, M.; Shibata, S.

    1998-01-01

    The life prediction study of major equipment materials used in heavily corrosive nitric acid solutions of the RRP was carried out. The nitric acid recovery made of type 304ULC austenitic steel and the dissolver made of type 705 metallic zirconium are selected on the present study. This study is composed of major three programs, namely, the mock-up tests by small-sized equipments simulated to the practical design, laboratory tests for examining corrosion controlling factors by small specimens and to establish the data base system for the life prediction. Important parameters on this study was extracted with analyzing the past data of the life prediction on the Tokai reprocessing equipments. The mock-ups design was made by considering the quantitative evaluation of the most important parts on objective equipments, namely, heat conducting tubes in an acid recovery evaporator and a thermal jacket in a dissolver. From pre-examinations, the effects of radioactive species, nitric acid solution chemistry, the corrosion mechanisms were elucidated. Mock-up testing conditions corrosion monitoring methods and a data base concept for the the life prediction were selected from pre-examination data by referencing the plant operation planning. (author)

  13. Prediction of Corrosion of Advanced Materials and Fabricated Components

    Energy Technology Data Exchange (ETDEWEB)

    A. Anderko; G. Engelhardt; M.M. Lencka (OLI Systems Inc.); M.A. Jakab; G. Tormoen; N. Sridhar (Southwest Research Institute)

    2007-09-29

    The goal of this project is to provide materials engineers, chemical engineers and plant operators with a software tool that will enable them to predict localized corrosion of process equipment including fabricated components as well as base alloys. For design and revamp purposes, the software predicts the occurrence of localized corrosion as a function of environment chemistry and assists the user in selecting the optimum alloy for a given environment. For the operation of existing plants, the software enables the users to predict the remaining life of equipment and help in scheduling maintenance activities. This project combined fundamental understanding of mechanisms of corrosion with focused experimental results to predict the corrosion of advanced, base or fabricated, alloys in real-world environments encountered in the chemical industry. At the heart of this approach is the development of models that predict the fundamental parameters that control the occurrence of localized corrosion as a function of environmental conditions and alloy composition. The fundamental parameters that dictate the occurrence of localized corrosion are the corrosion and repassivation potentials. The program team, OLI Systems and Southwest Research Institute, has developed theoretical models for these parameters. These theoretical models have been applied to predict the occurrence of localized corrosion of base materials and heat-treated components in a variety of environments containing aggressive and non-aggressive species. As a result of this project, a comprehensive model has been established and extensively verified for predicting the occurrence of localized corrosion as a function of environment chemistry and temperature by calculating the corrosion and repassivation potentials.To support and calibrate the model, an experimental database has been developed to elucidate (1) the effects of various inhibiting species as well as aggressive species on localized corrosion of nickel

  14. Using ABAQUS Scripting Interface for Materials Evaluation and Life Prediction

    Science.gov (United States)

    Powers, Lynn M.; Arnold, Steven M.; Baranski, Andrzej

    2006-01-01

    An ABAQUS script has been written to aid in the evaluation of the mechanical behavior of viscoplastic materials. The purposes of the script are to: handle complex load histories; control load/displacement with alternate stopping criteria; predict failure and life; and verify constitutive models. Material models from the ABAQUS library may be used or the UMAT routine may specify mechanical behavior. User subroutines implemented include: UMAT for the constitutive model; UEXTERNALDB for file manipulation; DISP for boundary conditions; and URDFIL for results processing. Examples presented include load, strain and displacement control tests on a single element model. The tests are creep with a life limiting strain criterion, strain control with a stress limiting cycle and a complex interrupted cyclic relaxation test. The techniques implemented in this paper enable complex load conditions to be solved efficiently with ABAQUS.

  15. Thinner plantar fascia predicts decreased pain after extracorporeal shock wave therapy.

    Science.gov (United States)

    Liang, Huey-Wen; Wang, Tyng-Guey; Chen, Wen-Shiang; Hou, Sheng-Mou

    2007-07-01

    Increased plantar fascia thickness is common with chronic plantar fasciitis, and reduction of the thickness after extracorporeal shock wave therapy or steroid injection has been reported. We hypothesized a decrease of plantar fascia thickness was associated with pain reduction after extracorporeal shock wave therapy. Fifty-three eligible patients with 78 symptomatic feet were randomly treated with piezoelectric-type extracorporeal shock wave therapy of two intensity levels (0.12 and 0.56 mJ/mm2). Two thousand shock waves for three consecutive sessions were applied at weekly intervals. A visual analog scale for pain, the Foot Function Index, the Short Form-36 Health Survey, and ultrasonographic measurement of plantar fascia thickness were evaluated at baseline and 3 and 6 months after treatment. We analyzed the association between pain level and plantar fascia thickness with generalized estimating equation analysis and adjusted for demographic and treatment-related variables. Patients with thinner plantar fascia experienced less pain after treatment; high-intensity treatment and regular exercise were associated with lower pain level. The overall success rates were 63% and 60% at the 3- and 6-month followups. High- and low-intensity treatments were associated with similar improvements in pain and function. Receiving high-intensity treatment, although associated with less pain at followup, did not provide a higher success rate.

  16. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    Energy Technology Data Exchange (ETDEWEB)

    Matouš, Karel, E-mail: kmatous@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States); Geers, Marc G.D.; Kouznetsova, Varvara G. [Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands); Gillman, Andrew [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2017-02-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  17. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    International Nuclear Information System (INIS)

    Matouš, Karel; Geers, Marc G.D.; Kouznetsova, Varvara G.; Gillman, Andrew

    2017-01-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  18. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    Science.gov (United States)

    Matouš, Karel; Geers, Marc G. D.; Kouznetsova, Varvara G.; Gillman, Andrew

    2017-02-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today's electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials. Deeper attention is given to multiscale modeling in space and to computational homogenization in addressing challenging materials science questions. Moreover, we discuss a state-of-the-art platform in predictive image-based, multiscale modeling with co-designed simulations and experiments that executes on the world's largest supercomputers. Such a modeling framework consists of experimental tools, computational methods, and digital data strategies. Once fully completed, this collaborative and interdisciplinary framework can be the basis of Virtual Materials Testing standards and aids in the development of new material formulations. Moreover, it will decrease the time to market of innovative products.

  19. Predictive modeling of terrestrial radiation exposure from geologic materials

    Science.gov (United States)

    Haber, Daniel A.

    Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys from the National Uranium Resource Evaluation (NURE) Survey. Using these data, geospatial areas, referred to as background radiation units, homogenous in terms of K, U, and Th are defined and the gamma ray exposure rate is predicted. The prediction is compared to data collected via detailed aerial survey by our partner National Security Technologies, LLC (NSTec), allowing for the refinement of the technique. High resolution radiation exposure rate models have been developed for two study areas in Southern Nevada that include the alluvium on the western shore of Lake Mohave, and Government Wash north of Lake Mead; both of these areas are arid with little soil moisture and vegetation. We determined that by using geologic units to define radiation background units of exposed bedrock and ASTER visualizations to subdivide radiation background units of alluvium, regions of homogeneous geochemistry can be defined allowing for the exposure rate to be predicted. Soil and rock samples have been collected at Government Wash and Lake Mohave as well as a third site near Cameron, Arizona. K, U, and Th concentrations of these samples have been determined using inductively coupled mass spectrometry (ICP-MS) and laboratory counting using radiation detection equipment. In addition, many sample locations also have

  20. A New Material Constitutive Model for Predicting Cladding Failure

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Joe; Dunham, Robert [ANATECH Corp., San Diego, CA (United States); Rashid, Mark [University of California Davis, Davis, CA (United States); Machiels, Albert [EPRI, Palo Alto, CA (United States)

    2009-06-15

    An important issue in fuel performance and safety evaluations is the characterization of the effects of hydrides on cladding mechanical response and failure behavior. The hydride structure formed during power operation transforms the cladding into a complex multi-material composite, with through-thickness concentration profile that causes cladding ductility to vary by more than an order of magnitude between ID and OD. However, current practice of mechanical property testing treats the cladding as a homogeneous material characterized by a single stress-strain curve, regardless of its hydride morphology. Consequently, as irradiation conditions and hydrides evolution change, new material property testing is required, which results in a state of continuous need for valid material property data. A recently developed constitutive model, treats the cladding as a multi-material composite in which the metal and the hydride platelets are treated as separate material phases with their own elastic-plastic and fracture properties and interacting at their interfaces with appropriate constraint conditions between them to ensure strain and stress compatibility. An essential feature of the model is a multi-phase damage formulation that models the complex interaction between the hydride phases and the metal matrix and the coupled effect of radial and circumferential hydrides on cladding stress-strain response. This gives the model the capability of directly predicting cladding failure progression during the loading event and, as such, provides a unique tool for constructing failure criteria analytically where none could be developed by conventional material testing. Implementation of the model in a fuel behavior code provides the capability to predict in-reactor operational failures due to PCI or missing pellet surfaces (MPS) without having to rely on failure criteria. Even, a stronger motivation for use of the model is in the transportation accidents analysis of spent fuel

  1. Predicting material failure using mathematics; Mit Mathematik Materialversagen vorhersagen

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Christian [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2016-06-15

    Numerical simulations provide insights into materials, technical procedures or processes that are hardly possible by means of measurement technology, or require a lot of effort. In BAM's ConDrop research project (Numerical Drop Test Analyses of Steel Sheet Containers for the Konrad Repository), scientists are developing a method to predict the deformation and failure behaviour of containers for low- and intermediate- level radioactive waste for the Konrad repository. [German] Numerische Simulationen erlauben Einblicke in Materialien, technische Verfahren oder Prozesse, die mit Mitteln der Messtechnik kaum oder nur unter grossem Aufwand moeglich sind. Im BAM-Forschungsvorhaben ConDrop entwickeln Wissenschaftlerinnen und Wissenschaftler damit eine Methode, um das Verformungs- und Versagensverhalten von Behaeltern fuer schwach- und mittelradioaktive Abfaelle fuer das Endlager Konrad vorherzusagen.

  2. Life prediction of advanced materials for gas turbine application

    Energy Technology Data Exchange (ETDEWEB)

    Zamrik, S.Y.; Ray, A.; Koss, D.A. [Pennsylvania State Univ., University Park, PA (United States)

    1995-10-01

    Most of the studies on the low cycle fatigue life prediction have been reported under isothermal conditions where the deformation of the material is strain dependent. In the development of gas turbines, components such as blades and vanes are exposed to temperature variations in addition to strain cycling. As a result, the deformation process becomes temperature and strain dependent. Therefore, the life of the component becomes sensitive to temperature-strain cycling which produces a process known as {open_quotes}thermomechanical fatigue, or TMF{close_quotes}. The TMF fatigue failure phenomenon has been modeled using conventional fatigue life prediction methods, which are not sufficiently accurate to quantitatively establish an allowable design procedure. To add to the complexity of TMF life prediction, blade and vane substrates are normally coated with aluminide, overlay or thermal barrier type coatings (TBC) where the durability of the component is dominated by the coating/substrate constitutive response and by the fatigue behavior of the coating. A number of issues arise from TMF depending on the type of temperature/strain phase cycle: (1) time-dependent inelastic behavior can significantly affect the stress response. For example, creep relaxation during a tensile or compressive loading at elevated temperatures leads to a progressive increase in the mean stress level under cyclic loading. (2) the mismatch in elastic and thermal expansion properties between the coating and the substrate can lead to significant deviations in the coating stress levels due to changes in the elastic modulii. (3) the {open_quotes}dry{close_quotes} corrosion resistance coatings applied to the substrate may act as primary crack initiation sites. Crack initiation in the coating is a function of the coating composition, its mechanical properties, creep relaxation behavior, thermal strain range and the strain/temperature phase relationship.

  3. Predictive Multiscale Modeling of Nanocellulose Based Materials and Systems

    International Nuclear Information System (INIS)

    Kovalenko, Andriy

    2014-01-01

    Cellulose Nanocrysals (CNC) is a renewable biodegradable biopolymer with outstanding mechanical properties made from highly abundant natural source, and therefore is very attractive as reinforcing additive to replace petroleum-based plastics in biocomposite materials, foams, and gels. Large-scale applications of CNC are currently limited due to its low solubility in non-polar organic solvents used in existing polymerization technologies. The solvation properties of CNC can be improved by chemical modification of its surface. Development of effective surface modifications has been rather slow because extensive chemical modifications destabilize the hydrogen bonding network of cellulose and deteriorate the mechanical properties of CNC. We employ predictive multiscale theory, modeling, and simulation to gain a fundamental insight into the effect of CNC surface modifications on hydrogen bonding, CNC crystallinity, solvation thermodynamics, and CNC compatibilization with the existing polymerization technologies, so as to rationally design green nanomaterials with improved solubility in non-polar solvents, controlled liquid crystal ordering and optimized extrusion properties. An essential part of this multiscale modeling approach is the statistical- mechanical 3D-RISM-KH molecular theory of solvation, coupled with quantum mechanics, molecular mechanics, and multistep molecular dynamics simulation. The 3D-RISM-KH theory provides predictive modeling of both polar and non-polar solvents, solvent mixtures, and electrolyte solutions in a wide range of concentrations and thermodynamic states. It properly accounts for effective interactions in solution such as steric effects, hydrophobicity and hydrophilicity, hydrogen bonding, salt bridges, buffer, co-solvent, and successfully predicts solvation effects and processes in bulk liquids, solvation layers at solid surface, and in pockets and other inner spaces of macromolecules and supramolecular assemblies. This methodology

  4. Predictive Multiscale Modeling of Nanocellulose Based Materials and Systems

    Science.gov (United States)

    Kovalenko, Andriy

    2014-08-01

    Cellulose Nanocrysals (CNC) is a renewable biodegradable biopolymer with outstanding mechanical properties made from highly abundant natural source, and therefore is very attractive as reinforcing additive to replace petroleum-based plastics in biocomposite materials, foams, and gels. Large-scale applications of CNC are currently limited due to its low solubility in non-polar organic solvents used in existing polymerization technologies. The solvation properties of CNC can be improved by chemical modification of its surface. Development of effective surface modifications has been rather slow because extensive chemical modifications destabilize the hydrogen bonding network of cellulose and deteriorate the mechanical properties of CNC. We employ predictive multiscale theory, modeling, and simulation to gain a fundamental insight into the effect of CNC surface modifications on hydrogen bonding, CNC crystallinity, solvation thermodynamics, and CNC compatibilization with the existing polymerization technologies, so as to rationally design green nanomaterials with improved solubility in non-polar solvents, controlled liquid crystal ordering and optimized extrusion properties. An essential part of this multiscale modeling approach is the statistical- mechanical 3D-RISM-KH molecular theory of solvation, coupled with quantum mechanics, molecular mechanics, and multistep molecular dynamics simulation. The 3D-RISM-KH theory provides predictive modeling of both polar and non-polar solvents, solvent mixtures, and electrolyte solutions in a wide range of concentrations and thermodynamic states. It properly accounts for effective interactions in solution such as steric effects, hydrophobicity and hydrophilicity, hydrogen bonding, salt bridges, buffer, co-solvent, and successfully predicts solvation effects and processes in bulk liquids, solvation layers at solid surface, and in pockets and other inner spaces of macromolecules and supramolecular assemblies. This methodology

  5. Looking Māori predicts decreased rates of home ownership: institutional racism in housing based on perceived appearance.

    Science.gov (United States)

    Houkamau, Carla A; Sibley, Chris G

    2015-01-01

    This study examined differences in rates of home ownership among Māori (the indigenous peoples of New Zealand). We identified systematic factors that predicted why some Māori were more likely to own their own home (partially or fully) relative to other Māori. Data were drawn from a large national postal sample of 561 self-identified Māori collected as part of the New Zealand Attitudes and Values Study. As predicted, our analyses indicated that self-reported appearance as Māori, or the extent to which people thought they personally displayed features which visibly identified them as Māori to others, significantly predicted decreased rates of home ownership. This association held when adjusting for numerous demographic covariates, such as education, level of deprivation of the immediate area, household income, age, relationship status, region of residence, and so forth. Our analyses suggest there is, or at least has been in the recent past, institutional racism against Māori in New Zealand's home lending industry based on merely appearing more Māori.

  6. Effectiveness of common fish screen materials for protecting lamprey ammocoetes—Influence of sweeping velocities and decreasing flows

    Science.gov (United States)

    Mesa, Matthew G.; Liedtke, Theresa L.; Weiland, Lisa K.; Christiansen, Helena E.

    2017-12-14

    In previous tests of the effectiveness of four common fish screen materials for excluding lamprey ammocoetes, we determined that woven wire (WW) allowed substantially more entrainment than perforated plate (PP), profile bar (PB), or Intralox (IL) material. These tests were simplistic because they used small vertically-oriented screens positioned perpendicular to the flow without a bypass or a sweeping velocity (SV). In the subsequent test discussed in this report, we exposed ammocoetes to much larger (2.5-m-wide) screen panels with flows up to 10 ft3 /s, a SV component, and a simulated bypass channel. The addition of a SV modestly improved protection of lamprey ammocoetes for all materials tested. A SV of 35 cm/s with an approach velocity (AV) of 12 cm/s, was able to provide protection for fish about 5–15 mm smaller than the protection provided by an AV of 12 cm/s without a SV component. The best-performing screen panels (PP, IL, and PB) provided nearly complete protection from entrainment for fish greater than 50-mm toal length, but the larger openings in the WW material only protected fish greater than 100-mm total length. Decreasing the AV and SV by 50 percent expanded the size range of protected lampreys by about 10–15 mm for those exposed to IL and WW screens, and it decreased the protective ability of PP screens by about 10 mm. Much of the improvement for IL and WW screens under the reduced flow conditions resulted from an increase in the number of lampreys swimming away from the screen. Fish of all sizes became impinged (that is, stuck on the screen surface for more than 1 s) on the screens, with the rate of impingement highest on PP (39– 72 percent) and lowest on WW (7–22 percent). Although impingements were common, injuries were rare, and 24-h post-test survival was greater than 99 percent. Our results refined the level of protection provided by these screen materials when both an AV and SV are present and confirmed our earlier recommendation that

  7. Predicting timing of clinical outcomes in patients with chronic kidney disease and severely decreased glomerular filtration rate.

    Science.gov (United States)

    Grams, Morgan E; Sang, Yingying; Ballew, Shoshana H; Carrero, Juan Jesus; Djurdjev, Ognjenka; Heerspink, Hiddo J L; Ho, Kevin; Ito, Sadayoshi; Marks, Angharad; Naimark, David; Nash, Danielle M; Navaneethan, Sankar D; Sarnak, Mark; Stengel, Benedicte; Visseren, Frank L J; Wang, Angela Yee-Moon; Köttgen, Anna; Levey, Andrew S; Woodward, Mark; Eckardt, Kai-Uwe; Hemmelgarn, Brenda; Coresh, Josef

    2018-03-24

    Patients with chronic kidney disease and severely decreased glomerular filtration rate (GFR) are at high risk for kidney failure, cardiovascular disease (CVD) and death. Accurate estimates of risk and timing of these clinical outcomes could guide patient counseling and therapy. Therefore, we developed models using data of 264,296 individuals in 30 countries participating in the international Chronic Kidney Disease Prognosis Consortium with estimated GFR (eGFR)s under 30 ml/min/1.73m 2 . Median participant eGFR and urine albumin-to-creatinine ratio were 24 ml/min/1.73m 2 and 168 mg/g, respectively. Using competing-risk regression, random-effect meta-analysis, and Markov processes with Monte Carlo simulations, we developed two- and four-year models of the probability and timing of kidney failure requiring kidney replacement therapy (KRT), a non-fatal CVD event, and death according to age, sex, race, eGFR, albumin-to-creatinine ratio, systolic blood pressure, smoking status, diabetes mellitus, and history of CVD. Hypothetically applied to a 60-year-old white male with a history of CVD, a systolic blood pressure of 140 mmHg, an eGFR of 25 ml/min/1.73m 2 and a urine albumin-to-creatinine ratio of 1000 mg/g, the four-year model predicted a 17% chance of survival after KRT, a 17% chance of survival after a CVD event, a 4% chance of survival after both, and a 28% chance of death (9% as a first event, and 19% after another CVD event or KRT). Risk predictions for KRT showed good overall agreement with the published kidney failure risk equation, and both models were well calibrated with observed risk. Thus, commonly-measured clinical characteristics can predict the timing and occurrence of clinical outcomes in patients with severely decreased GFR. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  8. A review of formulas for predicting irradiation embrittlement of reactors vessel materials

    International Nuclear Information System (INIS)

    Petrequin, P.

    1995-01-01

    Formulas developed in different countries for predicting irradiation embrittlement of reactors vessel materials are presented. Results of predictions were compared with different data sets, from surveillance programmes or studies in test reactors, with different residual elements contents. Figs

  9. Perspective: Role of structure prediction in materials discovery and design

    Directory of Open Access Journals (Sweden)

    Richard J. Needs

    2016-05-01

    Full Text Available Materials informatics owes much to bioinformatics and the Materials Genome Initiative has been inspired by the Human Genome Project. But there is more to bioinformatics than genomes, and the same is true for materials informatics. Here we describe the rapidly expanding role of searching for structures of materials using first-principles electronic-structure methods. Structure searching has played an important part in unraveling structures of dense hydrogen and in identifying the record-high-temperature superconducting component in hydrogen sulfide at high pressures. We suggest that first-principles structure searching has already demonstrated its ability to determine structures of a wide range of materials and that it will play a central and increasing part in materials discovery and design.

  10. Advanced Materials Test Methods for Improved Life Prediction of Turbine Engine Components

    National Research Council Canada - National Science Library

    Stubbs, Jack

    2000-01-01

    Phase I final report developed under SBIR contract for Topic # AF00-149, "Durability of Turbine Engine Materials/Advanced Material Test Methods for Improved Use Prediction of Turbine Engine Components...

  11. Prediction of material damage in orthotropic metals for virtual structural testing

    OpenAIRE

    Ravindran, S.

    2010-01-01

    Models based on the Continuum Damage Mechanics principle are increasingly used for predicting the initiation and growth of damage in materials. The growing reliance on 3-D finite element (FE) virtual structural testing demands implementation and validation of robust material models that can predict the material behaviour accurately. The use of these models within numerical analyses requires suitable material data. EU aerospace companies along with Cranfield University and other similar resear...

  12. Materials aging: first predictive modeling of iron under irradiation

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    Researchers from the CEA-Bruyeres-le-Chatel have been able to quantitatively foresee for the very first time the evolution of irradiation defects inside a structural material. Their results, obtained with iron, will contribute to better understand the aging of the materials of today's nuclear power plants and of future nuclear systems. Short paper. (J.S.)

  13. Theoretical model for the hydrogen-material interaction as a basis for prediction of the material mechanical properties

    International Nuclear Information System (INIS)

    Indeitsev, D.A.; Polyanskiy, V.A.; Sukhanov, A.A.; Belyaev, A.A.

    2009-01-01

    The natural law concentration of hydrogen inside the materials has a distribution over the different binding energies. This distribution is changing under the mechanical tension. The model of interaction of the small hydrogen concentration with materials provides one with an instrument for modeling the materials fatigue and destruction, as well as the prediction of material properties during exploitation. The well-known models are of the phenomenological nature. However if one takes into account the physical mechanism then one obtains an accurate model and the instrument for the reliable prediction. The two-continuum model of the solid material is a substantiation for the present study. This model describes the interaction between the low concentration of hydrogen and the material. The redistribution of the hydrogen between the different binding energy levels is taken into account, too

  14. Predicting the Coupling Properties of Axially-Textured Materials

    Directory of Open Access Journals (Sweden)

    María E. Fuentes-Montero

    2013-10-01

    Full Text Available A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones.

  15. Predicting the Coupling Properties of Axially-Textured Materials

    Science.gov (United States)

    Fuentes-Cobas, Luis E.; Muñoz-Romero, Alejandro; Montero-Cabrera, María E.; Fuentes-Montero, Luis; Fuentes-Montero, María E.

    2013-01-01

    A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones. PMID:28788370

  16. Predictive Simulation of Material Failure Using Peridynamics -- Advanced Constitutive Modeling, Verification and Validation

    Science.gov (United States)

    2016-03-31

    AFRL-AFOSR-VA-TR-2016-0309 Predictive simulation of material failure using peridynamics- advanced constitutive modeling, verification , and validation... Self -explanatory. 8. PERFORMING ORGANIZATION REPORT NUMBER. Enter all unique alphanumeric report numbers assigned by the performing organization, e.g...for public release. Predictive simulation of material failure using peridynamics-advanced constitutive modeling, verification , and validation John T

  17. Prediction of Thermal Transport Properties of Materials with Microstructural Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Youping

    2017-10-10

    This project aims at overcoming the major obstacle standing in the way of progress in dynamic multiscale simulation, which is the lack of a concurrent atomistic-continuum method that allows phonons, heat and defects to pass through the atomistic-continuum interface. The research has led to the development of a concurrent atomistic-continuum (CAC) methodology for multiscale simulations of materials microstructural, mechanical and thermal transport behavior. Its efficacy has been tested and demonstrated through simulations of dislocation dynamics and phonon transport coupled with microstructural evolution in a variety of materials and through providing visual evidences of the nature of phonon transport, such as showing the propagation of heat pulses in single and polycrystalline solids is partially ballistic and partially diffusive. In addition to providing understanding on phonon scattering with phase interface and with grain boundaries, the research has contributed a multiscale simulation tool for understanding of the behavior of complex materials and has demonstrated the capability of the tool in simulating the dynamic, in situ experimental studies of nonequilibrium transient transport processes in material samples that are at length scales typically inaccessible by atomistically resolved methods.

  18. Physicomechanical properties of porous fiber materials and prediction of them

    International Nuclear Information System (INIS)

    Kostornov, A.G.; Galstyan, L.G.

    1985-01-01

    A comparison is presented of the experimentally determined values of certain properties of porous fiber materials obtained by the optimum method from monodisperse fibers of copper, nickel, and Nichrome of different diameters with the corresponding theoretical values. The electrical conductivity, tensile strength, and modulus of elasticity, the basic properties of a porous body, which are determined both by the structural characteristics of the elements and by the condition of the interparticle contacts, were considered

  19. Older Age Predicts Decreased Metastasis and Prostate Cancer-Specific Death for Men Treated With Radiation Therapy: Meta-Analysis of Radiation Therapy Oncology Group Trials

    Energy Technology Data Exchange (ETDEWEB)

    Hamstra, Daniel A., E-mail: dhamm@umich.edu [University of Michigan, Ann Arbor, Michigan (United States); Bae, Kyounghwa [Radiation Therapy Oncology Group, Philadelphia, Pennsylvania (United States); Pilepich, Miljenko V. [UCLA Medical Center, Los Angeles, California (United States); Hanks, Gerald E. [Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Grignon, David J. [Indiana University-Purdue University Indianapolis, Indiana (United States); McGowan, David G. [Cross Cancer Institute, Edmonton, Alberta (Canada); Roach, Mack [UCSF, San Francisco, California (United States); Lawton, Colleen [Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Lee, R. Jeffrey [Intermountain Medical Center, Salt Lake City, Utah (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, California (United States)

    2011-12-01

    Purpose: The impact of age on prostate cancer (PCa) outcome has been controversial; therefore, we analyzed the effect of age on overall survival (OS), distant metastasis, prostate cancer-specific death (PCSD), and nonprostate cancer death (NPCD) on patients with locally advanced PCa. Methods and Materials: Patients who participated in four Radiation Therapy Oncology Group (RTOG) phase III trials, 8531, 8610, 9202, and 9413, were studied. Cox proportional hazards regression was used for OS analysis, and cumulative events analysis with Fine and Gray's regression was used for analyses of metastasis, PCSD, and NPCD. Results: Median follow-up of 4,128 patients with median age of 70 (range, 43-88 years) was 7.3 years. Most patients had high-risk disease: cT3 to cT4 (54%) and Gleason scores (GS) of 7 (45%) and 8 to 10 (27%). Older age ({<=}70 vs. >70 years) predicted for decreased OS (10-year rate, 55% vs. 41%, respectively; p < 0.0001) and increased NPCD (10-year rate, 28% vs. 46%, respectively; p < 0.0001) but decreased metastasis (10-year rate, 27% vs. 20%, respectively; p < 0.0001) and PCSD (10-year rate, 18% vs. 14%, respectively; p < 0.0001). To account for competing risks, outcomes were analyzed in 2-year intervals, and age-dependent differences in metastasis and PCSD persisted, even in the earliest time periods. When adjusted for other covariates, an age of >70 years remained associated with decreased OS (hazard ratio [HR], 1.56 [95% confidence interval [CI], 1.43-1.70] p < 0.0001) but with decreased metastasis (HR, 0.72 [95% CI, 0.63-0.83] p < 0.0001) and PCSD (HR, 0.78 [95% CI, 0.66-0.92] p < 0.0001). Finally, the impact of the duration of androgen deprivation therapy as a function of age was evaluated. Conclusions: These data support less aggressive PCa in older men, independent of other clinical features. While the biological underpinning of this finding remains unknown, stratification by age in future trials appears to be warranted.

  20. Fatigue life prediction of autofrettage tubes using actual material behaviour

    International Nuclear Information System (INIS)

    Jahed, Hamid; Farshi, Behrooz; Hosseini, Mohammad

    2006-01-01

    There is a profound Bauschinger effect in the behaviour of high-strength steels used in autofrettaged tubes. This has led to development of methods capable of considering experimentally obtained (actual) material behaviour in residual stress calculations. The extension of these methods to life calculations is presented here. To estimate the life of autofrettaged tubes with a longitudinal surface crack emanating from the bore more accurately, instead of using idealized models, the experimental loading-unloading stress-strain behaviour is employed. The resulting stresses are then used to calculate stress intensity factors by the weight function method as input to fatigue life determination. Fatigue lives obtained using the actual material behaviour are then compared with the results of frequently used ideal models including those considering Bauschinger effect factors and strain hardening in unloading. Using standard fatigue crack growth relationships, life of the vessel is then calculated based on recommended initial and final crack length. It is shown that the life gain due to autofrettage above 70% overstrain is considerable

  1. Life Prediction of Spent Fuel Storage Canister Material

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, Ronald

    2018-04-16

    The original purpose of this project was to develop a probabilistic model for SCC-induced failure of spent fuel storage canisters, exposed to a salt-air environment in the temperature range 30-70°C for periods up to and exceeding 100 years. The nature of this degradation process, which involves multiple degradation mechanisms, combined with variable and uncertain environmental conditions dictates a probabilistic approach to life prediction. A final report for the original portion of the project was submitted earlier. However, residual stress measurements for as-welded and repair welds could not be performed within the original time of the project. As a result of this, a no-cost extension was granted in order to complete these tests. In this report, we report on the results of residual stress measurements.

  2. Prediction of Radioactive Material Proliferation in Abukuma Basin using USLE

    Science.gov (United States)

    Yi, C. J.

    2014-12-01

    Due to the nuclear-power plant accident after the 2011 Great East Japan Earthquake and Tsunami, the residents who had resided within 20 km from the Daiichi Fukushima Nuclear Power Plant had forced to leave their hometown. The impacts by the radioactive contamination extended to numerous social elements, such as food, economy, civil engineering, community rebuilding, etc. Japanese government agencies have measured the level of radioactive contamination in urban, agricultural area, forest, riverine and ocean. The research found that the concentration level of cesium-137 (137Cs) is higher in the forest than an open area such as paddy field or rural town. Litter layers and surface layers, especially, are found to be significantly contaminated. The study calculated the estimation of contaminated soil erosion using the USLE which the idea is based on scenario that addresses a question, what if 137Cs would carry out from the forest after intensive rainfall. Predicting radioactively contaminated areas after intense rainfall is a critical matter for the future watershed risk management.

  3. Ternary alloy material prediction using genetic algorithm and cluster expansion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chong [Iowa State Univ., Ames, IA (United States)

    2015-12-01

    This thesis summarizes our study on the crystal structures prediction of Fe-V-Si system using genetic algorithm and cluster expansion. Our goal is to explore and look for new stable compounds. We started from the current ten known experimental phases, and calculated formation energies of those compounds using density functional theory (DFT) package, namely, VASP. The convex hull was generated based on the DFT calculations of the experimental known phases. Then we did random search on some metal rich (Fe and V) compositions and found that the lowest energy structures were body centered cube (bcc) underlying lattice, under which we did our computational systematic searches using genetic algorithm and cluster expansion. Among hundreds of the searched compositions, thirteen were selected and DFT formation energies were obtained by VASP. The stability checking of those thirteen compounds was done in reference to the experimental convex hull. We found that the composition, 24-8-16, i.e., Fe3VSi2 is a new stable phase and it can be very inspiring to the future experiments.

  4. Predictive Modeling of Terrestrial Radiation Exposure from Geologic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Malchow, Russell L. [National Security Technologies, LLC; Haber, Daniel University of Nevada, Las Vegas; Burnley, Pamela [University of Nevada, Las Vegas; Marsac, Kara [University of Nevada, Las Vegas; Hausrath, Elisabeth [University of Nevada, Las Vegas; Adcock, Christopher [University of Nevada, Las Vegas

    2015-01-01

    Aerial gamma ray surveys are important for those working in nuclear security and industry for determining locations of both anthropogenic radiological sources and natural occurrences of radionuclides. During an aerial gamma ray survey, a low flying aircraft, such as a helicopter, flies in a linear pattern across the survey area while measuring the gamma emissions with a sodium iodide (NaI) detector. Currently, if a gamma ray survey is being flown in an area, the only way to correct for geologic sources of gamma rays is to have flown the area previously. This is prohibitively expensive and would require complete national coverage. This project’s goal is to model the geologic contribution to radiological backgrounds using published geochemical data, GIS software, remote sensing, calculations, and modeling software. K, U and Th are the three major gamma emitters in geologic material. U and Th are assumed to be in secular equilibrium with their daughter isotopes. If K, U, and Th abundance values are known for a given geologic unit the expected gamma ray exposure rate can be calculated using the Grasty equation or by modeling software. Monte Carlo N-Particle Transport software (MCNP), developed by Los Alamos National Laboratory, is modeling software designed to simulate particles and their interactions with matter. Using this software, models have been created that represent various lithologies. These simulations randomly generate gamma ray photons at energy levels expected from natural radiologic sources. The photons take a random path through the simulated geologic media and deposit their energy at the end of their track. A series of nested spheres have been created and filled with simulated atmosphere to record energy deposition. Energies deposited are binned in the same manner as the NaI detectors used during an aerial survey. These models are used in place of the simplistic Grasty equation as they take into account absorption properties of the lithology which the

  5. Evolutionary Modeling Predicts a Decrease in Postcopulatory Sperm Viability as a Response to Increasing Levels of Sperm Competition

    NARCIS (Netherlands)

    Engqvist, Leif

    Sperm competition has been found to have a strong influence on the evolution of many male and female reproductive traits. Theoretical models have shown that, with increasing levels of sperm competition, males are predicted to increase ejaculate investment, and there is ample empirical evidence

  6. Combinatory Models for Predicting the Effective Thermal Conductivity of Frozen and Unfrozen Food Materials

    OpenAIRE

    K. S. Reddy; P Karthikeyan

    2010-01-01

    A model to predict the effective thermal conductivity of heterogeneous materials is proposed based on unit cell approach. The model is combined with four fundamental effective thermal conductivity models (Parallel, Series, Maxwell-Eucken-I, and Maxwell-Eucken-II) to evolve a unifying equation for the estimation of effective thermal conductivity of porous and nonporous food materials. The effect of volume fraction (ν) on the structure composition factor (ψ) of the food materials is studied. Th...

  7. On the classification and prediction of characteristics of heat resisting materials durability

    International Nuclear Information System (INIS)

    Krivenyuk, V.V.

    1976-01-01

    The proposed methods - one of which is based on the direct or indirect use of comparable temperature and load conditions, while the other takes into account in addition structural features of the material that are governed by the short-term ductility characteristics - are practically equivalent to the Larson and Miller method as regards accuracy and reliability of prediction. The classification of materials employed in the theory of high-temperature strength may promote the development of rapid methods of predicting the long-term strength and deformation properties by also taking into consideration the state of the material characterized by the short-term mechanical properties

  8. Not New, but Nearly Forgotten: The Testing Effect Decreases or Even Disappears as the Complexity of Learning Materials Increases

    Science.gov (United States)

    van Gog, Tamara; Sweller, John

    2015-01-01

    The testing effect is a finding from cognitive psychology with relevance for education. It shows that after an initial study period, taking a practice test improves long-term retention compared to not taking a test and--more interestingly--compared to restudying the learning material. Boundary conditions of the effect that have received attention…

  9. MOlecular MAterials Property Prediction Package (MOMAP) 1.0: a software package for predicting the luminescent properties and mobility of organic functional materials

    Science.gov (United States)

    Niu, Yingli; Li, Wenqiang; Peng, Qian; Geng, Hua; Yi, Yuanping; Wang, Linjun; Nan, Guangjun; Wang, Dong; Shuai, Zhigang

    2018-04-01

    MOlecular MAterials Property Prediction Package (MOMAP) is a software toolkit for molecular materials property prediction. It focuses on luminescent properties and charge mobility properties. This article contains a brief descriptive introduction of key features, theoretical models and algorithms of the software, together with examples that illustrate the performance. First, we present the theoretical models and algorithms for molecular luminescent properties calculation, which includes the excited-state radiative/non-radiative decay rate constant and the optical spectra. Then, a multi-scale simulation approach and its algorithm for the molecular charge mobility are described. This approach is based on hopping model and combines with Kinetic Monte Carlo and molecular dynamics simulations, and it is especially applicable for describing a large category of organic semiconductors, whose inter-molecular electronic coupling is much smaller than intra-molecular charge reorganisation energy.

  10. Anti-Müllerian hormone serum values and ovarian reserve: can it predict a decrease in fertility after ovarian stimulation by ART cycles?

    Directory of Open Access Journals (Sweden)

    Tito Silvio Patrelli

    Full Text Available BACKGROUND: A variety of indicators of potentially successful ovarian stimulation cycles are available, including biomarkers such as anti-Mullerian hormone. The aim of our study was to confirm the usefulness of serum anti-Mullerian hormone assay in predicting ovarian response and reproductive outcome in women eligible for ART cycles. MATERIALS: Forty-six women undergoing ART cycles at the Centre for Reproductive Medicine in Parma were recruited from March-to-June 2010. INCLUSION CRITERIA: age<42 years; body-mass-index = 20-25; regular menstrual cycles; basal serum FSH concentration <12 IU/L and basal serum estradiol concentration <70 pg/mL. The couples included in our study reported a variety of primary infertility causes. All women underwent FSH stimulation and pituitary suppression (GnRH-agonist/GnRH-antagonist protocols. Women were considered poor-responders if they had ≤ 3 oocytes; normal-responders 4-9 oocytes and high-responders ≥ 10 oocytes. Serum samples for the AMH assays were obtained on the first and last days of stimulation. A P value ≤ 0.05 was considered statistically significant. RESULT: FSH levels increased significantly when AMH levels decreased. The total dose of r-FSH administered to induce ovulation was not correlated to AMH. The number of follicles on the hCG, serum estradiol levels on the hCG-day, and the number of retrieved oocytes were significantly correlated to AMH. The number of fertilized oocytes was significantly correlated to the AMH levels. No significant correlation was found between obtained embryos or transferred embryos and AMH. Basal serum AMH levels were significantly higher than those measured on the hCG-day, which appeared significantly reduced. There was a significant correlation between AMH in normal responders and AMH in both high and poor responders. CONCLUSIONS: Our data confirm the clinical usefulness of AMH in ART-cycles to customize treatment protocols and suggest the necessity of verifying an

  11. High alanine aminotransferase is associated with decreased hepatic insulin sensitivity and predicts the development of type 2 diabetes

    DEFF Research Database (Denmark)

    Vozarova, Barbora; Stefan, Norbert; Lindsay, Robert S

    2002-01-01

    -sectionally associated with obesity and whole-body and hepatic insulin resistance and prospectively associated with a decline in hepatic insulin sensitivity and the development of type 2 diabetes. Our findings indicate that high ALT is a marker of risk for type 2 diabetes and suggest a potential role of the liver...... with prospective changes in liver or whole-body insulin sensitivity and/or insulin secretion and whether these elevated enzymes predict the development of type 2 diabetes in Pima Indians. We measured ALT, AST, and GGT in 451 nondiabetic (75-g oral glucose tolerance test) Pima Indians (aged 30 +/- 6 years, body fat...... 33 +/- 8%, ALT 45 +/- 29 units/l, AST 34 +/- 18 units/l, and GGT 56 +/- 40 units/l [mean +/- SD]) who were characterized for body composition (hydrodensitometry or dual-energy X-ray absorptiometry), whole-body insulin sensitivity (M), and hepatic insulin sensitivity (hepatic glucose output [HGO...

  12. Effects of Surface and Subsurface Bed Material Composition on Gravel Transport and Flow Competence Relations—Possibilities for Prediction

    Science.gov (United States)

    Bunte, K.; Abt, S. R.; Swingle, K. W.; Cenderelli, D. A.; Gaeuman, D. A.

    2014-12-01

    Bedload transport and flow competence relations are difficult to predict in coarse-bedded steep streams where widely differing sediment supply, bed stability, and complex flow hydraulics greatly affect amounts and sizes of transported gravel particles. This study explains how properties of bed material surface and subsurface size distributions are directly related to gravel transport and may be used for prediction of gravel transport and flow competence relations. Gravel transport, flow competence, and bed material size were measured in step-pool and plane-bed streams. Power functions were fitted to gravel transport QB=aQb and flow competence Dmax=cQd relations; Q is water discharge. Frequency distributions of surface FDsurf and subsurface FDsub bed material were likewise described by power functions FDsurf=hD j and FDsub=kDm fitted over six 0.5-phi size classes within 4 to 22.4 mm. Those gravel sizes are typically mobile even in moderate floods. Study results show that steeper subsurface bed material size distributions lead to steeper gravel transport and flow competence relations, whereas larger amounts of sediment contained in those 6 size bedmaterial classes (larger h and k) flatten the relations. Similarly, steeper surface size distributions decrease the coefficients of the gravel transport and flow competence relations, whereas larger amounts of sediment within the six bed material classes increase the intercepts of gravel transport and flow competence relations. Those relations are likely causative in streams where bedload stems almost entirely from the channel bed as opposed to direct (unworked) contributions from hillslopes and tributaries. The exponent of the subsurface bed material distribution m predicted the gravel transport exponent b with r2 near 0.7 and flow competence exponent d with r2 near 0.5. The intercept of bed surface distributions h increased the intercept a of gravel transport and c of the flow competence relations with r2 near 0.6.

  13. Decreased material-activation of the complement system using low-energy plasma polymerized poly(vinyl pyrrolidone) coatings

    DEFF Research Database (Denmark)

    Andersen, T.E.; Kolmos, H.J.; Palarasah, Yaseelan

    2011-01-01

    In the current study we investigate the activation of blood complement on medical device silicone rubber and present a plasma polymerized vinyl pyrrolidone (ppVP) coating which strongly decreases surface-activation of the blood complement system. We show that uncoated silicone and polystyrene...... surface. The ppVP surface is furthermore characterized physically and chemically using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR), which indicates preservation of chemical functionality by the applied plasma process. Overall, the pp...

  14. Prediction of Fracture Behavior in Rock and Rock-like Materials Using Discrete Element Models

    Science.gov (United States)

    Katsaga, T.; Young, P.

    2009-05-01

    The study of fracture initiation and propagation in heterogeneous materials such as rock and rock-like materials are of principal interest in the field of rock mechanics and rock engineering. It is crucial to study and investigate failure prediction and safety measures in civil and mining structures. Our work offers a practical approach to predict fracture behaviour using discrete element models. In this approach, the microstructures of materials are presented through the combination of clusters of bonded particles with different inter-cluster particle and bond properties, and intra-cluster bond properties. The geometry of clusters is transferred from information available from thin sections, computed tomography (CT) images and other visual presentation of the modeled material using customized AutoCAD built-in dialog- based Visual Basic Application. Exact microstructures of the tested sample, including fractures, faults, inclusions and void spaces can be duplicated in the discrete element models. Although the microstructural fabrics of rocks and rock-like structures may have different scale, fracture formation and propagation through these materials are alike and will follow similar mechanics. Synthetic material provides an excellent condition for validating the modelling approaches, as fracture behaviours are known with the well-defined composite's properties. Calibration of the macro-properties of matrix material and inclusions (aggregates), were followed with the overall mechanical material responses calibration by adjusting the interfacial properties. The discrete element model predicted similar fracture propagation features and path as that of the real sample material. The path of the fractures and matrix-inclusion interaction was compared using computed tomography images. Initiation and fracture formation in the model and real material were compared using Acoustic Emission data. Analysing the temporal and spatial evolution of AE events, collected during the

  15. Comparison of Ablation Predictions for Carbonaceous Materials Using CEA and JANAF-Based Species Thermodynamics

    Science.gov (United States)

    Milos, Frank S.

    2011-01-01

    In most previous work at NASA Ames Research Center, ablation predictions for carbonaceous materials were obtained using a species thermodynamics database developed by Aerotherm Corporation. This database is derived mostly from the JANAF thermochemical tables. However, the CEA thermodynamics database, also used by NASA, is considered more up to date. In this work, the FIAT code was modified to use CEA-based curve fits for species thermodynamics, then analyses using both the JANAF and CEA thermodynamics were performed for carbon and carbon phenolic materials over a range of test conditions. The ablation predictions are comparable at lower heat fluxes where the dominant mechanism is carbon oxidation. However, the predictions begin to diverge in the sublimation regime, with the CEA model predicting lower recession. The disagreement is more significant for carbon phenolic than for carbon, and this difference is attributed to hydrocarbon species that may contribute to the ablation rate.

  16. Prevalence of nursing diagnosis of decreased cardiac output and the predictive value of defining characteristics in patients under evaluation for heart transplant

    OpenAIRE

    Matos, Lígia Neres; Guimarães, Tereza Cristina Felippe; Brandão, Marcos Antônio Gomes; Santoro, Deyse Conceição

    2012-01-01

    The purposes of the study were to identify the prevalence of defining characteristics (DC) of decreased cardiac output (DCO) in patients with cardiac insufficiency under evaluation for heart transplantation, and to ascertain the likelihood of defining characteristics being predictive factors for the existence of reduction in cardiac output. Data was obtained by retrospective documental analysis of the clinical records of right-sided heart catheterizations in 38 patients between 2004 and 2009....

  17. Thermal property prediction and measurement of organic phase change materials in the liquid phase near the melting point

    International Nuclear Information System (INIS)

    O’Connor, William E.; Warzoha, Ronald; Weigand, Rebecca; Fleischer, Amy S.; Wemhoff, Aaron P.

    2014-01-01

    Highlights: • Liquid-phase thermal properties for five phase change materials were estimated. • Various liquid phase and phase transition thermal properties were measured. • The thermal diffusivity was found using a best path to prediction approach. • The thermal diffusivity predictive method shows 15% agreement for organic PCMs. - Abstract: Organic phase change materials (PCMs) are a popular choice for many thermal energy storage applications including solar energy, building envelope thermal barriers, and passive cooling of portable electronics. Since the extent of phase change during a heating or cooling process is dependent upon rapid thermal penetration into the PCM, accurate knowledge of the thermal diffusivity of the PCM in both solid and liquid phases is crucial. This study addresses the existing gaps in information for liquid-phase PCM properties by examining an approach that determines the best path to prediction (BPP) for the thermal diffusivity of both alkanes and unsaturated acids. Knowledge of the BPP will enable researchers to explore the influence of PCM molecular structure on bulk thermophysical properties, thereby allowing the fabrication of optimized PCMs. The BPP method determines which of the tens of thousands of combinations of 22 different available theoretical techniques provides best agreement with thermal diffusivity values based on reported or measured density, heat capacity, and thermal conductivity for each of five PCMs (heneicosane, tricosane, tetracosane, oleic acid, and linoleic acid) in the liquid phase near the melting point. Separate BPPs were calibrated for alkanes based on heneicosane and tetracosane, and for the unsaturated acids. The alkane and unsaturated acid BPPs were then tested on a variety of similar materials, showing agreement with reported/measured thermal diffusivity within ∼15% for all materials. The alkane BPP was then applied to find that increasing the length of alkane chains decreases the PCM thermal

  18. Systematic prediction of new ferroelectric inorganic materials in point group 6

    International Nuclear Information System (INIS)

    Abrahams, S.C.

    1990-01-01

    A total of seven new families and sixteen structurally different inorganic materials with point group 6 are shown to satisfy the criteria presented previously by the present author for predicting ferroelectricity. In case each prediction is experimentally verified, the 183 individual entries for point group 6 listed in the Inorganic Crystal Structure Database will result in over 80 new ferroelectrics, of which about 30 are rare-earth isomorphs. The total number of 'pure'

  19. Predicting the distribution of bed material accumulation using river network sediment budgets

    Science.gov (United States)

    Wilkinson, Scott N.; Prosser, Ian P.; Hughes, Andrew O.

    2006-10-01

    Assessing the spatial distribution of bed material accumulation in river networks is important for determining the impacts of erosion on downstream channel form and habitat and for planning erosion and sediment management. A model that constructs spatially distributed budgets of bed material sediment is developed to predict the locations of accumulation following land use change. For each link in the river network, GIS algorithms are used to predict bed material supply from gullies, river banks, and upstream tributaries and to compare total supply with transport capacity. The model is tested in the 29,000 km2 Murrumbidgee River catchment in southeast Australia. It correctly predicts the presence or absence of accumulation in 71% of river links, which is significantly better performance than previous models, which do not account for spatial variability in sediment supply and transport capacity. Representing transient sediment storage is important for predicting smaller accumulations. Bed material accumulation is predicted in 25% of the river network, indicating its importance as an environmental problem in Australia.

  20. Coupled hygrothermal, electrochemical, and mechanical modelling for deterioration prediction in reinforced cementitious materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Lepech, M.

    2017-01-01

    In this paper a coupled hygrothermal, electrochemical, and mechanical modelling approach for the deterioration prediction in cementitious materials is briefly outlined. Deterioration prediction is thereby based on coupled modelling of (i) chemical processes including among others transport of hea......, i.e. information, such as such as corrosion current density, damage state of concrete cover, etc., are constantly exchanged between the models....... and matter as well as phase assemblage on the nano and micro scale, (ii) corrosion of steel including electrochemical processes at the reinforcement surface, and (iii) material performance including corrosion- and load-induced damages on the meso and macro scale. The individual FEM models are fully coupled...

  1. Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods

    Science.gov (United States)

    Ma, Zheng-Dong

    2017-12-01

    Macro-architectured cellular (MAC) material is defined as a class of engineered materials having configurable cells of relatively large (i.e., visible) size that can be architecturally designed to achieve various desired material properties. Two types of novel MAC materials, negative Poisson's ratio material and biomimetic tendon reinforced material, were introduced in this study. To estimate the effective material properties for structural analyses and to optimally design such materials, a set of suitable homogenization methods was developed that provided an effective means for the multiscale modeling of MAC materials. First, a strain-based homogenization method was developed using an approach that separated the strain field into a homogenized strain field and a strain variation field in the local cellular domain superposed on the homogenized strain field. The principle of virtual displacements for the relationship between the strain variation field and the homogenized strain field was then used to condense the strain variation field onto the homogenized strain field. The new method was then extended to a stress-based homogenization process based on the principle of virtual forces and further applied to address the discrete systems represented by the beam or frame structures of the aforementioned MAC materials. The characteristic modes and the stress recovery process used to predict the stress distribution inside the cellular domain and thus determine the material strengths and failures at the local level are also discussed.

  2. Evaluation and prediction of neutron embrittlement in reactor pressure vessel materials. Final report

    International Nuclear Information System (INIS)

    Hawthorne, J.R.; Menke, B.H.; Loss, F.J.; Watson, H.E.; Hiser, A.L.; Gray, R.A.

    1982-12-01

    This study evaluates the effects of fast neutron irradiation on the mechanical properties of eight nuclear reactor vessel materials. The materials include submerged arc weldments, three plates, and one forging. The materials are in the unirradiated and irradiated conditions with regard to tensile, Charpy impact, and static and dynamic fracture toughness properties. Correlations between impact and fracture toughness parameters are developed from the experimental results. The observed shifts in transition temperature and the drop in upper-shelf energy are compared with predictions developed from the Regulatory Guide 1.99.1 trend curves

  3. Do Materialism, Intrinsic Aspirations, and Meaning in Life Predict Students' Meanings of Education?

    Science.gov (United States)

    Henderson-King, Donna; Mitchell, Amanda M.

    2011-01-01

    Though there is a deep literature on factors that predict college attendance and on the effects of college attendance on students' development, there has been little research on what education actually means to students themselves. This study was conducted to examine whether materialism, intrinsic aspirations, and the search for meaning in life…

  4. Predicted phototoxicities of carbon nano-material by quantum mechanical calculations

    Science.gov (United States)

    The purpose of this research is to develop a predictive model for the phototoxicity potential of carbon nanomaterials (fullerenols and single-walled carbon nanotubes). This model is based on the quantum mechanical (ab initio) calculations on these carbon-based materials and compa...

  5. Model to predict the radiological consequences of transportation of radioactive material through an urban environment

    International Nuclear Information System (INIS)

    Taylor, J.M.; Daniel, S.L.; DuCharme, A.R.; Finley, N.N.

    1977-01-01

    A model has been developed which predicts the radiological consequences of the transportation of radioactive material in and around urban environments. This discussion of the model includes discussion of the following general topics: health effects from radiation exposure, urban area characterization, computation of dose resulting from normal transportation, computation of dose resulting from vehicular accidents or sabotage, and preliminary results and conclusions

  6. Crack path predictions and experiments in plane structures considering anisotropic properties and material interfaces

    Directory of Open Access Journals (Sweden)

    P.O. Judt

    2015-10-01

    Full Text Available In many engineering applications special requirements are directed to a material's fracture behavior and the prediction of crack paths. Especially if the material exhibits anisotropic elastic properties or fracture toughnesses, e.g. in textured or composite materials, the simulation of crack paths is challenging. Here, the application of path independent interaction integrals (I-integrals, J-, L- and M-integrals is beneficial for an accurate crack tip loading analysis. Numerical tools for the calculation of loading quantities using these path-invariant integrals are implemented into the commercial finite element (FE-code ABAQUS. Global approaches of the integrals are convenient considering crack tips approaching other crack faces, internal boundaries or material interfaces. Curved crack faces require special treatment with respect to integration contours. Numerical crack paths are predicted based on FE calculations of the boundary value problem in connection with an intelligent adaptive re-meshing algorithm. Considering fracture toughness anisotropy and accounting for inelastic effects due to small plastic zones in the crack tip region, the numerically predicted crack paths of different types of specimens with material interfaces and internal boundaries are compared to subcritically grown paths obtained from experiments.

  7. A diffusivity model for predicting VOC diffusion in porous building materials based on fractal theory

    International Nuclear Information System (INIS)

    Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping

    2015-01-01

    Highlights: • Fractal theory is introduced into the prediction of VOC diffusion coefficient. • MSFC model of the diffusion coefficient is developed for porous building materials. • The MSFC model contains detailed pore structure parameters. • The accuracy of the MSFC model is verified by independent experiments. - Abstract: Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber.

  8. Life Prediction/Reliability Data of Glass-Ceramic Material Determined for Radome Applications

    Science.gov (United States)

    Choi, Sung R.; Gyekenyesi, John P.

    2002-01-01

    Brittle materials, ceramics, are candidate materials for a variety of structural applications for a wide range of temperatures. However, the process of slow crack growth, occurring in any loading configuration, limits the service life of structural components. Therefore, it is important to accurately determine the slow crack growth parameters required for component life prediction using an appropriate test methodology. This test methodology also should be useful in determining the influence of component processing and composition variables on the slow crack growth behavior of newly developed or existing materials, thereby allowing the component processing and composition to be tailored and optimized to specific needs. Through the American Society for Testing and Materials (ASTM), the authors recently developed two test methods to determine the life prediction parameters of ceramics. The two test standards, ASTM 1368 for room temperature and ASTM C 1465 for elevated temperatures, were published in the 2001 Annual Book of ASTM Standards, Vol. 15.01. Briefly, the test method employs constant stress-rate (or dynamic fatigue) testing to determine flexural strengths as a function of the applied stress rate. The merit of this test method lies in its simplicity: strengths are measured in a routine manner in flexure at four or more applied stress rates with an appropriate number of test specimens at each applied stress rate. The slow crack growth parameters necessary for life prediction are then determined from a simple relationship between the strength and the applied stress rate. Extensive life prediction testing was conducted at the NASA Glenn Research Center using the developed ASTM C 1368 test method to determine the life prediction parameters of a glass-ceramic material that the Navy will use for radome applications.

  9. A top-down approach for the prediction of hardness and toughness of hierarchical materials

    International Nuclear Information System (INIS)

    Carpinteri, Alberto; Paggi, Marco

    2009-01-01

    Many natural and man-made materials exhibit structure over more than one length scale. In this paper, we deal with hierarchical grained composite materials that have recently been designed to achieve superior hardness and toughness as compared to their traditional counterparts. Their nested structure, where meso-grains are recursively composed of smaller and smaller micro-grains at the different scales with a fractal-like topology, is herein studied from a hierarchical perspective. Considering a top-down approach, i.e. from the largest to the smallest scale, we propose a recursive micromechanical model coupled with a generalized fractal mixture rule for the prediction of hardness and toughness of a grained material with n hierarchical levels. A relationship between hardness and toughness is also derived and the analytical predictions are compared with experimental data.

  10. Forensic DNA Phenotyping: Predicting human appearance from crime scene material for investigative purposes.

    Science.gov (United States)

    Kayser, Manfred

    2015-09-01

    Forensic DNA Phenotyping refers to the prediction of appearance traits of unknown sample donors, or unknown deceased (missing) persons, directly from biological materials found at the scene. "Biological witness" outcomes of Forensic DNA Phenotyping can provide investigative leads to trace unknown persons, who are unidentifiable with current comparative DNA profiling. This intelligence application of DNA marks a substantially different forensic use of genetic material rather than that of current DNA profiling presented in the courtroom. Currently, group-specific pigmentation traits are already predictable from DNA with reasonably high accuracies, while several other externally visible characteristics are under genetic investigation. Until individual-specific appearance becomes accurately predictable from DNA, conventional DNA profiling needs to be performed subsequent to appearance DNA prediction. Notably, and where Forensic DNA Phenotyping shows great promise, this is on a (much) smaller group of potential suspects, who match the appearance characteristics DNA-predicted from the crime scene stain or from the deceased person's remains. Provided sufficient funding being made available, future research to better understand the genetic basis of human appearance will expectedly lead to a substantially more detailed description of an unknown person's appearance from DNA, delivering increased value for police investigations in criminal and missing person cases involving unknowns. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Crystal Graph Convolutional Neural Networks for an Accurate and Interpretable Prediction of Material Properties

    Science.gov (United States)

    Xie, Tian; Grossman, Jeffrey C.

    2018-04-01

    The use of machine learning methods for accelerating the design of crystalline materials usually requires manually constructed feature vectors or complex transformation of atom coordinates to input the crystal structure, which either constrains the model to certain crystal types or makes it difficult to provide chemical insights. Here, we develop a crystal graph convolutional neural networks framework to directly learn material properties from the connection of atoms in the crystal, providing a universal and interpretable representation of crystalline materials. Our method provides a highly accurate prediction of density functional theory calculated properties for eight different properties of crystals with various structure types and compositions after being trained with 1 04 data points. Further, our framework is interpretable because one can extract the contributions from local chemical environments to global properties. Using an example of perovskites, we show how this information can be utilized to discover empirical rules for materials design.

  12. Computer program for prediction of the deposition of material released from fixed and rotary wing aircraft

    Science.gov (United States)

    Teske, M. E.

    1984-01-01

    This is a user manual for the computer code ""AGDISP'' (AGricultural DISPersal) which has been developed to predict the deposition of material released from fixed and rotary wing aircraft in a single-pass, computationally efficient manner. The formulation of the code is novel in that the mean particle trajectory and the variance about the mean resulting from turbulent fluid fluctuations are simultaneously predicted. The code presently includes the capability of assessing the influence of neutral atmospheric conditions, inviscid wake vortices, particle evaporation, plant canopy and terrain on the deposition pattern.

  13. Predicting the microstructure-dependent mechanical performance of materials for early-stage design

    International Nuclear Information System (INIS)

    Dimiduk, D.M.; Uchic, M.D.; Parathasarathy, T.A.; Rao, S.I.; Choi, Y.-S.

    2004-01-01

    A description is offered of a simulation and testing methodology for structural materials that incorporates the influence of the local, microscopic and submicroscopic heterogeneous nature of material properties directly into design procedures. The new methodology builds upon a multitude of rapid microstructural and property assessments of selected local regions of a material (i.e. single-crystal regions, defected regions, grain aggregates, etc.), perhaps from a fully-processed component, or from materials specifically prepared to represent selected aspects of the full-scale process. The results from these assessments are used to define parameters within a hierarchy of mathematical and numerical representations of the material, and together in turn these may be used in design performance simulation codes to predict the intrinsic response of larger-scale structures. Further, the methodology may be used to anticipate the effects of defects on the performance of the full-scale structure. Most steps of this alternative design and test methodology are amenable to automation, and the methodology as a whole will reduce the number of iterative large-scale cycles required to qualify a material's suitability for structural service; thus, the new method is a framework for accelerating the development of structural materials

  14. Preliminary lifetime predictions for 304 stainless steel as the LANL ABC blanket material

    International Nuclear Information System (INIS)

    Park, J.J.; Buksa, J.J.; Houts, M.G.; Arthur, E.D.

    1997-11-01

    The prediction of materials lifetime in the preconceptual Los Alamos National Laboratory (LANL) Accelerator-Based Conversion of Plutonium (ABC) is of utmost interest. Because Hastelloy N showed good corrosion resistance to the Oak Ridge National Laboratory Molten Salt Reactor Experiment fuel salt that is similar to the LANL ABC fuel salt, Hastelloy N was originally proposed for the LANL ABC blanket material. In this paper, the possibility of using 304 stainless steel as a replacement for the Hastelloy N is investigated in terms of corrosion issues and fluence-limit considerations. An attempt is made, based on the previous Fast Flux Test Facility design data, to predict the preliminary lifetime estimate of the 304 stainless steel used in the blanket region of the LANL ABC

  15. Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

    Directory of Open Access Journals (Sweden)

    Mijajlović Miroslav M.

    2016-01-01

    Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

  16. Prediction of detonation and JWL eos parameters of energetic materials using EXPLO5 computer code

    CSIR Research Space (South Africa)

    Peter, Xolani

    2016-09-01

    Full Text Available Ballistic Organization Cape Town, South Africa 27-29 September 2016 1 PREDICTION OF DETONATION AND JWL EOS PARAMETERS OF ENERGETIC MATERIALS USING EXPLO5 COMPUTER CODE X. Peter*, Z. Jiba, M. Olivier, I.M. Snyman, F.J. Mostert and T.J. Sono.... Nowadays many numerical methods and programs are being used for carrying out thermodynamic calculations of the detonation parameters of condensed explosives, for example a BKW Fortran (Mader, 1967), Ruby (Cowperthwaite and Zwisler, 1974) TIGER...

  17. Chairside CAD/CAM materials. Part 3: Cyclic fatigue parameters and lifetime predictions.

    Science.gov (United States)

    Wendler, Michael; Belli, Renan; Valladares, Diana; Petschelt, Anselm; Lohbauer, Ulrich

    2018-06-01

    Chemical and mechanical degradation play a key role on the lifetime of dental restorative materials. Therefore, prediction of their long-term performance in the oral environment should base on fatigue, rather than inert strength data, as commonly observed in the dental material's field. The objective of the present study was to provide mechanistic fatigue parameters of current dental CAD/CAM materials under cyclic biaxial flexure and assess their suitability in predicting clinical fracture behaviors. Eight CAD/CAM materials, including polycrystalline zirconia (IPS e.max ZirCAD), reinforced glasses (Vitablocs Mark II, IPS Empress CAD), glass-ceramics (IPS e.max CAD, Suprinity PC, Celtra Duo), as well as hybrid materials (Enamic, Lava Ultimate) were evaluated. Rectangular plates (12×12×1.2mm 3 ) with highly polished surfaces were prepared and tested in biaxial cyclic fatigue in water until fracture using the Ball-on-Three-Balls (B3B) test. Cyclic fatigue parameters n and A* were obtained from the lifetime data for each material and further used to build SPT diagrams. The latter were used to compare in-vitro with in-vivo fracture distributions for IPS e.max CAD and IPS Empress CAD. Susceptibility to subcritical crack growth under cyclic loading was observed for all materials, being more severe (n≤20) in lithium-based glass-ceramics and Vitablocs Mark II. Strength degradations of 40% up to 60% were predicted after only 1 year of service. Threshold stress intensity factors (K th ) representing the onset of subcritical crack growth (SCG), were estimated to lie in the range of 0.37-0.44 of K Ic for the lithium-based glass-ceramics and Vitablocs Mark II and between 0.51-0.59 of K Ic for the other materials. Failure distributions associated with mechanistic estimations of strength degradation in-vitro showed to be useful in interpreting failure behavior in-vivo. The parameter K th stood out as a better predictor of clinical performance in detriment to the SCG n

  18. Prediction of porosity of food materials during drying: Current challenges and directions.

    Science.gov (United States)

    Joardder, Mohammad U H; Kumar, C; Karim, M A

    2017-07-18

    Pore formation in food samples is a common physical phenomenon observed during dehydration processes. The pore evolution during drying significantly affects the physical properties and quality of dried foods. Therefore, it should be taken into consideration when predicting transport processes in the drying sample. Characteristics of pore formation depend on the drying process parameters, product properties and processing time. Understanding the physics of pore formation and evolution during drying will assist in accurately predicting the drying kinetics and quality of food materials. Researchers have been trying to develop mathematical models to describe the pore formation and evolution during drying. In this study, existing porosity models are critically analysed and limitations are identified. Better insight into the factors affecting porosity is provided, and suggestions are proposed to overcome the limitations. These include considerations of process parameters such as glass transition temperature, sample temperature, and variable material properties in the porosity models. Several researchers have proposed models for porosity prediction of food materials during drying. However, these models are either very simplistic or empirical in nature and failed to consider relevant significant factors that influence porosity. In-depth understanding of characteristics of the pore is required for developing a generic model of porosity. A micro-level analysis of pore formation is presented for better understanding, which will help in developing an accurate and generic porosity model.

  19. Precision Obtained Using an Artificial Neural Network for Predicting the Material Removal Rate in Ultrasonic Machining

    Directory of Open Access Journals (Sweden)

    Gaoyan Zhong

    2017-12-01

    Full Text Available The present study proposes a back propagation artificial neural network (BPANN to provide improved precision for predicting the material removal rate (MRR in ultrasonic machining. The BPANN benefits from the advantage of artificial neural networks (ANNs in dealing with complex input-output relationships without explicit mathematical functions. In our previous study, a conventional linear regression model and improved nonlinear regression model were established for modelling the MRR in ultrasonic machining to reflect the influence of machining parameters on process response. In the present work, we quantitatively compare the prediction precision obtained by the previously proposed regression models and the presently proposed BPANN model. The results of detailed analyses indicate that the BPANN model provided the highest prediction precision of the three models considered. The present work makes a positive contribution to expanding the applications of ANNs and can be considered as a guide for modelling complex problems of general machining.

  20. Analytical method for predicting plastic flow in notched fiber composite materials

    International Nuclear Information System (INIS)

    Flynn, P.L.; Ebert, L.J.

    1977-01-01

    An analytical system was developed for prediction of the onset and progress of plastic flow of oriented fiber composite materials in which both externally applied complex stress states and stress raisers were present. The predictive system was a unique combination of two numerical systems, the ''SAAS II'' finite element analysis system and a micromechanics finite element program. The SAAS II system was used to generate the three-dimensional stress distributions, which were used as the input into the finite element micromechanics program. Appropriate yielding criteria were then applied to this latter program. The accuracy of the analytical system was demonstrated by the agreement between the analytically predicted and the experimentally measured flow values of externally notched tungsten wire reinforced copper oriented fiber composites, in which the fiber fraction was 50 vol pct

  1. Computer code to predict the heat of explosion of high energy materials

    International Nuclear Information System (INIS)

    Muthurajan, H.; Sivabalan, R.; Pon Saravanan, N.; Talawar, M.B.

    2009-01-01

    The computational approach to the thermochemical changes involved in the process of explosion of a high energy materials (HEMs) vis-a-vis its molecular structure aids a HEMs chemist/engineers to predict the important thermodynamic parameters such as heat of explosion of the HEMs. Such a computer-aided design will be useful in predicting the performance of a given HEM as well as in conceiving futuristic high energy molecules that have significant potential in the field of explosives and propellants. The software code viz., LOTUSES developed by authors predicts various characteristics of HEMs such as explosion products including balanced explosion reactions, density of HEMs, velocity of detonation, CJ pressure, etc. The new computational approach described in this paper allows the prediction of heat of explosion (ΔH e ) without any experimental data for different HEMs, which are comparable with experimental results reported in literature. The new algorithm which does not require any complex input parameter is incorporated in LOTUSES (version 1.5) and the results are presented in this paper. The linear regression analysis of all data point yields the correlation coefficient R 2 = 0.9721 with a linear equation y = 0.9262x + 101.45. The correlation coefficient value 0.9721 reveals that the computed values are in good agreement with experimental values and useful for rapid hazard assessment of energetic materials

  2. A review on fatigue life prediction methods for anti-vibration rubber materials

    Directory of Open Access Journals (Sweden)

    Xiaoli WANG

    2016-08-01

    Full Text Available Anti-vibration rubber, because of its superior elasticity, plasticity, waterproof and trapping characteristics, is widely used in the automotive industry, national defense, construction and other fields. The theory and technology of predicting fatigue life is of great significance to improve the durability design and manufacturing of anti-vibration rubber products. According to the characteristics of the anti-vibration rubber products in service, the technical difficulties for analyzing fatigue properties of anti-vibration rubber materials are pointed out. The research progress of the fatigue properties of rubber materials is reviewed from three angles including methods of fatigue crack initiation, fatigue crack propagation and fatigue damage accumulation. It is put forward that some nonlinear characteristics of rubber under fatigue loading, including the Mullins effect, permanent deformation and cyclic stress softening, should be considered in the further study of rubber materials. Meanwhile, it is indicated that the fatigue damage accumulation method based on continuum damage mechanics might be more appropriate to solve fatigue damage and life prediction problems for complex rubber materials and structures under fatigue loading.

  3. A diffusivity model for predicting VOC diffusion in porous building materials based on fractal theory.

    Science.gov (United States)

    Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping

    2015-12-15

    Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. A Duration Prediction Using a Material-Based Progress Management Methodology for Construction Operation Plans

    Directory of Open Access Journals (Sweden)

    Yongho Ko

    2017-04-01

    Full Text Available Precise and accurate prediction models for duration and cost enable contractors to improve their decision making for effective resource management in terms of sustainability in construction. Previous studies have been limited to cost-based estimations, but this study focuses on a material-based progress management method. Cost-based estimations typically used in construction, such as the earned value method, rely on comparing the planned budget with the actual cost. However, accurately planning budgets requires analysis of many factors, such as the financial status of the sectors involved. Furthermore, there is a higher possibility of changes in the budget than in the total amount of material used during construction, which is deduced from the quantity take-off from drawings and specifications. Accordingly, this study proposes a material-based progress management methodology, which was developed using different predictive analysis models (regression, neural network, and auto-regressive moving average as well as datasets on material and labor, which can be extracted from daily work reports from contractors. A case study on actual datasets was conducted, and the results show that the proposed methodology can be efficiently used for progress management in construction.

  5. Combinatory Models for Predicting the Effective Thermal Conductivity of Frozen and Unfrozen Food Materials

    Directory of Open Access Journals (Sweden)

    K. S. Reddy

    2010-01-01

    Full Text Available A model to predict the effective thermal conductivity of heterogeneous materials is proposed based on unit cell approach. The model is combined with four fundamental effective thermal conductivity models (Parallel, Series, Maxwell-Eucken-I, and Maxwell-Eucken-II to evolve a unifying equation for the estimation of effective thermal conductivity of porous and nonporous food materials. The effect of volume fraction (ν on the structure composition factor (ψ of the food materials is studied. The models are compared with the experimental data of various foods at the initial freezing temperature. The effective thermal conductivity estimated by the Maxwell-Eucken-I + Present model shows good agreement with the experimental data with a minimum average deviation of ±8.66% and maximum deviation of ±42.76% of Series + Present Model. The combined models have advantages over other empirical and semiempirical models.

  6. Influence of mesh density, cortical thickness and material properties on human rib fracture prediction.

    Science.gov (United States)

    Li, Zuoping; Kindig, Matthew W; Subit, Damien; Kent, Richard W

    2010-11-01

    The purpose of this paper was to investigate the sensitivity of the structural responses and bone fractures of the ribs to mesh density, cortical thickness, and material properties so as to provide guidelines for the development of finite element (FE) thorax models used in impact biomechanics. Subject-specific FE models of the second, fourth, sixth and tenth ribs were developed to reproduce dynamic failure experiments. Sensitivity studies were then conducted to quantify the effects of variations in mesh density, cortical thickness, and material parameters on the model-predicted reaction force-displacement relationship, cortical strains, and bone fracture locations for all four ribs. Overall, it was demonstrated that rib FE models consisting of 2000-3000 trabecular hexahedral elements (weighted element length 2-3mm) and associated quadrilateral cortical shell elements with variable thickness more closely predicted the rib structural responses and bone fracture force-failure displacement relationships observed in the experiments (except the fracture locations), compared to models with constant cortical thickness. Further increases in mesh density increased computational cost but did not markedly improve model predictions. A ±30% change in the major material parameters of cortical bone lead to a -16.7 to 33.3% change in fracture displacement and -22.5 to +19.1% change in the fracture force. The results in this study suggest that human rib structural responses can be modeled in an accurate and computationally efficient way using (a) a coarse mesh of 2000-3000 solid elements, (b) cortical shells elements with variable thickness distribution and (c) a rate-dependent elastic-plastic material model. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. A Critical Plane-energy Model for Multiaxial Fatigue Life Prediction of Homogeneous and Heterogeneous Materials

    Science.gov (United States)

    Wei, Haoyang

    A new critical plane-energy model is proposed in this thesis for multiaxial fatigue life prediction of homogeneous and heterogeneous materials. Brief review of existing methods, especially on the critical plane-based and energy-based methods, are given first. Special focus is on one critical plane approach which has been shown to work for both brittle and ductile metals. The key idea is to automatically change the critical plane orientation with respect to different materials and stress states. One potential drawback of the developed model is that it needs an empirical calibration parameter for non-proportional multiaxial loadings since only the strain terms are used and the out-of-phase hardening cannot be considered. The energy-based model using the critical plane concept is proposed with help of the Mroz-Garud hardening rule to explicitly include the effect of non-proportional hardening under fatigue cyclic loadings. Thus, the empirical calibration for non-proportional loading is not needed since the out-of-phase hardening is naturally included in the stress calculation. The model predictions are compared with experimental data from open literature and it is shown the proposed model can work for both proportional and non-proportional loadings without the empirical calibration. Next, the model is extended for the fatigue analysis of heterogeneous materials integrating with finite element method. Fatigue crack initiation of representative volume of heterogeneous materials is analyzed using the developed critical plane-energy model and special focus is on the microstructure effect on the multiaxial fatigue life predictions. Several conclusions and future work is drawn based on the proposed study.

  8. Exposure to predicted precipitation patterns decreases population size and alters community structure of cyanobacteria in biological soil crusts from the Chihuahuan Desert.

    Science.gov (United States)

    Fernandes, Vanessa M C; Machado de Lima, Náthali Maria; Roush, Daniel; Rudgers, Jennifer; Collins, Scott L; Garcia-Pichel, Ferran

    2018-01-01

    Cyanobacteria typically colonize the surface of arid soils, building biological soil crust (biocrusts) that provide a variety of ecosystem benefits, ranging from fertilization to stabilization against erosion. We investigated how future scenarios in precipitation anticipated for the Northern Chihuahuan Desert affected abundance and composition of biocrust cyanobacteria in two grassland ecosystems. Scenarios included a decrease in precipitation and a delay of monsoon rainfall. After three years, both treatments negatively affected cyanobacteria, although the effects of monsoon delay were milder than those of decreased precipitation. Mature biocrusts in black grama grassland suffered severe losses in cyanobacterial biomass and diversity, but compositionally simpler biocrusts in blue grama-dominated grassland maintained biomass, only suffering diversity losses. This could be partially explained by the differential sensitivity of cyanobacterial taxa: nitrogen-fixing Scytonema spp. were the most sensitive, followed by phylotypes in the Microcoleus steenstrupii complex. Microcoleus vaginatus was the least affected in all cases, but is known to be very sensitive to warming. We predict that altered precipitation will tend to prevent biocrusts from reaching successional maturity, selecting for M. vaginatus over competing M. steenstrupii, among pioneer biocrust-formers. A shift towards heat-sensitive M. vaginatus could ultimately destabilize biocrusts when precipitation changes are combined with global warming. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. Prediction of the niche effect for single flat panels with or without attached sound absorbing materials.

    Science.gov (United States)

    Sgard, Franck; Atalla, Noureddine; Nélisse, Hugues

    2015-01-01

    The sound transmission loss (STL) of a test sample measured in sound transmission facilities is affected by the opening in which it is located. This is called the niche effect. This paper uses a modal approach to study the STL of a rectangular plate with or without an attached porous material located inside a box-shaped niche. The porous material is modeled as a limp equivalent fluid. The proposed model is validated by comparison with finite element/boundary element computations. Using a condensation of the pressure fields in the niche, the niche effect is interpreted in terms of a modification of the modal blocked pressure fields acting on the panel induced by the front cavity and by a modification of the radiation efficiency of the panel modes due to the presence of the back cavity. The modal approach is then used to investigate the impact of (1) the presence of a porous material attached to the panel on the niche effect and (2) the niche effect on the assessment of the porous material insertion loss. A simplified model for the porous material based on a transfer matrix approach is also proposed to predict the STL of the system and its validity is discussed.

  10. Material properties that predict preservative uptake for silicone hydrogel contact lenses.

    Science.gov (United States)

    Green, J Angelo; Phillips, K Scott; Hitchins, Victoria M; Lucas, Anne D; Shoff, Megan E; Hutter, Joseph C; Rorer, Eva M; Eydelman, Malvina B

    2012-11-01

    To assess material properties that affect preservative uptake by silicone hydrogel lenses. We evaluated the water content (using differential scanning calorimetry), effective pore size (using probe penetration), and preservative uptake (using high-performance liquid chromatography with spectrophotometric detection) of silicone and conventional hydrogel soft contact lenses. Lenses grouped similarly based on freezable water content as they did based on total water content. Evaluation of the effective pore size highlighted potential differences between the surface-treated and non-surface-treated materials. The water content of the lens materials and ionic charge are associated with the degree of preservative uptake. The current grouping system for testing contact lens-solution interactions separates all silicone hydrogels from conventional hydrogel contact lenses. However, not all silicone hydrogel lenses interact similarly with the same contact lens solution. Based upon the results of our research, we propose that the same material characteristics used to group conventional hydrogel lenses, water content and ionic charge, can also be used to predict uptake of hydrophilic preservatives for silicone hydrogel lenses. In addition, the hydrophobicity of silicone hydrogel contact lenses, although not investigated here, is a unique contact lens material property that should be evaluated for the uptake of relatively hydrophobic preservatives and tear components.

  11. Micromechanics model for predicting anisotropic electrical conductivity of carbon fiber composite materials

    Science.gov (United States)

    Haider, Mohammad Faisal; Haider, Md. Mushfique; Yasmeen, Farzana

    2016-07-01

    Heterogeneous materials, such as composites consist of clearly distinguishable constituents (or phases) that show different electrical properties. Multifunctional composites have anisotropic electrical properties that can be tailored for a particular application. The effective anisotropic electrical conductivity of composites is strongly affected by many parameters including volume fractions, distributions, and orientations of constituents. Given the electrical properties of the constituents, one important goal of micromechanics of materials consists of predicting electrical response of the heterogeneous material on the basis of the geometries and properties of the individual phases, a task known as homogenization. The benefit of homogenization is that the behavior of a heterogeneous material can be determined without resorting or testing it. Furthermore, continuum micromechanics can predict the full multi-axial properties and responses of inhomogeneous materials, which are anisotropic in nature. Effective electrical conductivity estimation is performed by using classical micromechanics techniques (composite cylinder assemblage method) that investigates the effect of the fiber/matrix electrical properties and their volume fractions on the micro scale composite response. The composite cylinder assemblage method (CCM) is an analytical theory that is based on the assumption that composites are in a state of periodic structure. The CCM was developed to extend capabilities variable fiber shape/array availability with same volume fraction, interphase analysis, etc. The CCM is a continuum-based micromechanics model that provides closed form expressions for upper level length scales such as macro-scale composite responses in terms of the properties, shapes, orientations and constituent distributions at lower length levels such as the micro-scale.

  12. Quantifying the Pathway and Predicting Spontaneous Emulsification during Material Exchange in a Two Phase Liquid System.

    Science.gov (United States)

    Spooner, Stephen; Rahnama, Alireza; Warnett, Jason M; Williams, Mark A; Li, Zushu; Sridhar, Seetharaman

    2017-10-30

    Kinetic restriction of a thermodynamically favourable equilibrium is a common theme in materials processing. The interfacial instability in systems where rate of material exchange is far greater than the mass transfer through respective bulk phases is of specific interest when tracking the transient interfacial area, a parameter integral to short processing times for productivity streamlining in all manufacturing where interfacial reaction occurs. This is even more pertinent in high-temperature systems for energy and cost savings. Here the quantified physical pathway of interfacial area change due to material exchange in liquid metal-molten oxide systems is presented. In addition the predicted growth regime and emulsification behaviour in relation to interfacial tension as modelled using phase-field methodology is shown. The observed in-situ emulsification behaviour links quantitatively the geometry of perturbations as a validation method for the development of simulating the phenomena. Thus a method is presented to both predict and engineer the formation of micro emulsions to a desired specification.

  13. Appetite - decreased

    Science.gov (United States)

    Loss of appetite; Decreased appetite; Anorexia ... Any illness can reduce appetite. If the illness is treatable, the appetite should return when the condition is cured. Loss of appetite can cause weight ...

  14. Computer simulation for prediction of performance and thermodynamic parameters of high energy materials

    International Nuclear Information System (INIS)

    Muthurajan, H.; Sivabalan, R.; Talawar, M.B.; Asthana, S.N.

    2004-01-01

    A new code viz., Linear Output Thermodynamic User-friendly Software for Energetic Systems (LOTUSES) developed during this work predicts the theoretical performance parameters such as density, detonation factor, velocity of detonation, detonation pressure and thermodynamic properties such as heat of detonation, heat of explosion, volume of explosion gaseous products. The same code also assists in the prediction of possible explosive decomposition products after explosion and power index. The developed code has been validated by calculating the parameters of standard explosives such as TNT, PETN, RDX, and HMX. Theoretically predicated parameters are accurate to the order of ±5% deviation. To the best of our knowledge, no such code is reported in literature which can predict a wide range of characteristics of known/unknown explosives with minimum input parameters. The code can be used to obtain thermochemical and performance parameters of high energy materials (HEMs) with reasonable accuracy. The code has been developed in Visual Basic having enhanced windows environment, and thereby advantages over the conventional codes, written in Fortran. The theoretically predicted HEMs performance can be directly printed as well as stored in text (.txt) or HTML (.htm) or Microsoft Word (.doc) or Adobe Acrobat (.pdf) format in the hard disk. The output can also be copied into the Random Access Memory as clipboard text which can be imported/pasted in other software as in the case of other codes

  15. Movement Intention Prediction to Find a New Exoskeleton Design with Light and Comfortable Materials

    Science.gov (United States)

    Plaza Torres, Ing. Mauricio; Fredy Bernal, Ing; Andrés Cifuentes, Ing.

    2017-12-01

    This paper presents a discussion about the design a novel exoskeleton and the implementation of superficial magnetic sensor and pressure sensor for find patterns and parameters in order to predicting the intention of movement for people with musculoskeletal system problem in lower limbs. The information is obtained through reading position and movement by magnetic and pressure sensor installed in different parts of the body. The advantage of this sensor is the location of the position reference of the every part of the body. Using the sensor in some parts of the body is possible to calculate the muscle contraction for the prediction of intended movement and to find a new design with light and comfortable materials.

  16. Importance of the gas phase role to the prediction of energetic material behavior: An experimental study

    International Nuclear Information System (INIS)

    Ali, A.N.; Son, S.F.; Asay, B.W.; Sander, R.K.

    2005-01-01

    Various thermal (radiative, conductive, and convective) initiation experiments are performed to demonstrate the importance of the gas phase role in combustion modeling of energetic materials (EM). A previously published condensed phase model that includes a predicted critical irradiance above which ignition is not possible is compared to experimental laser ignition results for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT). Experimental results conflict with the predicted critical irradiance concept. The failure of the model is believed to result from a misconception about the role of the gas phase in the ignition process of energetic materials. The model assumes that ignition occurs at the surface and that evolution of gases inhibits ignition. High speed video of laser ignition, oven cook-off and hot wire ignition experiments captures the ignition of HMX and TNT in the gas phase. A laser ignition gap test is performed to further evaluate the effect of gas phase laser absorption and gas phase disruption on the ignition process. Results indicate that gas phase absorption of the laser energy is probably not the primary factor governing the gas phase ignition observations. It is discovered that a critical gap between an HMX pellet and a salt window of 6 mm±0.4 mm exists below which ignition by CO 2 laser is not possible at the tested irradiances of 29 W/cm 2 and 38 W/cm 2 for HMX ignition. These observations demonstrate that a significant disruption of the gas phase, in certain scenarios, will inhibit ignition, independent of any condensed phase processes. These results underscore the importance of gas phase processes and illustrate that conditions can exist where simple condensed phase models are inadequate to accurately predict the behavior of energetic materials

  17. Importance of the gas phase role to the prediction of energetic material behavior: An experimental study

    Science.gov (United States)

    Ali, A. N.; Son, S. F.; Asay, B. W.; Sander, R. K.

    2005-03-01

    Various thermal (radiative, conductive, and convective) initiation experiments are performed to demonstrate the importance of the gas phase role in combustion modeling of energetic materials (EM). A previously published condensed phase model that includes a predicted critical irradiance above which ignition is not possible is compared to experimental laser ignition results for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT). Experimental results conflict with the predicted critical irradiance concept. The failure of the model is believed to result from a misconception about the role of the gas phase in the ignition process of energetic materials. The model assumes that ignition occurs at the surface and that evolution of gases inhibits ignition. High speed video of laser ignition, oven cook-off and hot wire ignition experiments captures the ignition of HMX and TNT in the gas phase. A laser ignition gap test is performed to further evaluate the effect of gas phase laser absorption and gas phase disruption on the ignition process. Results indicate that gas phase absorption of the laser energy is probably not the primary factor governing the gas phase ignition observations. It is discovered that a critical gap between an HMX pellet and a salt window of 6mm±0.4mm exists below which ignition by CO2 laser is not possible at the tested irradiances of 29W /cm2 and 38W/cm2 for HMX ignition. These observations demonstrate that a significant disruption of the gas phase, in certain scenarios, will inhibit ignition, independent of any condensed phase processes. These results underscore the importance of gas phase processes and illustrate that conditions can exist where simple condensed phase models are inadequate to accurately predict the behavior of energetic materials.

  18. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approx. 9 inches from the source) dominated by direct wave propagation, mid-field environment (approx. 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This report documents the outcome of the assessment.

  19. Comparison of actual and predicted routes used in the shipment of radioactive materials

    International Nuclear Information System (INIS)

    Joy, D.S.; Johnson, P.E.; Harrison, I.G.

    1985-01-01

    A number of highway controlled shipments of radioactive materials have been made over the past several years. An excellent example showing the variability of actual routes is the transfer of 45 shipments between the Three Mile Island reactor in Pennsylvania and Scoville, Idaho in 1982 and 1983. Six different routes varying between 2273 and 2483 miles were used. Approximately 75% of these shipments followed a common route which passed through ten Urbanized Areas, defined by the Census Bureau as having a population exceeding 100,000 people. Other routes, while shorter in distance, passed through as many as 14 Urbanized Areas. Routes predicted by the Oak Ridge routing model did not exactly duplicate actual routes used. However, the analysis shows that the routing model does make a good estimate of transportation routes actually chosen by shippers of radioactive materials. In actual practice, a number of factors (weather, road conditions, driver preference, etc.) influence the actual route taken. 5 refs., 1 fig., 1 tab

  20. TEMPERATURE PREDICTION IN 3013 CONTAINERS IN K AREA MATERIAL STORAGE (KAMS) FACILITY USING REGRESSION METHODS

    International Nuclear Information System (INIS)

    Gupta, N

    2008-01-01

    3013 containers are designed in accordance with the DOE-STD-3013-2004. These containers are qualified to store plutonium (Pu) bearing materials such as PuO2 for 50 years. DOT shipping packages such as the 9975 are used to store the 3013 containers in the K-Area Material Storage (KAMS) facility at Savannah River Site (SRS). DOE-STD-3013-2004 requires that a comprehensive surveillance program be set up to ensure that the 3013 container design parameters are not violated during the long term storage. To ensure structural integrity of the 3013 containers, thermal analyses using finite element models were performed to predict the contents and component temperatures for different but well defined parameters such as storage ambient temperature, PuO 2 density, fill heights, weights, and thermal loading. Interpolation is normally used to calculate temperatures if the actual parameter values are different from the analyzed values. A statistical analysis technique using regression methods is proposed to develop simple polynomial relations to predict temperatures for the actual parameter values found in the containers. The analysis shows that regression analysis is a powerful tool to develop simple relations to assess component temperatures

  1. Pathways to Structure-Property Relationships of Peptide-Materials Interfaces: Challenges in Predicting Molecular Structures.

    Science.gov (United States)

    Walsh, Tiffany R

    2017-07-18

    challenges in their successful application to model the biotic-abiotic interface, related to several factors. For instance, simulations require a plausible description of the chemistry and the physics of the interface, which comprises two very different states of matter, in the presence of liquid water. Also, it is essential that the conformational ensemble be comprehensively characterized under these conditions; this is especially challenging because intrinsically disordered peptides do not typically admit one single structure or set of structures. Moreover, a plausible structural model of the substrate is required, which may require a high level of detail, even for single-element materials such as Au surfaces or graphene. Developing and applying strategies to make credible predictions of the conformational ensemble of adsorbed peptides and using these to construct structure-property relationships of these interfaces have been the goals of our efforts. We have made substantial progress in developing interatomic potentials for these interfaces and adapting advanced conformational sampling approaches for these purposes. This Account summarizes our progress in the development and deployment of interfacial force fields and molecular simulation techniques for the purpose of elucidating these insights at biomolecule-materials interfaces, using examples from our laboratories ranging from noble-metal interfaces to graphitic substrates (including carbon nanotubes and graphene) and oxide materials (such as titania). In addition to the well-established application areas of plasmonic materials, biosensing, and the production of medical implant materials, we outline new directions for this field that have the potential to bring new advances in areas such as energy materials and regenerative medicine.

  2. Multi-Axial Damage Index and Accumulation Model for Predicting Fatigue Life of CMC Materials, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The fatigue life of CMCs must be well characterized for the safe and reliable use of these materials as integrated TPS components. Existing fatigue life prediction...

  3. Multiscale paradigms in integrated computational materials science and engineering materials theory, modeling, and simulation for predictive design

    CERN Document Server

    Runge, Keith; Muralidharan, Krishna

    2016-01-01

    This book presents cutting-edge concepts, paradigms, and research highlights in the field of computational materials science and engineering, and provides a fresh, up-to-date perspective on solving present and future materials challenges. The chapters are written by not only pioneers in the fields of computational materials chemistry and materials science, but also experts in multi-scale modeling and simulation as applied to materials engineering. Pedagogical introductions to the different topics and continuity between the chapters are provided to ensure the appeal to a broad audience and to address the applicability of integrated computational materials science and engineering for solving real-world problems.

  4. Microstructural Quantification, Property Prediction, and Stochastic Reconstruction of Heterogeneous Materials Using Limited X-Ray Tomography Data

    Science.gov (United States)

    Li, Hechao

    An accurate knowledge of the complex microstructure of a heterogeneous material is crucial for quantitative structure-property relations establishment and its performance prediction and optimization. X-ray tomography has provided a non-destructive means for microstructure characterization in both 3D and 4D (i.e., structural evolution over time). Traditional reconstruction algorithms like filtered-back-projection (FBP) method or algebraic reconstruction techniques (ART) require huge number of tomographic projections and segmentation process before conducting microstructural quantification. This can be quite time consuming and computationally intensive. In this thesis, a novel procedure is first presented that allows one to directly extract key structural information in forms of spatial correlation functions from limited x-ray tomography data. The key component of the procedure is the computation of a "probability map", which provides the probability of an arbitrary point in the material system belonging to specific phase. The correlation functions of interest are then readily computed from the probability map. Using effective medium theory, accurate predictions of physical properties (e.g., elastic moduli) can be obtained. Secondly, a stochastic optimization procedure that enables one to accurately reconstruct material microstructure from a small number of x-ray tomographic projections (e.g., 20 - 40) is presented. Moreover, a stochastic procedure for multi-modal data fusion is proposed, where both X-ray projections and correlation functions computed from limited 2D optical images are fused to accurately reconstruct complex heterogeneous materials in 3D. This multi-modal reconstruction algorithm is proved to be able to integrate the complementary data to perform an excellent optimization procedure, which indicates its high efficiency in using limited structural information. Finally, the accuracy of the stochastic reconstruction procedure using limited X

  5. Solubility of fragrance raw materials in water: Experimental study, correlations, and Mod. UNIFAC (Do) predictions

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula, E-mail: ula@ch.pw.edu.p [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Paduszynski, Kamil; Niszczota, Zaneta K. [Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

    2011-01-15

    The (liquid + liquid) and (solid + liquid) phase equilibria of nine binary mixtures containing fragrance raw materials (FRM) such as aliphatic ketones and compounds based on cyclohexane with water were investigated. The systems {l_brace}2-heptanone, or 2-nonanone, or 2-undecanone, or 2-tridecanone, or cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or 2-cyclohexyl ethanol (2CE) or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA) + water (2){r_brace} have been measured by a dynamic method in wide range of temperatures from (290 to 360) K and ambient pressure. For all systems immiscibility in the liquid phase was detected. The experimental data was correlated by means of the NRTL equation, utilizing parameters derived from the (liquid + liquid) equilibrium. Additionally, the binary mixtures were predicted with the Mod. UNIFAC (Do) model, with known from literature parameters, with very good results.

  6. Solubility of fragrance raw materials in water: Experimental study, correlations, and Mod. UNIFAC (Do) predictions

    International Nuclear Information System (INIS)

    Domanska, Urszula; Paduszynski, Kamil; Niszczota, Zaneta K.

    2011-01-01

    The (liquid + liquid) and (solid + liquid) phase equilibria of nine binary mixtures containing fragrance raw materials (FRM) such as aliphatic ketones and compounds based on cyclohexane with water were investigated. The systems {2-heptanone, or 2-nonanone, or 2-undecanone, or 2-tridecanone, or cyclohexyl carboxylic acid (CCA), or cyclohexyl acetic acid (CAA), or 2-cyclohexyl ethanol (2CE) or cyclohexyl acetate (CA), or 2-cyclohexyl ethyl acetate (2CEA) + water (2)} have been measured by a dynamic method in wide range of temperatures from (290 to 360) K and ambient pressure. For all systems immiscibility in the liquid phase was detected. The experimental data was correlated by means of the NRTL equation, utilizing parameters derived from the (liquid + liquid) equilibrium. Additionally, the binary mixtures were predicted with the Mod. UNIFAC (Do) model, with known from literature parameters, with very good results.

  7. Predicting the mechanical properties of brittle porous materials with various porosity and pore sizes.

    Science.gov (United States)

    Cui, Zhiwei; Huang, Yongmin; Liu, Honglai

    2017-07-01

    In this work, a micromechanical study using the lattice spring model (LSM) was performed to predict the mechanical properties of BPMs by simulation of the Brazilian test. Stress-strain curve and Weibull plot were analyzed for the determination of fracture strength and Weibull modulus. The presented model composed of linear elastic elements is capable of reproducing the non-linear behavior of BPMs resulting from the damage accumulation and provides consistent results which are in agreement with experimental measurements. Besides, it is also found that porosity shows significant impact on fracture strength while pore size dominates the Weibull modulus, which enables us to establish how choices made in the microstructure to meet the demand of brittle porous materials functioning in various operating conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Structural predictions for Correlated Electron Materials Using the Functional Dynamical Mean Field Theory Approach

    Science.gov (United States)

    Haule, Kristjan

    2018-04-01

    The Dynamical Mean Field Theory (DMFT) in combination with the band structure methods has been able to address reach physics of correlated materials, such as the fluctuating local moments, spin and orbital fluctuations, atomic multiplet physics and band formation on equal footing. Recently it is getting increasingly recognized that more predictive ab-initio theory of correlated systems needs to also address the feedback effect of the correlated electronic structure on the ionic positions, as the metal-insulator transition is almost always accompanied with considerable structural distortions. We will review recently developed extension of merger between the Density Functional Theory (DFT) and DMFT method, dubbed DFT+ embedded DMFT (DFT+eDMFT), whichsuccessfully addresses this challenge. It is based on the stationary Luttinger-Ward functional to minimize the numerical error, it subtracts the exact double-counting of DFT and DMFT, and implements self-consistent forces on all atoms in the unit cell. In a few examples, we will also show how the method elucidated the important feedback effect of correlations on crystal structure in rare earth nickelates to explain the mechanism of the metal-insulator transition. The method showed that such feedback effect is also essential to understand the dynamic stability of the high-temperature body-centered cubic phase of elemental iron, and in particular it predicted strong enhancement of the electron-phonon coupling over DFT values in FeSe, which was very recently verified by pioneering time-domain experiment.

  9. Crystal plasticity-based modeling for predicting anisotropic behaviour and formability of metallic materials

    International Nuclear Information System (INIS)

    Pham, Son; Jeong, Youngung; Creuziger, Adam; Iadicola, Mark; Foecke, Tim; Rollett, Anthony

    2016-01-01

    Metallic materials often exhibit anisotropic behaviour under complex load paths because of changes in microstructure, e.g., dislocations and crystallographic texture. In this study, we present the development of constitutive model based on dislocations, point defects and texture in order to predict anisotropic response under complex load paths. In detail, dislocation/solute atom interactions were considered to account for strain aging and static recovery. A hardening matrix based on the interaction of dislocations was built to represent the cross-hardening of different slip systems. Clear differentiation between forward and backward slip directions of dislocations was made to describe back stresses during path changes. In addition, we included dynamic recovery in order to better account for large plastic deformation. The model is validated against experimental data for AA5754-O with path changes, e.g., Figure 1 [1] Another effort is to include microstructure in forming predictions with a minimal increase in computational time. This effort enables comprehensive investigations of the influence of texture-induced anisotropy on formability [2]. Application of these improvements to predict forming limits of various BCC textures, such as γ, ρ, α, η and ϵ fibers and a random (R) texture. These simulations demonstrate that the crystallographic texture has significant (both positive and negative) effects on the forming limit diagrams (Figure 2). For example, the y fiber texture, that is often sought through thermo-mechanical processing due to high r-value, had the highest forming limit in the balanced biaxial strain path but the lowest forming limit under the plane strain path among textures under consideration. (paper)

  10. Extreme events and predictability of catastrophic failure in composite materials and in the Earth

    Science.gov (United States)

    Main, I.; Naylor, M.

    2012-05-01

    Despite all attempts to isolate and predict extreme earthquakes, these nearly always occur without obvious warning in real time: fully deterministic earthquake prediction is very much a `black swan'. On the other hand engineering-scale samples of rocks and other composite materials often show clear precursors to dynamic failure under controlled conditions in the laboratory, and successful evacuations have occurred before several volcanic eruptions. This may be because extreme earthquakes are not statistically special, being an emergent property of the process of dynamic rupture. Nevertheless, probabilistic forecasting of event rate above a given size, based on the tendency of earthquakes to cluster in space and time, can have significant skill compared to say random failure, even in real-time mode. We address several questions in this debate, using examples from the Earth (earthquakes, volcanoes) and the laboratory, including the following. How can we identify `characteristic' events, i.e. beyond the power law, in model selection (do dragon-kings exist)? How do we discriminate quantitatively between stationary and non-stationary hazard models (is a dragon likely to come soon)? Does the system size (the size of the dragon's domain) matter? Are there localising signals of imminent catastrophic failure we may not be able to access (is the dragon effectively invisible on approach)? We focus on the effect of sampling effects and statistical uncertainty in the identification of extreme events and their predictability, and highlight the strong influence of scaling in space and time as an outstanding issue to be addressed by quantitative studies, experimentation and models.

  11. A relation to predict the failure of materials and potential application to volcanic eruptions and landslides.

    Science.gov (United States)

    Hao, Shengwang; Liu, Chao; Lu, Chunsheng; Elsworth, Derek

    2016-06-16

    A theoretical explanation of a time-to-failure relation is presented, with this relationship then used to describe the failure of materials. This provides the potential to predict timing (tf - t) immediately before failure by extrapolating the trajectory as it asymptotes to zero with no need to fit unknown exponents as previously proposed in critical power law behaviors. This generalized relation is verified by comparison with approaches to criticality for volcanic eruptions and creep failure. A new relation based on changes with stress is proposed as an alternative expression of Voight's relation, which is widely used to describe the accelerating precursory signals before material failure and broadly applied to volcanic eruptions, landslides and other phenomena. The new generalized relation reduces to Voight's relation if stress is limited to increase at a constant rate with time. This implies that the time-derivatives in Voight's analysis may be a subset of a more general expression connecting stress derivatives, and thus provides a potential method for forecasting these events.

  12. Flexural fatigue life prediction of closed hat-section using materially nonlinear axial fatigue characteristics

    Science.gov (United States)

    Razzaq, Zia

    1989-01-01

    Straight or curved hat-section members are often used as structural stiffeners in aircraft. For instance, they are employed as stiffeners for the dorsal skin as well as in the aerial refueling adjacent area structure in F-106 aircraft. The flanges of the hat-section are connected to the aircraft skin. Thus, the portion of the skin closing the hat-section interacts with the section itself when resisting the stresses due to service loads. The flexural fatigue life of such a closed section is estimated using materially nonlinear axial fatigue characteristics. It should be recognized that when a structural shape is subjected to bending, the fatigue life at the neutral axis is infinity since the normal stresses are zero at that location. Conversely, the fatigue life at the extreme fibers where the normal bending stresses are maximum can be expected to be finite. Thus, different fatigue life estimates can be visualized at various distances from the neural axis. The problem becomes compounded further when significant portions away from the neutral axis are stressed into plastic range. A theoretical analysis of the closed hat-section subjected to flexural cyclic loading is first conducted. The axial fatigue characteristics together with the related axial fatigue life formula and its inverted form given by Manson and Muralidharan are adopted for an aluminum alloy used in aircraft construction. A closed-form expression for predicting the flexural fatigue life is then derived for the closed hat-section including materially nonlinear action. A computer program is written to conduct a study of the variables such as the thicknesses of the hat-section and the skin, and the type of alloy used. The study has provided a fundamental understanding of the flexural fatigue life characteristics of a practical structural component used in aircraft when materially nonlinear action is present.

  13. Moderate efficiency of clinicians' predictions decreased for blurred clinical conditions and benefits from the use of BRASS index. A longitudinal study on geriatric patients' outcomes.

    Science.gov (United States)

    Signorini, Giulia; Dagani, Jessica; Bulgari, Viola; Ferrari, Clarissa; de Girolamo, Giovanni

    2016-01-01

    Accurate prognosis is an essential aspect of good clinical practice and efficient health services, particularly for chronic and disabling diseases, as in geriatric populations. This study aims to examine the accuracy of clinical prognostic predictions and to devise prediction models combining clinical variables and clinicians' prognosis for a geriatric patient sample. In a sample of 329 consecutive older patients admitted to 10 geriatric units, we evaluated the accuracy of clinicians' prognosis regarding three outcomes at discharge: global functioning, length of stay (LoS) in hospital, and destination at discharge (DD). A comprehensive set of sociodemographic, clinical, and treatment-related information were also collected. Moderate predictive performance was found for all three outcomes: area under receiver operating characteristic curve of 0.79 and 0.78 for functioning and LoS, respectively, and moderate concordance, Cohen's K = 0.45, between predicted and observed DD. Predictive models found the Blaylock Risk Assessment Screening Score together with clinicians' judgment relevant to improve predictions for all outcomes (absolute improvement in adjusted and pseudo-R(2) up to 19%). Although the clinicians' estimates were important factors in predicting global functioning, LoS, and DD, more research is needed regarding both methodological aspects and clinical measurements, to improve prognostic clinical indices. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Simulation of the Press Hardening Process and Prediction of the Final Mechanical Material Properties

    Science.gov (United States)

    Hochholdinger, Bernd; Hora, Pavel; Grass, Hannes; Lipp, Arnulf

    2011-08-01

    Press hardening is a well-established production process in the automotive industry today. The actual trend of this process technology points towards the manufacturing of parts with tailored properties. Since the knowledge of the mechanical properties of a structural part after forming and quenching is essential for the evaluation of for example the crash performance, an accurate as possible virtual assessment of the production process is more than ever necessary. In order to achieve this, the definition of reliable input parameters and boundary conditions for the thermo-mechanically coupled simulation of the process steps is required. One of the most important input parameters, especially regarding the final properties of the quenched material, is the contact heat transfer coefficient (IHTC). The CHTC depends on the effective pressure or the gap distance between part and tool. The CHTC at different contact pressures and gap distances is determined through inverse parameter identification. Furthermore a simulation strategy for the subsequent steps of the press hardening process as well as adequate modeling approaches for part and tools are discussed. For the prediction of the yield curves of the material after press hardening a phenomenological model is presented. This model requires the knowledge of the microstructure within the part. By post processing the nodal temperature history with a CCT diagram the quantitative distribution of the phase fractions martensite, bainite, ferrite and pearlite after press hardening is determined. The model itself is based on a Hockett-Sherby approach with the Hockett-Sherby parameters being defined in function of the phase fractions and a characteristic cooling rate.

  15. Predicting critical temperatures of iron(II) spin crossover materials: Density functional theory plus U approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yachao, E-mail: yczhang@nano.gznc.edu.cn [Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Normal College, Guiyang 550018, Guizhou (China)

    2014-12-07

    A first-principles study of critical temperatures (T{sub c}) of spin crossover (SCO) materials requires accurate description of the strongly correlated 3d electrons as well as much computational effort. This task is still a challenge for the widely used local density or generalized gradient approximations (LDA/GGA) and hybrid functionals. One remedy, termed density functional theory plus U (DFT+U) approach, introduces a Hubbard U term to deal with the localized electrons at marginal computational cost, while treats the delocalized electrons with LDA/GGA. Here, we employ the DFT+U approach to investigate the T{sub c} of a pair of iron(II) SCO molecular crystals (α and β phase), where identical constituent molecules are packed in different ways. We first calculate the adiabatic high spin-low spin energy splitting ΔE{sub HL} and molecular vibrational frequencies in both spin states, then obtain the temperature dependent enthalpy and entropy changes (ΔH and ΔS), and finally extract T{sub c} by exploiting the ΔH/T − T and ΔS − T relationships. The results are in agreement with experiment. Analysis of geometries and electronic structures shows that the local ligand field in the α phase is slightly weakened by the H-bondings involving the ligand atoms and the specific crystal packing style. We find that this effect is largely responsible for the difference in T{sub c} of the two phases. This study shows the applicability of the DFT+U approach for predicting T{sub c} of SCO materials, and provides a clear insight into the subtle influence of the crystal packing effects on SCO behavior.

  16. Development of Multiscale Materials Modeling Techniques and Coarse- Graining Strategies for Predicting Materials Degradation in Extreme Irradiation Environments

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, Brian [Univ. of Tennessee, Knoxville, TN (United States)

    2016-01-12

    Exposure of metallic structural materials to irradiation environments results in significant microstructural evolution, property changes and performance degradation, which limits the extended operation of current generation light water reactors and restricts the design of advanced fission and fusion reactors [1-8]. This effect of irradiation on materials microstructure and properties is a classic example of an inherently multiscale phenomenon, as schematically illustrated in Figure 1a. Pertinent processes range from the atomic nucleus to structural component length scales, spanning more than 15 orders of magnitude. Time scales bridge more than 22 orders of magnitude, with the shortest being less than a femtosecond [1,8]. Further, the mix of radiation-induced features formed and the corresponding property degradation depend on a wide range of material and irradiation variables. This emphasizes the importance of closely integrating models with high-resolution experimental characterization of the evolving radiation- damaged microstructure, including measurements performed in-situ during irradiation. In this article, we review some recent successes through the use of closely coordinated modeling and experimental studies of the defect cluster evolution in irradiated body-centered cubic materials, followed by a discussion of outstanding challenges still to be addressed, which are necessary for the development of comprehensive models of radiation effects in structural materials.

  17. Prediction of Material Properties of Nanostructured Polymer Composites Using Atomistic Simulations

    Science.gov (United States)

    Hinkley, J.A.; Clancy, T.C.; Frankland, S.J.V.

    2009-01-01

    Atomistic models of epoxy polymers were built in order to assess the effect of structure at the nanometer scale on the resulting bulk properties such as elastic modulus and thermal conductivity. Atomistic models of both bulk polymer and carbon nanotube polymer composites were built. For the bulk models, the effect of moisture content and temperature on the resulting elastic constants was calculated. A relatively consistent decrease in modulus was seen with increasing temperature. The dependence of modulus on moisture content was less consistent. This behavior was seen for two different epoxy systems, one containing a difunctional epoxy molecule and the other a tetrafunctional epoxy molecule. Both epoxy structures were crosslinked with diamine curing agents. Multifunctional properties were calculated with the nanocomposite models. Molecular dynamics simulation was used to estimate the interfacial thermal (Kapitza) resistance between the carbon nanotube and the surrounding epoxy matrix. These estimated values were used in a multiscale model in order to predict the thermal conductivity of a nanocomposite as a function of the nanometer scaled molecular structure.

  18. Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis

    Directory of Open Access Journals (Sweden)

    Roberto Carretta

    2015-01-01

    Full Text Available Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r=0.65–0.94. Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.

  19. Pore-Scale Simulation for Predicting Material Transport Through Porous Media

    International Nuclear Information System (INIS)

    Goichi Itoh; Jinya Nakamura; Koji Kono; Tadashi Watanabe; Hirotada Ohashi; Yu Chen; Shinya Nagasaki

    2002-01-01

    Microscopic models of real-coded lattice gas automata (RLG) method with a special boundary condition and lattice Boltzmann method (LBM) are developed for simulating three-dimensional fluid dynamics in complex geometry. Those models enable us to simulate pore-scale fluid dynamics that is an essential part for predicting material transport in porous media precisely. For large-scale simulation of porous media with high resolution, the RLG and LBM programs are designed for parallel computation. Simulation results of porous media flow by the LBM with different pressure gradient conditions show quantitative agreements with macroscopic relations of Darcy's law and Kozeny-Carman equation. As for the efficiency of parallel computing, a standard parallel computation by using MPI (Message Passing Interface) is compared with the hybrid parallel computation of MPI-node parallel technique. The benchmark tests conclude that in case of using large number of computing node, the parallel performance declines due to increase of data communication between nodes and the hybrid parallel computation totally shows better performance in comparison with the standard parallel computation. (authors)

  20. Predicting Teachers’ use of Digital Learning Materials: Combining Self-Determination Theory and the Integrative Model of Behavior Prediction

    NARCIS (Netherlands)

    Kreijns, Karel; Vermeulen, Marjan; Van Acker, Frederik; Van Buuren, Hans

    2018-01-01

    In this article, we report on a study that investigated the motivational (e.g., intrinsic motivation) and dispositional variables (e.g., attitudes) that determine teachers’ intention to use or not to use Digital Learning Materials (DLMs). To understand the direct and indirect relationships between

  1. Integrated Predictive Tools for Customizing Microstructure and Material Properties of Additively Manufactured Aerospace Components

    Energy Technology Data Exchange (ETDEWEB)

    Radhakrishnan, Balasubramaniam [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fattebert, Jean-Luc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gorti, Sarma B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Haxhimali, Timor [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); El-Wardany, Tahany [United Technologies Research Center (UTRC), East Hartford, CT (United States); Acharya, Ranadip [United Technologies Research Center (UTRC), East Hartford, CT (United States); Staroselsky, Alexander [United Technologies Research Center (UTRC), East Hartford, CT (United States)

    2017-12-01

    Additive Manufacturing (AM) refers to a process by which digital three-dimensional (3-D) design data is converted to build up a component by depositing material layer-by-layer. United Technologies Corporation (UTC) is currently involved in fabrication and certification of several AM aerospace structural components made from aerospace materials. This is accomplished by using optimized process parameters determined through numerous design-of-experiments (DOE)-based studies. Certification of these components is broadly recognized as a significant challenge, with long lead times, very expensive new product development cycles and very high energy consumption. Because of these challenges, United Technologies Research Center (UTRC), together with UTC business units have been developing and validating an advanced physics-based process model. The specific goal is to develop a physics-based framework of an AM process and reliably predict fatigue properties of built-up structures as based on detailed solidification microstructures. Microstructures are predicted using process control parameters including energy source power, scan velocity, deposition pattern, and powder properties. The multi-scale multi-physics model requires solution and coupling of governing physics that will allow prediction of the thermal field and enable solution at the microstructural scale. The state-of-the-art approach to solve these problems requires a huge computational framework and this kind of resource is only available within academia and national laboratories. The project utilized the parallel phase-fields codes at Oak Ridge National Laboratory (ORNL) and Lawrence Livermore National Laboratory (LLNL), along with the high-performance computing (HPC) capabilities existing at the two labs to demonstrate the simulation of multiple dendrite growth in threedimensions (3-D). The LLNL code AMPE was used to implement the UTRC phase field model that was previously developed for a model binary alloy, and

  2. Research on simulation technology for CBRN threat assessment system. Prediction technology for atmospheric dispersion of CBRN materials

    International Nuclear Information System (INIS)

    Miura, Hiroaki; Yano, Masanori; Nakata, Mitsuhiro; Takeda, Masaki

    2013-01-01

    The technical survey is conducted on the CBRN (Chemical, Biological, Radiological and Nuclear) Threat Assessment System Simulation Technology. The dispersion property of CBRN materials is summarized, and the current simulation techniques for CBRN materials dispersion are described. The effects of advection-diffusion, sedimentation by the gravity, buoyancy and wash-out by rainfall on the dispersion property of CBRN materials should be considered in the simulation modeling. The concentration distribution of CBRN materials is predicted through the meteorological analysis, the flow analysis and the dispersion analysis, and the hazard map will be produced from that. A selection of simulation method, model, domain and number of computational grid points is necessary to perform the simulation, considering the balance between calculation cost and prediction accuracy. For construction of CBRN Threat Assessment System, it is important how to integrate the developed simulation element technologies and threat assessment technologies. (author)

  3. Abs-initio, Predictive Calculations for Optoelectronic and Advanced Materials Research

    Science.gov (United States)

    Bagayoko, Diola

    2010-10-01

    Most density functional theory (DFT) calculations find band gaps that are 30-50 percent smaller than the experimental ones. Some explanations of this serious underestimation by theory include self-interaction and the derivative discontinuity of the exchange correlation energy. Several approaches have been developed in the search for a solution to this problem. Most of them entail some modification of DFT potentials. The Green function and screened Coulomb approximation (GWA) is a non-DFT formalism that has led to some improvements. Despite these efforts, the underestimation problem has mostly persisted in the literature. Using the Rayleigh theorem, we describe a basis set and variational effect inherently associated with calculations that employ a linear combination of atomic orbitals (LCAO) in a variational approach of the Rayleigh-Ritz type. This description concomitantly shows a source of large underestimation errors in calculated band gaps, i.e., an often dramatic lowering of some unoccupied energies on account of the Rayleigh theorem as opposed to a physical interaction. We present the Bagayoko, Zhao, and Williams (BZW) method [Phys. Rev. B 60, 1563 (1999); PRB 74, 245214 (2006); and J. Appl. Phys. 103, 096101 (2008)] that systematically avoids this effect and leads (a) to DFT and LDA calculated band gaps of semiconductors in agreement with experiment and (b) theoretical predictions of band gaps that are confirmed by experiment. Unlike most calculations, BZW computations solve, self-consistently, a system of two coupled equations. DFT-BZW calculated effective masses and optical properties (dielectric functions) also agree with measurements. We illustrate ten years of success of the BZW method with its results for GaN, C, Si, 3C-SIC, 4H-SiC, ZnO, AlAs, Ge, ZnSe, w-InN, c-InN, InAs, CdS, AlN and nanostructures. We conclude with potential applications of the BZW method in optoelectronic and advanced materials research.

  4. Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials, E706 (IIF)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This guide presents a method for predicting reference transition temperature adjustments for irradiated light-water cooled power reactor pressure vessel materials based on Charpy V-notch 30-ftlbf (41-J) data. Radiation damage calculative procedures have been developed from a statistical analysis of an irradiated material database that was available as of May 2000. The embrittlement correlation used in this guide was developed using the following variables: copper and nickel contents, irradiation temperature, and neutron fluence. The form of the model was based on current understanding for two mechanisms of embrittlement: stable matrix damage (SMD) and copper-rich precipitation (CRP); saturation of copper effects (for different weld materials) was included. This guide is applicable for the following specific materials, copper, nickel, and phosphorus contents, range of irradiation temperature, and neutron fluence based on the overall database: 1.1.1 MaterialsA 533 Type B Class 1 and 2, A302 Grade B, A302 G...

  5. Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jianmin [Northwestern Univ., Evanston, IL (United States)

    2017-09-20

    Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

  6. Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

    International Nuclear Information System (INIS)

    Qu, Jianmin

    2017-01-01

    Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

  7. Wealth and happiness across the world: material prosperity predicts life evaluation, whereas psychosocial prosperity predicts positive feeling.

    Science.gov (United States)

    Diener, Ed; Ng, Weiting; Harter, James; Arora, Raksha

    2010-07-01

    The Gallup World Poll, the first representative sample of planet Earth, was used to explore the reasons why happiness is associated with higher income, including the meeting of basic needs, fulfillment of psychological needs, increasing satisfaction with one's standard of living, and public goods. Across the globe, the association of log income with subjective well-being was linear but convex with raw income, indicating the declining marginal effects of income on subjective well-being. Income was a moderately strong predictor of life evaluation but a much weaker predictor of positive and negative feelings. Possessing luxury conveniences and satisfaction with standard of living were also strong predictors of life evaluation. Although the meeting of basic and psychological needs mediated the effects of income on life evaluation to some degree, the strongest mediation was provided by standard of living and ownership of conveniences. In contrast, feelings were most associated with the fulfillment of psychological needs: learning, autonomy, using one's skills, respect, and the ability to count on others in an emergency. Thus, two separate types of prosperity-economic and social psychological-best predict different types of well-being.

  8. A model to predict radon exhalation from walls to indoor air based on the exhalation from building material samples

    International Nuclear Information System (INIS)

    Sahoo, B.K.; Sapra, B.K.; Gaware, J.J.; Kanse, S.D.; Mayya, Y.S.

    2011-01-01

    In recognition of the fact that building materials are an important source of indoor radon, second only to soil, surface radon exhalation fluxes have been extensively measured from the samples of these materials. Based on this flux data, several researchers have attempted to predict the inhalation dose attributable to radon emitted from walls and ceilings made up of these materials. However, an important aspect not considered in this methodology is the enhancement of the radon flux from the wall or the ceiling constructed using the same building material. This enhancement occurs mainly because of the change in the radon diffusion process from the former to the latter configuration. To predict the true radon flux from the wall based on the flux data of building material samples, we now propose a semi-empirical model involving radon diffusion length and the physical dimensions of the samples as well as wall thickness as other input parameters. This model has been established by statistically fitting the ratio of the solution to radon diffusion equations for the cases of three-dimensional cuboidal shaped building materials (such as brick, concrete block) and one dimensional wall system to a simple mathematical function. The model predictions have been validated against the measurements made at a new construction site. This model provides an alternative tool (substitute to conventional 1-D model) to estimate radon flux from a wall without relying on 226 Ra content, radon emanation factor and bulk density of the samples. Moreover, it may be very useful in the context of developing building codes for radon regulation in new buildings. - Research highlights: → A model is proposed to predict radon flux from wall using flux of building material. → It is established based on the diffusion mechanism in building material and wall. → Study showed a large difference in radon flux from building material and wall. → Model has been validated against the measurements made at

  9. Analysis of the ways to decrease residual stresses on heat exchanging tubes and steam generator collector surfaces for reducing the material corrosion damage

    International Nuclear Information System (INIS)

    Stepanov, G.V.; Kharchenko, V.V.; Shatco, A.A.; Dranchenko, V.V.; Titov, V.F.

    1994-01-01

    Computer simulations have been carried out to analyze the effect of heat exchanger tube pressing forming process into a steam generator collector, on its residual stresses and strains. The program takes into consideration kinetic process peculiarities, material non-linear rheological properties, separate deformation of tubes and collectors in the presence of a clearance and their contact interaction, damage and crack appearance. 4 figs

  10. Low adiponectin levels at baseline and decreasing adiponectin levels over 10 years of follow-up predict risk of the metabolic syndrome

    DEFF Research Database (Denmark)

    Lindberg, S; Jensen, J S; Bjerre, Mette

    2017-01-01

    AIM: Adiponectin is the most abundant adipokine and may play a key role in the interplay between obesity, inflammation, insulin resistance and the metabolic syndrome (MetS). Thus, this large population-based cohort investigated whether adiponectin at baseline and/or a decrease in adiponectin during......-up were inversely associated with an increase in the number of components of MetS (Pvs 7.0mg/L (95% CI: 6.3-7.9) for those with four to five components. CONCLUSIONS/INTERPRETATION: Low plasma...

  11. Fast and simple method for prediction of the micromechanical parameters and macromechanical properties of composite materials

    OpenAIRE

    Delgado Aguilar, Marc; Julián Pérez, Fernando; Pèlach Serra, Maria Àngels; Espinach Orús, Xavier; Méndez González, José Alberto; Mutjé Pujol, Pere

    2016-01-01

    The method described in the present work was assessed through the production of composite materials made of polypropylene reinforced with chemical thermomechanical pulp of hemp core fibers. Composite materials were obtained by extrusion and injection molding, and by the addition of a coupling agent to ensure a good interphase between fiber and matrix. In all cases, the composite materials were considered as semi-aligned reinforced. Tensile strength was selected as a representative...

  12. A statistical method for predicting sound absorbing property of porous metal materials by using quartet structure generation set

    International Nuclear Information System (INIS)

    Guan, Dong; Wu, Jiu Hui; Jing, Li

    2015-01-01

    Highlights: • A random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. • Effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. • This method could be utilized to guide the design and fabrication of the sound-absorption porous metal materials. - Abstract: In this paper, a statistical method for predicting sound absorption properties of porous metal materials is presented. To reflect the stochastic distribution characteristics of the porous metal materials, a random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. Then by using the transfer-function approach along with the QSGS tool, we investigate the sound absorbing performance of porous metal materials with complex stochastic geometries. The statistical method has been validated by the good agreement among the numerical results for metal rubber from this method and a previous empirical model and the corresponding experimental data. Furthermore, the effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. Therefore, the present method is a reliable and robust method for predicting the sound absorption performance of porous metal materials, and could be utilized to guide the design and fabrication of the sound-absorption porous metal materials

  13. Supplementary Material for: DASPfind: new efficient method to predict drug–target interactions

    KAUST Repository

    Ba Alawi, Wail

    2016-01-01

    Abstract Background Identification of novel drug–target interactions (DTIs) is important for drug discovery. Experimental determination of such DTIs is costly and time consuming, hence it necessitates the development of efficient computational methods for the accurate prediction of potential DTIs. To-date, many computational methods have been proposed for this purpose, but they suffer the drawback of a high rate of false positive predictions. Results Here, we developed a novel computational DTI prediction method, DASPfind. DASPfind uses simple paths of particular lengths inferred from a graph that describes DTIs, similarities between drugs, and similarities between the protein targets of drugs. We show that on average, over the four gold standard DTI datasets, DASPfind significantly outperforms other existing methods when the single top-ranked predictions are considered, resulting in 46.17 % of these predictions being correct, and it achieves 49.22 % correct single top ranked predictions when the set of all DTIs for a single drug is tested. Furthermore, we demonstrate that our method is best suited for predicting DTIs in cases of drugs with no known targets or with few known targets. We also show the practical use of DASPfind by generating novel predictions for the Ion Channel dataset and validating them manually. Conclusions DASPfind is a computational method for finding reliable new interactions between drugs and proteins. We show over six different DTI datasets that DASPfind outperforms other state-of-the-art methods when the single top-ranked predictions are considered, or when a drug with no known targets or with few known targets is considered. We illustrate the usefulness and practicality of DASPfind by predicting novel DTIs for the Ion Channel dataset. The validated predictions suggest that DASPfind can be used as an efficient method to identify correct DTIs, thus reducing the cost of necessary experimental verifications in the process of drug discovery

  14. Rapid decrease of circulating tumor DNA predicted the treatment effect of nivolumab in a lung cancer patient within only 5 days

    Directory of Open Access Journals (Sweden)

    Yuki Iijima

    2017-01-01

    Full Text Available A 77-year-old Japanese man presented to our hospital with a 1-month history of low back pain and was diagnosed as having stage IV EGFR mutation-positive lung adenocarcinoma. After treatment with EGFR tyrosine kinase inhibitor and cytotoxic chemotherapy, nivolumab was started as fourth-line therapy. Remarkable regression of the primary tumor was observed, suggesting high anti-tumor activity of nivolumab. We retrospectively investigated the change in circulating tumor DNA (ctDNA variant allele fractions in serial plasma samples before and after the nivolumab therapy. Targeted sequencing analysis showed tumor-derived TP53R249S and EGFRL858R mutations detectable in plasma, and the timing of decrease was only 5 days, much earlier than the appearance of radiological changes. Overall, these results suggest that ctDNA might reflect tumor burden and might be a surrogate marker of the therapeutic efficacy of immune checkpoint therapy.

  15. On the Rule of Mixtures for Predicting Stress-Softening and Residual Strain Effects in Biological Tissues and Biocompatible Materials

    Directory of Open Access Journals (Sweden)

    Alex Elías-Zúñiga

    2014-01-01

    Full Text Available In this work, we use the rule of mixtures to develop an equivalent material model in which the total strain energy density is split into the isotropic part related to the matrix component and the anisotropic energy contribution related to the fiber effects. For the isotropic energy part, we select the amended non-Gaussian strain energy density model, while the energy fiber effects are added by considering the equivalent anisotropic volumetric fraction contribution, as well as the isotropized representation form of the eight-chain energy model that accounts for the material anisotropic effects. Furthermore, our proposed material model uses a phenomenological non-monotonous softening function that predicts stress softening effects and has an energy term, derived from the pseudo-elasticity theory, that accounts for residual strain deformations. The model’s theoretical predictions are compared with experimental data collected from human vaginal tissues, mice skin, poly(glycolide-co-caprolactone (PGC25 3-0 and polypropylene suture materials and tracheal and brain human tissues. In all cases examined here, our equivalent material model closely follows stress-softening and residual strain effects exhibited by experimental data.

  16. On the Rule of Mixtures for Predicting Stress-Softening and Residual Strain Effects in Biological Tissues and Biocompatible Materials

    Science.gov (United States)

    Elías-Zúñiga, Alex; Baylón, Karen; Ferrer, Inés; Serenó, Lídia; Garcia-Romeu, Maria Luisa; Bagudanch, Isabel; Grabalosa, Jordi; Pérez-Recio, Tania; Martínez-Romero, Oscar; Ortega-Lara, Wendy; Elizalde, Luis Ernesto

    2014-01-01

    In this work, we use the rule of mixtures to develop an equivalent material model in which the total strain energy density is split into the isotropic part related to the matrix component and the anisotropic energy contribution related to the fiber effects. For the isotropic energy part, we select the amended non-Gaussian strain energy density model, while the energy fiber effects are added by considering the equivalent anisotropic volumetric fraction contribution, as well as the isotropized representation form of the eight-chain energy model that accounts for the material anisotropic effects. Furthermore, our proposed material model uses a phenomenological non-monotonous softening function that predicts stress softening effects and has an energy term, derived from the pseudo-elasticity theory, that accounts for residual strain deformations. The model’s theoretical predictions are compared with experimental data collected from human vaginal tissues, mice skin, poly(glycolide-co-caprolactone) (PGC25 3-0) and polypropylene suture materials and tracheal and brain human tissues. In all cases examined here, our equivalent material model closely follows stress-softening and residual strain effects exhibited by experimental data. PMID:28788466

  17. The Cost of Materialism in a Collectivistic Culture: Predicting Risky Behavior Engagement in Chinese Adolescents

    Science.gov (United States)

    Auerbach, Randy P.; McWhinnie, Chad M.; Goldfinger, Marc; Abela, John R. Z.; Zhu, Xiongzhao; Yao, Shuqiao

    2010-01-01

    The goals of the current study were to examine whether (a) negative events mediate the relationship between materialism and risky behavior engagement and (b) materialism moderates the relationship between stress and engagement in risky behaviors in Chinese youth. At Time 1, 406 adolescents (ages 14-19) from Yue Yang, China, completed measures…

  18. Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring

    International Nuclear Information System (INIS)

    Oh, Sung Ha; Choi, Bok Lok

    2014-01-01

    This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses

  19. Physics-based Modeling Tools for Life Prediction and Durability Assessment of Advanced Materials, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The technical objectives of this program are: (1) to develop a set of physics-based modeling tools to predict the initiation of hot corrosion and to address pit and...

  20. Influence of precision of emission characteristic parameters on model prediction error of VOCs/formaldehyde from dry building material.

    Directory of Open Access Journals (Sweden)

    Wenjuan Wei

    Full Text Available Mass transfer models are useful in predicting the emissions of volatile organic compounds (VOCs and formaldehyde from building materials in indoor environments. They are also useful for human exposure evaluation and in sustainable building design. The measurement errors in the emission characteristic parameters in these mass transfer models, i.e., the initial emittable concentration (C 0, the diffusion coefficient (D, and the partition coefficient (K, can result in errors in predicting indoor VOC and formaldehyde concentrations. These errors have not yet been quantitatively well analyzed in the literature. This paper addresses this by using modelling to assess these errors for some typical building conditions. The error in C 0, as measured in environmental chambers and applied to a reference living room in Beijing, has the largest influence on the model prediction error in indoor VOC and formaldehyde concentration, while the error in K has the least effect. A correlation between the errors in D, K, and C 0 and the error in the indoor VOC and formaldehyde concentration prediction is then derived for engineering applications. In addition, the influence of temperature on the model prediction of emissions is investigated. It shows the impact of temperature fluctuations on the prediction errors in indoor VOC and formaldehyde concentrations to be less than 7% at 23±0.5°C and less than 30% at 23±2°C.

  1. Metal-ceramic materials. Study and prediction of effective mechanical properties

    International Nuclear Information System (INIS)

    Karakulov, Valerii V.; Smolin, Igor Yu.

    2016-01-01

    Mechanical behavior of stochastic metal-ceramic composite materials was numerically simulated on mesoscopic scale level. Deformation of mesoscopic volumes of composites, whose structure consists of a metal matrix and randomly distributed ceramic inclusions, was numerically simulated. The results of the numerical simulation were used for evaluation of the effective elastic and strength properties of metal-ceramic materials with different parameters of the structure. The values of the effective mechanical properties of investigated materials were obtained, and the character of the dependence of the effective elastic and strength properties on the structure parameters of composites was determined.

  2. Prediction of serviceability of the material working under conditions of dynamic contact with liquid medium

    International Nuclear Information System (INIS)

    Veksler, Yu.G.; Poluyanov, V.B.

    1977-01-01

    A method is suggested for selecting materials working in contact with fusible liquid metals under namic loading. It is recommended to determine the rate of failure in short-time tests of materials which have shown good corrosion resistence. A material thus selected is subject to short-time cavitation mechanical strength test and a creep test. After that the cavitation-mechanical strength is to be calculated with an account for variation of transverse cross-section area. An equation of cavitation failure rate vs. time is given

  3. Decreased expression of miR‑490‑3p in colorectal cancer predicts poor prognosis and promotes cell proliferation and invasion by targeting RAB14.

    Science.gov (United States)

    Wang, Bo; Yin, Mujun; Cheng, Cheng; Jiang, Hongpeng; Jiang, Kewei; Shen, Zhanlong; Ye, Yingjiang; Wang, Shan

    2018-06-19

    Growing evidence indicates a potential role for miR‑490‑3p in tumorigenesis. However, its function in colorectal carcinoma (CRC) remains undefined. In this study, miR‑490‑3p was markedly downregulated in fifty colorectal cancer tissue samples compared with the corresponding adjacent non‑cancerous specimens, by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression levels of miR‑490‑3p were closely associated with tumor differentiation and distant metastasis. In addition, both Kaplan-Meier and multivariate analyses indicated CRC patients with elevated miR‑490‑3p amounts had prolonged overall survival. Overexpression of miR‑490‑3p markedly reduced proliferation, colony formation and invasion in CRC cells by enhancing apoptosis and promoting G2/M phase arrest. Furthermore, ectopic expression of miR‑490‑3p resulted in decreased expression of RAB14, which was directly targeted by miR‑490‑3p, as shown by the dual-luciferase reporter gene assay. Finally, in a nude mouse model, miR‑490‑3p overexpression significantly suppressed the growth of CRC cells. The above results indicated that miR‑490‑3p might constitute a prognostic indicator and a novel molecular target for miRNA-based CRC therapy.

  4. MMORPG escapism predicts decreased well-being: examination of gaming time, game realism beliefs, and online social support for offline problems.

    Science.gov (United States)

    Kaczmarek, Lukasz D; Drążkowski, Dariusz

    2014-05-01

    Massively multiplayer online role-playing game (MMORPG) escapists are individuals who indulge in the MMORPG environment to avoid real world problems. Though a relationship between escapism and deteriorated well-being has been established, little is known about particular pathways that mediate this relationship. In the current study, we examined this topic by testing an integrative model of MMORPG escapism, which includes game realism beliefs, gaming time, offline social support, and online social support for offline problems. MMORPG players (N=1,056) completed measures of escapist motivation, game realism beliefs, social support, well-being, and reported gaming time. The tested structural equation model had a good fit to the data. We found that individuals with escapist motivation endorsed stronger game realism beliefs and spent more time playing MMORPGs, which, in turn, increased online support but decreased offline social support. Well-being was favorably affected by both online and offline social support, although offline social support had a stronger effect. The higher availability of online social support for offline problems did not compensate for the lower availability of offline support among MMORPG escapists. Understanding the psychological factors related to depletion of social resources in MMORPG players can help optimize MMORPGs as leisure activities.

  5. Predictive equation of state method for heavy materials based on the Dirac equation and density functional theory

    Science.gov (United States)

    Wills, John M.; Mattsson, Ann E.

    2012-02-01

    Density functional theory (DFT) provides a formally predictive base for equation of state properties. Available approximations to the exchange/correlation functional provide accurate predictions for many materials in the periodic table. For heavy materials however, DFT calculations, using available functionals, fail to provide quantitative predictions, and often fail to be even qualitative. This deficiency is due both to the lack of the appropriate confinement physics in the exchange/correlation functional and to approximations used to evaluate the underlying equations. In order to assess and develop accurate functionals, it is essential to eliminate all other sources of error. In this talk we describe an efficient first-principles electronic structure method based on the Dirac equation and compare the results obtained with this method with other methods generally used. Implications for high-pressure equation of state of relativistic materials are demonstrated in application to Ce and the light actinides. Sandia National Laboratories is a multi-program laboratory managed andoperated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  6. The use of repassivation potential in predicting the performance of high-level nuclear waste container materials

    International Nuclear Information System (INIS)

    Sridhar, N.; Dunn, D.; Cragnolino, G.

    1995-01-01

    Localized corrosion in aqueous environments forms an important bounding condition for the performance assessment of high-level waste (HLW) container materials. A predictive methodology using repassivation potential is examined in this paper. It is shown, based on long-term (continuing for over 11 months) testing of alloy 825, that repassivation potential of deep pits or crevices is a conservative and robust parameter for the prediction of localized corrosion. In contrast, initiation potentials measured by short-term tests are non-conservative and highly sensitive to several surface and environmental factors. Corrosion data from various field tests and plant equipment performance are analyzed in terms of the applicability of repassivation potential. The applicability of repassivation potential for predicting the occurrence of stress corrosion cracking (SCC) and intergranular corrosion in chloride containing environments is also examined

  7. Meatal Swabs Contain Less Cellular Material and Are Associated with a Decrease in Gram Stain Smear Quality Compared to Urethral Swabs in Men.

    Science.gov (United States)

    Jordan, Stephen J; Schwebke, Jane R; Aaron, Kristal J; Van Der Pol, Barbara; Hook, Edward W

    2017-07-01

    Urethral swabs are the samples of choice for point-of-care Gram stain testing to diagnose Neisseria gonorrhoeae infection and nongonococcal urethritis (NGU) in men. As an alternative to urethral swabs, meatal swabs have been recommended for the collection of urethral discharge to diagnose N. gonorrhoeae and Chlamydia trachomatis infection in certain populations by nucleic acid amplification testing (NAAT), as they involve a less invasive collection method. However, as meatal swabs could be sampling a reduced surface area and result in fewer collected epithelial cells compared to urethral swabs, the adequacy of meatal swab specimens to collect sufficient cellular material for Gram stain testing remains unknown. We enrolled 66 men who underwent either urethral or meatal swabbing and compared the cellular content and Gram stain failure rate. We measured the difference in swab cellular content using the Cepheid Xpert CT/NG sample adequacy control crossing threshold (SAC CT ) and determined the failure rate of Gram stain smears (GSS) due to insufficient cellular material. In the absence of discharge, meatal smears were associated with a significant reduction in cellular content ( P = 0.0118), which corresponded with a GSS failure rate significantly higher than that for urethral swabs (45% versus 3%, respectively; P < 0.0001). When discharge was present, there was no difference among results from urethral and meatal swabs. Therefore, if GSS testing is being considered for point-of-care diagnosis of N. gonorrhoeae infection or NGU in men, meatal swabs should be avoided in the absence of a visible discharge. Copyright © 2017 American Society for Microbiology.

  8. The use of computational thermodynamics to predict properties of multicomponent materials for nuclear applications

    International Nuclear Information System (INIS)

    Sundman, B.; Gueneau, C.

    2013-01-01

    Computational Thermodynamics is based on physically realistic models to describe metallic and oxide crystalline phases as well as the liquid and gas in a consistent manner. The models are used to assess experimental and theoretical data for many different materials and several thermodynamic databases has been developed for steels, ceramics, semiconductor materials as well as materials for nuclear applications. Within CEA a long term work is ongoing to develop a database for the properties of nuclear fuels and structural materials. An overview of the modelling technique will be given and several examples of the application of the database to different problems, both for traditional phase diagram calculations and its use in simulating phase transformations. The following diagrams (Fig. 1, Fig. 2 and Fig.3) show calculations in the U-Pu-O system. (authors)

  9. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    Science.gov (United States)

    Anggraeni, Novia Antika

    2015-04-01

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano's inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 - 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between -2.86 up to 5.49 days.

  10. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    International Nuclear Information System (INIS)

    Anggraeni, Novia Antika

    2015-01-01

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano’s inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 – 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between −2.86 up to 5.49 days

  11. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    Energy Technology Data Exchange (ETDEWEB)

    Anggraeni, Novia Antika, E-mail: novia.antika.a@gmail.com [Geophysics Sub-department, Physics Department, Faculty of Mathematic and Natural Science, Universitas Gadjah Mada. BLS 21 Yogyakarta 55281 (Indonesia)

    2015-04-24

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano’s inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 – 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between −2.86 up to 5.49 days.

  12. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  13. Development of a Novel Approach for Fatigue Life Prediction of Structural Materials

    Science.gov (United States)

    2008-12-01

    Mughrabi, H., 1989, "Plasticity-Induced Martensitic Transformation of AISI 304L Stainless Steel ," Mat Sci Eng A114, pp. LI 1-LI 6. [26] Krupp, U...four structural materials: aluminum 7075T651 alloy, stainless steel AL6-XN, stainless steel 304L, and Aerospace Steel 4340. It was confirmed that...four structural materials: aluminum 7075T651 alloy, stainless steel AL6-XN, stainless steel 304L, and Aerospace Steel 4340. Fatigue and cyclic

  14. How can we predict microstructural changes caused by the multiscale irradiation process occurred in materials having complicated and hierarchical structures?

    International Nuclear Information System (INIS)

    Morishita, Kazunori; Watanabe, Yoshiyuki; Yoshimatsu, Jun-ichi

    2008-01-01

    Challenging efforts are discussed to establish an advanced methodology for prediction of material's property and performance changes by irradiation, which will be necessary by all means for the advanced reactor maintenance technology in the future. The changes of material's properties and performance caused by irradiation, such as irradiation-induced hardening, ductility loss, and material's degradation leading to reduction in reactor lifetime, are primarily determined by microstructural changes in materials during irradiation, where athermal lattice defects are continuously produced by collisions between an irradiating particle and a target material atom, and subsequently the defects are aggregated via diffusion in the form of dislocation loops, voids, and solute precipitation. These radiation damage processes are in essence multiscale phenomena, which involve varying time- and length-scales, from ballistic binary collisions to collective atomic motion in the thermal spike stage followed by the thermal activation process. In this report, the multiscale modeling approach is proposed to understand the processes in materials having complicated and hierarchical structures. (author)

  15. Predictive modelling of migration from packaging materials into food products for regulatory purposes

    NARCIS (Netherlands)

    Helmroth, E.; Rijk, R.; Dekker, M.; Jongen, W.

    2002-01-01

    Migration of low-molecular weight compounds is one of the most important problems of packaging plastics and other plastics intended to come into contact with food products. Since migration experiments are time consuming and expensive, predictive modelling has been introduced as a promising

  16. Prediction of material creep behaviour for strain based life assessment applications

    Energy Technology Data Exchange (ETDEWEB)

    Rantala, J.H.; Hurst, R.C. [EC JRC IAM, Petten (Netherlands); Bregani, F. [ENEL, Milan (Italy)

    1998-12-31

    In this work the idea of using constant load uniaxial creep test results instead of constant stress results for developing a CDM creep model for the P92 material is demonstrated. Due to limited availability of creep test results this work is based on incomplete test data and a general stress rupture line. In spite of these limitations a material creep model was developed for use in a FE analysis. Using P91 material as an example, a method is proposed to account for differences in strain evolution as a function of stress which normally manifests itself as lower strain values at low stresses in a normalised time-strain plot. This allows the CDM model to be used both in FE analysis and in strain-based life assessment engineering calculations. (orig.) 3 refs.

  17. Prediction of material creep behaviour for strain based life assessment applications

    Energy Technology Data Exchange (ETDEWEB)

    Rantala, J H; Hurst, R C [EC JRC IAM, Petten (Netherlands); Bregani, F [ENEL, Milan (Italy)

    1999-12-31

    In this work the idea of using constant load uniaxial creep test results instead of constant stress results for developing a CDM creep model for the P92 material is demonstrated. Due to limited availability of creep test results this work is based on incomplete test data and a general stress rupture line. In spite of these limitations a material creep model was developed for use in a FE analysis. Using P91 material as an example, a method is proposed to account for differences in strain evolution as a function of stress which normally manifests itself as lower strain values at low stresses in a normalised time-strain plot. This allows the CDM model to be used both in FE analysis and in strain-based life assessment engineering calculations. (orig.) 3 refs.

  18. Steel fibre concrete, a safer material for reactor construction. A general theory for rupture prediction

    International Nuclear Information System (INIS)

    Rammant, J.P.; Van Laethem, L.; Backx, E.

    1977-01-01

    The effect of steel fibre reinforcement on the mechanical behavior of concrete reactor structures is studied. It is shown that this material leads to a higher safety factor for highly stressed concrete structures like prestressed concrete pressure vessels. The reinforcement of concrete with short steel fibres results clearly in a fundamental change of the material properties. The study comprises basic experiments, the elaboration of an expression of the material laws, the development of a general computer program and the comparison of computational results with more elaborate experiments. Basic experimental work is conducted to determine the material characteristics of the fibre reinforced concrete. It is shown how the fibre reinforcement mechanism is translated into mathematical formulae by expressing the principal characteristics as matrix relationships. These relationships describe the elasto-plastic behavior and the cracked behavior. Probabilistic principles are used to express to fibre efficiency, such that a general stress-strain relationship is incorporated in a subsequent computer program. A general finite element program is developed which includes the new matrix relationships, the pull-out of fibres and the general stress-strain equations. A nonlinear calculation method gives the propagation of the distributed cracks with increasing load untill failure of the structure. Similarly, thermal cycling conditions are accounted for. For example the crack propagation in a fibre reinforced beam was measured by the photostress coating technique: the comparison with the computed crack propagation reveals an excellent agreement. Other comparative studies on simple structural parts are also reported

  19. A review of predictive nonlinear theories for multiscale modeling of heterogeneous materials

    NARCIS (Netherlands)

    Matous, K.; Geers, M.G.D.; Kouznetsova, V.; Gillman, A.

    2017-01-01

    Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today’s electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous

  20. Near infrared spectroscopy based monitoring of extraction processes of raw material with the help of dynamic predictive modeling

    Science.gov (United States)

    Wang, Haixia; Suo, Tongchuan; Wu, Xiaolin; Zhang, Yue; Wang, Chunhua; Yu, Heshui; Li, Zheng

    2018-03-01

    The control of batch-to-batch quality variations remains a challenging task for pharmaceutical industries, e.g., traditional Chinese medicine (TCM) manufacturing. One difficult problem is to produce pharmaceutical products with consistent quality from raw material of large quality variations. In this paper, an integrated methodology combining the near infrared spectroscopy (NIRS) and dynamic predictive modeling is developed for the monitoring and control of the batch extraction process of licorice. With the spectra data in hand, the initial state of the process is firstly estimated with a state-space model to construct a process monitoring strategy for the early detection of variations induced by the initial process inputs such as raw materials. Secondly, the quality property of the end product is predicted at the mid-course during the extraction process with a partial least squares (PLS) model. The batch-end-time (BET) is then adjusted accordingly to minimize the quality variations. In conclusion, our study shows that with the help of the dynamic predictive modeling, NIRS can offer the past and future information of the process, which enables more accurate monitoring and control of process performance and product quality.

  1. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available . It is generally included as part of a structurally insulated panel (SIP) where the foam is sandwiched between external skins of steel, wood or cement. Cement composites Cement bonded composites are an important class of building materials. These products... for their stone buildings, including the Egyptians, Aztecs and Inca’s. As stone is a very dense material it requires intensive heating to become warm. Rocks were generally stacked dry but mud, and later cement, can be used as a mortar to hold the rocks...

  2. Data supporting the prediction of the properties of eutectic organic phase change materials

    Directory of Open Access Journals (Sweden)

    Samer Kahwaji

    2018-04-01

    Full Text Available The data presented in this article include the molar masses, melting temperatures, latent heats of fusion and temperature-dependent heat capacities of fifteen fatty acid phase change materials (PCMs. The data are used in conjunction with the thermodynamic models discussed in Kahwaji and White (2018 [1] to develop a computational tool that calculates the eutectic compositions and thermal properties of eutectic mixtures of PCMs. The computational tool is part of this article and consists of a Microsoft Excel® file available in Mendeley Data repository [2]. A description of the computational tool along with the properties of nearly 100 binary mixtures of fatty acid PCMs calculated using this tool are also included in the present article. The Excel® file is designed such that it can be easily modified or expanded by users to calculate the properties of eutectic mixtures of other classes of PCMs. Keywords: Phase change materials, PCM, Eutectic, Thermal properties, Thermal energy storage

  3. Model to predict radiological consequences of transportation accidents involving dispersal of radioactive material in urban areas

    International Nuclear Information System (INIS)

    Taylor, J.M.; Daniel, S.L.

    1978-01-01

    The analysis of accidental releases of radioactive material which may result from transportation accidents in high-density urban areas is influenced by several urban characteristics which make computer simulation the calculational method of choice. These urban features fall into four categories. Each of these categories contains time- and location-dependent parameters which must be coupled to the actual time and location of the release in the calculation of the anticipated radiological consequences. Due to the large number of dependent parameters a computer model, METRAN, has been developed to quantify these radiological consequences. Rather than attempt to describe an urban area as a single entity, a specific urban area is subdivided into a set of cells of fixed size to permit more detailed characterization. Initially, the study area is subdivided into a set of 2-dimensional cells. A uniform set of time-dependent physical characteristics which describe the land use, population distribution, traffic density, etc., within that cell are then computed from various data sources. The METRAN code incorporates several details of urban areas. A principal limitation of the analysis is the limited availability of accurate information to use as input data. Although the code was originally developed to analyze dispersal of radioactive material, it is currently being evaluated for use in analyzing the effects of dispersal of other hazardous materials in both urban and rural areas

  4. Fatigue, fracture, and life prediction criteria for composite materials in magnets

    International Nuclear Information System (INIS)

    Wong, F.M.G.

    1990-06-01

    An explosively-bonded copper/Inconel 718/copper laminate conductor was proposed to withstand the severe face compression stresses in the central core of the Alcator C-MOD tokamak toroidal field (TF) magnet. Due to the severe duty of the TF magnet, it is critical that an accurate estimate of useful life be determined. As part of the effort to formulate an appropriate life prediction, fatigue crack growth experiments were performed on the laminate as well as its components. Metallographic evaluation of the laminate interface revealed many shear bands in the Inconel 718. Shear bands and shear band cracks were produced in the Inconel 718 as a result of the explosion bonding process. These shear bands were shown to have a detrimental effect on the crack growth behavior of the laminate, by significantly reducing the load carrying capability of the reinforcement layer and providing for easy crack propagation paths. Fatigue crack growth rate was found not only to be dependent on temperature but also on orientation. Fatigue cracks grew faster in directions which contained shear bands in the plane of the propagating crack. Fractography showed crack advancement by fatigue cracking in the Inconel 718 and ductile tearing of the copper at the interface. However, further away from the interfaces, the copper exhibited fatigue striations indicating that cracks were now propagating by fatigue. Laminate life prediction results showed a strong dependence on shear band orientation, and exhibited little variation between room temperature and 77 degree K. Predicted life of this laminate was lower when the crack propagation was along a shear band than when crack propagation was across the shear bands. Shear bands appear to have a dominating effect on crack growth behavior

  5. Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

    Directory of Open Access Journals (Sweden)

    W.-S. W. DeRieux

    2018-05-01

    Full Text Available Secondary organic aerosol (SOA accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH, and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg. We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7 as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ, and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS, resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI and atmospheric pressure photoionization (APPI. Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and

  6. Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

    Science.gov (United States)

    Wong DeRieux, Wing-Sy; Li, Ying; Lin, Peng; Laskin, Julia; Laskin, Alexander; Bertram, Allan K.; Nizkorodov, Sergey A.; Shiraiwa, Manabu

    2018-05-01

    Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol-1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ˜ 1100 g mol-1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg/T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ˜ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon-Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon-Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2-5 orders

  7. A mobile dose prediction system based on artificial neural networks for NPP emergencies with radioactive material releases

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Claudio M.N.A.; Schirru, Roberto; Gomes, Kelcio J.; Cunha, José Luiz, E-mail: cmnap@ien.gov.br, E-mail: schirru@lmp.ufrj.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    This work presents the approach of a mobile dose prediction system for NPP emergencies with nuclear material release. The objective is to provide extra support to field teams decisions when plant information systems are not available. However, predicting doses due to atmospheric dispersion of radionuclide generally requires execution of complex and computationally intensive physical models. In order to allow such predictions to be made by using limited computational resources such as mobile phones, it is proposed the use of artificial neural networks (ANN) previously trained (offline) with data generated by precise simulations using the NPP atmospheric dispersion system. Typical situations for each postulated accident and respective source terms, as well as a wide range of meteorological conditions have been considered. As a first step, several ANN architectures have been investigated in order to evaluate their ability for dose prediction in hypothetical scenarios in the vicinity of CNAAA Brazilian NPP, in Angra dos Reis, Brazil. As a result, good generalization and a correlation coefficient of 0.99 was achieved for a validation data set (untrained patterns). Then, selected ANNs have been coded in Java programming language to run as an Android application aimed to plot the spatial dose distribution into a map.In this paper, the general architecture of the proposed system is described; numerical results and comparisons between investigated ANN architectures are discussed; performance and limitations of running the Application into a commercial mobile phone are evaluated and possible improvements and future works are pointed. (author)

  8. Development of a mobile dose prediction system based on artificial neural networks for NPP emergencies with radioactive material releases

    International Nuclear Information System (INIS)

    Pereira, Claudio M.N.A.; Schirru, Roberto; Gomes, Kelcio J.; Cunha, José L.

    2017-01-01

    This work presents the approach of a mobile dose prediction system for NPP emergencies with nuclear material release. The objective is to provide extra support to field teams decisions when plant information systems are not available. However, predicting doses due to atmospheric dispersion of radionuclide generally requires execution of complex and computationally intensive physical models. In order to allow such predictions to be made by using limited computational resources such as mobile phones, it is proposed the use of artificial neural networks (ANN) previously trained (offline) with data generated by precise simulations using the NPP atmospheric dispersion system. Typical situations for each postulated accident and respective source terms, as well as a wide range of meteorological conditions have been considered. As a first step, several ANN architectures have been investigated in order to evaluate their ability for dose prediction in hypothetical scenarios in the vicinity of CNAAA Brazilian NPP, in Angra dos Reis, Brazil. As a result, good generalization and a correlation coefficient of 0.99 was achieved for a validation data set (untrained patterns). Then, selected ANNs have been coded in Java programming language to run as an Android application aimed to plot the spatial dose distribution into a map. In this paper, the general architecture of the proposed system is described; numerical results and comparisons between investigated ANN architectures are discussed; performance and limitations of running the Application into a commercial mobile phone are evaluated and possible improvements and future works are pointed.

  9. A mobile dose prediction system based on artificial neural networks for NPP emergencies with radioactive material releases

    International Nuclear Information System (INIS)

    Pereira, Claudio M.N.A.; Schirru, Roberto; Gomes, Kelcio J.; Cunha, José Luiz

    2017-01-01

    This work presents the approach of a mobile dose prediction system for NPP emergencies with nuclear material release. The objective is to provide extra support to field teams decisions when plant information systems are not available. However, predicting doses due to atmospheric dispersion of radionuclide generally requires execution of complex and computationally intensive physical models. In order to allow such predictions to be made by using limited computational resources such as mobile phones, it is proposed the use of artificial neural networks (ANN) previously trained (offline) with data generated by precise simulations using the NPP atmospheric dispersion system. Typical situations for each postulated accident and respective source terms, as well as a wide range of meteorological conditions have been considered. As a first step, several ANN architectures have been investigated in order to evaluate their ability for dose prediction in hypothetical scenarios in the vicinity of CNAAA Brazilian NPP, in Angra dos Reis, Brazil. As a result, good generalization and a correlation coefficient of 0.99 was achieved for a validation data set (untrained patterns). Then, selected ANNs have been coded in Java programming language to run as an Android application aimed to plot the spatial dose distribution into a map.In this paper, the general architecture of the proposed system is described; numerical results and comparisons between investigated ANN architectures are discussed; performance and limitations of running the Application into a commercial mobile phone are evaluated and possible improvements and future works are pointed. (author)

  10. Prediction and verification of creep behavior in metallic materials and components for the space shuttle thermal protection system

    Science.gov (United States)

    Davis, J. W.; Cramer, B. A.

    1976-01-01

    A method of analysis was developed for predicting permanent cyclic creep deflections in stiffened panel structures. This method uses creep equations based on cyclic tensile creep tests and a computer program to predict panel deflections as a function of mission cycle. Four materials were investigated - a titanium alloy (Ti-6Al-4V), a cobalt alloy (L605), and two nickel alloys (Rene'41 and TDNiCr). Steady-state and cyclic creep response data were obtained by testing tensile specimens fabricated from thin gage sheet (0.025 and 0.63 cm nominal). Steady-state and cyclic creep equations were developed which describe creep as a function of time, temperature and load. Tests were also performed on subsize (6.35 x 30.5 cm) rib and corrugation stiffened panels. These tests were used to correlate creep responses between elemental specimens and panels. The panel response was analyzed by use of a specially written computer program.

  11. Construction of ground-state preserving sparse lattice models for predictive materials simulations

    Science.gov (United States)

    Huang, Wenxuan; Urban, Alexander; Rong, Ziqin; Ding, Zhiwei; Luo, Chuan; Ceder, Gerbrand

    2017-08-01

    First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground states. However, despite recent advances, the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation, since this property is not guaranteed by default. In this paper, we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference data. The method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model parameters. The robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes, i.e., Li2xFe2(1-x)O2 and Li2xTi2(1-x)O2, for which the construction of cluster expansion models with compressive sensing alone has proven to be challenging. We demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction, but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative refinement. This method provides a general tool for building robust, compressed and constrained physical models with predictive power.

  12. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading. Volume 2, Part 1; Appendices

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O.; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approximately 9 inches from the source) dominated by direct wave propagation, mid-field environment (approximately 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This document contains appendices to the Volume I report.

  13. Predicting the Disorder–Order Transition of Solvent-Free Nanoparticle–Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2013-07-02

    The transition from a disordered to a face-centered-cubic phase in solvent-free oligomer-tethered nanoparticles is predicted using a density-functional theory for model hard spheres with tethered bead-spring oligomers. The transition occurs without a difference of volume fraction for the two phases, and the phase boundary is influenced by the loss of oligomer configurational entropy relative to an ideal random system in one phase compared with the other. When the particles are localized in the ordered phase, the cooperation of the oligomers in filling the space is hindered. Therefore, shorter oligomers feel a stronger entropic penalty in the ordered solid and favor the disordered phase. Strikingly, we found that the solvent-free system has a later transition than hard spheres for all investigated ratios of oligomer radius of gyration to particle radius. © 2013 American Chemical Society.

  14. Using molecular mechanics to predict bulk material properties of fibronectin fibers.

    Directory of Open Access Journals (Sweden)

    Mark J Bradshaw

    Full Text Available The structural proteins of the extracellular matrix (ECM form fibers with finely tuned mechanical properties matched to the time scales of cell traction forces. Several proteins such as fibronectin (Fn and fibrin undergo molecular conformational changes that extend the proteins and are believed to be a major contributor to the extensibility of bulk fibers. The dynamics of these conformational changes have been thoroughly explored since the advent of single molecule force spectroscopy and molecular dynamics simulations but remarkably, these data have not been rigorously applied to the understanding of the time dependent mechanics of bulk ECM fibers. Using measurements of protein density within fibers, we have examined the influence of dynamic molecular conformational changes and the intermolecular arrangement of Fn within fibers on the bulk mechanical properties of Fn fibers. Fibers were simulated as molecular strands with architectures that promote either equal or disparate molecular loading under conditions of constant extension rate. Measurements of protein concentration within micron scale fibers using deep ultraviolet transmission microscopy allowed the simulations to be scaled appropriately for comparison to in vitro measurements of fiber mechanics as well as providing estimates of fiber porosity and water content, suggesting Fn fibers are approximately 75% solute. Comparing the properties predicted by single molecule measurements to in vitro measurements of Fn fibers showed that domain unfolding is sufficient to predict the high extensibility and nonlinear stiffness of Fn fibers with surprising accuracy, with disparately loaded fibers providing the best fit to experiment. This work shows the promise of this microstructural modeling approach for understanding Fn fiber properties, which is generally applicable to other ECM fibers, and could be further expanded to tissue scale by incorporating these simulated fibers into three dimensional

  15. A Coupled Transport and Chemical Model for Durability Predictions of Cement Based Materials

    DEFF Research Database (Denmark)

    Jensen, Mads Mønster; Johannesson, Björn; Geiker, Mette Rica

    The use of multi-physics numerical models to estimate different durability indicators and determine the service life of cement based materials is increasing. Service life documentation for concrete used in new infrastructure structures is required and the service life requirement....... The differential equations includes exchange terms between the phases and species accounting for the exchange of physical quantities which are essential for a stringent physical description of concrete. Balance postulates for, mass, momentum and energy, together with an entropy inequality are studied within...... mixture theories. Special attention is paid to the criteria for the exchange terms in the studied balance postulates. A simple case of mixture theory is used to demonstrate how constitutive assumptions are used to obtain the governing equations for a specific model. The governing equation system used...

  16. Data supporting the prediction of the properties of eutectic organic phase change materials.

    Science.gov (United States)

    Kahwaji, Samer; White, Mary Anne

    2018-04-01

    The data presented in this article include the molar masses, melting temperatures, latent heats of fusion and temperature-dependent heat capacities of fifteen fatty acid phase change materials (PCMs). The data are used in conjunction with the thermodynamic models discussed in Kahwaji and White (2018) [1] to develop a computational tool that calculates the eutectic compositions and thermal properties of eutectic mixtures of PCMs. The computational tool is part of this article and consists of a Microsoft Excel® file available in Mendeley Data repository [2]. A description of the computational tool along with the properties of nearly 100 binary mixtures of fatty acid PCMs calculated using this tool are also included in the present article. The Excel® file is designed such that it can be easily modified or expanded by users to calculate the properties of eutectic mixtures of other classes of PCMs.

  17. Force-Field Prediction of Materials Properties in Metal-Organic Frameworks

    Science.gov (United States)

    2016-01-01

    In this work, MOF bulk properties are evaluated and compared using several force fields on several well-studied MOFs, including IRMOF-1 (MOF-5), IRMOF-10, HKUST-1, and UiO-66. It is found that, surprisingly, UFF and DREIDING provide good values for the bulk modulus and linear thermal expansion coefficients for these materials, excluding those that they are not parametrized for. Force fields developed specifically for MOFs including UFF4MOF, BTW-FF, and the DWES force field are also found to provide accurate values for these materials’ properties. While we find that each force field offers a moderately good picture of these properties, noticeable deviations can be observed when looking at properties sensitive to framework vibrational modes. This observation is more pronounced upon the introduction of framework charges. PMID:28008758

  18. Electrochemical properties of Ti-Ni-Sn materials predicted by {sup 119}Sn Mössbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ladam, A., E-mail: alix.ladam@univ-montp2.fr; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C. [Université de Montpellier, Institut Charles Gerhardt, UMR 5253 CNRS (France); Cenac-Morthe, C. [CNES, Service DCT/TV/El (France)

    2016-12-15

    The electrochemical activity of TiNiSn, TiNi {sub 2}Sn and Ti {sub 6}Sn {sub 5} compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti {sub 6}Sn {sub 5} by ball milling. The {sup 119}Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e {sub av}]. The values of [e {sub av}] are in the region of Li-rich Li-Sn alloys for Ti {sub 6}Sn {sub 5} and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e {sub av}] for Ti {sub 6}Sn {sub 5} and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  19. Prediction of Creep Behaviour of the Hybrid Composite Material Using the Accelerated Characterisation Method

    International Nuclear Information System (INIS)

    Larbi, S.; Berradj, M.; Djebbar, A.; Bilek, A.

    2011-01-01

    We present in this study a creep behavior in flexure of a hybrid composite consisting of a polyester matrix containing methyl methacrylate reinforced by two bidirectional fabrics. The first one is made with E-glass fibers and the second one is made of a knitted polyamide 66. The mass fractions are 13% for the glass fabric and 9% for the polyamide fabric. The specimens, of dimensions (L = 60, l = 15 and h = 2.3 mm) containing 06 alternating layers (2P/2V/2P) were fabricated by using the vacuum bag molding method. Bending tests performed at different temperatures allowed us first to determine the load levels for the creep tests. Creep tests at different loads (5 to 43 MPa) and different temperatures (23'deg' to 80'deg' C) show a noticeable increase of creep deformation for both tests under the same load and different temperatures just as those carried out at different loads under the same temperature. The initial deformation varies significantly with the load but very little with temperature. The application of the Findley model shows good correlation with experimental results. Model parameters were identified. Creep deformation satisfies the principle of superposition time-temperature-stress (TTSSP). Findley's model has subsequently been coupled with the principle of superposition of time-temperature-stress to plot master curves at different stresses and temperatures; this enables prediction of creep deformation in the long term. (author)

  20. Prediction of microwave absorption properties of tetrapod-needle zinc oxide whisker radar absorbing material without prior knowledge

    Science.gov (United States)

    Zhao, Yu-Chen; Wang, Jie; Liu, Jiang-Fan; Song, Zhong-Guo; Xi, Xiao-Li

    2017-07-01

    The radar absorbing material (RAM) containing a tetrapod-needle zinc oxide whisker (T-ZnOw) has been proved to have good efficiency of microwave absorption. However, the available theoretical models, which are intended to predict the microwave absorbing properties of such an interesting composite, still cannot work well without some prior knowledge, like the measured effective electromagnetic parameters of the prepared T-ZnOw composite. Hence, we propose a novel predictive method here to calculate the reflectivity of T-ZnOw RAM without prior knowledge. In this method, the absorbing ability of this kind of material is divided into three main aspects: the unstructured background, the conductive network, and the nanostructured particle. Then, the attenuation properties of these three parts are represented, respectively, by three different approaches: the equivalent spherical particle and the static strong fluctuation theory, the equivalent circuit model obtained from the complex impedance spectra technology, and the combination of four different microscopic electromagnetic responses. The operational calculation scheme can be obtained by integrating these three absorption effects into the existing theoretical attenuation model. The reasonable agreement between the theoretical and experimental data of a T-ZnON/SiO2 composite in the range of 8-14 GHz shows that the proposed scheme can predict the microwave absorption properties of the T-ZnOw RAM. Furthermore, a detailed analysis of these three mechanisms indicates that, on the one hand, the background plays a dominant role in determining the real part of the effective permittivity of the T-ZnOw composite while the network and the particle are the decisive factors of its material loss; on the other hand, an zero-phase impedance, i.e., a pure resistance, with appropriate resonance characteristic might be a rational physical description of the attenuation property of the conductive network, but it is difficult to realize

  1. Experimental Investigation and Prediction of Compressive Strength of Ultra-High Performance Concrete Containing Supplementary Cementitious Materials

    Directory of Open Access Journals (Sweden)

    Jisong Zhang

    2017-01-01

    Full Text Available Ultra-high performance concrete (UHPC has superior mechanical properties and durability to normal strength concrete. However, the high amount of cement, high environmental impact, and initial cost are regarded as disadvantages, restricting its wider application. Incorporation of supplementary cementitious materials (SCMs in UHPC is an effective way to reduce the amount of cement needed while contributing to the sustainability and cost. This paper investigates the mechanical properties and microstructure of UHPC containing fly ash (FA and silica fume (SF with the aim of contributing to this issue. The results indicate that, on the basis of 30% FA replacement, the incorporation of 10% and 20% SF showed equivalent or higher mechanical properties compared to the reference samples. The microstructure and pore volume of the UHPCs were also examined. Furthermore, to minimise the experimental workload of future studies, a prediction model is developed to predict the compressive strength of the UHPC using artificial neural networks (ANNs. The results indicate that the developed ANN model has high accuracy and can be used for the prediction of the compressive strength of UHPC with these SCMs.

  2. Life prediction of different commercial dental implants as influence by uncertainties in their fatigue material properties and loading conditions.

    Science.gov (United States)

    Pérez, M A

    2012-12-01

    Probabilistic analyses allow the effect of uncertainty in system parameters to be determined. In the literature, many researchers have investigated static loading effects on dental implants. However, the intrinsic variability and uncertainty of most of the main problem parameters are not accounted for. The objective of this research was to apply a probabilistic computational approach to predict the fatigue life of three different commercial dental implants considering the variability and uncertainty in their fatigue material properties and loading conditions. For one of the commercial dental implants, the influence of its diameter in the fatigue life performance was also studied. This stochastic technique was based on the combination of a probabilistic finite element method (PFEM) and a cumulative damage approach known as B-model. After 6 million of loading cycles, local failure probabilities of 0.3, 0.4 and 0.91 were predicted for the Lifecore, Avinent and GMI implants, respectively (diameter of 3.75mm). The influence of the diameter for the GMI implant was studied and the results predicted a local failure probability of 0.91 and 0.1 for the 3.75mm and 5mm, respectively. In all cases the highest failure probability was located at the upper screw-threads. Therefore, the probabilistic methodology proposed herein may be a useful tool for performing a qualitative comparison between different commercial dental implants. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. Nuclear Waste Disposal and Strategies for Predicting Long-Term Performance of Material

    International Nuclear Information System (INIS)

    Wicks, G.G.

    2001-01-01

    Ceramics have been an important part of the nuclear community for many years. On December 2, 1942, an historic event occurred under the West Stands of Stagg Field, at the University of Chicago. Man initiated his first self-sustaining nuclear chain reaction and controlled it. The impact of this event on civilization is considered by many as monumental and compared by some to other significant events in history, such as the invention of the steam engine and the manufacturing of the first automobile. Making this event possible and the successful operation of this first man-made nuclear reactor, was the use of forty tons of UO2. The use of natural or enriched UO2 is still used today as a nuclear fuel in many nuclear power plants operating world-wide. Other ceramic materials, such as 238Pu, are used for other important purposes, such as ceramic fuels for space exploration to provide electrical power to operate instruments on board spacecrafts. Radioisotopic Thermoelectric Generators (RTGs) are used to supply electrical power and consist of a nuclear heat source and converter to transform heat energy from radioactive decay into electrical power, thus providing reliable and relatively uniform power over the very long lifetime of a mission. These sources have been used in the Galileo spacecraft orbiting Jupiter and for scientific investigations of Saturn with the Cassini spacecraft. Still another very important series of applications using the unique properties of ceramics in the nuclear field, are as immobilization matrices for management of some of the most hazardous wastes known to man. For example, in long-term management of radioactive and hazardous wastes, glass matrices are currently in production immobilizing high-level radioactive materials, and cementious forms have also been produced to incorporate low level wastes. Also, as part of nuclear disarmament activities, assemblages of crystalline phases are being developed for immobilizing weapons grade plutonium, to

  4. Measured and Predicted Neutron Flux Distributions in a Material Surrounding a Cylindrical Duct

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, J; Sandlin, R

    1966-03-15

    The radial fast neutron flux attenuations in the material (iron) surrounding ducts of diameters 7, 9, and 15 cm and total duct length of about 1.5 m have been investigated with and without neutron scattering cans filled with D{sub 2}O in the duct. Experimentally the problem was solved by the use of foil activation techniques. Theoretically it was attacked by, in the first place, a Monte Carlo program specially written for this purpose and utilizing an importance sampling technique. In the second place non- and single-scattering removal flux codes were tried, and also simple hand calculations. The Monte Carlo results accounted well for the fast flux attenuation, while the non- and single-scattering methods overestimated the attenuation generally by a factor of 10 or less. Simple hand calculations using three empirical parameters could be fitted to the measured data within a factor of 1.2 - 1.3 at penetration depths greater than 3 - 4 cm. The distribution of the D{sub 2}O-scattered flux could well be described in terms of single scattering.

  5. Prediction of Optimal Designs for Material Removal Rate and Surface Roughness Characteristics

    Directory of Open Access Journals (Sweden)

    Maheswara Rao Ch

    2016-12-01

    Full Text Available The present work involves in finding the optimal combination of cutting parameters, in dry turning of EN19 steel using a tungsten carbide tool of nose radius 0.4 mm. The experiments were conducted on a CNC turret lathe as per the designed L9 (3^3 orthogonal array. In order to optimize the Material Removal Rate (MRR, Arithmetic Average Roughness (Ra and Average Peak-to-Valley Height Roughness (Rz individually, Single objective Taguchi method has been employed. From the results, the optimal combination of cutting parameters for MRR is found at: 225 m/min, 0.15 mm/rev and 0.6 mm. Optimal combination of Ra and Rz is found at: 225 m/min, 0.05 mm/rev and 0.6 mm. Analysis of variance (ANOVA is used to find the influence of cutting parameters on the responses. ANOVA results revealed that speed and feed has high influence on MRR. Speed has high influence in affecting the Roughness parameters. Linear regression models for the responses were prepared using the MINITAB-16 software. From the results, it is found that the models prepared are more significant and accurate.

  6. Method of predicting air pollution of coal mines with use of new synthetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, V V; Putilina, O.N.

    1988-08-01

    Presents a methodological approach that enables on the basis of laboratory experiment to give a hygienic evaluation of synthetic materials used in coal mines to harden coal and rock masses to prevent rock falls and caving and for hermetization of ventilation equipment. Polyurethane, carbamidoformaldehyde and phenolformaldehyde plastic foam are studied in an experiment tha examined quantitative emission ofsubstances from their original components in the process of forming contaminants. Synthetics in a beaker are placed in an exsiccator, mixed with air, samples of volatiles particles collected and dynamics of their emission are calculated using regression and linear equations. Amounts of 2,4- toluenediisocyanate and diethylamine produced by polyurethane, and formaldehyde and methanol from carbamidoformaldehyde did not exceed limits of maximum concentrations; phenolformaldehyde plastic foam produced amounts of phenols and formaldehydes that are significantly higher than maximal permissible concentrations. Laboratory procedure and use of formulae were confirmed by testing air in a Donetsugol' mine. Polyurethane and carbamidoformaldehyde didnot contaminate air above hygienically safe limits, while phenolformaldehyde plastic foam exceeded safety limits proving need for hygienic measures to protect miners from its contaminants. Adequacy of laboratory-mathematical method to evaluate emissions of harmful chemicals from resins under mining conditions shows value of laboratory testing of many resins for safety in mine use. 4 refs.

  7. Crust behavior and erosion rate prediction of EPR sacrificial material impinged by core melt jet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen; Liu, Ming, E-mail: ming.liu@mail.xjtu.edu.cn; Wang, Jinshi; Chong, Daotong; Yan, Junjie

    2017-04-01

    Highlights: • A numerical code was developed to analyze melt jet-concrete interaction in the frame of MPS method. • Crust and ablated concrete layer at UO{sub 2}-ZrO{sub 2} melt and concrete interface periodically developed and collapsed. • Concrete surface temperature fluctuated around a low temperature and ablation temperature. • Concrete erosion by Fe-Zr melt jet was significantly faster than that by UO{sub 2}-ZrO{sub 2} melt jet. - Abstract: Sacrificial material is a special ferro-siliceous concrete, designed in the ex-vessel core melt stabilization system of European Pressurized water Reactor (EPR). Given a localized break of RPV lower head, the melt directly impinges onto the dry concrete in form of compact jet. The concrete erosion behavior influences the failure of melt plug, and further affects melt spreading. In this study, a numerical code was developed in the frame of Moving Particle Semi-implicit (MPS) method, to analyze the crust behavior and erosion rate of sacrificial concrete, impinged by prototypic melt jet. In validation of numerical modeling, the time-dependent erosion depth and erosion configuration matched well with the experimental data. Sensitivity study of sacrificial concrete erosion indicates that the crust and ablated concrete layer presented at UO{sub 2}-ZrO{sub 2} melt and concrete interface, whereas no crust could be found in the interaction of Fe-Zr melt with concrete. The crust went through stabilization-fracture-reformation periodic process, accompanied with accumulating and collapsing of molten concrete layer. The concrete surface temperature fluctuated around a low temperature and ablation temperature. It increased as the concrete surface layer was heated to melting, and dropped down when the cold concrete was revealed. The erosion progression was fast in the conditions of small jet diameter and large concrete inclination angle, and it was significantly faster in the erosion by metallic melt jet than by oxidic melt jet.

  8. Mn2C sheet as an electrode material for lithium-ion battery: A first-principles prediction

    International Nuclear Information System (INIS)

    Zhou, Yungang; Zu, Xiaotao

    2017-01-01

    Graphical abstract: Combined with strong Li bond, low Li diffusion barrier, superior electrical conductivity and high theoretical capacity, Mn 2 C Sheet is found to be a new promising electrode material for Lithium-Ion Battery. - Highlights: • Li atom bind strongly with Mn 2 C sheet with a very low adsorption energy. • Pristine Mn 2 C sheet exhibits metallic character. • Li atom can easily and freely migrate on the Mn 2 C sheet. • Lithiation to a high content is feasible. • Theoretical capacity of Mn 2 C sheet arrives at 879 mAhg −1 . - Abstract: A search for high-efficiency electrode materials is crucial for the application of Li-ion batteries (LIBs). Using density functional theory (DFT), we assess the Mn 2 C sheet, a new MXene, as a suitable electrode material. Our studies show that Li atoms can bind strongly to the Mn 2 C sheet, with low adsorption energy of −1.93 eV. A pristine Mn 2 C sheet exhibits metallic characteristic, offering an intrinsic advantage for the transportation of electrons in material. A very low energy barrier of 0.05 eV is predicted, showing that Li ion can easily and freely migrate on the Mn 2 C sheet. In addition, with the increase of Li content, adsorption energy varies minimally within a range of energy that spans only 0.27 eV, showing that lithiation to a high content is feasible. Furthermore, we found that, because of the bilayer adsorptions on both sides of the Mn 2 C sheet, the theoretical capacity of the Mn 2 C sheet is 879 mAhg −1 , which is greater than that of most two-dimentional (2D) electrode materials. All these results reveal a new promising MXene material for LIBs. We also studied the effects of oxidation and fluorination on the electrochemical properties of the Mn 2 C sheet and found that oxidation and fluorination will fade the electrochemical properties of the Mn 2 C sheet in general.

  9. In-Service Design and Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation

    International Nuclear Information System (INIS)

    G. R. Odette; G. E. Lucas

    2005-01-01

    This final report on ''In-Service Design and Performance Prediction of Advanced Fusion Material Systems by Computational Modeling and Simulation'' (DE-FG03-01ER54632) consists of a series of summaries of work that has been published, or presented at meetings, or both. It briefly describes results on the following topics: (1) A Transport and Fate Model for Helium and Helium Management; (2) Atomistic Studies of Point Defect Energetics, Dynamics and Interactions; (3) Multiscale Modeling of Fracture consisting of: (3a) A Micromechanical Model of the Master Curve (MC) Universal Fracture Toughness-Temperature Curve Relation, KJc(T - To), (3b) An Embrittlement DTo Prediction Model for the Irradiation Hardening Dominated Regime, (3c) Non-hardening Irradiation Assisted Thermal and Helium Embrittlement of 8Cr Tempered Martensitic Steels: Compilation and Analysis of Existing Data, (3d) A Model for the KJc(T) of a High Strength NFA MA957, (3e) Cracked Body Size and Geometry Effects of Measured and Effective Fracture Toughness-Model Based MC and To Evaluations of F82H and Eurofer 97, (3f) Size and Geometry Effects on the Effective Toughness of Cracked Fusion Structures; (4) Modeling the Multiscale Mechanics of Flow Localization-Ductility Loss in Irradiation Damaged BCC Alloys; and (5) A Universal Relation Between Indentation Hardness and True Stress-Strain Constitutive Behavior. Further details can be found in the cited references or presentations that generally can be accessed on the internet, or provided upon request to the authors. Finally, it is noted that this effort was integrated with our base program in fusion materials, also funded by the DOE OFES

  10. The early predictive value of a decrease of metabolic tumor volume in repeated 18F-FDG PET/CT for recurrence of locally advanced non-small cell lung cancer with concurrent radiochemotherapy

    International Nuclear Information System (INIS)

    Huang, Wei; Liu, Bo; Fan, Min; Zhou, Tao; Fu, Zheng; Zhang, Zicheng; Li, Hongsheng; Li, Baosheng

    2015-01-01

    Highlights: •The patients underwent the second FDG PET during the early stage of concurrent chemoradiotherapy (CCRT). •To our knowledge, this could be the first study showing that the repeated FDG PET during the early stage of CCRT has added value by being a prognostic factor for recurrence of the locally advanced NSCLC patients. •This is a result of continuous research. •The decrease of MTV was the only significant risk factor for recurrence. -- Abstract: Purpose: The aim of this study is to investigate the value of [ 18 F] fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F FDG PET/CT) to predict recurrence of patients with locally advanced non-small cell lung cancer (NSCLC) during the early stage of concurrent chemoradiotherapy (CCRT). Methods: A total of 53 stage III NSCLC patients without diabetics or undergoing surgery were enrolled in the prospective study. Those patients were evaluated by FDG PET before and following 40 Gy radiotherapy (RT) with a concurrent cisplatin-based heterogeneous chemotherapy regimen. Semiquantitative assessment was used to determine maximum and mean SUVs (SUVmax/SUVmean) and metabolic tumor volume (MTV) of the primary tumor. The prognostic significance of PET/CT parameters and other clinical variables was assessed using Cox regression analyses. The cutoffs of PET/CT parameters which have been determined by the previous study were used to separate the groups with Kaplan–Meier curves. Results: Recurrence rates at 1- and 2-years were 18.9% (10/53) and 50.9% (27/53) for all patients, respectively. Cox regression analysis showed that the only prognostic factor for recurrence was a decrease of MTV. Using the cutoff of 29.7%, a decrease of MTV can separate the patients into 2 groups with Kaplan–Meier curve successfully. Conclusion: The prospective study has reinforced the early predictive value of MTV in repeated 18 F-FDG PET/CT for recurrence in a subgroup of locally advanced NSCLC who underwent CCRT. A

  11. Prediction of SEM–X-ray images’ data of cement-based materials using artificial neural network algorithm

    Directory of Open Access Journals (Sweden)

    Ashraf Ragab Mohamed

    2014-09-01

    Full Text Available Recent advances of computational capabilities have motivated the development of more sophisticated models to simulate cement-based hydration. However, the input parameters for such models, obtained from SEM–X-ray image analyses, are quite complicated and hinder their versatile application. This paper addresses the utilization of the artificial neural networks (ANNs to predict the SEM–X-ray images’ data of cement-based materials (surface area fraction and the cement phases’ correlation functions. ANNs have been used to correlate these data, already obtained for 21 types of cement, to basic cement data (cement compounds and fineness. Two approaches have been proposed; the ANN, and the ANN-regression method. Comparisons have shown that the ANN proves effectiveness in predicting the surface area fraction, while the ANN-regression is more computationally suitable for the correlation functions. Results have shown good agreement between the proposed techniques and the actual data with respect to hydration products, degree of hydration, and simulated images.

  12. Ab-Initio Description and Prediction of Properties of Carbon-Based and Other Non-Metallic Materials

    Science.gov (United States)

    Bagayoko, D.; Zhao, G. L.; Hasan, S.

    2001-01-01

    We have resolved the long-standing problem consisting of 30%-50% theoretical underestimates of the band gaps of non-metallic materials. We describe the Bagayoko, Zhao, and Williams (BZW) method that rigorously circumvents the basis-set and variational effect presumed to be a cause of these underestimates. We present ab-initio, computational results that are in agreement with experiment for diamond (C), silicon (Si), silicon carbides (3C-SiC and 4H-SiC), and other semiconductors (GaN, BaTiO3, AlN, ZnSe, ZnO). We illustrate the predictive capability of the BZW method in the case of the newly discovered cubic phase of silicon nitride (c-Si3N4) and of selected carbon nanotabes [(10,0), and (8,4)]. Our conclusion underscores the inescapable need for the BZW method in ab-initio calculations that employ a basis set in a variational approach. Current nanoscale trends amplify this need. We estimate that the potential impact of applications of the BZW method in advancing our understanding of nonmetallic materials, in informing experiment, and particularly in guiding device design and fabrication is simply priceless.

  13. Slow and stopped light in active gain composite materials of metal nanoparticles. Ultralarge group index-bandwidth product predicted

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang-Hyon; Choe, Song-Hyok [Institute of Lasers, State Academy of Sciences, Unjong District, Pyongyang (Korea, Democratic People' s Republic of)

    2017-08-15

    Chip-compatible slow light devices with large group index-bandwidth products and low losses are of great interest in the community of modern photonics. In this work, active gain materials containing metal nanoparticles are proposed as the slow and stopped light materials. Gain-assisted high field enhancement in metal nanoparticles and the resultant strong dispersion lead to such phenomena. From the Maxwell-Garnett model, it is revealed that the metal nanocomposite exhibits the infinitely large group index when the gain of the host medium and the filling factor of metal nanoparticles satisfy a critical condition. For the gain of the host above the critical value, one can observe slowing down effect with amplification of light pulses. Significantly large group index-bandwidth products, which vary from a few to several thousand or even infinity depending on the gain value of the host medium, have been numerically predicted in active silica glasses containing spheroidal metal nanoparticles, as examples. The proposed scheme inherently provides the widely varying operating spectral range by changing the aspect ratio of metal nanoparticles and chip-compatibility with low cost. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Rational molecular dynamics scheme for predicting optimum concentration loading of nano-additive in phase change materials

    Directory of Open Access Journals (Sweden)

    Monisha Rastogi

    2015-10-01

    Full Text Available The present study deals with the diffusion and phase transition behaviour of paraffin reinforced with carbon nano-additives namely graphene oxide (GO and surface functionalized single walled carbon nanotubes (SWCNT. Bulk disordered systems of paraffin hydrocarbons impregnated with carbon nano-additives have been generated in realistic equilibrium conformations for potential application as latent heat storage systems. Ab initio molecular dynamics(MD in conjugation with COMPASS forcefield has been implemented using periodic boundary conditions. The proposed scheme allows determination of optimum nano-additive loading for improving thermo-physical properties through analysis of mass, thermal and transport properties; and assists in determination of composite behaviour and related performance from microscopic point of view. It was observed that nanocomposites containing 7.8 % surface functionalised SWCNT and 55% GO loading corresponds to best latent heat storage system. The propounded methodology could serve as a by-pass route for economically taxing and iterative experimental procedures required to attain the optimum composition for best performance. The results also hint at the large unexplored potential of ab-initio classical MD techniques for predicting performance of new nanocomposites for potential phase change material applications.

  15. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  16. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    International Nuclear Information System (INIS)

    Chinnadurai, T.; Vendan, S.A.

    2016-01-01

    This study focuses on investigating the effects of process parameters, namely, Peak current (Ip), Pulse on time (Ton), Pulse off time (Toff), Water pressure (Wp), Wire feed rate (Wf), Wire tension (Wt), Servo voltage (Sv) and Servo feed setting (Sfs), on the Material Removal Rate (MRR) and Surface Roughness (SR) for Wire electrical discharge machining (Wire-EDM) of nickel using Taguchi method. Response Surface Methodology (RSM) is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA) method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used. (Author)

  17. Rational molecular dynamics scheme for predicting optimum concentration loading of nano-additive in phase change materials

    Science.gov (United States)

    Rastogi, Monisha; Vaish, Rahul; Madhar, Niyaz Ahamad; Shaikh, Hamid; Al-Zahrani, S. M.

    2015-10-01

    The present study deals with the diffusion and phase transition behaviour of paraffin reinforced with carbon nano-additives namely graphene oxide (GO) and surface functionalized single walled carbon nanotubes (SWCNT). Bulk disordered systems of paraffin hydrocarbons impregnated with carbon nano-additives have been generated in realistic equilibrium conformations for potential application as latent heat storage systems. Ab initio molecular dynamics(MD) in conjugation with COMPASS forcefield has been implemented using periodic boundary conditions. The proposed scheme allows determination of optimum nano-additive loading for improving thermo-physical properties through analysis of mass, thermal and transport properties; and assists in determination of composite behaviour and related performance from microscopic point of view. It was observed that nanocomposites containing 7.8 % surface functionalised SWCNT and 55% GO loading corresponds to best latent heat storage system. The propounded methodology could serve as a by-pass route for economically taxing and iterative experimental procedures required to attain the optimum composition for best performance. The results also hint at the large unexplored potential of ab-initio classical MD techniques for predicting performance of new nanocomposites for potential phase change material applications.

  18. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Chinnadurai, T.; Vendan, S.A.

    2016-07-01

    This study focuses on investigating the effects of process parameters, namely, Peak current (Ip), Pulse on time (Ton), Pulse off time (Toff), Water pressure (Wp), Wire feed rate (Wf), Wire tension (Wt), Servo voltage (Sv) and Servo feed setting (Sfs), on the Material Removal Rate (MRR) and Surface Roughness (SR) for Wire electrical discharge machining (Wire-EDM) of nickel using Taguchi method. Response Surface Methodology (RSM) is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA) method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used. (Author)

  19. Prediction of the fate of radioactive material in the South Pacific Ocean using a global high-resolution ocean model

    International Nuclear Information System (INIS)

    Hazell, Douglas R.; England, Matthew H.

    2003-01-01

    We investigate the release of radioactive contaminants from Moruroa Atoll in a global high-resolution off-line model. The spread of tracer is studied in a series of simulations with varying release depths and time-scales, and into ocean velocity fields corresponding to long-term annual mean, seasonal, and interannually varying scenarios. In the instantaneous surface release scenarios we find that the incorporation of a seasonal cycle greatly influences tracer advection, with maximum concentrations still found within the French Polynesia region after 10 years. In contrast, the maximum trace is located in the southeast Pacific when long-term annual mean fields are used. This emphasizes the importance of the seasonal cycle in models of pollution dispersion on large scales. We further find that during an El Nino/Southern Oscillation (ENSO) event reduced currents in the region of Moruroa Atoll result in increased concentrations of radioactive material in French Polynesia, as direct flushing from the source is reduced. In terms of the sensitivity to tracer release time-rates, we find that a gradual input results in maximum concentrations in the near vicinity of French Polynesia. This contrasts the instantaneous-release scenarios, which see maximum concentrations and tracer spread across much of the South Pacific Ocean. For example, in as little as seven years radioactive contamination can reach the east coast of Australia diluted by only a factor of 1000 of the initial concentration. A comparison of results is made with previous studies. Overall, we find much higher concentrations of radionuclides in the South Pacific than has previously been predicted using coarser-resolution models

  20. Classifying organic materials by oxygen-to-carbon elemental ratio to predict the activation regime of Cloud Condensation Nuclei (CCN

    Directory of Open Access Journals (Sweden)

    M. Kuwata

    2013-05-01

    Full Text Available The governing highly soluble, slightly soluble, or insoluble activation regime of organic compounds as cloud condensation nuclei (CCN was examined as a function of oxygen-to-carbon elemental ratio (O : C. New data were collected for adipic, pimelic, suberic, azelaic, and pinonic acids. Secondary organic materials (SOMs produced by α-pinene ozonolysis and isoprene photo-oxidation were also included in the analysis. The saturation concentrations C of the organic compounds in aqueous solutions served as the key parameter for delineating regimes of CCN activation, and the values of C were tightly correlated to the O : C ratios. The highly soluble, slightly soluble, and insoluble regimes of CCN activation were found to correspond to ranges of [O : C] > 0.6, 0.2 < [O : C] < 0.6, and [O : C] < 0.2, respectively. These classifications were evaluated against CCN activation data of isoprene-derived SOM (O : C = 0.69–0.72 and α-pinene-derived SOM (O : C = 0.38–0.48. Isoprene-derived SOM had highly soluble activation behavior, consistent with its high O : C ratio. For α-pinene-derived SOM, although CCN activation can be modeled as a highly soluble mechanism, this behavior was not predicted by the O : C ratio, for which a slightly soluble mechanism was anticipated. Complexity in chemical composition, resulting in continuous water uptake and the absence of a deliquescence transition that can thermodynamically limit CCN activation, might explain the difference in the behavior of α-pinene-derived SOM compared to that of pure organic compounds. The present results suggest that atmospheric particles dominated by hydrocarbon-like organic components do not activate (i.e., insoluble regime whereas those dominated by oxygenated organic components activate (i.e., highly soluble regime for typical atmospheric cloud life cycles.

  1. Nondestructive characterization of materials (ultrasonic and micromagnetic techniques) for strength and toughness prediction and the detection of early creep damage

    International Nuclear Information System (INIS)

    Dobmann, G.; Kroening, M.; Theiner, W.; Willems, H.; Fiedler, U.

    1995-01-01

    In recent years, nondestructive testing techniques for materials characterization have been developed in Germany under the sponsorship of the Ministry of Research and Development, as part of the Reactor Safety Research Programme, in order to provide techniques for PSI and ISI that are sensitive and reliable, in particular with respect to the prediction of strength and toughness. As ferritic steels (pressure vessels and pipelines in the primary circuit) are of special interest, R and D was concentrated on micromagnetic techniques which are sensitive to the microstructure and its changes under service and/or repair conditions. In order to characterize microstructural states superimposed by residual stresses in an unambiguous way, numerical modelling was applied using advanced tools of mathematical approximation theory, i.e. multiregression algorithms and neural networks.For the detection of early creep damage in fossil power plant applications, i.e. micropores and their subsequent development to linked pores and microcracks, besides the micromagnetic techniques an ultrasonic technique was also applied and optimized for in situ applications on components such as pipe bends. Whereas the ultrasonic technique is sensitive to pore concentrations as small as about 0.2%, the parameters of the micromagnetic techniques are mainly influenced by temperature- and load-induced microstructural changes occurring in service, dependent on the steel quality. The techniques are applied at two pipe bends (steel grades 14MoV63 and X20CrMoV121) loaded under near practical conditions during seven inspection intervals between 2048h and 21000h to evaluate the progress of damage. (orig.)

  2. Moderation of Stimulus Material on the Prediction of IQ with Infants' Performance in the Visual Expectation Paradigm: Do Greebles Make the Task More Challenging?

    Science.gov (United States)

    Teubert, Manuel; Lohaus, Arnold; Fassbender, Ina; Vöhringer, Isabel A.; Suhrke, Janina; Poloczek, Sonja; Freitag, Claudia; Lamm, Bettina; Teiser, Johanna; Keller, Heidi; Knopf, Monika; Schwarzer, Gudrun

    2015-01-01

    The objective of this study was to examine the role of the stimulus material for the prediction of later IQ by early learning measures in the Visual Expectation Paradigm (VExP). The VExP was assessed at 9?months using two types of stimuli, Greebles and human faces. Greebles were assumed to be associated with a higher load on working memory in…

  3. A quantitative prediction model of SCC rate for nuclear structure materials in high temperature water based on crack tip creep strain rate

    International Nuclear Information System (INIS)

    Yang, F.Q.; Xue, H.; Zhao, L.Y.; Fang, X.R.

    2014-01-01

    Highlights: • Creep is considered to be the primary mechanical factor of crack tip film degradation. • The prediction model of SCC rate is based on crack tip creep strain rate. • The SCC rate calculated at the secondary stage of creep is recommended. • The effect of stress intensity factor on SCC growth rate is discussed. - Abstract: The quantitative prediction of stress corrosion cracking (SCC) of structure materials is essential in safety assessment of nuclear power plants. A new quantitative prediction model is proposed by combining the Ford–Andresen model, a crack tip creep model and an elastic–plastic finite element method. The creep at the crack tip is considered to be the primary mechanical factor of protective film degradation, and the creep strain rate at the crack tip is suggested as primary mechanical factor in predicting the SCC rate. The SCC rates at secondary stage of creep are recommended when using the approach introduced in this study to predict the SCC rates of materials in high temperature water. The proposed approach can be used to understand the SCC crack growth in structural materials of light water reactors

  4. H2O2 can Increase Lignin Disintegration and Decrease Cellulose Decomposition in the Process of Solid-State Fermentation (SSF by Aspergillus oryzae Using Corn Stalk as Raw Materials

    Directory of Open Access Journals (Sweden)

    Zhicai Zhang

    2014-04-01

    Full Text Available H2O2 is both bactericidal and the main oxidant responsible for lignin degradation reaction catalyzed by manganese peroxidase (MnP and lignin peroxidase (LiP. Thus, H2O2 treatment of corn stalk and the implementation of solid-substrate fermentation (SSF is possible to increase the removal rate of lignin from stalk in the process of SSF and after SSF, while avoiding the need to sterilize the raw materials. To demonstrate this approach, SSF was initially carried out using corn stalk pretreated with different concentrations of H2O2 as a substrate. A. oryzae was found to grow well in the 3% H2O2-pretreated corn stalk. H2O2-pretreated corn stalk showed increased MnP and LiP synthesis and disintegration of lignin, but inhibited cellulase synthesis and cellulose degradation. Production of the SSF (200 g on the 10th day was hydrolyzed in the presence of additional 600 mL different concentration of H2O2 aqueous solution. The total removal of lignin (73.15% of hydrolysis for 10 h at 3% H2O2 solution was highest and far higher than that at the 12th day, as achieved by conventional SSF. Applying this strategy in practice may shorten the time of lignin degradation, increase the removal of lignin, and decrease the loss of cellulose. Thus, this study has provided a foundation for further study saccharification of corn stalk.

  5. Developing a Material Response Model of Biopolymer-Stabilized Regolith to Predict Micrometeorite Damage of ISRU Habitat Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed space technology research aims to investigate the micrometeorite impact performance of Regolith Biocomposite (RBC), an innovative in-situ material...

  6. Decreasing Relative Risk Premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    relative risk premium in the small implies decreasing relative risk premium in the large, and decreasing relative risk premium everywhere implies risk aversion. We finally show that preferences with decreasing relative risk premium may be equivalently expressed in terms of certain preferences on risky......We consider the risk premium demanded by a decision maker with wealth x in order to be indifferent between obtaining a new level of wealth y1 with certainty, or to participate in a lottery which either results in unchanged present wealth or a level of wealth y2 > y1. We define the relative risk...... premium as the quotient between the risk premium and the increase in wealth y1–x which the decision maker puts on the line by choosing the lottery in place of receiving y1 with certainty. We study preferences such that the relative risk premium is a decreasing function of present wealth, and we determine...

  7. Decreasing Serial Cost Sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Østerdal, Lars Peter

    The increasing serial cost sharing rule of Moulin and Shenker [Econometrica 60 (1992) 1009] and the decreasing serial rule of de Frutos [Journal of Economic Theory 79 (1998) 245] have attracted attention due to their intuitive appeal and striking incentive properties. An axiomatic characterization...... of the increasing serial rule was provided by Moulin and Shenker [Journal of Economic Theory 64 (1994) 178]. This paper gives an axiomatic characterization of the decreasing serial rule...

  8. Decreasing serial cost sharing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Østerdal, Lars Peter Raahave

    2009-01-01

    The increasing serial cost sharing rule of Moulin and Shenker (Econometrica 60:1009-1037, 1992) and the decreasing serial rule of de Frutos (J Econ Theory 79:245-275, 1998) are known by their intuitive appeal and striking incentive properties. An axiomatic characterization of the increasing serial...... rule was provided by Moulin and Shenker (J Econ Theory 64:178-201, 1994). This paper gives an axiomatic characterization of the decreasing serial rule....

  9. A model to predict the level of artificial radionuclides in environmental materials in the Severn Estuary and the Bristol Channel

    International Nuclear Information System (INIS)

    McColl, N.P.

    1988-01-01

    The NRPB SEVERN compartment model, of the Bristol Channel and Severn Estuary, has been developed for used in predicting environmental concentrations of artificial radionuclides present in the estuary. A comparison between predicted and measured values of salinity and environmental 137 Cs concentrations has demonstrated the overall validity of the model. SEVERN has been used to assess the radiological impact of radionuclides present in the estuary which result from low-level routine discharges from the nuclear power industry. (author)

  10. Replacing the nucleus pulposus of the intervertebral disk: prediction of suitable properties of a replacement material using finite element analysis.

    Science.gov (United States)

    Meakin, J R

    2001-03-01

    An axisymmetric finite element model of a human lumbar disk was developed to investigate the properties required of an implant to replace the nucleus pulposus. In the intact disk, the nucleus was modeled as a fluid, and the annulus as an elastic solid. The Young's modulus of the annulus was determined empirically by matching model predictions to experimental results. The model was checked for sensitivity to the input parameter values and found to give reasonable behavior. The model predicted that removal of the nucleus would change the response of the annulus to compression. This prediction was consistent with experimental results, thus validating the model. Implants to fill the cavity produced by nucleus removal were modeled as elastic solids. The Poisson's ratio was fixed at 0.49, and the Young's modulus was varied from 0.5 to 100 MPa. Two sizes of implant were considered: full size (filling the cavity) and small size (smaller than the cavity). The model predicted that a full size implant would reverse the changes to annulus behavior, but a smaller implant would not. By comparing the stress distribution in the annulus, the ideal Young's modulus was predicted to be approximately 3 MPa. These predictions have implications for current nucleus implant designs. Copyright 2001 Kluwer Academic Publishers

  11. Transcatheter Arterial Embolization for Primary Postpartum Hemorrhage: Predictive Factors of Need for Embolic Material Conversion of Gelatin Sponge Particles to N-Butyl Cyanoacrylate

    International Nuclear Information System (INIS)

    Tanahashi, Yukichi; Goshima, Satoshi; Kondo, Hiroshi; Ando, Tomohiro; Noda, Yoshifumi; Kawada, Hiroshi; Kawai, Nobuyuki; Kotoku, Junichi; Furui, Shigeru; Matsuo, Masayuki

    2017-01-01

    PurposeTo identify predictive factors for embolic material conversion to N-butyl cyanoacrylate (NBCA) for the treatment of primary postpartum hemorrhage (PPH) after failed transcatheter arterial embolization (TAE) using gelatin sponge (GS).Materials and MethodsInstitutional review board approval was obtained. We retrospectively studied 62 consecutive women with primary PPH who underwent TAE between January 2006 and March 2015. Five of them were excluded for the following: cardiopulmonary arrest at arrival (n = 1), uterine inversion (n = 1), and hysterectomy after TAE (n = 3). Remaining 57 women (age range, 21–43 years; mean, 32.6 years) comprised study population. TAE was initially performed using GS in all cases and then converted to NBCA after two embolizations using GS with persistent hemodynamic instability or vaginal bleeding. The patients’ background, uterine height, vital signs, laboratory tests, disseminated intravascular coagulation score, and details of procedure were reviewed. Univariate and multivariate analyses were performed to determine factors related to embolic material conversion.ResultsTechnical success rate was 100%. Fourteen patients (25%) needed embolic material conversion to NBCA. Univariate analysis showed that uterine height, systolic blood pressure (sBP), and hemoglobin level were significantly related to embolic material conversion to NBCA (P = 0.029, 0.030, and 0.042). Logistic regression analysis showed that uterine height (odds ratio, 1.37; P = 0.025) and sBP (odds ratio, 0.96; P = 0.003) were associated with embolic material conversion to NBCA.ConclusionUterine height and sBP can be predictive factors for embolic material conversion to NBCA for the treatment of PPH.Level of EvidenceLevel 4, Case Control Study

  12. Transcatheter Arterial Embolization for Primary Postpartum Hemorrhage: Predictive Factors of Need for Embolic Material Conversion of Gelatin Sponge Particles to N-Butyl Cyanoacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Tanahashi, Yukichi; Goshima, Satoshi, E-mail: gossy@par.odn.ne.jp [Gifu University Hospital, Department of Radiology (Japan); Kondo, Hiroshi [Teikyo University School of Medicine, Department of Radiology (Japan); Ando, Tomohiro; Noda, Yoshifumi; Kawada, Hiroshi; Kawai, Nobuyuki [Gifu University Hospital, Department of Radiology (Japan); Kotoku, Junichi [Teikyo University School of Medicine, Department of Radiological Technology, Faculty of Medical Technology (Japan); Furui, Shigeru [Teikyo University School of Medicine, Department of Radiology (Japan); Matsuo, Masayuki [Gifu University Hospital, Department of Radiology (Japan)

    2017-02-15

    PurposeTo identify predictive factors for embolic material conversion to N-butyl cyanoacrylate (NBCA) for the treatment of primary postpartum hemorrhage (PPH) after failed transcatheter arterial embolization (TAE) using gelatin sponge (GS).Materials and MethodsInstitutional review board approval was obtained. We retrospectively studied 62 consecutive women with primary PPH who underwent TAE between January 2006 and March 2015. Five of them were excluded for the following: cardiopulmonary arrest at arrival (n = 1), uterine inversion (n = 1), and hysterectomy after TAE (n = 3). Remaining 57 women (age range, 21–43 years; mean, 32.6 years) comprised study population. TAE was initially performed using GS in all cases and then converted to NBCA after two embolizations using GS with persistent hemodynamic instability or vaginal bleeding. The patients’ background, uterine height, vital signs, laboratory tests, disseminated intravascular coagulation score, and details of procedure were reviewed. Univariate and multivariate analyses were performed to determine factors related to embolic material conversion.ResultsTechnical success rate was 100%. Fourteen patients (25%) needed embolic material conversion to NBCA. Univariate analysis showed that uterine height, systolic blood pressure (sBP), and hemoglobin level were significantly related to embolic material conversion to NBCA (P = 0.029, 0.030, and 0.042). Logistic regression analysis showed that uterine height (odds ratio, 1.37; P = 0.025) and sBP (odds ratio, 0.96; P = 0.003) were associated with embolic material conversion to NBCA.ConclusionUterine height and sBP can be predictive factors for embolic material conversion to NBCA for the treatment of PPH.Level of EvidenceLevel 4, Case Control Study.

  13. The comparison of two continuum damage mechanics-based material models for formability prediction of AA6082 under hot stamping conditions

    Science.gov (United States)

    Shao, Z.; Li, N.; Lin, J.

    2017-09-01

    The hot stamping and cold die quenching process has experienced tremendous development in order to obtain shapes of structural components with great complexity in automotive applications. Prediction of the formability of a metal sheet is significant for practical applications of forming components in the automotive industry. Since microstructural evolution in an alloy at elevated temperature has a large effect on formability, continuum damage mechanics (CDM)-based material models can be used to characterise the behaviour of metals when a forming process is conducted at elevated temperatures. In this paper, two sets of unified multi-axial constitutive equations based on material’s stress states and strain states, respectively, were calibrated and used to effectively predict the thermo-mechanical response and forming limits of alloys under complex hot stamping conditions. In order to determine and calibrate the two material models, formability tests of AA6082 using a developed novel biaxial testing system were conducted at various temperatures and strain rates under hot stamping conditions. The determined unified constitutive equations from experimental data are presented in this paper. It is found that both of the stress-state based and strain-state based material models can predict the formability of AA6082 under hot stamping conditions.

  14. Effect of Decreasing Cobalt Content on the Electrochemical Properties and Structural Stability of Li_(1-x)Ni_(y)Co_(z)Al_(0.05)O_(2) Type Cathode Materials

    OpenAIRE

    Ghatak, Kamalika; Kumar, Hemant; Nadimpalli, Siva; Datta, Dibakar

    2017-01-01

    In Lithium ion batteries (LIBs), proper design of cathode materials influences its intercalation behavior, overall cost, structural stability, and its impact on environment. At present, the most common type of cathode materials, NCA , has very high cobalt concentration. Since cobalt is toxic and expensive, the existing design of cathode materials is not cost-effective, and environmentally benign. However, these immensely important issues have not yet been properly addressed. Therefore, we hav...

  15. Decreasing relative risk premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    2007-01-01

    such that the corresponding relative risk premium is a decreasing function of present wealth, and we determine the set of associated utility functions. We find a new characterization of risk vulnerability and determine a large set of utility functions, closed under summation and composition, which are both risk vulnerable...

  16. Decreasing asthma morbidity

    African Journals Online (AJOL)

    1994-12-12

    Dec 12, 1994 ... Apart from the optimal use of drugs, various supplementary methods have been tested to decrease asthma morbidity, usually in patients from reiatively affluent socio-economic backgrounds. A study of additional measures taken in a group of moderate to severe adult asthmatics from very poor socio- ...

  17. Photopolymer holographic recording material

    Science.gov (United States)

    Lawrence, J. R.; O'Neill, F. T.; Sheridan, J. T.

    Photopolymers are promising materials for use in holography. They have many advantages, such as ease of preparation, and are capable of efficiencies of up to 100%. A disadvantage of these materials is their inability to record high spatial frequency gratings when compared to other materials such as dichromated gelatin and silver halide photographic emulsion. Until recently, the drop off at high spatial frequencies of the material response was not predicted by any of the diffusion based models available. It has recently been proposed that this effect is due to polymer chains growing away from their initiation point and causing a smeared profile to be recorded. This is termed a non-local material response. Simple analytic expressions have been derived using this model and fits to experimental data have allowed values to be estimated for material parameters such as the diffusion coefficient of monomer, the ratio of polymerisation rate to diffusion rate and the distance that the polymer chains spread during holographic recording. The model predicts that the spatial frequency response might be improved by decreasing the mean polymer chain lengths and/or by increasing the mobility of the molecules used in the material. The experimental work carried out to investigate these predictions is reported here. This work involved (a) the changing of the molecular weights of chemical components within the material (dyes and binders) and (b) the addition of a chemical retarder in order to shorten the polymer chains, thereby decreasing the extent of the non-local effect. Although no significant improvement in spatial frequency response was observed the model appears to offer an improved understanding of the operation of the material.

  18. Soil erosion model predictions using parent material/soil texture-based parameters compared to using site-specific parameters

    Science.gov (United States)

    R. B. Foltz; W. J. Elliot; N. S. Wagenbrenner

    2011-01-01

    Forested areas disturbed by access roads produce large amounts of sediment. One method to predict erosion and, hence, manage forest roads is the use of physically based soil erosion models. A perceived advantage of a physically based model is that it can be parameterized at one location and applied at another location with similar soil texture or geological parent...

  19. Evaluating weather factors and material response during outdoor exposure to determine accelerated test protocols for predicting service life

    Science.gov (United States)

    R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

    2005-01-01

    To develop service life prediction methods for the study of sealants, a fully instrumented weather station was installed at an outdoor test site near Madison, WI. Temperature, relative humidiy, rainfall, ultraviolet (UV) radiation at 18 wavelengths, and wind speed and direction are being continuously measured and stored. The weather data can be integrated over time to...

  20. Technologies for Decreasing Mining Losses

    Science.gov (United States)

    Valgma, Ingo; Väizene, Vivika; Kolats, Margit; Saarnak, Martin

    2013-12-01

    In case of stratified deposits like oil shale deposit in Estonia, mining losses depend on mining technologies. Current research focuses on extraction and separation possibilities of mineral resources. Selective mining, selective crushing and separation tests have been performed, showing possibilities of decreasing mining losses. Rock crushing and screening process simulations were used for optimizing rock fractions. In addition mine backfilling, fine separation, and optimized drilling and blasting have been analyzed. All tested methods show potential and depend on mineral usage. Usage in addition depends on the utilization technology. The questions like stability of the material flow and influences of the quality fluctuations to the final yield are raised.

  1. Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing

    Science.gov (United States)

    Held, Christian; Liewald, Mathias; Schleich, Ralf; Sindel, Manfred

    2010-06-01

    The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.

  2. Application Of A New Semi-Empirical Model For Forming Limit Prediction Of Sheet Material Including Superposed Loads Of Bending And Shearing

    International Nuclear Information System (INIS)

    Held, Christian; Liewald, Mathias; Schleich, Ralf; Sindel, Manfred

    2010-01-01

    The use of lightweight materials offers substantial strength and weight advantages in car body design. Unfortunately such kinds of sheet material are more susceptible to wrinkling, spring back and fracture during press shop operations. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, new investigations at the Institute for Metal Forming Technology have shown that High Strength Steel Sheet Material and Aluminum Alloys show increased formability in case of bending loads are superposed to stretching loads. Likewise, by superposing shearing on in plane uniaxial or biaxial tension formability changes because of materials crystallographic texture. Such mixed stress and strain conditions including bending and shearing effects can occur in deep-drawing processes of complex car body parts as well as subsequent forming operations like flanging. But changes in formability cannot be described by using the conventional FLC. Hence, for purpose of improvement of failure prediction in numerical simulation codes significant failure criteria for these strain conditions are missing. Considering such aspects in defining suitable failure criteria which is easy to implement into FEA a new semi-empirical model has been developed considering the effect of bending and shearing in sheet metals formability. This failure criterion consists of the combination of the so called cFLC (combined Forming Limit Curve), which considers superposed bending load conditions and the SFLC (Shear Forming Limit Curve), which again includes the effect of shearing on sheet metal's formability.

  3. Efficient and accurate two-scale FE-FFT-based prediction of the effective material behavior of elasto-viscoplastic polycrystals

    Science.gov (United States)

    Kochmann, Julian; Wulfinghoff, Stephan; Ehle, Lisa; Mayer, Joachim; Svendsen, Bob; Reese, Stefanie

    2017-09-01

    Recently, two-scale FE-FFT-based methods (e.g., Spahn et al. in Comput Methods Appl Mech Eng 268:871-883, 2014; Kochmann et al. in Comput Methods Appl Mech Eng 305:89-110, 2016) have been proposed to predict the microscopic and overall mechanical behavior of heterogeneous materials. The purpose of this work is the extension to elasto-viscoplastic polycrystals, efficient and robust Fourier solvers and the prediction of micromechanical fields during macroscopic deformation processes. Assuming scale separation, the macroscopic problem is solved using the finite element method. The solution of the microscopic problem, which is embedded as a periodic unit cell (UC) in each macroscopic integration point, is found by employing fast Fourier transforms, fixed-point and Newton-Krylov methods. The overall material behavior is defined by the mean UC response. In order to ensure spatially converged micromechanical fields as well as feasible overall CPU times, an efficient but simple solution strategy for two-scale simulations is proposed. As an example, the constitutive behavior of 42CrMo4 steel is predicted during macroscopic three-point bending tests.

  4. A predictive formula of the contraction stress in restorative and luting materials attending to free and adhered surfaces, volume and deformation.

    Science.gov (United States)

    Miguel, A; de la Macorra, J C

    2001-05-01

    To find a predictive formula of stress, considering the surfaces (free, adhered) involved, the volume and characteristics of material and the deformation of the measuring system. 231 samples of five chemically cured restoratives (Silar (SIL, 23), Clearfil F2 (CLE, 39), P10 (P10, 33), Concise (CON, 30), Isopast (ISO, 28)) and four luting (3M Experimental 241 (EXM, 20), Variolink II (VAR, 13), Vitremer LC (VTM, 20) and Dyract Cem (DYR, 25)) materials were allowed to polymerize until they reached a maximum tension (T(max), 25 min) between six pairs (null 5.81, 8.5, 11.26, 12.42, 17.02, 23.14 mm) of polished metallic discs (range of distances: 0.02-5.9 mm) mounted in a tension machine. The deformation of the measuring system was measured for the recorded forces. A descriptive non-linear formula T(max)=KVol(-3.267)FS(3.283)AS(0.642)Def(0.561) was found that individualizes the material's characteristics (K) that considers volume (Vol), free (FS) and adhered (AS) surfaces and deformation (Def) of the system for each force. This formula renders good correlation (material K (r(2) coefficient)): SIL 0.9998 (0.995), CLE 1.0062 (0.989), P10 1.0224 (0.990), CON 0.9908 (0.992), ISO 0.9648 (0.974), EXM 1.0083 (0.991), VAR 0.9777 (0.996), VTM 0.9925 (0.993), DYR 0.9971 (0.997) between actual T(max) and calculated Tension. There are statistically significant differences (p=0.002) between K values of both (restorative and luting) groups. Predictive parameters have influence in a different way to what is actually considered, if the system is allowed to have deformation, as occurs naturally and volume and material's characteristics are considered.

  5. A multi-scale study based on phase field to predict the microstructure of irradiated materials: application to silver-copper alloy

    International Nuclear Information System (INIS)

    Demange, Gilles

    2015-01-01

    It is of dramatic matter for industry to be able to predict the evolution of material microstructure under working conditions. This requires a clear understanding of the underlying mechanisms, which act on numerous space and time scales. Because it intrinsically performs a scale jump, we chose to use a phase field approach, which is widely used amidst the condensed matter community to study the aging of materials. The first challenge of this work was to extend this formalism beyond its thermodynamic scope and embrace the case of far from equilibrium systems when subjected to irradiation. For that purpose, we adopted the model of ion mixing, developed by Gras Marti to account for ballistic exchanges within a displacements cascade. Based on a numerical scheme and analytical method, we were able to describe the generic microstructure signature for materials under irradiation.We then applied this formalism to the particular case of the immiscible binary alloy AgCu.With the joined use of the phase field approach and atomistic methods, we managed to predict how the temperature and the irradiation flux tailor the main microstructure features such as the size, the concentration and the distribution of copper precipitates. This eventually allowed us to simulate a diffraction pattern in grazing incidence, which is directly comparable to experimental ones. (author) [fr

  6. Potential tank waste material anomalies located near the liquid observation wells: Model predicted responses of a neutron moisture detection system

    International Nuclear Information System (INIS)

    Finfrock, S.H.; Toffer, H.; Watson, W.T.

    1994-09-01

    Extensive analyses have been completed to demonstrate that a neutron moisture probe can be used to recognize anomalies in materials and geometry surrounding the liquid observation wells (LOWs). Furthermore, techniques can be developed that will permit the interpretation of detector readings, perturbed by the presence of anomalies, as more accurate moisture concentrations. This analysis effort extends the usefulness of a neutron moisture probe system significantly, especially in the complicated geometries and material conditions that may be encountered in the waste tanks. Both static-source and pulsed-source neutron probes were considered in the analyses. Four different detector configurations were investigated: Thermal and epithermal neutron detectors located in both the near and far field

  7. Integrated Prediction and Mitigation Methods of Materials Damage and Lifetime Assessment during Plasma Operation and Various Instabilities in Fusion Devices

    Energy Technology Data Exchange (ETDEWEB)

    Hassanein, Ahmed [Purdue Univ., West Lafayette, IN (United States)

    2015-03-31

    This report describes implementation of comprehensive and integrated models to evaluate plasma material interactions during normal and abnormal plasma operations. The models in full3D simulations represent state-of-the art worldwide development with numerous benchmarking of various tokamak devices and plasma simulators. In addition, significant number of experimental work has been performed in our center for materials under extreme environment (CMUXE) at Purdue to benchmark the effect of intense particle and heat fluxes on plasma-facing components. This represents one-year worth of work and resulted in more than 23 Journal Publications and numerous conferences presentations. The funding has helped several students to obtain their M.Sc. and Ph.D. degrees and many of them are now faculty members in US and around the world teaching and conducting fusion research. Our work has also been recognized through many awards.

  8. Integrated Prediction and Mitigation Methods of Materials Damage and Lifetime Assessment during Plasma Operation and Various Instabilities in Fusion Devices

    International Nuclear Information System (INIS)

    Hassanein, Ahmed

    2015-01-01

    This report describes implementation of comprehensive and integrated models to evaluate plasma material interactions during normal and abnormal plasma operations. The models in full3D simulations represent state-of-the art worldwide development with numerous benchmarking of various tokamak devices and plasma simulators. In addition, significant number of experimental work has been performed in our center for materials under extreme environment (CMUXE) at Purdue to benchmark the effect of intense particle and heat fluxes on plasma-facing components. This represents one-year worth of work and resulted in more than 23 Journal Publications and numerous conferences presentations. The funding has helped several students to obtain their M.Sc. and Ph.D. degrees and many of them are now faculty members in US and around the world teaching and conducting fusion research. Our work has also been recognized through many awards.

  9. Ductile Tearing of Thin Aluminum Plates Under Blast Loading. Predictions with Fully Coupled Models and Biaxial Material Response Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Corona, Edmundo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gullerud, Arne S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haulenbeek, Kimberly K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reu, Phillip L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    The work presented in this report concerns the response and failure of thin 2024- T3 aluminum alloy circular plates to a blast load produced by the detonation of a nearby spherical charge. The plates were fully clamped around the circumference and the explosive charge was located centrally with respect to the plate. The principal objective was to conduct a numerical model validation study by comparing the results of predictions to experimental measurements of plate deformation and failure for charges with masses in the vicinity of the threshold between no tearing and tearing of the plates. Stereo digital image correlation data was acquired for all tests to measure the deflection and strains in the plates. The size of the virtual strain gage in the measurements, however, was relatively large, so the strain measurements have to be interpreted accordingly as lower bounds of the actual strains in the plate and of the severity of the strain gradients. A fully coupled interaction model between the blast and the deflection of the structure was considered. The results of the validation exercise indicated that the model predicted the deflection of the plates reasonably accurately as well as the distribution of strain on the plate. The estimation of the threshold charge based on a critical value of equivalent plastic strain measured in a bulge test, however, was not accurate. This in spite of efforts to determine the failure strain of the aluminum sheet under biaxial stress conditions. Further work is needed to be able to predict plate tearing with some degree of confidence. Given the current technology, at least one test under the actual blast conditions where the plate tears is needed to calibrate the value of equivalent plastic strain when failure occurs in the numerical model. Once that has been determined, the question of the explosive mass value at the threshold could be addressed with more confidence.

  10. An exponential material model for prediction of the flow curves of several AZ series magnesium alloys in tension and compression

    International Nuclear Information System (INIS)

    Fereshteh-Saniee, F.; Barati, F.; Badnava, H.; Fallah Nejad, Kh.

    2012-01-01

    Highlights: ► The exponential model can represent flow behaviors of AZ series Mg alloys very well. ► Strain rate sensitivities of AZ series Mg alloys in compression are nearly the same. ► Effect of zinc element on tensile activation energy is higher than on compressive one. ► Activation energies of AZ80 and AZ81 in tension were greater than in compression. ► Tensile and compressive rate sensitivities of AZ80 are not close to each other. -- Abstract: This paper is concerned with flow behaviors of several magnesium alloys, such as AZ31, AZ80 and AZ81, in tension and compression. The experiments were performed at elevated temperatures and for various strain rates. In order to eliminate the effect of inhomogeneous deformation in tensile and compression tests, the Bridgeman’s and numerical correction factors were respectively employed. A two-section exponential mathematical model was also utilized for prediction of flow stresses of different magnesium alloys in tension and compression. Moreover, based on the compressive flow model proposed, the peak stress and the relevant true strain could be estimated. The true stress and strain of the necking point can also be predicted using the corresponding relations. It was found that the flow behaviors estimated by the exponential flow model were encouragingly in very good agreement with experimental findings.

  11. Of cuts and cracks: data analytics on constrained graphs for early prediction of failure in cementitious materials

    Directory of Open Access Journals (Sweden)

    Kahagalage Sanath

    2017-01-01

    Full Text Available Using data from discrete element simulations, we develop a data analytics approach using network flow theory to study force transmission and failure in a ‘dog-bone’ concrete specimen submitted to uniaxial tension. With this approach, we establish the extent to which the bottlenecks, i.e., a subset of contacts that impedes flow and are prone to becoming overloaded, can predict the location of the ultimate macro-crack. At the heart of this analysis is a capacity function that quantifies, in relative terms, the maximum force that can be transmitted through the different contacts or edges in the network. Here we set this function to be solely governed by the size of the contact area between the deformable spherical grains. During all the initial stages of the loading history, when no bonds are broken, we find the bottlenecks coincide consistently with, and therefore predict, the location of the crack that later forms in the failure regime after peak force. When bonds do start to break, they are spread throughout the specimen: in, near, and far from, the bottlenecks. In one stage leading up to peak force, bonds collectively break in the lower portion of the specimen, momentarily shifting the bottlenecks to this location. Just before and around peak force, however, the bottlenecks return to their original location and remain there until the macro-crack emerges right along the bottlenecks.

  12. Cerebral oxygen transport failure?: decreasing hemoglobin and hematocrit levels after ischemic stroke predict poor outcome and mortality: STroke: RelevAnt Impact of hemoGlobin, Hematocrit and Transfusion (STRAIGHT)--an observational study.

    Science.gov (United States)

    Kellert, Lars; Martin, Evgenia; Sykora, Marek; Bauer, Harald; Gussmann, Philipp; Diedler, Jennifer; Herweh, Christian; Ringleb, Peter A; Hacke, Werner; Steiner, Thorsten; Bösel, Julian

    2011-10-01

    Although conceivably relevant for penumbra oxygenation, the optimal levels of hemoglobin (Hb) and hematocrit (Hct) in patients with acute ischemic stroke are unknown. We identified patients from our prospective local stroke database who received intravenous thrombolysis based on multimodal magnet resonance imaging during the years 1998 to 2009. A favorable outcome at 3 months was defined as a modified Rankin Scale score≤2 and a poor outcome as a modified Rankin Scale score≥3. The dynamics of Hemoglobin (Hb), Hematocrit (Hct), and other relevant laboratory parameters as well as cardiovascular risk factors were retrospectively assessed and analyzed between these 2 groups. Of 217 patients, 114 had a favorable and 103 a poor outcome. In a multivariable regression model, anemia until day 5 after admission (odds ratio [OR]=2.61; 95% CI, 1.33 to 5.11; P=0.005), Hb nadir (OR=0.81; 95% CI, 0.67 to 0.99; P=0.038), and Hct nadir (OR=0.93; 95% CI, 0.87 to 0.99; P=0.038) remained independent predictors for poor outcome at 3 months. Mortality after 3 months was independently associated with Hb nadir (OR=0.80; 95% CI, 0.65 to 0.98; P=0.028) and Hb decrease (OR=1.34; 95% CI, 1.01 to 1.76; P=0.04) as well as Hct decrease (OR=1.12; 95% CI, 1.01 to 1.23; P=0.027). Poor outcome and mortality after ischemic stroke are strongly associated with low and further decreasing Hb and Hct levels. This decrease of Hb and Hct levels after admission might be more relevant and accessible to treatment than are baseline levels.

  13. Prediction of dosage-based parameters from the puff dispersion of airborne materials in urban environments using the CFD-RANS methodology

    Science.gov (United States)

    Efthimiou, G. C.; Andronopoulos, S.; Bartzis, J. G.

    2018-02-01

    One of the key issues of recent research on the dispersion inside complex urban environments is the ability to predict dosage-based parameters from the puff release of an airborne material from a point source in the atmospheric boundary layer inside the built-up area. The present work addresses the question of whether the computational fluid dynamics (CFD)-Reynolds-averaged Navier-Stokes (RANS) methodology can be used to predict ensemble-average dosage-based parameters that are related with the puff dispersion. RANS simulations with the ADREA-HF code were, therefore, performed, where a single puff was released in each case. The present method is validated against the data sets from two wind-tunnel experiments. In each experiment, more than 200 puffs were released from which ensemble-averaged dosage-based parameters were calculated and compared to the model's predictions. The performance of the model was evaluated using scatter plots and three validation metrics: fractional bias, normalized mean square error, and factor of two. The model presented a better performance for the temporal parameters (i.e., ensemble-average times of puff arrival, peak, leaving, duration, ascent, and descent) than for the ensemble-average dosage and peak concentration. The majority of the obtained values of validation metrics were inside established acceptance limits. Based on the obtained model performance indices, the CFD-RANS methodology as implemented in the code ADREA-HF is able to predict the ensemble-average temporal quantities related to transient emissions of airborne material in urban areas within the range of the model performance acceptance criteria established in the literature. The CFD-RANS methodology as implemented in the code ADREA-HF is also able to predict the ensemble-average dosage, but the dosage results should be treated with some caution; as in one case, the observed ensemble-average dosage was under-estimated slightly more than the acceptance criteria. Ensemble

  14. The Use of OXYGEN-18 in the Development of Methods for Controlled Sputter Deposition of High Critical Transition Temperature Material Thin Films of Predicted Composition and Good Uniformity

    Science.gov (United States)

    Tidrow, Steven Clay

    Two primary concerns, in the sputter deposition of high T_{c} material films, are the prevention of oxygen deficiency in the films and the elimination of the negative ion effect. "Oxygen deficiency" occurs when the amount of oxygen incorporated into the film is less than the amount of oxygen required to form the superconducting material lattice. Oxygen deficiency is due to the volatile nature of oxygen. The negative ion effect occurs when an atom or molecule (typically oxygen) gains an extra electron, is accelerated away from the target and impinges upon a film being grown directly in front of the sputtering target. The impinging particle has enough energy to cause resputtering of the deposited film. The presence of Sr and to a greater extent Ba, may enhance the negative ion effect in these materials. However, it is oxygen which readily forms negative ions that is primarily responsible for the negative ion effect. Thus, oxygen must be given special attention in the sputter deposition of high T_{c} material films. A specially designed sputtering system is used to demonstrate that the negative ion effect can be reduced such that large uniform high T_{c} material films possessing predicted and repeated composition can be grown in an on-axis arrangement. Utilizing this same sputtering system and the volatile nature of oxygen, it is demonstrated that oxygen processes occurring in the chamber during growth of high T_ {c} material films can be investigated using the tracer ^{18}O. In particular, it is shown that ^{18}O can be utilized as a tool for (1) investigating the negative ion effect, (2) investigating oxygen incorporation into high T_{c} material films, (3) investigating oxygen incorporation into the target, (4) tailoring films for oxygen migration and interface investigations and (5) tailoring films for the other specific oxygen investigations. Such sputtering systems that utilize the tracer ^{18}O are necessary for systematic growth of high T_ {c} material films

  15. Methodology for predicting the life of waste-package materials, and components using multifactor accelerated life tests

    International Nuclear Information System (INIS)

    Thomas, R.E.; Cote, R.W.

    1983-09-01

    Accelerated life tests are essential for estimating the service life of waste-package materials and components. A recommended methodology for generating accelerated life tests is described in this report. The objective of the methodology is to define an accelerated life test program that is scientifically and statistically defensible. The methodology is carried out using a select team of scientists and usually requires 4 to 12 man-months of effort. Specific agendas for the successive meetings of the team are included in the report for use by the team manager. The agendas include assignments for the team scientists and a different set of assignments for the team statistician. The report also includes descriptions of factorial tables, hierarchical trees, and associated mathematical models that are proposed as technical tools to guide the efforts of the design team

  16. H2O2 can Increase Lignin Disintegration and Decrease Cellulose Decomposition in the Process of Solid-State Fermentation (SSF) by Aspergillus oryzae Using Corn Stalk as Raw Materials

    OpenAIRE

    Zhicai Zhang; Jun Jia; Ming Li; Qiaoxia Pang

    2014-01-01

    H2O2 is both bactericidal and the main oxidant responsible for lignin degradation reaction catalyzed by manganese peroxidase (MnP) and lignin peroxidase (LiP). Thus, H2O2 treatment of corn stalk and the implementation of solid-substrate fermentation (SSF) is possible to increase the removal rate of lignin from stalk in the process of SSF and after SSF, while avoiding the need to sterilize the raw materials. To demonstrate this approach, SSF was initially carried out using corn stalk pretreate...

  17. Improving the prediction of the final part geometry in high strength steels U drawing by means of advanced material and friction models

    Science.gov (United States)

    de Argandoña, Eneko Saenz; Mendiguren, Joseba; Otero, Irune; Mugarra, Endika; Otegi, Nagore; Galdos, Lander

    2018-05-01

    Steel has been used in vehicles from the automotive industry's inception. Different steel grades are continually being developed in order to satisfy new fuel economy requirements. For example, advanced high strength steel grades (AHSS) are widely used due to their good strength/weight ratio. Because each steel grade has a different microstructure composition and hardness, they show different behaviors when they are subjected to different strain paths. Similarly, the friction behavior when using different contact pressures is considerably altered. In the present paper, four different steel grades, ZSt380, DP600, DP780 and Fortiform 1050 materials are deeply characterized using uniaxial and cyclic tension-compression tests. Coefficient of friction (COF) is also obtained using strip drawing tests. These results have been used to calibrate mixed kinematic-hardening material models as well as pressure dependent friction models. Finally, the geometrical accuracy of the different material and friction models has been evaluated by comparing the numerical predictions with experimental demonstrators obtained using a U-Drawing tester.

  18. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    Science.gov (United States)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2015-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the Storage Division of the NETL and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science

  19. The development of a model to predict the effects of worker and task factors on foot placements in manual material handling tasks.

    Science.gov (United States)

    Wagner, David W; Reed, Matthew P; Chaffin, Don B

    2010-11-01

    Accurate prediction of foot placements in relation to hand locations during manual materials handling tasks is critical for prospective biomechanical analysis. To address this need, the effects of lifting task conditions and anthropometric variables on foot placements were studied in a laboratory experiment. In total, 20 men and women performed two-handed object transfers that required them to walk to a shelf, lift an object from the shelf at waist height and carry the object to a variety of locations. Five different changes in the direction of progression following the object pickup were used, ranging from 45° to 180° relative to the approach direction. Object weights of 1.0 kg, 4.5 kg, 13.6 kg were used. Whole-body motions were recorded using a 3-D optical retro-reflective marker-based camera system. A new parametric system for describing foot placements, the Quantitative Transition Classification System, was developed to facilitate the parameterisation of foot placement data. Foot placements chosen by the subjects during the transfer tasks appeared to facilitate a change in the whole-body direction of progression, in addition to aiding in performing the lift. Further analysis revealed that five different stepping behaviours accounted for 71% of the stepping patterns observed. More specifically, the most frequently observed behaviour revealed that the orientation of the lead foot during the actual lifting task was primarily affected by the amount of turn angle required after the lift (R(2) = 0.53). One surprising result was that the object mass (scaled by participant body mass) was not found to significantly affect any of the individual step placement parameters. Regression models were developed to predict the most prevalent step placements and are included in this paper to facilitate more accurate human motion simulations and ergonomics analyses of manual material lifting tasks. STATEMENT OF RELEVANCE: This study proposes a method for parameterising the steps

  20. The role of the experimental data base used to identify material parameters in predicting the cyclic plastic response of an austenitic steel

    International Nuclear Information System (INIS)

    Djimli, Lynda; Taleb, Lakhdar; Meziani, Salim

    2010-01-01

    The first objective of this paper investigates the influence of the previous strain history on ratcheting. New tests were performed where different strain-controlled histories have been applied prior to ratcheting tests. It is demonstrated that under the same conditions, one can observe ratcheting, plastic shakedown or elasticity according to the prior strain-controlled history. The second objective points out the correlation between the experimental data base devoted to the identification of the material parameters and the quality of the predictions in cyclic plasticity. The results suggest that the choice of the tests should be closely linked to the capabilities of the model. In particular, the presence of non proportional strain-controlled tests in the data base may be not a good choice if the model itself is not able to represent explicitly such a character. All tests considered here were performed on 304L SS at room temperature.

  1. The prediction of creep damage in type 347 weld metal. Part I: the determination of material properties from creep and tensile tests

    International Nuclear Information System (INIS)

    Spindler, M.W.

    2005-01-01

    Calculations of creep damage under conditions of strain control are often carried out using either a time fraction approach or a ductility exhaustion approach. In the case of the time fraction approach the rupture strength is used to calculate creep damage, whereas creep ductility is used in the ductility exhaustion approach. In part I of this paper the methods that are used to determine these material properties are applied to some creep and constant strain rate tests on a Type 347 weld metal. In addition, new developments to the ductility exhaustion approach are described which give improved predictions of creep damage at failure in these tests. These developments use reverse modelling to determine the most appropriate creep damage model as a function of strain rate, stress and temperature. Hence, the new approach is no longer a ductility exhaustion approach but is a true creep damage model

  2. Normalized Synergy Predicts That CD8 Co-Receptor Contribution to T Cell Receptor (TCR and pMHC Binding Decreases As TCR Affinity Increases in Human Viral-Specific T Cells

    Directory of Open Access Journals (Sweden)

    Chad M. Williams

    2017-07-01

    Full Text Available The discovery of naturally occurring T cell receptors (TCRs that confer specific, high-affinity recognition of pathogen and cancer-associated antigens remains a major goal in cellular immunotherapies. The contribution of the CD8 co-receptor to the interaction between the TCR and peptide-bound major histocompatibility complex (pMHC has previously been correlated with the activation and responsiveness of CD8+ T cells. However, these studies have been limited to model systems of genetically engineered hybridoma TCRs or transgenic mouse TCRs against either a single epitope or an array of altered peptide ligands. CD8 contribution in a native human antigen-specific T cell response remains elusive. Here, using Hepatitis C Virus-specific precursor CTLs spanning a large range of TCR affinities, we discovered that the functional responsiveness of any given TCR correlated with the contribution of CD8 to TCR/pMHC binding. Furthermore, we found that CD8 contribution to TCR/pMHC binding in the two-dimensional (2D system was more accurately reflected by normalized synergy (CD8 cooperation normalized by total TCR/pMHC bonds rather than synergy (total CD8 cooperation alone. While synergy showed an increasing trend with TCR affinity, normalized synergy was demonstrated to decrease with the increase of TCR affinity. Critically, normalized synergy was shown to correlate with CTL functionality and peptide sensitivity, corroborating three-dimensional (3D analysis of CD8 contribution with respect to TCR affinity. In addition, we identified TCRs that were independent of CD8 for TCR/pMHC binding. Our results resolve the current discrepancy between 2D and 3D analysis on CD8 contribution to TCR/pMHC binding, and demonstrate that naturally occurring high-affinity TCRs are more capable of CD8-independent interactions that yield greater functional responsiveness even with CD8 blocking. Taken together, our data suggest that addition of the normalized synergy parameter to our

  3. Predicting Multicomponent Adsorption Isotherms in Open-Metal Site Materials Using Force Field Calculations Based on Energy Decomposed Density Functional Theory.

    Science.gov (United States)

    Heinen, Jurn; Burtch, Nicholas C; Walton, Krista S; Fonseca Guerra, Célia; Dubbeldam, David

    2016-12-12

    For the design of adsorptive-separation units, knowledge is required of the multicomponent adsorption behavior. Ideal adsorbed solution theory (IAST) breaks down for olefin adsorption in open-metal site (OMS) materials due to non-ideal donor-acceptor interactions. Using a density-function-theory-based energy decomposition scheme, we develop a physically justifiable classical force field that incorporates the missing orbital interactions using an appropriate functional form. Our first-principles derived force field shows greatly improved quantitative agreement with the inflection points, initial uptake, saturation capacity, and enthalpies of adsorption obtained from our in-house adsorption experiments. While IAST fails to make accurate predictions, our improved force field model is able to correctly predict the multicomponent behavior. Our approach is also transferable to other OMS structures, allowing the accurate study of their separation performances for olefins/paraffins and further mixtures involving complex donor-acceptor interactions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Price of forest chips decreasing

    International Nuclear Information System (INIS)

    Hakkila, P.

    2001-01-01

    Use of forest chips was studied in 1999 in the national Puuenergia (Wood Energy) research program. Wood combusting heating plants were questioned about are the main reasons restricting the increment of the use of forest chips. Heating plants, which did not use forest chips at all or which used less than 250 m 3 (625 bulk- m 3 ) in 1999 were excluded. The main restrictions for additional use of forest chips were: too high price of forest chips; lack of suppliers and/or uncertainty of deliveries; technical problems of reception and processing of forest chips; insufficiency of boiler output especially in winter; and unsatisfactory quality of chips. The price of forest chips becomes relatively high because wood biomass used for production of forest chips has to be collected from wide area. Heavy equipment has to be used even though small fragments of wood are processed, which increases the price of chips. It is essential for forest chips that the costs can be pressed down because competition with fossil fuels, peat and industrial wood residues is hard. Low market price leads to the situation in which forest owner gets no price of the raw material, the entrepreneurs operate at the limit of profitability and renovation of machinery is difficult, and forest chips suppliers have to sell the chips at prime costs. Price of forest chips has decreased significantly during the past decade. Nominal price of forest chips is now lower than two decades ago. The real price of chips has decreased even more than the nominal price, 35% during the past decade and 20% during the last five years. Chips, made of small diameter wood, are expensive because the price includes the felling costs and harvesting is carried out at thinning lots. Price is especially high if chips are made of delimbed small diameter wood due to increased the work and reduced amount of chips. The price of logging residue chips is most profitable because cutting does not cause additional costs. Recovery of chips is

  5. PERFORM 60: Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

    International Nuclear Information System (INIS)

    Al Mazouzi, A.; Alamo, A.; Lidbury, D.; Moinereau, D.; Van Dyck, S.

    2011-01-01

    Highlights: → Multi-scale and multi-physics modelling are adopted by PERFORM 60 to predict irradiation damage in nuclear structural materials. → PERFORM 60 allows to Consolidate the community and improve the interaction between universities/industries and safety authorities. → Experimental validation at the relevant scale is a key for developing the multi-scale modelling methodology. - Abstract: In nuclear power plants, materials undergo degradation due to severe irradiation conditions that may limit their operational lifetime. Utilities that operate these reactors need to quantify the ageing and potential degradation of certain essential structures of the power plant to ensure their safe and reliable operation. So far, the monitoring and mitigation of these degradation phenomena rely mainly on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the materials behaviour in a nuclear environment. Indeed, within the PERFECT project of the EURATOM framework program (FP6), a first step has been successfully reached through the development of a simulation platform that contains several advanced numerical tools aiming at the prediction of irradiation damage in both the reactor pressure vessel (RPV) and its internals using available, state-of-the-art-knowledge. These tools allow simulation of irradiation effects on the nanostructure and the constitutive behaviour of the RPV low alloy steels, as well as their fracture mechanics properties. For the more highly irradiated reactor internals, which are commonly produced using austenitic stainless steels, the first partial models were established, describing radiation effects on the nanostructure and providing a first description of the

  6. PERFORM 60 - Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, Sylvain, E-mail: sylvain.leclercq@edf.f [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France); Lidbury, David [SERCO Assurance - Walton House, 404 Faraday Street, Birchwood Park, Warrington, Cheshire WA3 6GA (United Kingdom); Van Dyck, Steven [SCK-CEN, Nuclear Material Science, Boeretang 200, BE, 2400 Mol (Belgium); Moinereau, Dominique [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France); Alamo, Ana [CEA Saclay, DEN/DSOE, 91191 Gif-sur-Yvette (France); Mazouzi, Abdou Al [EDF R and D, Materials and Mechanics of Components, Avenue des Renardieres - Ecuelles, 77818 Moret sur Loing Cedex (France)

    2010-11-01

    In nuclear power plants, materials may undergo degradation due to severe irradiation conditions that may limit their operational life. Utilities that operate these reactors need to quantify the ageing and the potential degradations of some essential structures of the power plant to ensure safe and reliable plant operation. So far, the material databases needed to take account of these degradations in the design and safe operation of installations mainly rely on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and continuous progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the effects of irradiation on materials microstructure. A first step towards this goal has been successfully reached through the development of the RPV-2 and Toughness Module numerical tools by the scientific community created around the FP6 PERFECT project. These tools allow to simulate irradiation effects on the constitutive behaviour of the reactor pressure vessel low alloy steel, and also on its failure properties. Relying on the existing PERFECT Roadmap, the 4 years Collaborative Project PERFORM 60 has mainly for objective to develop multi-scale tools aimed at predicting the combined effects of irradiation and corrosion on internals (austenitic stainless steels) and also to improve existing ones on RPV (bainitic steels). PERFORM 60 is based on two technical sub-projects: (i) RPV and (ii) internals. In addition to these technical sub-projects, the Users' Group and Training sub-project shall allow representatives of constructors, utilities, research organizations... from Europe, USA and Japan to receive the information and training to get their own appraisal on limits and potentialities of the developed tools. An important effort will also be made to teach

  7. PERFORM 60 - Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

    Science.gov (United States)

    Leclercq, Sylvain; Lidbury, David; Van Dyck, Steven; Moinereau, Dominique; Alamo, Ana; Mazouzi, Abdou Al

    2010-11-01

    In nuclear power plants, materials may undergo degradation due to severe irradiation conditions that may limit their operational life. Utilities that operate these reactors need to quantify the ageing and the potential degradations of some essential structures of the power plant to ensure safe and reliable plant operation. So far, the material databases needed to take account of these degradations in the design and safe operation of installations mainly rely on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and continuous progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the effects of irradiation on materials microstructure. A first step towards this goal has been successfully reached through the development of the RPV-2 and Toughness Module numerical tools by the scientific community created around the FP6 PERFECT project. These tools allow to simulate irradiation effects on the constitutive behaviour of the reactor pressure vessel low alloy steel, and also on its failure properties. Relying on the existing PERFECT Roadmap, the 4 years Collaborative Project PERFORM 60 has mainly for objective to develop multi-scale tools aimed at predicting the combined effects of irradiation and corrosion on internals (austenitic stainless steels) and also to improve existing ones on RPV (bainitic steels). PERFORM 60 is based on two technical sub-projects: (i) RPV and (ii) internals. In addition to these technical sub-projects, the Users' Group and Training sub-project shall allow representatives of constructors, utilities, research organizations… from Europe, USA and Japan to receive the information and training to get their own appraisal on limits and potentialities of the developed tools. An important effort will also be made to teach young

  8. Development of a fission product transport module predicting the behavior of radiological materials during sever accidents in a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyung Seok; Rhee, Bo Wook; Kim, Dong Ha [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-09-15

    Korea Atomic Energy Research Institute is developing a fission product transport module for predicting the behavior of radioactive materials in the primary cooling system of a nuclear power plant as a separate module, which will be connected to a severe accident analysis code, Core Meltdown Progression Accident Simulation Software (COMPASS). This fission product transport (COMPASS-FP) module consists of a fission product release model, an aerosol generation model, and an aerosol transport model. In the fission product release model there are three submodels based on empirical correlations, and they are used to simulate the fission product gases release from the reactor core. In the aerosol generation model, the mass conservation law and Raoult's law are applied to the mixture of vapors and droplets of the fission products in a specified control volume to find the generation of the aerosol droplet. In the aerosol transport model, empirical correlations available from the open literature are used to simulate the aerosol removal processes owing to the gravitational settling, inertia impaction, diffusiophoresis, and thermophoresis. The COMPASS-FP module was validated against Aerosol Behavior Code Validation and Evaluation (ABCOVE-5) test performed by Hanford Engineering Development Laboratory for comparing the prediction and test data. The comparison results assuming a non-spherical aerosol shape for the suspended aerosol mass concentration showed a good agreement with an error range of about ±6%. It was found that the COMPASS-FP module produced the reasonable results of the fission product gases release, the aerosol generation, and the gravitational settling in the aerosol removal processes for ABCOVE-5. However, more validation for other aerosol removal models needs to be performed.

  9. Method for decreasing radiation hazard in transporting radioactive material

    International Nuclear Information System (INIS)

    Wodrich, D.D.

    1975-01-01

    At the end of their useful life, fuel rods are removed from a nuclear reactor and transferred underwater into a shipping cask. The water in the pool of the nuclear reactor system (or fuels reprocessing plant) may contain troublesome amounts of radioactive isotopes, creating biological hazards for any shipping cask unless adequately cleaned after contacting pool water. Potential contamination of substantially all of the entire exterior of the shipping cask is avoided because such shipping cask is at least predominantly immersed in fresh water within a vertically shiftable container which can be, for example, shifted between the bottom and the surface of the pool. Fresh water is supplied to the interior of the shiftable container whereby substantially all of the exterior of the shipping cask is immersed in fresh water, maintained at a pressure and/or flow velocity preventing the pool water from contacting the exterior of the shipping cask

  10. Development of a molecular dynamic based cohesive zone model for prediction of an equivalent material behavior for Al/Al2O3 composite

    Energy Technology Data Exchange (ETDEWEB)

    Sazgar, A. [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Movahhedy, M.R., E-mail: movahhed@sharif.edu [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mahnama, M. [School of Mechanical Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Sohrabpour, S. [Center of Excellence in Design, Robotics and Automation, Department of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2017-01-02

    The interfacial behavior of composites is often simulated using a cohesive zone model (CZM). In this approach, a traction-separation (T-S) relation between the matrix and reinforcement particles, which is often obtained from experimental results, is employed. However, since the determination of this relation from experimental results is difficult, the molecular dynamics (MD) simulation may be used as a virtual environment to obtain this relation. In this study, MD simulations under the normal and shear loadings are used to obtain the interface behavior of Al/Al2O3 composite material and to derive the T-S relation. For better agreement with Al/Al2O3 interfacial behavior, the exponential form of the T-S relation suggested by Needleman [1] is modified to account for thermal effects. The MD results are employed to develop a parameterized cohesive zone model which is implemented in a finite element model of the matrix-particle interactions. Stress-strain curves obtained from simulations under different loading conditions and volume fractions show a close correlation with experimental results. Finally, by studying the effects of strain rate and volume fraction of particles in Al(6061-T6)/Al2O3 composite, an equivalent homogeneous model is introduced which can predict the overall behavior of the composite.

  11. Standard practice for prediction of the long-term behavior of materials, including waste forms, used in engineered barrier systems (EBS) for geological disposal of high-level radioactive waste

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes test methods and data analyses used to develop models for the prediction of the long-term behavior of materials, such as engineered barrier system (EBS) materials and waste forms, used in the geologic disposal of spent nuclear fuel (SNF) and other high-level nuclear waste in a geologic repository. The alteration behavior of waste form and EBS materials is important because it affects the retention of radionuclides by the disposal system. The waste form and EBS materials provide a barrier to release either directly (as in the case of waste forms in which the radionuclides are initially immobilized), or indirectly (as in the case of containment materials that restrict the ingress of groundwater or the egress of radionuclides that are released as the waste forms and EBS materials degrade). 1.1.1 Steps involved in making such predictions include problem definition, testing, modeling, and model confirmation. 1.1.2 The predictions are based on models derived from theoretical considerat...

  12. Dimensional changes of alginate dental impression materials.

    Science.gov (United States)

    Nallamuthu, N; Braden, M; Patel, M P

    2006-12-01

    The weight loss and corresponding dimensional changes of two dental alginate impression materials have been studied. The weight loss kinetics indicate this to be a diffusion controlled process, but with a boundary condition at the surface of the concentration decreasing exponentially with time. This is in marked contrast to most desorption processes, where the surface concentration becomes instantaneously zero. The appropriate theory has been developed for an exponential boundary condition, and its predictions compared with experimental data; the agreement was satisfactory. The diffusion coefficients for two thicknesses of the same material were not identical as predicted by theory; the possible reasons for this are discussed.

  13. Polymeric membrane materials: new aspects of empirical approaches to prediction of gas permeability parameters in relation to permanent gases, linear lower hydrocarbons and some toxic gases.

    Science.gov (United States)

    Malykh, O V; Golub, A Yu; Teplyakov, V V

    2011-05-11

    Membrane gas separation technologies (air separation, hydrogen recovery from dehydrogenation processes, etc.) use traditionally the glassy polymer membranes with dominating permeability of "small" gas molecules. For this purposes the membranes based on the low free volume glassy polymers (e.g., polysulfone, tetrabromopolycarbonate and polyimides) are used. On the other hand, an application of membrane methods for VOCs and some toxic gas recovery from air, separation of the lower hydrocarbons containing mixtures (in petrochemistry and oil refining) needs the membranes with preferable penetration of components with relatively larger molecular sizes. In general, this kind of permeability is characterized for rubbers and for the high free volume glassy polymers. Data files accumulated (more than 1500 polymeric materials) represent the region of parameters "inside" of these "boundaries." Two main approaches to the prediction of gas permeability of polymers are considered in this paper: (1) the statistical treatment of published transport parameters of polymers and (2) the prediction using model of ≪diffusion jump≫ with consideration of the key properties of the diffusing molecule and polymeric matrix. In the frames of (1) the paper presents N-dimensional methods of the gas permeability estimation of polymers using the correlations "selectivity/permeability." It is found that the optimal accuracy of prediction is provided at n=4. In the frames of the solution-diffusion mechanism (2) the key properties include the effective molecular cross-section of penetrating species to be responsible for molecular transportation in polymeric matrix and the well known force constant (ε/k)(eff i) of {6-12} potential for gas-gas interaction. Set of corrected effective molecular cross-section of penetrant including noble gases (He, Ne, Ar, Kr, Xe), permanent gases (H(2), O(2), N(2), CO), ballast and toxic gases (CO(2), NO(,) NO(2), SO(2), H(2)S) and linear lower hydrocarbons (CH(4

  14. Materials with structural hierarchy

    Science.gov (United States)

    Lakes, Roderic

    1993-01-01

    The role of structural hierarchy in determining bulk material properties is examined. Dense hierarchical materials are discussed, including composites and polycrystals, polymers, and biological materials. Hierarchical cellular materials are considered, including cellular solids and the prediction of strength and stiffness in hierarchical cellular materials.

  15. Influences of cyclic deformation on creep property and creep-fatigue life prediction considering them

    International Nuclear Information System (INIS)

    Takahashi, Yukio

    2009-01-01

    Evaluation of creep-fatigue is essential in design and life management of high-temperature components in power generation plants. Cyclic deformation may alter creep property of the materials and its consideration may improve predictability of creep-fatigue failure life. To understand them, creep tests were conducted for the materials subjected to cyclic loading and their creep rupture and deformation behaviors were compared with those of as-received materials. Both 316FR and modified 9Cr-1Mo steel were tested. (1) Creep rupture time and elongation generally tend to decrease with cyclic loading in both materials, and especially elongation of 316FR drastically decreases by being cyclically deformed. (2) Amount of primary creep deformation decreases by cyclic loading and the ways to improve its predictability were developed. (3) Use of creep rupture ductility after cyclic deformation, instead of that of as-received material, brought about clear improvement of life prediction in a modified ductility exhaustion approach. (author)

  16. Distraction decreases prefrontal oxygenation: A NIRS study.

    Science.gov (United States)

    Ozawa, Sachiyo; Hiraki, Kazuo

    2017-04-01

    When near-infrared spectroscopy (NIRS) is used to measure emotion-related cerebral blood flow (CBF) changes in the prefrontal cortex regions, the functional distinction of CBF changes is often difficult because NIRS is unable to measure neural activity in deeper brain regions that play major roles in emotional processing. The CBF changes could represent cognitive control of emotion and emotional responses to emotional materials. Supposing that emotion-related CBF changes in the prefrontal cortex regions during distraction are emotional responses, we examined whether oxygenated hemoglobin (oxyHb) decreases. Attention-demanding tasks cause blood flow decreases, and we thus compared the effects of visually paced tapping with different tempos, on distraction. The results showed that the oxyHb level induced by emotional stimulation decreased with fast-tempo tapping significantly more than slow-tempo tapping in ventral medial prefrontal cortex regions. Moreover, a Global-Local task following tapping showed significantly greater local-minus-global response time (RT) difference scores in the fast- and mid-tempo condition compared with those in the slow-tempo, suggesting an increased attentional focus, and decreased negative emotion. The overall findings indicate that oxyHb changes in a relatively long distraction task, as measured by NIRS, are associated with emotional responses, and oxyHb can be decreased by successfully performing attention-demanding distraction tasks. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Airplane radiation dose decrease during a strong Forbush decrease

    Czech Academy of Sciences Publication Activity Database

    Spurný, František; Kudela, K.; Dachev, T.

    2004-01-01

    Roč. 2, S05001 (2004), s. 1-4 ISSN 1542-7390 Grant - others:EC project(XE) FIGM-CT2000-00068 Institutional research plan: CEZ:AV0Z1048901 Keywords : airplane dose * Forbush decrease * cosmic rays Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  18. Computational materials chemistry for carbon capture using porous materials

    International Nuclear Information System (INIS)

    Sharma, Abhishek; Malani, Ateeque; Huang, Runhong; Babarao, Ravichandar

    2017-01-01

    Control over carbon dioxide (CO 2 ) release is extremely important to decrease its hazardous effects on the environment such as global warming, ocean acidification, etc. For CO 2 capture and storage at industrial point sources, nanoporous materials offer an energetically viable and economically feasible approach compared to chemisorption in amines. There is a growing need to design and synthesize new nanoporous materials with enhanced capability for carbon capture. Computational materials chemistry offers tools to screen and design cost-effective materials for CO 2 separation and storage, and it is less time consuming compared to trial and error experimental synthesis. It also provides a guide to synthesize new materials with better properties for real world applications. In this review, we briefly highlight the various carbon capture technologies and the need of computational materials design for carbon capture. This review discusses the commonly used computational chemistry-based simulation methods for structural characterization and prediction of thermodynamic properties of adsorbed gases in porous materials. Finally, simulation studies reported on various potential porous materials, such as zeolites, porous carbon, metal organic frameworks (MOFs) and covalent organic frameworks (COFs), for CO 2 capture are discussed. (topical review)

  19. Source Characterization Model (SCM): A Predictive Capability for the Source Terms of Residual Energetic Materials from Burning and/or Detonation Activities

    National Research Council Canada - National Science Library

    Brown, Robert C; Kolb, Charles E; Conant, John A; Zhang, John; Dussault, David M; Rush, Tamera L; Conway, Brooke E; Morris, James W; Touma, Joe

    2004-01-01

    .... Detonation of energetic materials produces a wide range of air and surface pollutants, including carbon monoxide, nitrogen oxides, volatile organic compounds, acid gases, and particulate matter...

  20. [Why is bread consumption decreasing?].

    Science.gov (United States)

    Rolland, M F; Chabert, C; Serville, Y

    1977-01-01

    In France bread plays a very special and ambivalent role among our foodstuffs because of the considerable drop in its consumption, its alleged harmful effects on our health and the respect in which it is traditionally held. More than half the 1 089 adults interviewed in this study say they have decreased their consumption of bread in the last 10 years. The reasons given vary according to age, body weight and urbanization level. The main reasons given for this restriction are the desire to prevent or reduce obesity, the decrease in physical activity, the general reduction in food consumption and the possibility of diversifying foods even further. Moreover, the decreasing appeal of bread in relation to other foods, as well as a modification in the structure of meals, in which bread becomes less useful to accompany other food, accentuate this loss of attraction. However, the respect for bread as part of the staple diet remains very acute as 95 p. 100 of those interviewed express a reluctance to throw bread away, more for cultural than economic reasons. Mechanization and urbanization having brought about a decrease in energy needs, the most common alimentary adaptation is general caloric restriction by which glucids, and especially bread, are curtailed.

  1. Iron phosphate materials as cathodes for lithium batteries

    CERN Document Server

    Prosini, Pier Paolo

    2011-01-01

    ""Iron Phosphate Materials as Cathodes for Lithium Batteries"" describes the synthesis and the chemical-physical characteristics of iron phosphates, and presents methods of making LiFePO4 a suitable cathode material for lithium-ion batteries. The author studies carbon's ability to increase conductivity and to decrease material grain size, as well as investigating the electrochemical behaviour of the materials obtained. ""Iron Phosphate Materials as Cathodes for Lithium Batteries"" also proposes a model to explain lithium insertion/extraction in LiFePO4 and to predict voltage profiles at variou

  2. The assessment of serum-mediated phagocytosis of necrotic material by polymorphonuclear leukocytes to diagnose and predict the clinical features of systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Compagno, Michele; Gullstrand, Birgitta; Jacobsen, Søren

    2016-01-01

    BACKGROUND: Serum-mediated phagocytosis of antibody- and complement-opsonized necrotic cell material (NCM) by polymorphonuclear leukocytes can be quantified by using a flow cytometry-based assay. The phagocytosis of necrotic cell material (PNC) assay parallels the well-known lupus erythematosus c...

  3. Magical thinking decreases across adulthood.

    Science.gov (United States)

    Brashier, Nadia M; Multhaup, Kristi S

    2017-12-01

    Magical thinking, or illogical causal reasoning such as superstitions, decreases across childhood, but almost no data speak to whether this developmental trajectory continues across the life span. In four experiments, magical thinking decreased across adulthood. This pattern replicated across two judgment domains and could not be explained by age-related differences in tolerance of ambiguity, domain-specific knowledge, or search for meaning. These data complement and extend findings that experience, accumulated over decades, guides older adults' judgments so that they match, or even exceed, young adults' performance. They also counter participants' expectations, and cultural sayings (e.g., "old wives' tales"), that suggest that older adults are especially superstitious. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Does fertility decrease household consumption?

    OpenAIRE

    Jungho Kim; Henriette Engelhardt; Alexia Fürnkranz-Prskawetz; Arnstein Aassve

    2009-01-01

    This paper presents an empirical analysis of the relationship between fertility and a direct measure of poverty for Indonesia, a country, which has experienced unprecedented economic growth and sharp fertility declines over recent decades. It focuses on illustrating the sensitivity of the effect of fertility on household consumption with respect to the equivalence scale by applying the propensity score matching method. The analysis suggests that a newborn child decreases household consumption...

  5. New computational and experimental methods for determining the elastic and strength characteristics of materials and for predicting the behavior of structures

    Science.gov (United States)

    Lyukshin, B. A.; Barashkov, V. N.; Gerasimov, A. V.; Elkin, E. E.; Likhachev, V. N.; Mudarisov, Sh. Sh.; Cherepanov, O. I.

    1993-04-01

    Experimental methods for determining the physicomechanical characteristics of powder, polymer, and composite materials under thermal-force static and dynamic loads are presented. The results of the experimental investigations are used in numerical methods for calculating the stress — strain state and the stability and for describing the supercritical behavior as well as in methods for efficient design of strong machine-building structures made from new constructional materials.

  6. Decreasing Fires in Mediterranean Europe.

    Directory of Open Access Journals (Sweden)

    Marco Turco

    Full Text Available Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value. These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011 and a mixed trend in Portugal (1980-2011. Similar overall results were found for the annual number of fires (NF, which globally decreased by about 12600 in the study period (about -59%, except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts.

  7. Decreasing Fires in Mediterranean Europe.

    Science.gov (United States)

    Turco, Marco; Bedia, Joaquín; Di Liberto, Fabrizio; Fiorucci, Paolo; von Hardenberg, Jost; Koutsias, Nikos; Llasat, Maria-Carmen; Xystrakis, Fotios; Provenzale, Antonello

    2016-01-01

    Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts.

  8. Decreasing incidence rates of bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg; Pedersen, C; Jensen, T G

    2014-01-01

    BACKGROUND: Numerous studies have shown that the incidence rate of bacteremia has been increasing over time. However, few studies have distinguished between community-acquired, healthcare-associated and nosocomial bacteremia. METHODS: We conducted a population-based study among adults with first......-time bacteremia in Funen County, Denmark, during 2000-2008 (N = 7786). We reported mean and annual incidence rates (per 100,000 person-years), overall and by place of acquisition. Trends were estimated using a Poisson regression model. RESULTS: The overall incidence rate was 215.7, including 99.0 for community......-acquired, 50.0 for healthcare-associated and 66.7 for nosocomial bacteremia. During 2000-2008, the overall incidence rate decreased by 23.3% from 254.1 to 198.8 (3.3% annually, p incidence rate of community-acquired bacteremia decreased by 25.6% from 119.0 to 93.8 (3.7% annually, p

  9. Material characterization models and test methods for historic building materials

    DEFF Research Database (Denmark)

    Hansen, Tessa Kvist; Peuhkuri, Ruut Hannele; Møller, Eva B.

    2017-01-01

    Predictions of long term hygrothermal performance can be assessed by dynamic hygrothermal simulations, in which material parameters are crucial input. Material parameters for especially historic materials are often unknown; therefore, there is a need to determine important parameters, and simple...

  10. Rigidity spectrum of Forbush decrease

    International Nuclear Information System (INIS)

    Sakakibara, S.; Munakata, K.; Nagashima, K.

    1985-01-01

    Using data from neutron monitors and muon telescopes at surface and underground stations, the average rigidity spectrum of Forbush decreases (Fds) during the period of 1978-1982 were obtained. Thirty eight Ed-events are classified into two groups, Hard Fd and Soft FD according to size of Fd at the Sakashita station. It is found that a spectral form of a fractional-power type (P to the-gamma sub 1 (P+P sub c) to the -gamma sub2) is more suitable than that of a power-exponential type or of a power type with an upper limiting rigidity. The best fitted spectrum of the fractional-power type is expressed by gamma sub1 = 0.37, gamma sub2 = 0.89 and P subc = 10 GV for Hard Fd and gamma sub1 = 0.77, gamma sub2 = 1.02 and P sub c - 14GV for Soft Fd

  11. Method of decreasing nuclear power

    International Nuclear Information System (INIS)

    Masuda, Hiromi

    1987-01-01

    Purpose: To easily attain the power decreasing in a HWLWR type reactor and improve the reactor safety. Method: The method is applied to a nuclear reactor in which the reactor reactivity is controlled by control rods and liquid posions dissolved in moderators. Means for forecasting the control rod operation amount required for the reactor power down and means for removing liquid poisons in the moderators are provided. The control rod operation amount required for the power down is forecast before the power down and the liquid poisons in the moderators are removed. Then, the control rods are inserted into a deep insertion position to reduce the reactor power. This invention can facilitate easy power down, as well as provide effects of improving the controllability in the usual operation and of avoiding abrupt power down which leads to an improved availability. (Kamimura, M.)

  12. Calibration of SMA material model for the prediction of the ‘evolutionary’ load-bias behavior under conditions of extended thermal cycling

    International Nuclear Information System (INIS)

    Saleeb, A F; Dhakal, B; Padula II, S A; Gaydosh, D J

    2013-01-01

    This work is focused on the characterization of the cyclic response of the 55NiTi polycrystalline material system using a recently formulated, multimechanism-based, modeling framework. It has a number of significant contributions. First, it presents a comprehensive characterization of such a complex material system under broad thermo-mechanical loading conditions in isobaric experiments that cover: (a) the entire relevant stress range from 10 to 300 MPa, and (b) sufficient number of thermal cycles to enable the investigation of the details of the evolution of the cyclic strain-versus-temperature hysteresis loops. Second, the detailed comparisons presented for the model results and the experimental measurements provide the necessary validation of the modeling capabilities of the multimechanism framework. Third, specific plots are given detailing the variations with thermal cycling of the internal variables associated with each of the individual inelastic mechanisms. Fourth, an anatomical discussion details the interplay between the internal mechanisms to describe the material behavior within all the important response characteristic regions, thus providing a convenient means to complement the theoretical concepts in the mathematical approach. Given the comprehensive nature of this model, and its successful experimental validation under a wide range of conditions, it is believed that the model is capable of analyzing 55NiTi actuators. It is also emphasized that the insights provided in this work will carry forth to characterization of other SMA material systems. (paper)

  13. Predicting Multicomponent Adsorption Isotherms in Open-Metal Site Materials Using Force Field Calculations Based on Energy Decomposed Density Functional Theory

    NARCIS (Netherlands)

    Heinen, J.; Burtch, N.; Walton, K.; Fonseca Guerra, C.; Dubbeldam, D.

    2016-01-01

    For the design of adsorptive-separation units, knowledge is required of the multicomponent adsorption behavior. Ideal adsorbed solution theory (IAST) breaks down for olefin adsorption in open-metal site (OMS) materials due to non-ideal donor–acceptor interactions. Using a

  14. Lower Psychological Well-Being and Excessive Sexual Interest Predict Symptoms of Compulsive Use of Sexually Explicit Internet Material Among Adolescent Boys

    NARCIS (Netherlands)

    Doornwaard, Suzan M.; van Den Eijnden, Regina J J M; Baams, Laura; Vanwesenbeeck, Ine; Ter Bogt, Tom F M

    2016-01-01

    Although a growing body of literature addresses the effects of young people's use of sexually explicit Internet material, research on the compulsive use of this type of online content among adolescents and its associated factors is largely lacking. This study investigated whether factors from three

  15. Safety distance for preventing hot particle ignition of building insulation materials

    OpenAIRE

    Jiayun Song; Supan Wang; Haixiang Chen

    2014-01-01

    Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere ...

  16. Nonlinear ultrasonics for material state awareness

    Science.gov (United States)

    Jacobs, L. J.

    2014-02-01

    Predictive health monitoring of structural components will require the development of advanced sensing techniques capable of providing quantitative information on the damage state of structural materials. By focusing on nonlinear acoustic techniques, it is possible to measure absolute, strength based material parameters that can then be coupled with uncertainty models to enable accurate and quantitative life prediction. Starting at the material level, this review will present current research that involves a combination of sensing techniques and physics-based models to characterize damage in metallic materials. In metals, these nonlinear ultrasonic measurements can sense material state, before the formation of micro- and macro-cracks. Typically, cracks of a measurable size appear quite late in a component's total life, while the material's integrity in terms of toughness and strength gradually decreases due to the microplasticity (dislocations) and associated change in the material's microstructure. This review focuses on second harmonic generation techniques. Since these nonlinear acoustic techniques are acoustic wave based, component interrogation can be performed with bulk, surface and guided waves using the same underlying material physics; these nonlinear ultrasonic techniques provide results which are independent of the wave type used. Recent physics-based models consider the evolution of damage due to dislocations, slip bands, interstitials, and precipitates in the lattice structure, which can lead to localized damage.

  17. Breastfeeding Is Associated with Decreased Childhood Maltreatment.

    Science.gov (United States)

    Kremer, Kristen P; Kremer, Theodore R

    Child maltreatment has serious implications for youth outcomes, yet its associations with early parenting practices are not fully understood. This study investigated whether breastfeeding practices are correlated with childhood maltreatment. Data were utilized from the National Longitudinal Study of Adolescent to Adult Health, a nationally representative and longitudinal study of adolescents. The analytic sample comprised 4,159 adolescents. The outcome variables included four subtypes of childhood maltreatment (neglect, inadequate supervision, physical abuse, and sexual abuse). The primary independent variable was breastfeeding duration. Covariates of the child, mother, and household were included in analyses. Logistic regression models were employed to predict odds of maltreatment subtypes from breastfeeding duration and covariates. Compared with adolescents never breastfed, adolescents breastfed 9 months or longer had a reduced odds of having experienced neglect (odds ratio [OR] = 0.54; 95% confidence interval [CI] = 0.35-0.83) and sexual abuse (OR = 0.47; 95% CI = 0.24-0.93) after controlling for covariates. Breastfeeding duration is significantly associated with decreased childhood neglect and sexual abuse. Breastfeeding practices should be explored as a consideration among clinicians when assessing maltreatment risk. Further research should examine whether a causal relationship exists between breastfeeding and decreased maltreatment.

  18. Screened coulomb hybrid DFT investigation of band gap and optical absorption predictions of CuVO3, CuNbO3 and Cu 5Ta11O30 materials

    KAUST Repository

    Harb, Moussab

    2014-01-01

    We present a joint theoretical and experimental investigation of the optoelectronic properties of CuVO3, CuNbO3 and Cu 5Ta11O30 materials for potential photocatalytic and solar cell applications. In addition to the experimental results obtained by powder X-ray diffraction and UV-Vis spectroscopy of the materials synthesized under flowing N2 gas at atmospheric pressure via solid-state reactions, the electronic structure and the UV-Vis optical absorption coefficient of these compounds are predicted with high accuracy using advanced first-principles quantum methods based on DFT (including the perturbation theory approach DFPT) within the screened coulomb hybrid HSE06 exchange-correlation formalism. The calculated density of states are found to be in agreement with the UV-Vis diffuse reflectance spectra, predicting a small indirect band gap of 1.4 eV for CuVO3, a direct band gap of 2.6 eV for CuNbO3, and an indirect (direct) band gap of 2.1 (2.6) eV for Cu5Ta 11O30. It is confirmed that the Cu(i)-based multi-metal oxides possess a strong contribution of filled Cu(i) states in the valence band and of empty d0 metal states in the conduction band. Interestingly, CuVO3 with its predicted small indirect band gap of 1.4 eV shows the highest absorption coefficient in the visible range with a broad absorption edge extending to 886 nm. This novel result offers a great opportunity for this material to be an excellent candidate for solar cell applications. © the Partner Organisations 2014.

  19. Reactor pressure boundary material; the modeling for the prediction of the welding characteristics of SA508-cl.3 pressure vessel steel welds

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hee; Uhm, Sang Ho; Seo, Young Dae; Moon, Younk Ju; Kim, Bum Joo; Shim, Min Hyo [Hanyang University, Seoul (Korea)

    2002-03-01

    A metallurgical model for predicting the welding characteristics such as final microstructure and mechanical properties of HAZ was established and various kinetic parameters which was necessary to the model were measured and formulated through isothermal grain growth and isothermal transformation experiments. This model consisted of two sub-models; Grain growth model and Transformation model. Grain growth model was developed to calculate the thermal cycle from heat input and the change of austenite grain size which occurred during heating cycle. Transformation model described the phase transition behavior and predicted the final mechanical properties determined by structure-property relationships. The isothermal kinetics of grain growth and dissolution of precipitates were respectively described by well-known equation, dD/dt = M( {delta}F{sub e}ff ){sup m} and Whelan's analytical model. Isothermal transformation kinetics was expressed by Avrami equation. The reliabilities of each model were evaluated by HAZ microstructural simulation tests. It was found the both models were in good agreement. The applicability of this model was discussed by illustrating the results of the model. 129 refs., 81 figs., 11 tabs. (Author)

  20. QUALITY MANAGEMENT OF FOOD SYSTEMS WITH THE PREDICTED BIOPOTENTIAL ON THE BASIS OF PRODUCTS OF PROCESSING OF DOMESTIC LOW-OLIVE RAW MATERIALS

    Directory of Open Access Journals (Sweden)

    T. V. Alekseeva

    2015-01-01

    Full Text Available Summary. This receiving the vegetable complex food system (VCFS on the basis of the cake of germs of wheat (CGW is presented. The review of composition of vegetable oils from low-olive raw materials is given, prospects of its application for creation of food systems of the balanced structure on PNZС are analyzed. It is established that the ratio of -6 и -3 of fatty acids in oil of germs of wheat doesn't correspond to recommendations of scientific research institute of food of the Russian Academy of Medical Science. For the purpose of establishment of necessary balance of -6 и -3 in food system, the blend with oils of an amaranth and pumpkin is carried out. The review of composition of vegetable oils from low-olive raw materials is given. The optimum ratio the entered oil of an amaranth and pumpkin according to recommendations of scientific research institute of food of the Russian Academy of Medical Science, by means of the developed software products written on in the Python 2.6 language and in the imperative, structured, object-oriented programming language – Delphi 7.0 is picked up. On the basis of the obtained data, the mass fraction of the components entering a compounding of vegetable food system is defined. The technological process of production of a product including the following stages is described: reception and preparation of raw materials and materials, dispensing and mixing of components, crushing and packing. Physical and chemical indicators of the received product, a chemical composition of RKPS and an organoleptic assessment of an innovative product are given. Calculation of satisfaction of daily need of an organism for feedstuffs and energy of vegetable food system is made. The composition of protein of an innovative product is analyzed: the amino-acid structure of food system, biological value, and also following indicators is counted: utility coefficient, coefficient of comparable redundancy, coefficient of

  1. Prediction of the behavior of structural materials under irradiation through modeling of the microstructure. Progress report, November 1, 1980-October 31, 1981. Final report

    International Nuclear Information System (INIS)

    Wolfer, W.G.

    1981-10-01

    The research carried out over the period of about three years falls into three categories: effects of point-defect interactions on the formation of voids, dislocation loops, and network dislocations, during irradiation, and the consequences on the mechanical properties of structural materials; the development of a new mathematical tool to describe the evolution of systems far from a thermodynamic equilibrium state; and the development and exploration of a new technique to measure mechanically and non-destructively the creep damage, or the grain-boundary cavity formation, which is the cause of high-temperature stress rupture

  2. Optimal Super Dielectric Material

    Science.gov (United States)

    2015-09-01

    plate capacitor will reduce the net field to an unprecedented extent. This family of materials can form materials with dielectric values orders of... Capacitor -Increase Area (A)............8 b. Multi-layer Ceramic Capacitor -Decrease Thickness (d) .......10 c. Super Dielectric Material-Increase...circuit modeling, from [44], and B) SDM capacitor charge and discharge ...................................................22 Figure 15. Dielectric

  3. Research Opportunities in Corrosion Science for Long-Term Prediction of Materials Performance: A Report of the DOE Workshop on ''Corrosion Issues of Relevance to the Yucca Mountain Waste Repository''

    International Nuclear Information System (INIS)

    Payer, Joe H.; Scully, John R.

    2003-01-01

    The report summarizes the findings of a U.S. Department of Energy workshop on ''Corrosion Issues of Relevance to the Yucca Mountain Waste Repository''. The workshop was held on July 29-30, 2003 in Bethesda, MD, and was co-sponsored by the Office of Basic Energy Sciences and Office of Civilian Radioactive Waste Management. The workshop focus was corrosion science relevant to long-term prediction of materials performance in hostile environments, with special focus on relevance to the permanent disposal of nuclear waste at the Yucca Mountain Repository. The culmination of the workshop is this report that identifies both generic and Yucca Mountain Project-specific research opportunities in basic and applied topic areas. The research opportunities would be realized well after the U.S. Nuclear Regulatory Commission's initial construction-authorization licensing process. At the workshop, twenty-three invited scientists deliberated on basic and applied science opportunities in corrosion science relevant to long-term prediction of damage accumulation by corrosive processes that affect materials performance.

  4. Research Opportunities in Corrosion Science for Long-Term Prediction of Materials Performance: A Report of the DOE Workshop on “Corrosion Issues of Relevance to the Yucca Mountain Waste Repository”.

    Energy Technology Data Exchange (ETDEWEB)

    Payer, Joe H. [Case Western Reserve Univ., Cleveland, OH (United States); Scully, John R. [Univ. of Virginia, Charlottesville, VA (United States)

    2003-07-29

    The report summarizes the findings of a U.S. Department of Energy workshop on “Corrosion Issues of Relevance to the Yucca Mountain Waste Repository”. The workshop was held on July 29-30, 2003 in Bethesda, MD, and was co-sponsored by the Office of Basic Energy Sciences and Office of Civilian Radioactive Waste Management. The workshop focus was corrosion science relevant to long-term prediction of materials performance in hostile environments, with special focus on relevance to the permanent disposal of nuclear waste at the Yucca Mountain Repository. The culmination of the workshop is this report that identifies both generic and Yucca Mountain Project-specific research opportunities in basic and applied topic areas. The research opportunities would be realized well after the U.S. Nuclear Regulatory Commission’s initial construction-authorization licensing process. At the workshop, twenty-three invited scientists deliberated on basic and applied science opportunities in corrosion science relevant to long-term prediction of damage accumulation by corrosive processes that affect materials performance.

  5. Prediction of the Effects of Radiation FOr Reactor pressure vessel and in-core Materials using multi-scale modeling - 60 years foreseen plant lifetime (PERFORM-60 project)

    International Nuclear Information System (INIS)

    Al Mazouzi, A.; Bugat, S.; Leclercq, S.; Massoud, J.-P.; Moinereau, D.; Lidbury, D.; Van Dyck, S.; Marini, B.; Alamo, Ana

    2010-01-01

    The PERFECT project of the EURATOM framework program (FP6) is a first step through the development of a simulation platform that contains several advanced numerical tools aiming at the prediction of irradiation damage in both the reactor pressure vessel (RPV) and its internals using state-of-the-art knowledge. These tools allow simulation of irradiation effects on the microstructure and the constitutive behavior of the RPV low alloy steels, as well as their fracture mechanics properties. For the reactor internals, the first partial models were established, describing radiation damage to the microstructure and providing a first description of the stress corrosion behaviour of austenitic steels in primary environment, without physical linking of the radiation and corrosion effects. Thus, relying on the existing PERFECT Roadmap, the FP7 Collaborative Project PERFORM 60 has mainly for objective to develop similar tools that would allow the simulation of the combined effects of irradiation and corrosion on internals, in addition to a further improvement of the existing ones on RPV made of bainitic steels. From the managerial view point, PERFORM 60 is based on two technical sub-projects, namely (i) RPV and (ii) Internals. In addition, a Users' Group and a training scheme have been adopted in order to allow representatives of constructors, utilities, research organizations... from Europe, USA and Japan to participate actively in the process of appraising the limits and potentialities of the developed tools as well as their validation against qualified experimental data

  6. Materials by design

    International Nuclear Information System (INIS)

    Eberhardt, J.; Hay, P.J.; Carpenter, J.A. Jr.

    1986-01-01

    Major developments in materials characterization instrumentation over the past decade have helped significantly to elucidate complex processes and phenomena connected with the microstructure of materials and interfacial interactions. Equally remarkable advances in theoretical models and computer technology also have been taking place during this period. These latter now permit, for example, in selected cases the computation of material structures and bonding and the prediction of some material properties. Two assessments of the state of the art of instrumental techniques and theoretical methods for the study of material structures and properties have recently been conducted. This paper discusses aspects from these assessments of computational theoretical methods apply to materials

  7. Prediction of packaging seal life using thermoanalytical techniques

    International Nuclear Information System (INIS)

    Nigrey, P.J.

    1997-11-01

    In this study, Thermogravimetric Analysis (TGA) has been used to study silicone, Viton and Ethylene Propylene (EPDM) rubber. The studies have shown that TGA accurately predicts the relative order of thermo-oxidative stability of these three materials from the calculated activation energies. As expected, the greatest thermal stability was found in silicone rubber followed by Viton and EPDM rubber. The calculated lifetimes for these materials were in relatively close agreement with published values. The preliminary results also accurately reflect decreased thermal stability and lifetime for EPDM rubber exposed to radiation and chemicals. These results suggest TGA provides a rapid method to evaluate material stability

  8. Dictionary materials engineering, materials testing

    International Nuclear Information System (INIS)

    1994-01-01

    This dictionary contains about 9,500 entries in each part of the following fields: 1) Materials using and selection; 2) Mechanical engineering materials -Metallic materials - Non-metallic inorganic materials - Plastics - Composites -Materials damage and protection; 3) Electrical and electronics materials -Conductor materials - Semiconductors - magnetic materials - Dielectric materials - non-conducting materials; 4) Materials testing - Mechanical methods - Analytical methods - Structure investigation - Complex methods - Measurement of physical properties - Non-destructive testing. (orig.) [de

  9. WALS Prediction

    NARCIS (Netherlands)

    Magnus, J.R.; Wang, W.; Zhang, Xinyu

    2012-01-01

    Abstract: Prediction under model uncertainty is an important and difficult issue. Traditional prediction methods (such as pretesting) are based on model selection followed by prediction in the selected model, but the reported prediction and the reported prediction variance ignore the uncertainty

  10. Materials Informatics: Statistical Modeling in Material Science.

    Science.gov (United States)

    Yosipof, Abraham; Shimanovich, Klimentiy; Senderowitz, Hanoch

    2016-12-01

    Material informatics is engaged with the application of informatic principles to materials science in order to assist in the discovery and development of new materials. Central to the field is the application of data mining techniques and in particular machine learning approaches, often referred to as Quantitative Structure Activity Relationship (QSAR) modeling, to derive predictive models for a variety of materials-related "activities". Such models can accelerate the development of new materials with favorable properties and provide insight into the factors governing these properties. Here we provide a comparison between medicinal chemistry/drug design and materials-related QSAR modeling and highlight the importance of developing new, materials-specific descriptors. We survey some of the most recent QSAR models developed in materials science with focus on energetic materials and on solar cells. Finally we present new examples of material-informatic analyses of solar cells libraries produced from metal oxides using combinatorial material synthesis. Different analyses lead to interesting physical insights as well as to the design of new cells with potentially improved photovoltaic parameters. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Material Science

    Energy Technology Data Exchange (ETDEWEB)

    Won, Dong Yeon; Kim, Heung

    1987-08-15

    This book introduces material science, which includes key of a high-tech industry, new materials of dream like new metal material and semiconductor, classification of materials, microstructure of materials and characteristic. It mentions magic new materials such as shape memory alloy, fine ceramics, engineering fine ceramics, electronic ceramics, engineering plastic, glass, silicone conductor, optical fiber mixed materials and integrated circuit, challenge for new material and development of new materials.

  12. Material Science

    International Nuclear Information System (INIS)

    Won, Dong Yeon; Kim, Heung

    1987-08-01

    This book introduces material science, which includes key of a high-tech industry, new materials of dream like new metal material and semiconductor, classification of materials, microstructure of materials and characteristic. It mentions magic new materials such as shape memory alloy, fine ceramics, engineering fine ceramics, electronic ceramics, engineering plastic, glass, silicone conductor, optical fiber mixed materials and integrated circuit, challenge for new material and development of new materials.

  13. Materials and material testing

    International Nuclear Information System (INIS)

    Joergens, H.

    1978-01-01

    A review based on 105 literature quotations is given on the latest state of development in the steel sector and in the field of non-ferrous metals and plastics. The works quoted also include, preparation, working, welding including simulation methods, improvement of weldability, material mechanics (explanation of defects mechanisms by means of fracture mechanics), defect causes (corrosion, erosion, hydrogen influence), mechanical-technological and non-destructive material testing. Examples from the field of reactor building are also given within there topics. (IHOE) [de

  14. Predictive Mechanical Characterization of Macro-Molecular Material Chemistry Structures of Cement Paste at Nano Scale - Two-phase Macro-Molecular Structures of Calcium Silicate Hydrate, Tri-Calcium Silicate, Di-Calcium Silicate and Calcium Hydroxide

    Science.gov (United States)

    Padilla Espinosa, Ingrid Marcela

    Concrete is a hierarchical composite material with a random structure over a wide range of length scales. At submicron length scale the main component of concrete is cement paste, formed by the reaction of Portland cement clinkers and water. Cement paste acts as a binding matrix for the other components and is responsible for the strength of concrete. Cement paste microstructure contains voids, hydrated and unhydrated cement phases. The main crystalline phases of unhydrated cement are tri-calcium silicate (C3S) and di-calcium silicate (C2S), and of hydrated cement are calcium silicate hydrate (CSH) and calcium hydroxide (CH). Although efforts have been made to comprehend the chemical and physical nature of cement paste, studies at molecular level have primarily been focused on individual components. Present research focuses on the development of a method to model, at molecular level, and analysis of the two-phase combination of hydrated and unhydrated phases of cement paste as macromolecular systems. Computational molecular modeling could help in understanding the influence of the phase interactions on the material properties, and mechanical performance of cement paste. Present work also strives to create a framework for molecular level models suitable for potential better comparisons with low length scale experimental methods, in which the sizes of the samples involve the mixture of different hydrated and unhydrated crystalline phases of cement paste. Two approaches based on two-phase cement paste macromolecular structures, one involving admixed molecular phases, and the second involving cluster of two molecular phases are investigated. The mechanical properties of two-phase macromolecular systems of cement paste consisting of key hydrated phase CSH and unhydrated phases C3S or C2S, as well as CSH with the second hydrated phase CH were calculated. It was found that these cement paste two-phase macromolecular systems predicted an isotropic material behavior. Also

  15. Life Prediction Methodologies for Aerospace Materials

    National Research Council Canada - National Science Library

    Ashbaugh, N

    2001-01-01

    .... An investigation of elastic properties of colonies has continued with conjoint efforts in the experimental evaluation of test specimens containing large colonies and in finite element analysis...

  16. Life Prediction Methodologies for Aerospace Materials

    National Research Council Canada - National Science Library

    Ashbaugh, N. E; Brockman, R. A; Buchanan, D. J; Hartman, G. A; Huston, A. L; Li, K; Porter, W. J

    2004-01-01

    Superalloys IN-100, Ren 88DT, Waspaloy, and titanium alloys were investigated. For life-limiting responses in superalloys, highly localized stress-deformation behaviors associated with both typical and unusual defects were developed...

  17. Computational materials science: The emergence of predictive ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    some significant recent developments related to alloy and steel design as well as the study of ... of aggregates of atoms (Kumar et al 2002a), etc. and even problems such as the development ... Cu–Au type fcc or CsCl-type bcc struc- tures.

  18. Leaching materials from cavities

    International Nuclear Information System (INIS)

    Hodgson, T.D.; Jordan, T.W.J.

    1980-01-01

    A material is leached from a cavity by contacting the material with a liquid and subjecting the liquid to a number of pressure cycles, each pressure cycle involving a decrease in pressure to cause boiling of the liquid, followed by a rise in pressure to inhibit the boiling. The method may include the step of heating the liquid to a temperature near to its boiling point. The material may be nuclear fuel pellets or calcium carbonate pellets. (author)

  19. Nanostructured composite reinforced material

    Science.gov (United States)

    Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  20. Age and Stress Prediction

    Science.gov (United States)

    2000-01-01

    Genoa is a software product that predicts progressive aging and failure in a variety of materials. It is the result of a SBIR contract between the Glenn Research Center and Alpha Star Corporation. Genoa allows designers to determine if the materials they plan on applying to a structure are up to the task or if alternate materials should be considered. Genoa's two feature applications are its progressive failure simulations and its test verification. It allows for a reduction in inspection frequency, rapid design solutions, and manufacturing with low cost materials. It will benefit the aerospace, airline, and automotive industries, with future applications for other uses.

  1. Material synergism fusion-fission

    International Nuclear Information System (INIS)

    Sankara Rao, K.B.; Raj, B.; Cook, I.; Kohyama, A.; Dudarev, S.

    2007-01-01

    In fission and fusion reactors the common features such as operating temperatures and neutron exposures will have the greatest impact on materials performance and component lifetimes. Developing fast neutron irradiation resisting materials is a common issue for both fission and fusion reactors. The high neutron flux levels in both these systems lead to unique materials problems like void swelling, irradiation creep and helium embitterment. Both fission and fusion rely on ferritic-martensitic steels based on 9%Cr compositions for achieving the highest swelling resistance but their creep strength sharply decreases above ∝ 823K. The use of oxide dispersion strengthened (ODS) alloys is envisaged to increase the operating temperature of blanket systems in the fusion reactors and fuel clad tubes in fast breeder reactors. In view of high operating temperatures, cyclic and steady load conditions and the long service life, properties like creep, low cycle fatigue,fracture toughness and creepfatigue interaction are major considerations in the selection of structural materials and design of components for fission and fusion reactors. Currently, materials selection for fusion systems has to be based upon incomplete experimental database on mechanical properties. The usage of fairly well developed databases, in fission programmes on similar materials, is of great help in the initial design of fusion reactor components. Significant opportunities exist for sharing information on technology of irradiation testing, specimen miniaturization, advanced methods of property measurement, safe windows for metal forming, and development of common materials property data base system. Both fusion and fission programs are being directed to development of clean steels with very low trace and tramp elements, characterization of microstructure and phase stability under irradiation, assessment of irradiation creep and swelling behaviour, studies on compatibility with helium and developing

  2. Spontaneous entropy decrease and its statistical formula

    OpenAIRE

    Xing, Xiu-San

    2007-01-01

    Why can the world resist the law of entropy increase and produce self-organizing structure? Does the entropy of an isolated system always only increase and never decrease? Can be thermodymamic degradation and self-organizing evolution united? How to unite? In this paper starting out from nonequilibrium entropy evolution equation we proved that a new entropy decrease could spontaneously emerge in nonequilibrium system with internal attractive interaction. This new entropy decrease coexists wit...

  3. Phosphorus limitation and heat stress decrease calcification in Emiliania huxleyi

    Science.gov (United States)

    Gerecht, Andrea C.; Šupraha, Luka; Langer, Gerald; Henderiks, Jorijntje

    2018-02-01

    Calcifying haptophytes (coccolithophores) sequester carbon in the form of organic and inorganic cellular components (coccoliths). We examined the effect of phosphorus (P) limitation and heat stress on particulate organic and inorganic carbon (calcite) production in the coccolithophore Emiliania huxleyi. Both environmental stressors are related to rising CO2 levels and affect carbon production in marine microalgae, which in turn impacts biogeochemical cycling. Using semi-continuous cultures, we show that P limitation and heat stress decrease the calcification rate in E. huxleyi. However, using batch cultures, we show that different culturing approaches (batch versus semi-continuous) induce different physiologies. This affects the ratio of particulate inorganic (PIC) to organic carbon (POC) and complicates general predictions on the effect of P limitation on the PIC  /  POC ratio. We found heat stress to increase P requirements in E. huxleyi, possibly leading to lower standing stocks in a warmer ocean, especially if this is linked to lower nutrient input. In summary, the predicted rise in global temperature and resulting decrease in nutrient availability may decrease CO2 sequestration by E. huxleyi through lower overall carbon production. Additionally, the export of carbon may be diminished by a decrease in calcification and a weaker coccolith ballasting effect.

  4. Phosphorus limitation and heat stress decrease calcification in Emiliania huxleyi

    Directory of Open Access Journals (Sweden)

    A. C. Gerecht

    2018-02-01

    Full Text Available Calcifying haptophytes (coccolithophores sequester carbon in the form of organic and inorganic cellular components (coccoliths. We examined the effect of phosphorus (P limitation and heat stress on particulate organic and inorganic carbon (calcite production in the coccolithophore Emiliania huxleyi. Both environmental stressors are related to rising CO2 levels and affect carbon production in marine microalgae, which in turn impacts biogeochemical cycling. Using semi-continuous cultures, we show that P limitation and heat stress decrease the calcification rate in E. huxleyi. However, using batch cultures, we show that different culturing approaches (batch versus semi-continuous induce different physiologies. This affects the ratio of particulate inorganic (PIC to organic carbon (POC and complicates general predictions on the effect of P limitation on the PIC  ∕  POC ratio. We found heat stress to increase P requirements in E. huxleyi, possibly leading to lower standing stocks in a warmer ocean, especially if this is linked to lower nutrient input. In summary, the predicted rise in global temperature and resulting decrease in nutrient availability may decrease CO2 sequestration by E. huxleyi through lower overall carbon production. Additionally, the export of carbon may be diminished by a decrease in calcification and a weaker coccolith ballasting effect.

  5. Climate prediction and predictability

    Science.gov (United States)

    Allen, Myles

    2010-05-01

    Climate prediction is generally accepted to be one of the grand challenges of the Geophysical Sciences. What is less widely acknowledged is that fundamental issues have yet to be resolved concerning the nature of the challenge, even after decades of research in this area. How do we verify or falsify a probabilistic forecast of a singular event such as anthropogenic warming over the 21st century? How do we determine the information content of a climate forecast? What does it mean for a modelling system to be "good enough" to forecast a particular variable? How will we know when models and forecasting systems are "good enough" to provide detailed forecasts of weather at specific locations or, for example, the risks associated with global geo-engineering schemes. This talk will provide an overview of these questions in the light of recent developments in multi-decade climate forecasting, drawing on concepts from information theory, machine learning and statistics. I will draw extensively but not exclusively from the experience of the climateprediction.net project, running multiple versions of climate models on personal computers.

  6. Use of biofuels in road transport decreases

    International Nuclear Information System (INIS)

    Segers, R.

    2011-01-01

    The use of biofuels decreased from 3.5 percent, for all gasoline and diesel used by road transport in 2009, to 2 percent in 2010. Particularly the use of biodiesel decreased, dropping from 3.5 to 1.5 percent. The use of biogasoline remained stable, catering for 3 percent of all gasoline use. [nl

  7. Mastery Learning and the Decreasing Variability Hypothesis.

    Science.gov (United States)

    Livingston, Jennifer A.; Gentile, J. Ronald

    1996-01-01

    This report results from studies that tested two variations of Bloom's decreasing variability hypothesis using performance on successive units of achievement in four graduate classrooms that used mastery learning procedures. Data do not support the decreasing variability hypothesis; rather, they show no change over time. (SM)

  8. A prediction method of natural gas hydrate formation in deepwater gas well and its application

    Directory of Open Access Journals (Sweden)

    Yanli Guo

    2016-09-01

    Full Text Available To prevent the deposition of natural gas hydrate in deepwater gas well, the hydrate formation area in wellbore must be predicted. Herein, by comparing four prediction methods of temperature in pipe with field data and comparing five prediction methods of hydrate formation with experiment data, a method based on OLGA & PVTsim for predicting the hydrate formation area in wellbore was proposed. Meanwhile, The hydrate formation under the conditions of steady production, throttling and shut-in was predicted by using this method based on a well data in the South China Sea. The results indicate that the hydrate formation area decreases with the increase of gas production, inhibitor concentrations and the thickness of insulation materials and increases with the increase of thermal conductivity of insulation materials and shutdown time. Throttling effect causes a plunge in temperature and pressure in wellbore, thus leading to an increase of hydrate formation area.

  9. Modeling the effects of electrical and non-electrical parameters on the material removal and surface integrity in case of µEDM of a non-conductive ceramic material using a combined fuzzy-AOM approach

    DEFF Research Database (Denmark)

    Puthumana, Govindan

    2016-01-01

    Micro-EDM is a non-contact process based on the thermoelectric energy between a tool electrode and a workpiece. In μEDM process, the mechanism of material removal is melting and evaporation. The thermal energy in the discharge plasma helps remove material from the workpiece, at the same time...... and surface integrity for a non-conductive ceramic material. The fuzzy logic modeling system is employed for predicting the μEDM process responses. The trends in the material removal rate and hardness values with the chosen electrical and non-electrical parameter for the model and obtained using AOM approach...... are compared. The average deviation between the model predictions and the results obtained using AOM plots is less than 10%. The material removal rate (MRR) decreases linearly with voltage, indicating a difference in material removal mechanism in the μEDM of non-conductive materials....

  10. Optical materials

    International Nuclear Information System (INIS)

    Poker, D.B.; Ortiz, C.

    1989-01-01

    This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

  11. Strategic Materials

    National Research Council Canada - National Science Library

    Buhler, Carl; Burke, Adrian; Davis, Kirk; Gerhard, Michelle; Heil, Valerie; Hulse, Richard; Kwong, Ralph; Mahoney, Michael; Moran, Scott; Peek, Michael

    2006-01-01

    Some materials possess greater value than others. Materials that provide essential support for the nation's economic viability or enable critical military capabilities warrant special attention in security studies...

  12. Can Diuretics Decrease Your Potassium Level?

    Science.gov (United States)

    ... of low potassium? Can diuretics decrease your potassium level? Answers from Sheldon G. Sheps, M.D. Yes, ... your urine. This can lead to low potassium levels in your blood (hypokalemia). Signs and symptoms of ...

  13. Using a Nonaversive Procedure to Decrease Refusals.

    Science.gov (United States)

    Spooner, Fred; And Others

    1990-01-01

    A nonaversive technique was used to teach a severely handicapped woman to decrease her refusals. The technique employed precision teaching via precise daily measurement strategies, environmental analysis, and a focus on building appropriate behavior. (JDD)

  14. Autoimmune Response Confers Decreased Cardiac Function in ...

    African Journals Online (AJOL)

    inflammatory response; rather, autoimmune response would keep affecting decreased heart function in. RHD patients who ... untreated children. Nearly 30 - 45 % of the affected children could ..... Technology Department of Anhui Province (PR.

  15. Guilt decreasing marketing communication: an unexplored appeal

    OpenAIRE

    B. BUSACCA; SOSCIA I; PITRELLI E

    2007-01-01

    The phenomenon of guilt is relevant to a variety of consumption situations and practitioners around the world have continued to use it as a communication appeal. Marketing literature demonstrated that guilt as a distinct emotion can be aroused by advertising. Nevertheless, the capacity of advertising to decrease guilt was neglected by marketing scholars and the aim of this research is to assess the role of the guilt decreasing appeal in reducing anticipated guilt. Findings demonstrate the eff...

  16. Predictability of Conversation Partners

    Science.gov (United States)

    Takaguchi, Taro; Nakamura, Mitsuhiro; Sato, Nobuo; Yano, Kazuo; Masuda, Naoki

    2011-08-01

    Recent developments in sensing technologies have enabled us to examine the nature of human social behavior in greater detail. By applying an information-theoretic method to the spatiotemporal data of cell-phone locations, [C. Song , ScienceSCIEAS0036-8075 327, 1018 (2010)] found that human mobility patterns are remarkably predictable. Inspired by their work, we address a similar predictability question in a different kind of human social activity: conversation events. The predictability in the sequence of one’s conversation partners is defined as the degree to which one’s next conversation partner can be predicted given the current partner. We quantify this predictability by using the mutual information. We examine the predictability of conversation events for each individual using the longitudinal data of face-to-face interactions collected from two company offices in Japan. Each subject wears a name tag equipped with an infrared sensor node, and conversation events are marked when signals are exchanged between sensor nodes in close proximity. We find that the conversation events are predictable to a certain extent; knowing the current partner decreases the uncertainty about the next partner by 28.4% on average. Much of the predictability is explained by long-tailed distributions of interevent intervals. However, a predictability also exists in the data, apart from the contribution of their long-tailed nature. In addition, an individual’s predictability is correlated with the position of the individual in the static social network derived from the data. Individuals confined in a community—in the sense of an abundance of surrounding triangles—tend to have low predictability, and those bridging different communities tend to have high predictability.

  17. Predictability of Conversation Partners

    Directory of Open Access Journals (Sweden)

    Taro Takaguchi

    2011-09-01

    Full Text Available Recent developments in sensing technologies have enabled us to examine the nature of human social behavior in greater detail. By applying an information-theoretic method to the spatiotemporal data of cell-phone locations, [C. Song et al., Science 327, 1018 (2010SCIEAS0036-8075] found that human mobility patterns are remarkably predictable. Inspired by their work, we address a similar predictability question in a different kind of human social activity: conversation events. The predictability in the sequence of one’s conversation partners is defined as the degree to which one’s next conversation partner can be predicted given the current partner. We quantify this predictability by using the mutual information. We examine the predictability of conversation events for each individual using the longitudinal data of face-to-face interactions collected from two company offices in Japan. Each subject wears a name tag equipped with an infrared sensor node, and conversation events are marked when signals are exchanged between sensor nodes in close proximity. We find that the conversation events are predictable to a certain extent; knowing the current partner decreases the uncertainty about the next partner by 28.4% on average. Much of the predictability is explained by long-tailed distributions of interevent intervals. However, a predictability also exists in the data, apart from the contribution of their long-tailed nature. In addition, an individual’s predictability is correlated with the position of the individual in the static social network derived from the data. Individuals confined in a community—in the sense of an abundance of surrounding triangles—tend to have low predictability, and those bridging different communities tend to have high predictability.

  18. Structural prediction in aphasia

    Directory of Open Access Journals (Sweden)

    Tessa Warren

    2015-05-01

    Full Text Available There is considerable evidence that young healthy comprehenders predict the structure of upcoming material, and that their processing is facilitated when they encounter material matching those predictions (e.g., Staub & Clifton, 2006; Yoshida, Dickey & Sturt, 2013. However, less is known about structural prediction in aphasia. There is evidence that lexical prediction may be spared in aphasia (Dickey et al., 2014; Love & Webb, 1977; cf. Mack et al, 2013. However, predictive mechanisms supporting facilitated lexical access may not necessarily support structural facilitation. Given that many people with aphasia (PWA exhibit syntactic deficits (e.g. Goodglass, 1993, PWA with such impairments may not engage in structural prediction. However, recent evidence suggests that some PWA may indeed predict upcoming structure (Hanne, Burchert, De Bleser, & Vashishth, 2015. Hanne et al. tracked the eyes of PWA (n=8 with sentence-comprehension deficits while they listened to reversible subject-verb-object (SVO and object-verb-subject (OVS sentences in German, in a sentence-picture matching task. Hanne et al. manipulated case and number marking to disambiguate the sentences’ structure. Gazes to an OVS or SVO picture during the unfolding of a sentence were assumed to indicate prediction of the structure congruent with that picture. According to this measure, the PWA’s structural prediction was impaired compared to controls, but they did successfully predict upcoming structure when morphosyntactic cues were strong and unambiguous. Hanne et al.’s visual-world evidence is suggestive, but their forced-choice sentence-picture matching task places tight constraints on possible structural predictions. Clearer evidence of structural prediction would come from paradigms where the content of upcoming material is not as constrained. The current study used self-paced reading study to examine structural prediction among PWA in less constrained contexts. PWA (n=17 who

  19. Designing Material Materialising Design

    DEFF Research Database (Denmark)

    Nicholas, Paul

    2013-01-01

    Designing Material Materialising Design documents five projects developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts, School of Architecture. These projects explore the idea that new designed materials might require new design methods....... Focusing on fibre reinforced composites, this book sustains an exploration into the design and making of elastically tailored architectural structures that rely on the use of computational design to predict sensitive interdependencies between geometry and behaviour. Developing novel concepts...

  20. Predictable or not predictable? The MOV question

    International Nuclear Information System (INIS)

    Thibault, C.L.; Matzkiw, J.N.; Anderson, J.W.; Kessler, D.W.

    1994-01-01

    Over the past 8 years, the nuclear industry has struggled to understand the dynamic phenomena experienced during motor-operated valve (MOV) operation under differing flow conditions. For some valves and designs, their operational functionality has been found to be predictable; for others, unpredictable. Although much has been accomplished over this period of time, especially on modeling valve dynamics, the unpredictability of many valves and designs still exists. A few valve manufacturers are focusing on improving design and fabrication techniques to enhance product reliability and predictability. However, this approach does not address these issues for installed and inpredictable valves. This paper presents some of the more promising techniques that Wyle Laboratories has explored with potential for transforming unpredictable valves to predictable valves and for retrofitting installed MOVs. These techniques include optimized valve tolerancing, surrogated material evaluation, and enhanced surface treatments

  1. Hysteresis in Magnetocaloric Materials

    DEFF Research Database (Denmark)

    von Moos, Lars

    , obtained at the initial low and final high field. However, in first order materials thermal entropy hysteresis loops are obtained through characterization, corresponding to measurements done in an increasing and a decreasing temperature mode. Indirectly determining the MCE through the use of the Maxwell...... order materials, taking the magnetic and thermal history dependence of material properties into account, as well as the heat production due to hysteretic losses. MnFe(P,As) and Gd5Si2Ge2 compounds are modelled and it is found that the Preisach approach is suitable to reproduce material behavior in both......In this thesis the effects of hysteresis on magnetocaloric material properties and their performance in magnetic refrigeration devices are investigated. This is done through an experimental and model study of first order magnetocaloric materials MnFe(P,As) and Gd5Si2Ge2. The experimental...

  2. Decreased oxidative stress may contribute to the disease process in placenta accreta

    Science.gov (United States)

    Öztaş, Efser; Özler, Sibel; Ergin, Merve; Erel, Özcan; Gümüş Güler, Başak; Çağlar, Ali Turhan; Yücel, Aykan; Uygur, Dilek; Danışman, Nuri

    2017-08-23

    Background/aim: The main aim of this study was to investigate serum total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and arylesterase levels in pregnant women with placenta accreta and to compare those with age-matched healthy pregnant women. Materials and methods: A total of 27 pregnant women who had clinically and pathologically proven placenta accreta and 30 age- and BMI- matched healthy pregnant women were enrolled in this case control study. Maternal serum TOS, TAS, OSI, and arylesterase levels were evaluated using logistic regression analysis to determine if there was an association with abnormal placental invasion or not. Results: Decreased OSI (OR= 0.999, 95%CI: 0.998-1.000, P = 0.035) and increased arylesterase levels (OR= 0.981, 95%CI: 0.970-0.993, P = 0.001) were significantly associated with the presence of placenta accreta. Maternal serum TOS, TAS, OSI, and arylesterase levels were not predictive for adverse perinatal outcomes (P > 0.05). Conclusions: Decreased OSI and increased arylesterase levels are significantly associated with placenta accreta and may contribute to the abnormal invasion process.

  3. Materials with complex behaviour II properties, non-classical materials and new technologies

    CERN Document Server

    Oechsner, Andreas

    2012-01-01

    This book reviews developments and trends in advanced materials and their properties; modeling and simulation of non-classical materials and new technologies for joining materials. Offers tools for characterizing and predicting properties and behavior.

  4. Facing Global Challenges with Materials Innovation

    Science.gov (United States)

    Rizzo, Fernando

    2017-10-01

    The path of society evolution has long been associated with a growing demand for natural resources and continuous environmental degradation. During the last decades, this pace has accelerated considerably, despite the general concern with the legacy being left for the next generations. Looking ahead, the predicted growth of the world population, and the improvement of life conditions in most regions, point to an increasing demand for energy generation, resulting in additional pressure on the Earth's sustainability. Materials have had a key role in decreasing the use of natural resources, by either improving efficiency of existing technologies or enabling the development of radical new ones. The greenhouse effect (CO2 emissions) and the energy crisis are global challenges that can benefit from the development of new materials for the successful implementation of promising technologies and for the imperative replacement of fossil fuels by renewable sources.

  5. Playing prosocial video games increases empathy and decreases schadenfreude.

    Science.gov (United States)

    Greitemeyer, Tobias; Osswald, Silvia; Brauer, Markus

    2010-12-01

    Past research provided abundant evidence that exposure to violent video games increases aggressive tendencies and decreases prosocial tendencies. In contrast, research on the effects of exposure to prosocial video games has been relatively sparse. The present research found support for the hypothesis that exposure to prosocial video games is positively related to prosocial affect and negatively related to antisocial affect. More specifically, two studies revealed that playing a prosocial (relative to a neutral) video game increased interpersonal empathy and decreased reported pleasure at another's misfortune (i.e., schadenfreude). These results lend further credence to the predictive validity of the General Learning Model (Buckley & Anderson, 2006) for the effects of media exposure on social tendencies.

  6. Reliability of construction materials

    International Nuclear Information System (INIS)

    Merz, H.

    1976-01-01

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW) [de

  7. Earthquake prediction

    International Nuclear Information System (INIS)

    Ward, P.L.

    1978-01-01

    The state of the art of earthquake prediction is summarized, the possible responses to such prediction are examined, and some needs in the present prediction program and in research related to use of this new technology are reviewed. Three basic aspects of earthquake prediction are discussed: location of the areas where large earthquakes are most likely to occur, observation within these areas of measurable changes (earthquake precursors) and determination of the area and time over which the earthquake will occur, and development of models of the earthquake source in order to interpret the precursors reliably. 6 figures

  8. Fatigue life prediction in composites

    CSIR Research Space (South Africa)

    Huston, RJ

    1994-01-01

    Full Text Available Because of the relatively large number of possible failure mechanisms in fibre reinforced composite materials, the prediction of fatigue life in a component is not a simple process. Several mathematical and statistical models have been proposed...

  9. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  10. Aggregate Unemployment Decreases Individual Returns to Education

    Science.gov (United States)

    Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

    2009-01-01

    Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

  11. Genomic Prediction of Gene Bank Wheat Landraces

    Directory of Open Access Journals (Sweden)

    José Crossa

    2016-07-01

    Full Text Available This study examines genomic prediction within 8416 Mexican landrace accessions and 2403 Iranian landrace accessions stored in gene banks. The Mexican and Iranian collections were evaluated in separate field trials, including an optimum environment for several traits, and in two separate environments (drought, D and heat, H for the highly heritable traits, days to heading (DTH, and days to maturity (DTM. Analyses accounting and not accounting for population structure were performed. Genomic prediction models include genotype × environment interaction (G × E. Two alternative prediction strategies were studied: (1 random cross-validation of the data in 20% training (TRN and 80% testing (TST (TRN20-TST80 sets, and (2 two types of core sets, “diversity” and “prediction”, including 10% and 20%, respectively, of the total collections. Accounting for population structure decreased prediction accuracy by 15–20% as compared to prediction accuracy obtained when not accounting for population structure. Accounting for population structure gave prediction accuracies for traits evaluated in one environment for TRN20-TST80 that ranged from 0.407 to 0.677 for Mexican landraces, and from 0.166 to 0.662 for Iranian landraces. Prediction accuracy of the 20% diversity core set was similar to accuracies obtained for TRN20-TST80, ranging from 0.412 to 0.654 for Mexican landraces, and from 0.182 to 0.647 for Iranian landraces. The predictive core set gave similar prediction accuracy as the diversity core set for Mexican collections, but slightly lower for Iranian collections. Prediction accuracy when incorporating G × E for DTH and DTM for Mexican landraces for TRN20-TST80 was around 0.60, which is greater than without the G × E term. For Iranian landraces, accuracies were 0.55 for the G × E model with TRN20-TST80. Results show promising prediction accuracies for potential use in germplasm enhancement and rapid introgression of exotic germplasm

  12. Feasibility of using microencapsulated phase change materials as filler for improving low temperature performance of rubber sealing materials.

    Science.gov (United States)

    Tiwari, Avinash; Shubin, Sergey N; Alcock, Ben; Freidin, Alexander B; Thorkildsen, Brede; Echtermeyer, Andreas T

    2017-11-01

    The feasibility of a novel composite rubber sealing material to improve sealing under transient cooling (in a so-called blowdown scenario) is investigated here. A composite of hydrogenated nitrile butadiene rubber (HNBR) filled with Micro Encapsulated Phase Change Materials (MEPCM) is described. The fillers contain phase change materials that release heat during the phase transformation from liquid to solid while cooling. This exotherm locally heats the rubber and may improve the function of the seal during a blowdown event. A representative HNBR-MEPCM composite was made and the critical thermal and mechanical properties were obtained by simulating the temperature distribution during a blowdown event. Simulations predict that the MEPCM composites can delay the temperature decrease in a region of the seal during the transient blowdown. A sensitivity analysis of material properties is also presented which highlights possible avenues of improvement of the MEPCMs for sealing applications.

  13. Material control evaluation

    International Nuclear Information System (INIS)

    Waddoups, I.G.; Anspach, D.A.; Abbott, J.A.

    1993-01-01

    Changes in the Department of Energy's (DOE) scope of work have stimulated several laboratories and commercial companies to develop and apply technology to enhance nuclear material control. Accountability, inventory, radiation exposure, and insider protection concerns increase as many DOE facilities require increased storage. This paper summarizes a study of the existing material control technologies. The goal of the study is to identify, characterize, and quantify the trade-offs associated with using these technologies to provide real-time information on stored nuclear material that in turn supports decreasing the frequency of inventories conducted by site personnel

  14. Effect of continuum damage mechanics on spring back prediction in metal forming processes

    International Nuclear Information System (INIS)

    Nayebi, Ali; Shahabi, Mehdi

    2017-01-01

    The influence of considering the variations in material properties was investigated through continuum damage mechanics according to the Lemaitre isotropic unified damage law to predict the bending force and spring back in V-bending sheet metal forming processes, with emphasis on Finite element (FE) simulation considerations. The material constants of the damage model were calibrated through a uniaxial tensile test with an appropriate and convenient repeating strategy. Holloman’s isotropic and Ziegler’s linear kinematic hardening laws were employed to describe the behavior of a hardening material. To specify the ideal FE conditions for simulating spring back, the effect of the various numerical considerations during FE simulation was investigated and compared with the experimental outcome. Results indicate that considering continuum damage mechanics decreased the predicted bending force and improved the accuracy of spring back prediction.

  15. Predictive medicine

    NARCIS (Netherlands)

    Boenink, Marianne; ten Have, Henk

    2015-01-01

    In the last part of the twentieth century, predictive medicine has gained currency as an important ideal in biomedical research and health care. Research in the genetic and molecular basis of disease suggested that the insights gained might be used to develop tests that predict the future health

  16. Contrast Materials

    Science.gov (United States)

    ... is mixed with water before administration liquid paste tablet When iodine-based and barium-sulfate contrast materials ... for patients with kidney failure or allergies to MRI and/or computed tomography (CT) contrast material. Microbubble ...

  17. Computational materials design

    International Nuclear Information System (INIS)

    Snyder, R.L.

    1999-01-01

    Full text: Trial and error experimentation is an extremely expensive route to the development of new materials. The coming age of reduced defense funding will dramatically alter the way in which advanced materials have developed. In the absence of large funding we must concentrate on reducing the time and expense that the R and D of a new material consumes. This may be accomplished through the development of computational materials science. Materials are selected today by comparing the technical requirements to the materials databases. When existing materials cannot meet the requirements we explore new systems to develop a new material using experimental databases like the PDF. After proof of concept, the scaling of the new material to manufacture requires evaluating millions of parameter combinations to optimize the performance of the new device. Historically this process takes 10 to 20 years and requires hundreds of millions of dollars. The development of a focused set of computational tools to predict the final properties of new materials will permit the exploration of new materials systems with only a limited amount of materials characterization. However, to bound computational extrapolations, the experimental formulations and characterization will need to be tightly coupled to the computational tasks. The required experimental data must be obtained by dynamic, in-situ, very rapid characterization. Finally, to evaluate the optimization matrix required to manufacture the new material, very rapid in situ analysis techniques will be essential to intelligently monitor and optimize the formation of a desired microstructure. Techniques and examples for the rapid real-time application of XRPD and optical microscopy will be shown. Recent developments in the cross linking of the world's structural and diffraction databases will be presented as the basis for the future Total Pattern Analysis by XRPD. Copyright (1999) Australian X-ray Analytical Association Inc

  18. Dirac materials

    OpenAIRE

    Wehling, T. O.; Black-Schaffer, A. M.; Balatsky, A. V.

    2014-01-01

    A wide range of materials, like d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrodinger Hamiltonian. This emergent behavior of Dirac fermions in condensed matter systems defines the unifying framework for a class of materials we call "Dirac materials''. In order to establish this class of materials, we illustrate how Dirac fermions ...

  19. Magnetic Materials

    Science.gov (United States)

    Spaldin, Nicola A.

    2003-04-01

    Magnetic materials are the foundation of multi-billion dollar industries and the focus of intensive research across many disciplines. This book covers the fundamentals, basic theories and applications of magnetism and conventional magnetic materials. Based on a lecture course given by Nicola Spaldin in the Materials Department at University of California, Santa Barbara, the book is ideal for a one- semester course in magnetic materials. It contains numerous homework problems and solutions.

  20. Did liberalising bar hours decrease traffic accidents?

    Science.gov (United States)

    Green, Colin P; Heywood, John S; Navarro, Maria

    2014-05-01

    Legal bar closing times in England and Wales have historically been early and uniform. Recent legislation liberalised closing times with the object of reducing social problems thought associated with drinking to "beat the clock." Indeed, using both difference in difference and synthetic control approaches we show that one consequence of this liberalisation was a decrease in traffic accidents. This decrease is heavily concentrated among younger drivers. Moreover, we provide evidence that the effect was most pronounced in the hours of the week directly affected by the liberalisation: late nights and early mornings on weekends. This evidence survives a series of robustness checks and suggests at least one socially positive consequence of extending bar hours. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Decreased decorin expression in the tumor microenvironment

    International Nuclear Information System (INIS)

    Bozoky, Benedek; Savchenko, Andrii; Guven, Hayrettin; Ponten, Fredrik; Klein, George; Szekely, Laszlo

    2014-01-01

    Decorin is a small leucine-rich proteoglycan, synthesized and deposited by fibroblasts in the stroma where it binds to collagen I. It sequesters several growth factors and antagonizes numerous members of the receptor tyrosine kinase family. In experimental murine systems, it acted as a potent tumor suppressor. Examining the Human Protein Atlas online database of immunostained tissue samples we have surveyed decorin expression in silico in several different tumor types, comparing them with corresponding normal tissues. We found that decorin is abundantly secreted and deposited in normal connective tissue but its expression is consistently decreased in the tumor microenvironment. We developed a software to quantitate the difference in expression. The presence of two closely related proteoglycans in the newly formed tumor stroma indicated that the decreased decorin expression was not caused by the delay in proteoglycan deposition in the newly formed connective tissue surrounding the tumor

  2. Calming Meditation Increases Altruism, Decreases Parochialism

    OpenAIRE

    Frost, Karl

    2017-01-01

    It has been proposed that cultivating calm will increase altruism and decrease parochialism, where altruism is defined as self-sacrifice in support of others, regardless of group affiliation or identity, and parochialism is defined as prosocial self-sacrifice restricted to fellow members of a group. Such could be the case with a calming meditation practice. An alternate hypothesis, coming from the study of ritual, proposes that shared practices lead to bonding, increasing parochialism, but no...

  3. INVENTORY DECISIONS WITH DECREASING PURCHASING COSTS

    OpenAIRE

    XIANGPEI HU; HUIMIN WANG; YUNZENG WANG

    2012-01-01

    Costs of many items drop systematically throughout their life-cycles, due to advances in technology and competition. Motivated by the management of service parts for some high-tech products, this paper studies inventory decisions for such items. In a periodic review setting with stochastic demand, we model the purchasing costs of successive periods as a stochastic and decreasing sequence. Unit selling price of the item is determined as some mark-up of the purchasing cost and, hence, will chan...

  4. Decreased prefrontal cortical dopamine transmission in alcoholism.

    Science.gov (United States)

    Narendran, Rajesh; Mason, Neale Scott; Paris, Jennifer; Himes, Michael L; Douaihy, Antoine B; Frankle, W Gordon

    2014-08-01

    Basic studies have demonstrated that optimal levels of prefrontal cortical dopamine are critical to various executive functions such as working memory, attention, inhibitory control, and risk/reward decisions, all of which are impaired in addictive disorders such as alcoholism. Based on this and imaging studies of alcoholism that have demonstrated less dopamine in the striatum, the authors hypothesized decreased dopamine transmission in the prefrontal cortex in persons with alcohol dependence. To test this hypothesis, amphetamine and [11C]FLB 457 positron emission tomography were used to measure cortical dopamine transmission in 21 recently abstinent persons with alcohol dependence and 21 matched healthy comparison subjects. [11C]FLB 457 binding potential, specific compared to nondisplaceable uptake (BPND), was measured in subjects with kinetic analysis using the arterial input function both before and after 0.5 mg kg-1 of d-amphetamine. Amphetamine-induced displacement of [11C]FLB 457 binding potential (ΔBPND) was significantly smaller in the cortical regions in the alcohol-dependent group compared with the healthy comparison group. Cortical regions that demonstrated lower dopamine transmission in the alcohol-dependent group included the dorsolateral prefrontal cortex, medial prefrontal cortex, orbital frontal cortex, temporal cortex, and medial temporal lobe. The results of this study, for the first time, unambiguously demonstrate decreased dopamine transmission in the cortex in alcoholism. Further research is necessary to understand the clinical relevance of decreased cortical dopamine as to whether it is related to impaired executive function, relapse, and outcome in alcoholism.

  5. Materials at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Antoinette J [Los Alamos National Laboratory

    2010-01-01

    ,' LA-UR-08-1541. This document introduced three strategic thrusts that crosscut the Grand Challenges and define future laboratory directions and facilities: (1) Information Science and Technology enabl ing integrative and predictive science; (2) Experimental science focused on materials for the future; and (3) Fundamental forensic science for nuclear, biological, and chemical threats. The next step for the Materials Capability was to develop a strategic plan for the second thrust, Materials for the Future. within the context of a capabilities-based Laboratory. This work has involved extending our 2006-2007 Grand Challenge workshops, integrating materials fundamental challenges into the MaRIE definition, and capitalizing on the emerging materials-centric national security missions. Strategic planning workshops with broad leadership and staff participation continued to hone our scientific directions and reinforce our strength through interdependence. By the Fall of 2008, these workshops promoted our primary strength as the delivery of Predictive Performance in applications where Extreme Environments dominate and where the discovery of Emergent Phenomena is a critical. These planning efforts were put into action through the development of our FY10 LDRD Strategic Investment Plan where the Materials Category was defined to incorporate three central thrusts: Prediction and Control of Performance, Extreme Environments and Emergent Phenomena. As with all strategic planning, much of the benefit is in the dialogue and cross-fertilization of ideas that occurs during the process. By winter of 2008/09, there was much agreement on the evolving focus for the Materials Strategy, but there was some lingering doubt over Prediction and Control of Performance as one of the three central thrusts, because it overarches all we do and is, truly, the end goal for materials science and engineering. Therefore, we elevated this thrust within the overarching vision/mission and introduce the

  6. Composite materials

    International Nuclear Information System (INIS)

    Sambrook, D.J.

    1976-01-01

    A superconductor composite is described comprising at least one longitudinally extending superconductor filament or bundle of sub-filaments, each filament or bundle of sub-filaments being surrounded by and in good electrical contact with a matrix material, the matrix material comprising a plurality of longitudinally extending cells of a metal of high electrical conductivity surrounded by a material of lower electrical conductivity. The high electrical conductivity material surrounding the superconducting filament or bundle of sub-filaments is interrupted by a radially extending wall of the material of the lower electrical conductivity, the arrangement being such that at least two superconductor filaments or sub-filaments are circumferentially circumscribed by a single annulus of the material of high electrical conductivity. The annulus is electrically interrupted by a radially extending wall of the material of low electrical conductivity

  7. X-Ray and UV Photoelectron Spectroscopy | Materials Science | NREL

    Science.gov (United States)

    backsheet material, showing excellent quantitative agreement between measured and predicted peak area ratios XPS spectra of carbon 1s from polyethylene terephthalate backsheet material, showing excellent

  8. Aerospace materials and material technologies

    CERN Document Server

    Wanhill, R

    2017-01-01

    This book is a comprehensive compilation of chapters on materials (both established and evolving) and material technologies that are important for aerospace systems. It considers aerospace materials in three Parts. Part I covers Metallic Materials (Mg, Al, Al-Li, Ti, aero steels, Ni, intermetallics, bronzes and Nb alloys); Part II deals with Composites (GLARE, PMCs, CMCs and Carbon based CMCs); and Part III considers Special Materials. This compilation has ensured that no important aerospace material system is ignored. Emphasis is laid in each chapter on the underlying scientific principles as well as basic and fundamental mechanisms leading to processing, characterization, property evaluation and applications. A considerable amount of materials data is compiled and presented in appendices at the end of the book. This book will be useful to students, researchers and professionals working in the domain of aerospace materials.

  9. Theoretical isochrones with decreasing gravitational constant

    International Nuclear Information System (INIS)

    Vandenberg, D.A.

    1976-01-01

    Van Flandern has postulated a variation of the gravitational constant at the rate approximately -8 x 10 -11 /yr. This variation, consistent with Hoyle-Narlikar and Dirac cosmologies, has been assumed in the computation of a 5 x 10 9 yr theoretical isochrone. Present results show that, even for this age, theory predicts a cluster turn-off luminosity approximately 0.5 to 1.0 mag fainter than the observed turn-offs of globular clusters. Unsatisfactory agreement between theoretical and observed luminosity functions is also indicated. (author)

  10. Effect of fabric texture and material on perceived discomfort at high humidity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Rasmussen, Leif W.; Mackeprang, Jørgen

    1999-01-01

    This study investigated the effect of material (cotton/polyester) and texture (woven/knitted) of the inner layer of a clothing ensemble on human discomfort at high skin humidity. No clear effect on discomfort of material and texture could be detected. However, acceptability of skin humidity de......-crea-sed with increasing relative skin humidity. A model was developed that predicts the percentage of persons dissatisfied due to humid skin as a function of relative skin humidity. The model applies for woven and knitted cot-ton and polyester materials and for activity levels typical for office work. Even at very high...

  11. Materials Discovery | Materials Science | NREL

    Science.gov (United States)

    Discovery Materials Discovery Images of red and yellow particles NREL's research in materials characterization of sample by incoming beam and measuring outgoing particles, with data being stored and analyzed Staff Scientist Dr. Zakutayev specializes in design of novel semiconductor materials for energy

  12. Music decreases aortic stiffness and wave reflections.

    Science.gov (United States)

    Vlachopoulos, Charalambos; Aggelakas, Angelos; Ioakeimidis, Nikolaos; Xaplanteris, Panagiotis; Terentes-Printzios, Dimitrios; Abdelrasoul, Mahmoud; Lazaros, George; Tousoulis, Dimitris

    2015-05-01

    Music has been related to cardiovascular health and used as adjunct therapy in patients with cardiovascular disease. Aortic stiffness and wave reflections are predictors of cardiovascular risk. We investigated the short-term effect of classical and rock music on arterial stiffness and wave reflections. Twenty healthy individuals (22.5±2.5 years) were studied on three different occasions and listened to a 30-min music track compilation (classical, rock, or no music for the sham procedure). Both classical and rock music resulted in a decrease of carotid-femoral pulse wave velocity (PWV) immediately after the end of music listening (all pclassical or rock music in a more sustained way (nadir by 6.0% and 5.8%, respectively, at time zero post-music listening, all pmusic preference was taken into consideration, both classical and rock music had a more potent effect on PWV in classical aficionados (by 0.20 m/s, p=0.003 and 0.13 m/s, p=0.015, respectively), whereas there was no effect in rock aficionados (all p=NS). Regarding wave reflections, classical music led to a more potent response in classical aficionados (AIx decrease by 9.45%), whereas rock led to a more potent response to rock aficionados (by 10.7%, all pMusic, both classical and rock, decreases aortic stiffness and wave reflections. Effect on aortic stiffness lasts for as long as music is listened to, while classical music has a sustained effect on wave reflections. These findings may have important implications, extending the spectrum of lifestyle modifications that can ameliorate arterial function. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Power decreases trust in social exchange.

    Science.gov (United States)

    Schilke, Oliver; Reimann, Martin; Cook, Karen S

    2015-10-20

    How does lacking vs. possessing power in a social exchange affect people's trust in their exchange partner? An answer to this question has broad implications for a number of exchange settings in which dependence plays an important role. Here, we report on a series of experiments in which we manipulated participants' power position in terms of structural dependence and observed their trust perceptions and behaviors. Over a variety of different experimental paradigms and measures, we find that more powerful actors place less trust in others than less powerful actors do. Our results contradict predictions by rational actor models, which assume that low-power individuals are able to anticipate that a more powerful exchange partner will place little value on the relationship with them, thus tends to behave opportunistically, and consequently cannot be trusted. Conversely, our results support predictions by motivated cognition theory, which posits that low-power individuals want their exchange partner to be trustworthy and then act according to that desire. Mediation analyses show that, consistent with the motivated cognition account, having low power increases individuals' hope and, in turn, their perceptions of their exchange partners' benevolence, which ultimately leads them to trust.

  14. SPP will decrease price of transport

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    Starting next year gas utility Slovensky plynarensky priemysel, a.s., Bratislava (SPP) will decrease the fees for transport of gas to its client from third parties. This decision should have a positive effect mainly on large industrial customers. The fact that SPP decided not to apply the approved ruling to its full extent was the result of negotiations with the regulator and the Ministry of Economy. SPP is not afraid it might lose customers. This decision only gives them a competitive advantage. (Author)

  15. Decreasing Human Trafficking through Sex Work Decriminalization.

    Science.gov (United States)

    Albright, Erin; D'Adamo, Kate

    2017-01-01

    In order to decrease human trafficking, health care workers should support the full decriminalization of prostitution. Similar to trafficking in other forms of labor, preventing trafficking in the sex trade requires addressing the different forms of marginalization that create vulnerable communities. By removing punitive laws that prevent reporting of exploitation and abuse, decriminalization allows sex workers to work more safely, thereby reducing marginalization and vulnerability. Decriminalization can also help destigmatize sex work and help resist political, social, and cultural marginalization of sex workers. © 2017 American Medical Association. All Rights Reserved.

  16. Methodology of decreasing software complexity using ontology

    Science.gov (United States)

    DÄ browska-Kubik, Katarzyna

    2015-09-01

    In this paper a model of web application`s source code, based on the OSD ontology (Ontology for Software Development), is proposed. This model is applied to implementation and maintenance phase of software development process through the DevOntoCreator tool [5]. The aim of this solution is decreasing software complexity of that source code, using many different maintenance techniques, like creation of documentation, elimination dead code, cloned code or bugs, which were known before [1][2]. Due to this approach saving on software maintenance costs of web applications will be possible.

  17. Genomic prediction using subsampling.

    Science.gov (United States)

    Xavier, Alencar; Xu, Shizhong; Muir, William; Rainey, Katy Martin

    2017-03-24

    Genome-wide assisted selection is a critical tool for the genetic improvement of plants and animals. Whole-genome regression models in Bayesian framework represent the main family of prediction methods. Fitting such models with a large number of observations involves a prohibitive computational burden. We propose the use of subsampling bootstrap Markov chain in genomic prediction. Such method consists of fitting whole-genome regression models by subsampling observations in each round of a Markov Chain Monte Carlo. We evaluated the effect of subsampling bootstrap on prediction and computational parameters. Across datasets, we observed an optimal subsampling proportion of observations around 50% with replacement, and around 33% without replacement. Subsampling provided a substantial decrease in computation time, reducing the time to fit the model by half. On average, losses on predictive properties imposed by subsampling were negligible, usually below 1%. For each dataset, an optimal subsampling point that improves prediction properties was observed, but the improvements were also negligible. Combining subsampling with Gibbs sampling is an interesting ensemble algorithm. The investigation indicates that the subsampling bootstrap Markov chain algorithm substantially reduces computational burden associated with model fitting, and it may slightly enhance prediction properties.

  18. Deep Visual Attention Prediction

    Science.gov (United States)

    Wang, Wenguan; Shen, Jianbing

    2018-05-01

    In this work, we aim to predict human eye fixation with view-free scenes based on an end-to-end deep learning architecture. Although Convolutional Neural Networks (CNNs) have made substantial improvement on human attention prediction, it is still needed to improve CNN based attention models by efficiently leveraging multi-scale features. Our visual attention network is proposed to capture hierarchical saliency information from deep, coarse layers with global saliency information to shallow, fine layers with local saliency response. Our model is based on a skip-layer network structure, which predicts human attention from multiple convolutional layers with various reception fields. Final saliency prediction is achieved via the cooperation of those global and local predictions. Our model is learned in a deep supervision manner, where supervision is directly fed into multi-level layers, instead of previous approaches of providing supervision only at the output layer and propagating this supervision back to earlier layers. Our model thus incorporates multi-level saliency predictions within a single network, which significantly decreases the redundancy of previous approaches of learning multiple network streams with different input scales. Extensive experimental analysis on various challenging benchmark datasets demonstrate our method yields state-of-the-art performance with competitive inference time.

  19. Statins Decrease Oxidative Stress and ICD Therapies

    Directory of Open Access Journals (Sweden)

    Heather L. Bloom

    2010-01-01

    Full Text Available Recent studies demonstrate that statins decrease ventricular arrhythmias in internal cardioverter defibrillator (ICD patients. The mechanism is unknown, but evidence links increased inflammatory and oxidative states with increased arrhythmias. We hypothesized that statin use decreases oxidation. Methods. 304 subjects with ICDs were surveyed for ventricular arrhythmia. Blood was analyzed for derivatives of reactive oxygen species (DROMs and interleukin-6 (IL-6. Results. Subjects included 252 (83% men, 58% on statins, 20% had ventricular arrhythmias. Average age was 63 years and ejection fraction (EF 20%. ICD implant duration was 29 ± 27 months. Use of statins correlated with lower ICD events (r=0.12, P=.02. Subjects on statins had lower hsCRP (5.2 versus 6.3; P=.05 and DROM levels (373 versus 397; P=.03. Other factors, including IL-6 and EF did not differ between statin and nonstatin use, nor did beta-blocker or antiarrhythmic use. Multivariate cross-correlation analysis demonstrated that DROMs, statins, IL-6 and EF were strongly associated with ICD events. Multivariate regression shows DROMs to be the dominant predictor. Conclusion. ICD event rate correlates with DROMs, a measure of lipid peroxides. Use of statins is associated with reduced DROMs and fewer ICD events, suggesting that statins exert their effect through reducing oxidation.

  20. Serum Soluble Corin is Decreased in Stroke.

    Science.gov (United States)

    Peng, Hao; Zhu, Fangfang; Shi, Jijun; Han, Xiujie; Zhou, Dan; Liu, Yan; Zhi, Zhongwen; Zhang, Fuding; Shen, Yun; Ma, Juanjuan; Song, Yulin; Hu, Weidong

    2015-07-01

    Soluble corin was decreased in coronary heart disease. Given the connections between cardiac dysfunction and stroke, circulating corin might be a candidate marker of stroke risk. However, the association between circulating corin and stroke has not yet been studied in humans. Here, we aimed to examine the association in patients wtith stroke and community-based healthy controls. Four hundred eighty-one patients with ischemic stroke, 116 patients with hemorrhagic stroke, and 2498 healthy controls were studied. Serum soluble corin and some conventional risk factors of stroke were examined. Because circulating corin was reported to be varied between men and women, the association between serum soluble corin and stroke was evaluated in men and women, respectively. Patients with ischemic and hemorrhagic stroke had a significantly lower level of serum soluble corin than healthy controls in men and women (all P values, stroke than men in the highest quartile. Women in the lowest quartile of serum soluble corin were also more likely to have ischemic (OR, 3.10; 95% confidence interval, 1.76-5.44) and hemorrhagic (OR, 8.54; 95% confidence interval, 2.35-31.02) stroke than women in the highest quartile. ORs of ischemic and hemorrhagic stroke were significantly increased with the decreasing levels of serum soluble corin in men and women (all P values for trend, stroke compared with healthy controls. Our findings raise the possibility that serum soluble corin may have a pathogenic role in stroke. © 2015 American Heart Association, Inc.

  1. Lifestyle Decreases Risk Factors for Cardiovascular Diseases

    Science.gov (United States)

    Slavíček, Jaroslav; Kittnar, Otomar; Fraser, Gary E.; Medová, Eva; Konečná, Jana; Žižka, Robert; Dohnalová, Alena; Novák, Vladimír

    2009-01-01

    Summary The morbidity and mortality of the cardiovascular diseases is high in the developed countries. The lifestyle changes are capable to decrease it by 50%. The aim of the present study was to measure the parameters of some risk factors before and after a one-week NEW START rehabilitative retreat. 1,349 volunteers, 320 men, 1,029 woman, mean age 51±14.5 (SD) years participated in 30 rehabilitative retreats from 1999–2006 in the Czech Republic, using a low-fat, low-energy, lacto-ovo-vegetarian diet and exercise, in a stress-free environment. Body weight, height, BMI, blood pressure, heart rate, serum cholesterol and blood glucose were measured. Body weight decreased in 1,223 measured persons from 71.2±14.38 (SD) to 70.6±14.02 kg (pSeventh-day Adventists than in controls who never observed the diet and avail the lifestyle programs. The parameters were nonsignificantly changed one year after finishing the retreat in the sample of 68 persons showing the positive effect of retreats. Our results showed, that the intake of a low-fat, low-energy diet, over the course of one week in a stress-free environment, had positive impact on the risk factors of cardiovascular diseases. PMID:19256282

  2. Insulin-induced decrease in protein phosphorylation in rat adipocytes not explained by decreased A-kinase activity

    International Nuclear Information System (INIS)

    Egan, J.J.; Greenberg, A.S.; Chang, M.K.; Londos, C.

    1987-01-01

    In isolated rat adipocytes, insulin inhibits lipolysis to a greater extent than would be predicted by the decrease in (-/+)cAMP activity ratio of cAMP-dependent protein kinase [A-kinase], from which it was speculated that insulin promotes the dephosphorylation of hormone-sensitive lipase. They have examined the phosphorylation state of cellular proteins under conditions of varying A-kinase activities in the presence and absence of insulin. Protein phosphorylation was determined by SDS-PAGE electrophoresis of extracts from 32 P-loaded cells; glycerol and A-kinase activity ratios were measured in the cytosolic extracts from control, non-radioactive cells. Increased protein phosphorylation in general occurred over the same range of A-kinase activity ratios, 0.1-0.3, associated with increased glycerol release. The insulin-induced decrease in lipolysis was associated with a decrease in the 32 P content of several proteins, an effect not explained by the modest reduction in A-kinase activity by insulin. This effect of insulin on protein phosphorylation was lost as the A-kinase activity ratios exceeded 0.5. The results suggest that insulin promotes the dephosphorylation of those adipocyte proteins which are subject to phosphorylation by A-kinase

  3. Fracture in Soft Materials

    DEFF Research Database (Denmark)

    Hassager, Ole

    Fracture is a phenomenon that is generally associated with solids. A key element in fracture theory is the so-called weakest link idea that fracture initiates from the largest pre-existing material imperfection. However, recent work has demonstrated that fracture can also happen in liquids, where...... surface tension will act to suppress such imperfections. Therefore, the weakest link idea does not seem immediately applicable to fracture in liquids. This presentation will review fracture in liquids and argue that fracture in soft liquids is a material property independent of pre-existing imperfections....... The following questions then emerge: What is the material description needed to predict crack initiation, crack speed and crack shape in soft materials and liquids....

  4. Nano Materials

    International Nuclear Information System (INIS)

    Jin, In Ju; Lee, Ik Mo; Kwon, Yeung Gu

    2006-02-01

    This book introduces background of nano science such as summary, plenty room at the bottom, access way to nano technique, nanoparticles using bottom-up method which are a marvel of nature, and modern alchemy : chemical synthesis of artificial nano structure, understanding of quantum mechanics, STM/AFM, nano metal powder, ceramic nanoparticles, nano structure film, manufacture of nanoparticles using reverse micelle method, carbon nano tube, sol-gel material, nano energy material, nano catalyst nano bio material technology and spintronics.

  5. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  6. Material focus

    DEFF Research Database (Denmark)

    Sokoler, Tomas; Vallgårda, Anna K. A.

    2009-01-01

    In this paper we build on the notion of computational composites, which hold a material perspective on computational technology. We argue that a focus on the material aspects of the technology could be a fruitful approach to achieve new expressions and to gain a new view on the technology's role...... in design. We study two of the computer's material properties: computed causality and connectability and through developing two computational composites that utilize these properties we begin to explore their potential expressions....

  7. Materializing Ethnography

    OpenAIRE

    Geismar, H.; Horst, H. A.

    2004-01-01

    The articles in this volume were originally presented in a panel entitled ‘Material Methodologies’ at the American Anthropological Association meeting in New Orleans (November 2002). The panel was devised to tie together theoretical advances in the study of the material with the creative possibilities of fieldwork practices. Through detailed ethnographic discussion, we highlighted the ways in which a focus on a specifically material world enabled us to discover new perspecti...

  8. Materials characterisation

    International Nuclear Information System (INIS)

    Azali Muhammad

    2005-01-01

    Various nuclear techniques have been developed and employed by technologies and scientists worldwide to physically and chemically characterise the material particularly those that have applications in industry. These include small angle neutron scattering (SANS), x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) for the internal structural study of material, whereas, the x-ray fluorescence (XRF) for the chemical analysis, while the Moessbauer spectroscopy for the study on the magnetic properties and structural identity of material. Basic principle and instrumentations of the techniques are discussed in this chapter. Example of their applications in various disciplines particularly in characterisation of industrial materials also described

  9. Material chemistry and process

    International Nuclear Information System (INIS)

    1999-11-01

    The contents of this book are purpose of investigation, system of investigation, summary of investigation characteristic of this investigation, way to read the result table on prediction of investigation, object of investigation, important research and investigation fields, period of realizable prediction, cause of the obstacle for realization, propel way for studying and development, means of policy, comparison identical and similar task with the last time, illustration of future world in 2025 the result of investigation on material and the result of investigation on chemistry and process.

  10. Fracture propagation in cementitious materials

    DEFF Research Database (Denmark)

    Skocek, Jan

    , it is experimentally observed and numerically veried that the cracking plays an important role in mode-I as well as compressive experiments. The approximative particle model extended for materials with heterogeneous matrices predicts strengths matching favorably experimental records in a qualitative way.......Mechanical behavior of structures made from cementitious materials has been successfully modeled using non-linear fracture mechanics in recent decades. On the structural scale, an assumption of homogeneity of the material is valid and well established theories can be applied. However, if focus...... is put on phenomena of a similar scale as is the characteristic size of inhomogeneities of the material, a model which re ects the heterogeneous nature of the material needs to be applied. This is, indeed, the case for prediction of mechanical properties of a material based on the knowledge of properties...

  11. Decreasing barriers for nurse practitioner social entrepreneurship.

    Science.gov (United States)

    Sharp, Dayle B; Monsivais, Diane

    2014-10-01

    To describe difficulties associated with the business-related aspects of practice in role transition of rural nurse practitioners (NPs), and to give practice implications. This focused ethnographic study derived data from semi-structured interviews. Participants provided information about rural NP practice ownership and barriers. The sample consisted of 24 rural NPs living throughout the United States. The majority were 51-60 years of age (45%) and females (93%) who had been in rural practice for 1 to over 20 years. NP social entrepreneurs experience difficulties related to scope of practice, business skills, and role conflict. To decrease barriers for NP clinic ownership and management, NPs need to receive education related to financing a rural practice, legal/regulatory practices, strategic planning, leadership, and clinic management. ©2014 American Association of Nurse Practitioners.

  12. Decreasing Ambiguity of the Safety Culture Concept

    International Nuclear Information System (INIS)

    Inoue, Shiichiro; Hosoda, Satoshi; Suganuma, Takashi; Monta, Kazuo; Kameda, Akiyuki

    2001-01-01

    The status of the concept of ''safety culture'' is reviewed. It has not sufficiently taken root. One cause for this is the abstract nature of the concept. Organizations must become aware of the necessity of improving safety and have sufficient power to promote this. The culture of safety must be instilled in each employee, so that each of them will feel responsible for identifying weak points in plant safety. The authors devised a tool for a self-assessment of the safety culture. The tool will bring to light information divides, communication gaps, etc. Recognizing the vulnerabilities of the organization by themselves and discussing these weak points among them is the first step to decrease the ambiguity of the safety culture. The next step is to make these gaps known along with agreed-upon countermeasures. The concept of safety culture will be greatly clarified in this way and lead to safer nuclear power plants

  13. Fissile material proliferation risk

    International Nuclear Information System (INIS)

    Dreicer, J.S.; Rutherford, D.A.

    1996-01-01

    The proliferation risk of a facility depends on the material attractiveness, level of safeguards, and physical protection applied to the material in conjunction with an assessment of the impact of the socioeconomic circumstances and threat environment. Proliferation risk is a complementary extension of proliferation resistance. The authors believe a better determination of nuclear proliferation can be achieved by establishing the proliferation risk for facilities that contain nuclear material. Developing a method that incorporates the socioeconomic circumstances and threat environment inherent to each country enables a global proliferation assessment. To effectively reduce the nuclear danger, a broadly based set of criteria is needed that provides the capability to relatively assess a wide range of nuclear related sites and facilities in different countries and still ensure a global decrease in proliferation risk for fissile material (plutonium and highly enriched uranium)

  14. Prediction Markets

    DEFF Research Database (Denmark)

    Horn, Christian Franz; Ivens, Bjørn Sven; Ohneberg, Michael

    2014-01-01

    In recent years, Prediction Markets gained growing interest as a forecasting tool among researchers as well as practitioners, which resulted in an increasing number of publications. In order to track the latest development of research, comprising the extent and focus of research, this article...... provides a comprehensive review and classification of the literature related to the topic of Prediction Markets. Overall, 316 relevant articles, published in the timeframe from 2007 through 2013, were identified and assigned to a herein presented classification scheme, differentiating between descriptive...... works, articles of theoretical nature, application-oriented studies and articles dealing with the topic of law and policy. The analysis of the research results reveals that more than half of the literature pool deals with the application and actual function tests of Prediction Markets. The results...

  15. Low and decreasing self-esteem during adolescence predict adult depression two decades later.

    Science.gov (United States)

    Steiger, Andrea E; Allemand, Mathias; Robins, Richard W; Fend, Helmut A

    2014-02-01

    Previous studies revealed that low self-esteem is prospectively associated with depression. However, self-esteem has been shown to change over time. We thus hypothesized that not only level but also change in self-esteem affect depression. Using data from a 23-year longitudinal study (N = 1,527), we therefore examined the prospective effects of global and domain-specific self-esteem (physical attractiveness, academic competence) level and change on depressive symptoms 2 decades later. Self-esteem was assessed annually from age 12 to 16, and depression was assessed at age 16 and 35. Results from latent growth curve analyses demonstrated that both level and change in self-esteem served as predictors for adult depression. Individuals who entered adolescence with low self-esteem, and/or whose self-esteem declined further during the adolescent years, were more likely to exhibit symptoms of depression 2 decades later as adults; this pattern held both for global and domain-specific self-esteem. These findings highlight the importance of adolescent self-esteem development for mental health outcomes in adulthood. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  16. Predicting Nurses' Turnover: The Aversive Effects of Decreased Identity, Poor Interpersonal Communication, and Learned Helplessness.

    Science.gov (United States)

    Moreland, Jennifer J; Ewoldsen, David R; Albert, Nancy M; Kosicki, Gerald M; Clayton, Margaret F

    2015-01-01

    Through a social identity theoretical lens, this study examines how nurses' identification with their working small group, unit, or floor, nursing role (e.g., staff ER nurse, nurse practitioner), and nursing profession relate to nurses' interaction involvement, willingness to confront conflict, feelings of learned helplessness, and tenure (employment turnover) intentions. A cross-sectional survey (N = 466) was conducted at a large, quaternary care hospital system. Structural equation modeling uncovered direct and indirect effects between the five primary variables. Findings demonstrate direct relationships between nurse identity (as a latent variable) and interaction involvement, willingness to confront conflict, and tenure intentions. Feelings of learned helplessness are attenuated by increased nurse identity through interaction involvement and willingness to confront conflict. In addition, willingness to confront conflict and learned helplessness mediate the relationship between interaction involvement and nurses' tenure intentions. Theoretical extensions include indirect links between nurse identity and learned helplessness via interaction involvement and willingness to confront conflict. Implications for interpersonal communication theory development, health communication, and the nursing profession are discussed.

  17. Cortisol-induced increases of plasma oxytocin levels predict decreased immediate free recall of unpleasant words

    NARCIS (Netherlands)

    Tops, M.; Buisman-Pijlman, F.T.A; Boksem, M.A.S.; Wijers, A.A.; Korf, J.

    2012-01-01

    The manner in which individuals recall an autobiographical positive life event has affective consequences. Two studies addressed the processing styles during positive memory recall in a non-clinical sample. Participants retrieved a positive memory, which was self-generated (Study 1, n = 70) or

  18. Materials Frontiers to Empower Quantum Computing

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Antoinette Jane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sarrao, John Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Richardson, Christopher [Laboratory for Physical Sciences, College Park, MD (United States)

    2015-06-11

    This is an exciting time at the nexus of quantum computing and materials research. The materials frontiers described in this report represent a significant advance in electronic materials and our understanding of the interactions between the local material and a manufactured quantum state. Simultaneously, directed efforts to solve materials issues related to quantum computing provide an opportunity to control and probe the fundamental arrangement of matter that will impact all electronic materials. An opportunity exists to extend our understanding of materials functionality from electronic-grade to quantum-grade by achieving a predictive understanding of noise and decoherence in qubits and their origins in materials defects and environmental coupling. Realizing this vision systematically and predictively will be transformative for quantum computing and will represent a qualitative step forward in materials prediction and control.

  19. New materials

    International Nuclear Information System (INIS)

    Joshi, S.K.; Rao, C.N.R.; Tsuruta, T.

    1992-01-01

    The book contains the state-of-the art lectures delivered at the discussion meeting on new materials, a field in which rapid advances are taking place. The main objective of the meeting was to bring active scientists in this area from Japan and India together. The topics covered diverse aspects of modern materials including high temperature superconducting compounds. (M.G.B.)

  20. Materials science

    International Nuclear Information System (INIS)

    2002-01-01

    the document is a collection of papers on different aspects of materials science. It discusses many items such as semiconductors, surface properties and interfaces, construction and civil engineering, metallic materials, polymers and composites, biology and biomaterials, metallurgy etc.. - 1 - Document1 Document1

  1. Material Programming

    DEFF Research Database (Denmark)

    Vallgårda, Anna; Boer, Laurens; Tsaknaki, Vasiliki

    2017-01-01

    . Consequently we ask what the practice of programming and giving form to such materials would be like? How would we be able to familiarize ourselves with the dynamics of these materials and their different combinations of cause and effect? Which tools would we need and what would they look like? Will we program......, and color, but additionally being capable of sensing, actuating, and computing. Indeed, computers will not be things in and by themselves, but embedded into the materials that make up our surroundings. This also means that the way we interact with computers and the way we program them, will change...... these computational composites through external computers and then transfer the code them, or will the programming happen closer to the materials? In this feature we outline a new research program that floats between imagined futures and the development of a material programming practice....

  2. Composite material

    Science.gov (United States)

    Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  3. Materials science

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Materials Science Division is engaged in research on physical properties of materials and the effects of radiation upon them. This involves solid state materials undergoing phase transitions, energy storing materials, and biomaterials. The Division also offers research facilities for M.S. and Ph.D. thesis work in the fields of physics, chemistry, materials, and radiation sciences in cooperation with the various colleges and departments of the UPR Mayaguez Campus. It is anticipated that it will serve as a catalyst in starting energy-related research programs in cooperation with UPR faculty, especially programs involving solar energy. To encourage and promote cooperative efforts, contact is maintained with former graduate students and with visiting scientists from Latin American research institutions

  4. Touching Materiality

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2012-01-01

    Dripping ink pens, colourful paint on skin, vegetables pots on a school roof. In interviews with three generations of former school pupils, memories of material objects bore a relation to everyday school life in the past. Interwoven, these objects entered the memorising processes, taking...... the interviewer and interviewee beyond an exclusively linguistic understanding of memory. This article analyses how the shifting objects of materiality in personal and generational school memories connects to material as well as sensuous experiences of everyday school life and its complex processes of learning....... Drawing on anthropological writings, the article argues that the objects of materiality are part of important but non-verbalised memories of schooling. The Dutch philosopher Eelco Runia’s notions of presence and metonymy are incorporated as tools for approaching objects of materiality in memory studies....

  5. Troubleshooting at Reverse Osmosis performance decrease

    Energy Technology Data Exchange (ETDEWEB)

    Soons, Jan [KEMA (Netherlands)

    2011-07-01

    There are several causes for a decrease in Reverse Osmosis (RO) membrane performance each of which requiring actions to tackle the possible cause. Two of the main factors affecting the performance of the system are the feed quality (poor feed quality can lead to fouling of the membranes) and the operational conditions (including the maximum allowed pressure, minimum cleaning frequencies and types, recovery rate etc, which should be according to the design conditions). If necessary, pre-treatment will be applied in order to remove the fouling agents from the influent, reduce scaling (through the addition of anti-scalants) and for the protection of the membranes (for example, sodium metabisulphite addition for the removal of residual chlorine which can harm the membranes). Fouling is not strictly limited to the use of surface water as feed water, also relatively clean water sources will, over time, lead to organic and inorganic fouling when cleaning is not optimum. When fouling occurs, the TransMembrane Pressure (TMP) increases and more energy will be needed to produce the same amount of product water. Also, the cleaning rate will increase, reducing the production rate and increasing the chemical consumption and the produced waste streams. Furthermore, the quality of the effluent will decrease (lower rejection rates at higher pressures) and the lifetime of the membranes will decrease. Depending on the type of fouling different cleaning regimes will have to be applied: acidic treatment for inorganic fouling, the addition of bases against organic fouling. Therefore, it is very important to have a clear view of the type of fouling that is occurring, in order to apply the correct treatment methods. Another important aspect to be kept in mind is that the chemistry of the water - in the first place ruled by the feed water composition - can change during passage of the modules, in particular in cases where the RO system consists of two or more RO trains, and where the

  6. Cost decreases in environmental technology. Evidence from four case studies

    Energy Technology Data Exchange (ETDEWEB)

    Oosterhuis, F. [Instituut for Environmental Studies, Vrije Universiteit VU, Amsterdam (Netherlands)

    2007-07-15

    The cost of a new technology tends to decrease as its uptake grows, and environmental technology is no exception to this general rule. Factors that can bring about such cost reductions include economies of scale, 'learning-by-doing', incremental technological improvements, and growing competition. In preparing environmental policies, the potential for future cost reductions is often disregarded. The present study aims to provide some additional empirical evidence on the cost decreases in environmental technology and the factors that lie behind them. To this end, four exemplary case studies have been selected. The first case (NOx emission abatement by Selective Catalytic Reduction (SCR)), shows a wide variety in cost estimates, without a clear trend. This is even true for the costs of a fairly homogeneous type of investment (SCR in coal fired power plants). Nevertheless, it is clear that an important cost decrease has been achieved by prolonging the lifetime of the catalyst, which is one of the main cost components in SCR. In the second case (NH3 emission abatement by chemical air scrubbers in pig farming) there is not yet sufficient experience with the technology to draw conclusions on the development of costs. However, it is already clear that economizing on the capacity of the system can contribute to important cost savings. Three-way catalytic converters in cars have shown significant price decreases following their large scale introduction on the European market in the early 1990s. Probably economies of scale have played an important role in this case, as the size of the market made mass production possible. To some extent, cost reductions may also be attributed to improvements such as the need for less materials (e.g. platinum). Furthermore, the performance of catalytic converters has improved, implying that the cost per unit of emission reduction has decreased even more than the cost of the device itself. Market prices of Compact Fluorescent Lamps

  7. Heterogeneous Materials I and Heterogeneous Materials II

    International Nuclear Information System (INIS)

    Knowles, K M

    2004-01-01

    In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field of materials science interested in comparing predictions of properties with experimental results may well find the mathematical level quite daunting initially, as it is apparent that the author assumes a level of mathematics consistent with that taught in final year undergraduate and graduate theoretical physics courses. However, for such readers it is well worth persevering because of the in-depth coverage to which the various models are subjected, and also because of the extensive reference lists at the back of both volumes which direct readers to the various source references in the scientific literature. Thus, for the wider materials science scientific community the two volumes will be a valuable library resource. While I would have liked to see more comparison with experimental data on both ideal and 'real' heterogeneous materials than is provided by the author and a discussion of how to model strong nonlinear current--voltage behaviour in systems such as zinc oxide varistors, my overall

  8. Sled Towing Acutely Decreases Acceleration Sprint Time.

    Science.gov (United States)

    Wong, Megan A; Dobbs, Ian J; Watkins, Casey M; Barillas, Saldiam R; Lin, Anne; Archer, David C; Lockie, Robert G; Coburn, Jared W; Brown, Lee E

    2017-11-01

    Wong, MA, Dobbs, IJ, Watkins, C, Barillas, SR, Lin, A, Archer, DC, Lockie, RG, Coburn, JW, and Brown, LE. Sled towing acutely decreases acceleration sprint time. J Strength Cond Res 31(11): 3046-3051, 2017-Sled towing is a common form of overload training in sports to develop muscular strength for sprinting. This type of training leads to acute and chronic outcomes. Acute training potentially leads to postactivation potentiation (PAP), which is when subsequent muscle performance is enhanced after a preload stimulus. The purpose of this study was to determine differences between rest intervals after sled towing on acute sprint speed. Twenty healthy recreationally trained men (age = 22.3 ± 2.4 years, height = 176.95 ± 5.46 cm, mass = 83.19 ± 11.31 kg) who were currently active in a field sport twice a week for the last 6 months volunteered to participate. A maximal 30-meter (m) baseline (BL) body mass (BM) sprint was performed (with splits at 5, 10, 20, and 30 m) followed by 5 visits where participants sprinted 30 m towing a sled at 30% BM then rested for 2, 4, 6, 8, or 12 minutes. They were instructed to stand still during rest times. After the rest interval, they performed a maximal 30-m post-test BM sprint. Analysis of variance (ANOVA) revealed that post sled tow BM sprint times (4.47 ± 0.21 seconds) were less than BL times (4.55 ± 0.18 seconds) on an individualized rest interval basis. A follow-up 2 × 4 ANOVA showed that this decrease occurred only in the acceleration phase over the first 5 m (BL = 1.13 ± 0.08 seconds vs. Best = 1.08 ± 0.08 seconds), which may be the result of PAP and the complex relationship between fatigue and potentiation relative to the intensity of the sled tow and the rest interval. Therefore, coaches should test their athletes on an individual basis to determine optimal rest time after a 30-m 30% BM sled tow to enhance acute sprint speed.

  9. Hyper-arousal decreases human visual thresholds.

    Directory of Open Access Journals (Sweden)

    Adam J Woods

    Full Text Available Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water, a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1 and contrast thresholds (Experiment 2 were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

  10. Decreased lymphocyte dopamine transporter in romantic lovers.

    Science.gov (United States)

    Marazziti, Donatella; Baroni, Stefano; Giannaccini, Gino; Piccinni, Armando; Mucci, Federico; Catena-Dell'Osso, Mario; Rutigliano, Grazia; Massimetti, Gabriele; Dell'Osso, Liliana

    2017-06-01

    The role of dopamine (DA) in romantic love is suggested by different evidence and is supported by the findings of some brain imaging studies. The DA transporter (DAT) is a key structure in regulating the concentration of the neurotransmitter in the synaptic cleft. Given the presence of DAT in blood cells, the present study aimed to explore it in resting lymphocytes of 30 healthy subjects of both sexes in the early stage of romantic love (no longer than 6 months), as compared with 30 subjects involved in a long-lasting relationship. All subjects had no physical or psychiatric illness. The DAT was measured by means of the [3H]-WIN 35,428 binding and the [3H]-DA reuptake to resting lymphocytes membranes. Romantic love was assessed by a specific questionnaire developed by us. The results showed that the subjects in the early phase of romantic love had a global alteration of the lymphocyte DAT involving both a decreased number of proteins (Bmax) and a reduced functionality (Vmax). Taken together, these findings would indicate the presence of increased levels of DA in romantic love that, if paralleled by similar concentrations in the brain, would explain some peculiar features of this human feeling.

  11. COGNITIVE THERAPY DECREASE THE LEVEL OF DEPRESSION

    Directory of Open Access Journals (Sweden)

    Ah. Yusuf

    2017-07-01

    Full Text Available Introduction: Aging is a natural process in individuals. Most of the elderly have problems in dealing with this natural process. Lost of occupation, friends and loneliness may result in depression in this age group. Cognitive therapy changes pessimistic idea, unrealistic hopes and excessive self evaluation may result and justify depression. Cognitive therapy may help elderly to recognize the problem in life, to develop positive objective of life and to create more positive personality. The aimed of this study was to analyze the effect of cognitive therapy to reduce the level of depression. Method: This study was used a pre experimental pre post test design. Sample were 10 elderly people who met to the inclusion criteria. The independent variable was cognitive therapy and dependent variable was the level of depression in elderly. Data were collected by using Geriatric Depression Scale (GDS 15, then analyzed by using Wilcoxon Signed Rank Test with significance levelα≤0.05. Result: The result showed that cognitive therapy has an effect on reducing depression with significance level p=0.005. Discussion: It can be concluded that cognitive therapy was effective in reducing depression level in elderly. Further studies are recommended to analyze the effect of cognitive therapy on decreasing anxiety in elderly by measuring cathecolamin.

  12. Predicting unpredictability

    Science.gov (United States)

    Davis, Steven J.

    2018-04-01

    Analysts and markets have struggled to predict a number of phenomena, such as the rise of natural gas, in US energy markets over the past decade or so. Research shows the challenge may grow because the industry — and consequently the market — is becoming increasingly volatile.

  13. A Technique for Decreasing Reactivity of Coal Material to Suppress the Oxygen Absorption Process

    OpenAIRE

    Timofeeva, S. S.; Lugovtsova, Nataliya Yurievna; Gubanova, А. R.

    2016-01-01

    The paper describes the mechanisms of self-ignition formation in coal liable to spontaneous combustion, on the basis of experimental works performed to analyze heat and mass transfer in the coal-air system. A new approach was developed to the coal self-heating suppression and thermodynamic control of the oxidation process. The influence of coal moisture content and thermal behaviour of air in the cooling process was studied during moisture evaporation.

  14. Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

    International Nuclear Information System (INIS)

    Woodford, Curtis; Yartsev, Slav; Dar, A. Rashid; Bauman, Glenn; Van Dyk, Jake

    2007-01-01

    Purpose: To evaluate gross tumor volume (GTV) changes for patients with non-small-cell lung cancer by using daily megavoltage (MV) computed tomography (CT) studies acquired before each treatment fraction on helical tomotherapy and to relate the potential benefit of adaptive image-guided radiotherapy to changes in GTV. Methods and Materials: Seventeen patients were prescribed 30 fractions of radiotherapy on helical tomotherapy for non-small-cell lung cancer at London Regional Cancer Program from Dec 2005 to March 2007. The GTV was contoured on the daily MVCT studies of each patient. Adapted plans were created using merged MVCT-kilovoltage CT image sets to investigate the advantages of replanning for patients with differing GTV regression characteristics. Results: Average GTV change observed over 30 fractions was -38%, ranging from -12 to -87%. No significant correlation was observed between GTV change and patient's physical or tumor features. Patterns of GTV changes in the 17 patients could be divided broadly into three groups with distinctive potential for benefit from adaptive planning. Conclusions: Changes in GTV are difficult to predict quantitatively based on patient or tumor characteristics. If changes occur, there are points in time during the treatment course when it may be appropriate to adapt the plan to improve sparing of normal tissues. If GTV decreases by greater than 30% at any point in the first 20 fractions of treatment, adaptive planning is appropriate to further improve the therapeutic ratio

  15. Radiation amorphization of materials

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Chernyaeva, T.P.

    1993-01-01

    The results of experimental and theoretical research on radiation amorphization are presented in this analytical review. Mechanism and driving forces of radiation amorphization are described, kinetic and thermodynamic conditions of amorphization are formulated. Compositional criteria of radiation amorphization are presented, that allow to predict irradiation behaviour of materials, their tendency to radiation amorphization. Mechanism of transition from crystalline state to amorphous state are considered depending on dose, temperature, structure of primary radiation damage and flux level. (author). 134 refs., 4 tab., 25 fig

  16. UV curable materials development

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.G.

    1996-12-01

    Adhesives, coatings, and inks were selected for evaluation based on literature search and possible production applications. A differential photocalorimeter was used to measure degree of cure and allow prediction of optimum processing conditions. UV cure equipment were characterized and the ability to size equipment to specific materials cure needs established. Adhesion tests procedures were developed for the adhesives and solvent resistance testing procedures developed for the coatings and inks.

  17. Comparison of common lignin methods and modifications on forage and lignocellulosic biomass materials.

    Science.gov (United States)

    Goff, Ben M; Murphy, Patrick T; Moore, Kenneth J

    2012-03-15

    A variety of methods have been developed for estimating lignin concentration within plant materials. The objective of this study was to compare the lignin concentrations produced by six methods on a diverse population of forage and biomass materials and to examine the relationship between these concentrations and the portions of these materials that are available for utilisation by livestock or for ethanol conversion. Several methods produced lignin concentrations that were highly correlated with the digestibility of the forages, but there were few relationships between these methods and the available carbohydrate of the biomass materials. The use of Na₂SO₃ during preparation of residues for hydrolysis resulted in reduced lignin concentrations and decreased correlation with digestibility of forage materials, particularly the warm-season grasses. There were several methods that were well suited for predicting the digestible portion of forage materials, with the acid detergent lignin and Klason lignin method giving the highest correlation across the three types of forage. The continued use of Na₂SO₃ during preparation of Van Soest fibres needs to be evaluated owing to its ability to reduce lignin concentrations and effectiveness in predicting the utilisation of feedstuffs and feedstocks. Because there was little correlation between the lignin concentration and the biomass materials, there is a need to examine alternative or develop new methods to estimate lignin concentrations that may be used to predict the availability of carbohydrates for ethanol conversion. Copyright © 2011 Society of Chemical Industry.

  18. Projections of increased and decreased dengue incidence under climate change.

    Science.gov (United States)

    Williams, C R; Mincham, G; Faddy, H; Viennet, E; Ritchie, S A; Harley, D

    2016-10-01

    Dengue is the world's most prevalent mosquito-borne disease, with more than 200 million people each year becoming infected. We used a mechanistic virus transmission model to determine whether climate warming would change dengue transmission in Australia. Using two climate models each with two carbon emission scenarios, we calculated future dengue epidemic potential for the period 2046-2064. Using the ECHAM5 model, decreased dengue transmission was predicted under the A2 carbon emission scenario, whereas some increases are likely under the B1 scenario. Dengue epidemic potential may decrease under climate warming due to mosquito breeding sites becoming drier and mosquito survivorship declining. These results contradict most previous studies that use correlative models to show increased dengue transmission under climate warming. Dengue epidemiology is determined by a complex interplay between climatic, human host, and pathogen factors. It is therefore naive to assume a simple relationship between climate and incidence, and incorrect to state that climate warming will uniformly increase dengue transmission, although in general the health impacts of climate change will be negative.

  19. Decreasing particle number concentrations in a warming atmosphere and implications

    Directory of Open Access Journals (Sweden)

    F. Yu

    2012-03-01

    Full Text Available New particle formation contributes significantly to the number concentration of condensation nuclei (CN as well as cloud CN (CCN, a key factor determining aerosol indirect radiative forcing of the climate system. Using a physics-based nucleation mechanism that is consistent with a range of field observations of aerosol formation, it is shown that projected increases in global temperatures could significantly inhibit new particle, and CCN, formation rates worldwide. An analysis of CN concentrations observed at four NOAA ESRL/GMD baseline stations since the 1970s and two other sites since 1990s reveals long-term decreasing trends that are consistent in sign with, but are larger in magnitude than, the predicted temperature effects. The possible reasons for larger observed long-term CN reductions at remote sites are discussed. The combined effects of rising temperatures on aerosol nucleation rates and other chemical and microphysical processes may imply substantial decreases in future tropospheric particle abundances associated with global warming, delineating a potentially significant feedback mechanism that increases Earth's climate sensitivity to greenhouse gas emissions. Further research is needed to quantify the magnitude of such a feedback process.

  20. Pressure effects on thermal conductivity and expansion of geologic materials

    International Nuclear Information System (INIS)

    Sweet, J.N.

    1979-02-01

    Through analysis of existing data, an estimate is made of the effect of pressure or depth on the thermal conductivity and expansion of geologic materials which could be present in radioactive waste repositories. In the case of homogeneous dense materials, only small shifts are predicted to occur at depths less than or equal to 3 km, and these shifts will be insignificant as compared with those caused by temperature variations. As the porosity of the medium increases, the variation of conductivity and expansion with pressure becomes greater, with conductivity increasing and expansion decreasing as pressure increases. The pressure dependence of expansion can be found from data on the temperature variation of the isobaric compressibility. In a worst case estimate, a decrease in expansion of approx. 25% is predicted for 5% porous sandstone at a depth of 3 km. The thermal conductivity of a medium with gaseous inclusions increases as the porosity decreases, with the magnitude of the increase being dependent on the details of the porosity collapse. Based on analysis of existing data on tuff and sandstone, a weighted geometric mean formula is recommended for use in calculating the conductivity of porous rock. As a result of this study, it is recommended that measurement of rock porosity versus depth receive increased attention in exploration studies and that the effect of porosity on thermal conductivity and expansion should be examined in more detail

  1. Safety distance for preventing hot particle ignition of building insulation materials

    Directory of Open Access Journals (Sweden)

    Jiayun Song

    2014-01-01

    Full Text Available Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere aluminum particles with the same initial velocities and diameters, the horizontal and vertical distances traveled by particles with higher initial temperatures were higher. Smaller particles traveled farther when other conditions were the same. The critical temperature for an aluminum particle to ignite rigid polyurethane foam increased rapidly with the decrease of particle diameter. The horizontal and vertical safety distances were closely related to the initial temperature, diameter and initial velocity of particles. These results could help update the safety provision of firework display.

  2. Eutrophication decrease: Phosphate adsorption processes in presence of nitrates.

    Science.gov (United States)

    Boeykens, Susana P; Piol, M Natalia; Samudio Legal, Lisa; Saralegui, Andrea B; Vázquez, Cristina

    2017-12-01

    Eutrophication causes aquatic environment degradation as well as serious problems for different purposes of water uses. Phosphorus and nitrogen, mainly as phosphate and nitrate respectively, are considered responsible for eutrophication degradation. The focus of this work was the study of adsorption processes for decreasing phosphate and nitrate concentrations in bi-component aqueous systems. Dolomite and hydroxyapatite were selected as low-cost adsorbents. Obtained results showed that both adsorbents have high capacity for phosphate adsorption which the presence of nitrate does not modify. Hydroxyapatite proved to be the most efficient adsorbent, however, it showed a low percentage of desorption and few possibilities of reuse. Dolomite, on the other hand, allows a desorption of the adsorbed material that favours its reuse. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Laboratory test of source encapsulation for decreasing PCB concentrations

    DEFF Research Database (Denmark)

    Kolarik, Barbara; Andersen, Helle Vibeke; Markowicz, Pawel

    2016-01-01

    This study investigates the effect of encapsulation of tertiary PCB sources with PERMASORB™ Adsorber Wallpaper and the surface emissions trap (cTrap) on indoor air concentration of PCBs and on the PCB content in the source. The 40 weeks long laboratory investigation shows reduction of the air...... concentration by approx. 90% for both wallpapers, a level comparable to source removal. The potential for extraction of PCBs from the contaminated materials stays unclear for both wallpapers. The cTrap has shown potential to accumulate PCBs, however the total content of PCB in investigated sources has...... apparently increased. The opposite was observed for the PERMASORB™, where the total PCB content in the sources has decreased, with however only small concentration of PCBs in the wallpaper measured at the end of the experiment....

  4. The Alpha value decrease when the annual individual effective dose decreases?

    International Nuclear Information System (INIS)

    Sordi, Gian M.; Marchiusi, Thiago; Sousa, Jefferson de J.

    2008-01-01

    A recent IAEA publication tells that a few entities took different alpha values for maxima individual doses. Beyond to disregard the international agencies, that recommend only one alpha value for each country, the alpha values decreases when the individual doses decreases and the practice happens exactly the conversely as we will show in this paper. We will prove that the alpha value increase when the maximum individual doses decreases in a four different manner. The first one we call the theoretical conception and it is linked to the emergent of the ALARA policy and to the purpose that led to the 3/10 of the annual limits, for to decrease the individual doses as a first resort and a 1/10 as a last resort. The second prove will be based in a small mine example used in the ICRP publication number 55 concerning to the optimization and the quantitative decision-aiding techniques in radiological protection where we will determine the alpha value ranges in which each radiological protection options becomes the analytical solution. The third prove will be based in the determination of the optimized thickness example of a plane shielding for a radiation source exposed in the ICRP publication number 37. We will use, also, the numerical example provided there. Eventually, as four prove we will show that the alpha value dos not only increases with the maximum individual dose decrease, but also, with the shielding geometry. (author)

  5. Nuclear materials

    International Nuclear Information System (INIS)

    1996-01-01

    In 1998, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) performed 38 inspections, 25 of them were performed in co-operation with IAEA inspectors. There is no fresh nuclear fuel at Bohunice A-1 NPP at present. Fresh fuel of Bohunice V-1 and V-2 NPPs is inspected in the fresh fuel storage.There are 327 fresh fuel assemblies in Mochovce NPP fresh fuel storage. In addition to that, are also 71 small users of nuclear materials in Slovakia. In most cases they use: covers made of depleted uranium for non-destructive works, detection of level in production plants, covers for therapeutical sources at medical facilities. In. 1995, NRA SR issued 4 new licences for nuclear material withdrawal. In the next part manipulation with nuclear materials, spent fuel stores and illegal trafficking in nuclear materials are reported

  6. Composite Materials

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry......, viscoelastic behavior, and internal stress states. Other physical properties considered are thermal and electrical conductivities, diffusion coefficients, dielectric constants and magnetic permeability. Special attention is given to the effect of pore shape on the mechanical and physical behavior of porous....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro-thermal behavior...

  7. Hazardous materials

    Science.gov (United States)

    ... substances that could harm human health or the environment. Hazardous means dangerous, so these materials must be ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  8. Utopian Materialities

    DEFF Research Database (Denmark)

    Elgaard-Jensen, Torben

    2004-01-01

    In various ways, this paper makes the counter-intuitive claim that the utopian and the material are thoroughlyinterdependent, rather than worlds apart. First, through a reading of Thomas More's Utopia, it is argued thatUtopia is the product of particular kinds of relations, rather than merely...... a detachment from the known world.Second, the utopianism of a new economy firm is examined. It is argued that the physical set-up of the firm -in particular the distribution of tables and chairs - evoke a number of alternatives to ordinary work practice.In this way the materialities of the firm are crucial...... to its persuasive image of being the office of the future.The notion that utopia is achieved through material arrangements is finally related to the analysis of facts andfictions in ANT. It is argued, that even though Utopias are neither fact nor fiction, they are both material andeffective...

  9. Propulsion materials

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Edward J. [U.S. Dept. of Energy, Washington, D.C. (United States); Sullivan, Rogelio A. [U.S. Dept. of Energy, Washington, D.C. (United States); Gibbs, Jerry L. [U.S. Dept. of Energy, Washington, D.C. (United States)

    2008-01-01

    The Department of Energy’s (DOE’s) Office of Vehicle Technologies (OVT) is pleased to introduce the FY 2007 Annual Progress Report for the Propulsion Materials Research and Development Program. Together with DOE national laboratories and in partnership with private industry and universities across the United States, the program continues to engage in research and development (R&D) that provides enabling materials technology for fuel-efficient and environmentally friendly commercial and passenger vehicles.

  10. Encountering Materiality

    DEFF Research Database (Denmark)

    Svabo, Connie

    2016-01-01

    DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016.......DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016....

  11. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  12. A method for decreasing transport ac losses in multifilamentary and multistrip superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Majoros, M [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom)

    2000-07-01

    A new method is proposed for decreasing transport ac losses in multifilamentary superconductors by the decoupling of the filaments using a magnetic material in the form of thin layers surrounding the individual filaments. For a superconductor with an elliptical cross section, the magnetic material surrounding the filaments affects the local magnetic field distribution that both reduces the critical current of the filaments and induces the transport ac losses in the magnetic material. Even by taking into account any detrimental influences of the presence of the magnetic material around the filaments, the analysis of the experimental data supported by computer modelling confirmed that for a Bi2223 tape with 100 filaments individually covered by magnetic material, such as iron powder, the transport ac losses should be 65 times lower than for the same multifilamentary conductor without the magnetic coating on the filaments. With an increasing number of filaments, the ac loss decrease would be even larger. (author)

  13. Materials design and development of functional materials for industry

    International Nuclear Information System (INIS)

    Asahi, Ryoji; Morikawa, Takeshi; Hazama, Hirofumi; Matsubara, Masato

    2008-01-01

    It is now well recognized that we are witnessing a golden age of innovation with novel materials, with discoveries that are important for both basic science and industry. With the development of theory along with computing power, quantum materials design-the synthesis of materials with the desired properties in a controlled way via materials engineering on the atomic scale-is becoming a major component of materials research. Computational prediction based on first-principles calculations has helped to find an efficient way to develop materials that are much needed for industry, as we have seen in the successful development of visible-light sensitized photocatalysts and thermoelectric materials. Close collaboration between theory and experiment is emphasized as an essential for success

  14. Decreased active vasodilator sensitivity in aged skin.

    Science.gov (United States)

    Kenney, W L; Morgan, A L; Farquhar, W B; Brooks, E M; Pierzga, J M; Derr, J A

    1997-04-01

    Older men and women respond to local and reflex-mediated heat stress with an attenuated increase in cutaneous vascular conductance (CVC). This study was performed to test the hypothesis that an augmented or sustained noradrenergic vasoconstriction (VC) may play a role in this age-related difference. Fifteen young (22 +/- 1 yr) and 15 older (66 +/- 1 yr) men exercised at 50% peak oxygen uptake in a 36 degrees C environment. Skin perfusion was monitored at two sites on the right forearm by laser-Doppler flowmetry: one site pretreated with bretylium tosylate (BT) to block the local release of norepinephrine and thus VC and an adjacent control site. Blockade of reflex VC was verified during whole body cooling using a water-perfused suit. CVC (perfusion divided by mean arterial pressure) at each site was reported as a percentage of the maximal CVC (%CVCmax) induced at the end of each experiment by prolonged local heating at 42 degrees C. Neither age nor BT affected the %CVCmax (75-86%) attained at high core temperatures. During the early rise phase of CVC, the %CVCmax-change in esophageal temperature (delta T(es)) curve was shifted to the right in the older men (effective delta T(es) associated with 50% CVC response for young, 0.22 +/- 0.04 and 0.39 +/- 0.04 degrees C and for older, 0.73 +/- 0.04 and 0.85 +/- 0.04 degrees C at control and BT sites, respectively). BT had no interactive effect on this age difference, suggesting a lack of involvement of the VC system in the attenuated CVC response of individuals over the age of 60 yr. Additionally, increases in skin vascular conductance were quantitatively compared by measuring increases in total forearm vascular conductance (FVC, restricted to the forearm skin under these conditions). After the initial approximately 0.2 degrees C increase in T(es), FVC was 40-50% lower in the older men (P < 0.01) for the remainder of the exercise. Decreased active vasodilator sensitivity to increasing core temperature, coupled with

  15. Unification predictions

    International Nuclear Information System (INIS)

    Ghilencea, D.; Ross, G.G.; Lanzagorta, M.

    1997-07-01

    The unification of gauge couplings suggests that there is an underlying (supersymmetric) unification of the strong, electromagnetic and weak interactions. The prediction of the unification scale may be the first quantitative indication that this unification may extend to unification with gravity. We make a precise determination of these predictions for a class of models which extend the multiplet structure of the Minimal Supersymmetric Standard Model to include the heavy states expected in many Grand Unified and/or superstring theories. We show that there is a strong cancellation between the 2-loop and threshold effects. As a result the net effect is smaller than previously thought, giving a small increase in both the unification scale and the value of the strong coupling at low energies. (author). 15 refs, 5 figs

  16. Shape memory materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Compared with piezoelectric ceramics and magnetostrictive materials, the shape memory materials possess larger recoverable strain and recovery stress but slower response to external field. It is expected that the magneto-shape memory materials may develop considerable strain as well as rapid and precise shape control. Pseudoelasticity and shape memory effect (SME) resulted from martensitic transformation and its reverse transformation in shape memory materials were generally described. The requirements of appearing the shape memory effect in materials and the criteria for thermoelastic martensitic transformation were given. Some aspects concerning characteristics of martensitic transformation, and factors affecting SME in Ni-Ti, Cu-Zn-Al and Fe-Mn-Si based alloys as well as ZrO2 containing ceramics were briefly reviewed. Thermodynamic calculation of Ms temperature as function of grain size and parent ordering in Cu-Zn-Al was presented. The works on prediction of Ms in Fe-Mn-Si based alloys and in ZrO2-CeO2 were mentioned. Magnetic shape memory materials were briefly introduced.

  17. Would Outsourcing Increase or Decrease Wage Inequality? Two Models, Two Answers

    OpenAIRE

    Wenli Cheng; Dingsheng Zhang

    2005-01-01

    This paper develops two models to study the impact of outsourcing on wage inequality between skilled and unskilled labor in the developed country and the developing country. The first model assumes symmetric production technologies in both countries, and predicts that outsourcing will increase wage inequality in the developed country, but decrease wage inequality in the developing country. The second model assumes asymmetric technologies in the production of the intermediate good and predicts...

  18. Thermodynamics of nuclear materials

    International Nuclear Information System (INIS)

    1979-01-01

    Full text: The science of chemical thermodynamics has substantially contributed to the understanding of the many problems encountered in nuclear and reactor technology. These problems include reaction of materials with their surroundings and chemical and physical changes of fuels. Modern reactor technology, by its very nature, has offered new fields of investigations for the scientists and engineers concerned with the design of nuclear fuel elements. Moreover, thermodynamics has been vital in predicting the behaviour of new materials for fission as well as fusion reactors. In this regard, the Symposium was organized to provide a mechanism for review and discussion of recent thermodynamic investigations of nuclear materials. The Symposium was held in the Juelich Nuclear Research Centre, at the invitation of the Government of the Federal Republic of Germany. The International Atomic Energy Agency has given much attention to the thermodynamics of nuclear materials, as is evidenced by its sponsorship of four international symposia in 1962, 1965, 1967, and 1974. The first three meetings were primarily concerned with the fundamental thermodynamics of nuclear materials; as with the 1974 meeting, this last Symposium was primarily aimed at the thermodynamic behaviour of nuclear materials in actual practice, i.e., applied thermodynamics. Many advances have been made since the 1974 meeting, both in fundamental and applied thermodynamics of nuclear materials, and this meeting provided opportunities for an exchange of new information on this topic. The Symposium dealt in part with the thermodynamic analysis of nuclear materials under conditions of high temperatures and a severe radiation environment. Several sessions were devoted to the thermodynamic studies of nuclear fuels and fission and fusion reactor materials under adverse conditions. These papers and ensuing discussions provided a better understanding of the chemical behaviour of fuels and materials under these

  19. Materials Discovery via CALYPSO Methodology

    Science.gov (United States)

    Ma, Yanming

    2014-03-01

    Materials design has been the subject of topical interests in materials and physical sciences for long. Atomistic structures of materials occupy a central and often critical role, when establishing a correspondence between materials performance and their basic compositions. Theoretical prediction of atomistic structures of materials with the only given information of chemical compositions becomes crucially important, but it is extremely difficult as it basically involves in classifying a huge number of energy minima on the lattice energy surface. To tackle the problems, we have developed an efficient CALYPSO (Crystal structural AnLYsis by Particle Swarm Optimization) approach for structure prediction from scratch based on particle swarm optimization algorithm by taking the advantage of swarm intelligence and the spirit of structures smart learning. The method has been coded into CALYPSO software (http://www.calypso.cn) which is free for academic use. Currently, CALYPSO method is able to predict structures of three-dimensional crystals, isolated clusters or molecules, surface reconstructions, and two-dimensional layers. The applications of CALYPSO into purposed materials design of layered materials, high-pressure superconductors, and superhard materials were successfully made. Our design of superhard materials introduced a useful scheme, where the hardness value has been employed as the fitness function. This strategy might also be applicable into design of materials with other desired functional properties (e.g., thermoelectric figure of merit, topological Z2 number, etc.). For such a structural design, a well-understood structure to property formulation is required, by which functional properties of materials can be easily acquired at given structures. An emergent application is seen on design of photocatalyst materials.

  20. Bayesian optimization for materials science

    CERN Document Server

    Packwood, Daniel

    2017-01-01

    This book provides a short and concise introduction to Bayesian optimization specifically for experimental and computational materials scientists. After explaining the basic idea behind Bayesian optimization and some applications to materials science in Chapter 1, the mathematical theory of Bayesian optimization is outlined in Chapter 2. Finally, Chapter 3 discusses an application of Bayesian optimization to a complicated structure optimization problem in computational surface science. Bayesian optimization is a promising global optimization technique that originates in the field of machine learning and is starting to gain attention in materials science. For the purpose of materials design, Bayesian optimization can be used to predict new materials with novel properties without extensive screening of candidate materials. For the purpose of computational materials science, Bayesian optimization can be incorporated into first-principles calculations to perform efficient, global structure optimizations. While re...

  1. The construction of life prediction models for the design of Stirling engine heater components

    Science.gov (United States)

    Petrovich, A.; Bright, A.; Cronin, M.; Arnold, S.

    1983-01-01

    The service life of Stirling-engine heater structures of Fe-based high-temperature alloys is predicted using a numerical model based on a linear-damage approach and published test data (engine test data for a Co-based alloy and tensile-test results for both the Co-based and the Fe-based alloys). The operating principle of the automotive Stirling engine is reviewed; the economic and technical factors affecting the choice of heater material are surveyed; the test results are summarized in tables and graphs; the engine environment and automotive duty cycle are characterized; and the modeling procedure is explained. It is found that the statistical scatter of the fatigue properties of the heater components needs to be reduced (by decreasing the porosity of the cast material or employing wrought material in fatigue-prone locations) before the accuracy of life predictions can be improved.

  2. Stop signals decrease choices for palatable foods through decreased food evaluation

    Science.gov (United States)

    Veling, Harm; Aarts, Henk; Stroebe, Wolfgang

    2013-01-01

    The present study explores whether presenting specific palatable foods in close temporal proximity of stop signals in a go/no-go task decreases subsequent evaluations of such foods among participants with a relatively high appetite. Furthermore, we tested whether any decreased evaluations could mediate subsequent food choice. Participants first received a go/no-go task in which palatable foods were consistently linked to go cues or no-go cues within participants. Next, evaluation of the palatable foods was measured as well as food choice. Replicating previous work, results show that among participants with a relatively high appetite palatable foods associated with no-go cues are less often chosen as snacks compared to when these foods are associated with go cues, whereas this manipulation did not affect participants with a relatively low appetite. Moreover, this effect was completely mediated by decreased evaluation of the palatable foods that had been associated with the no-go cues, whereas evaluation of the foods associated with go cues did not mediate this effect. Results further showed that the devaluation effect of foods associated with no-go cues was independent of the amount of pairings (4 vs. 12 vs. 24) with the no-go cues. The current findings suggest that decreased food evaluation is a mechanism that explains effects of stop signals on food choice. PMID:24324451

  3. Prediction model of ammonium uranyl carbonate calcination by microwave heating using incremental improved Back-Propagation neural network

    Energy Technology Data Exchange (ETDEWEB)

    Li Yingwei [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Peng Jinhui, E-mail: jhpeng@kmust.edu.c [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Liu Bingguo [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Li Wei [Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Huang Daifu [No. 272 Nuclear Industry Factory, China National Nuclear Corporation, Hengyang, Hunan Province 421002 (China); Zhang Libo [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China)

    2011-05-15

    Research highlights: The incremental improved Back-Propagation neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward. The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ammonium uranyl carbonate (AUC). AUC can accept the microwave energy and microwave heating can quickly decompose AUC. In the experiment of microwave calcining of AUC, the contents of U and U{sup 4+} increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth. - Abstract: The incremental improved Back-Propagation (BP) neural network prediction model was put forward, which was very useful in overcoming the problems, such as long testing cycle, high testing quantity, difficulty of optimization for process parameters, many training data probably were offered by the way of increment batch and the limitation of the system memory could make the training data infeasible, which existed in the process of calcinations for ammonium uranyl carbonate (AUC) by microwave heating. The prediction model of the nonlinear system was built, which could effectively predict the experiment of microwave calcining of AUC. The predicted results indicated that the contents of U and U{sup 4+} were increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth.

  4. Prediction model of ammonium uranyl carbonate calcination by microwave heating using incremental improved Back-Propagation neural network

    International Nuclear Information System (INIS)

    Li Yingwei; Peng Jinhui; Liu Bingguo; Li Wei; Huang Daifu; Zhang Libo

    2011-01-01

    Research highlights: → The incremental improved Back-Propagation neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward. → The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ammonium uranyl carbonate (AUC). → AUC can accept the microwave energy and microwave heating can quickly decompose AUC. → In the experiment of microwave calcining of AUC, the contents of U and U 4+ increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth. - Abstract: The incremental improved Back-Propagation (BP) neural network prediction model was put forward, which was very useful in overcoming the problems, such as long testing cycle, high testing quantity, difficulty of optimization for process parameters, many training data probably were offered by the way of increment batch and the limitation of the system memory could make the training data infeasible, which existed in the process of calcinations for ammonium uranyl carbonate (AUC) by microwave heating. The prediction model of the nonlinear system was built, which could effectively predict the experiment of microwave calcining of AUC. The predicted results indicated that the contents of U and U 4+ were increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth.

  5. Supplementary materials

    Indian Academy of Sciences (India)

    Walaa Omar

    Elemental Composition Report. Page 1. Single Mass Analysis. Tolerance = 4.0 mDa / DBE: min = -1.5, max = 100.0. Element prediction: Off. Number of isotope peaks used for i-FIT = 2. Monoisotopic Mass, Even Electron Ions. 163 formula(e) evaluated with 1 results within limits (up to 50 closest results for each mass) ...

  6. Frost resistance of building materials

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    materials, has been developed.The importance of the pore structure on the development of stresses in the material during freezing is emphasized. To verify the model, experimental investigations are made on various concretes without air-entrainment and brick tiles with different porosities.Calculations......In this thesis it is shown that the critical degree of saturation is suitable as parameter for the frost resistance of porous building materials. A numerical model for prediction of critical degrees of saturation based on fracture mechanics and phase geometry of two-phase materials, e.g. porous...

  7. Introduction: Long term prediction

    International Nuclear Information System (INIS)

    Beranger, G.

    2003-01-01

    Making a decision upon the right choice of a material appropriate to a given application should be based on taking into account several parameters as follows: cost, standards, regulations, safety, recycling, chemical properties, supplying, transformation, forming, assembly, mechanical and physical properties as well as the behaviour in practical conditions. Data taken from a private communication (J.H.Davidson) are reproduced presenting the life time range of materials from a couple of minutes to half a million hours corresponding to applications from missile technology up to high-temperature nuclear reactors or steam turbines. In the case of deep storage of nuclear waste the time required is completely different from these values since we have to ensure the integrity of the storage system for several thousand years. The vitrified nuclear wastes should be stored in metallic canisters made of iron and carbon steels, stainless steels, copper and copper alloys, nickel alloys or titanium alloys. Some of these materials are passivating metals, i.e. they develop a thin protective film, 2 or 3 nm thick - the so-called passive films. These films prevent general corrosion of the metal in a large range of chemical condition of the environment. In some specific condition, localized corrosion such as the phenomenon of pitting, occurs. Consequently, it is absolutely necessary to determine these chemical condition and their stability in time to understand the behavior of a given material. In other words the corrosion system is constituted by the complex material/surface/medium. For high level nuclear wastes the main features for resolving problem are concerned with: geological disposal; deep storage in clay; waste metallic canister; backfill mixture (clay-gypsum) or concrete; long term behavior; data needed for modelling and for predicting; choice of appropriate solution among several metallic candidates. The analysis of the complex material/surface/medium is of great importance

  8. Predictability and Prediction for an Experimental Cultural Market

    Science.gov (United States)

    Colbaugh, Richard; Glass, Kristin; Ormerod, Paul

    Individuals are often influenced by the behavior of others, for instance because they wish to obtain the benefits of coordinated actions or infer otherwise inaccessible information. In such situations this social influence decreases the ex ante predictability of the ensuing social dynamics. We claim that, interestingly, these same social forces can increase the extent to which the outcome of a social process can be predicted very early in the process. This paper explores this claim through a theoretical and empirical analysis of the experimental music market described and analyzed in [1]. We propose a very simple model for this music market, assess the predictability of market outcomes through formal analysis of the model, and use insights derived through this analysis to develop algorithms for predicting market share winners, and their ultimate market shares, in the very early stages of the market. The utility of these predictive algorithms is illustrated through analysis of the experimental music market data sets [2].

  9. Layered materials

    Science.gov (United States)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and

  10. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  11. Application of micromechanical models of ductile fracture initiation to reactor pressure vessel materials

    International Nuclear Information System (INIS)

    Chaouadi, R.; Walle, E. van; Fabry, A.; Velde, J. van de; Meester, P. de

    1996-01-01

    The aim of the current study is the application of local micromechanical models to predict crack initiation in ductile materials. Two reactor pressure vessel materials have been selected for this study: JRQ IAEA monitor base metal (A533B Cl.1) and Doel-IV weld material. Charpy impact tests have been performed in both un-irradiated and irradiated conditions. In addition to standard tensile tests, notched tensile specimens have been tested. The upper shelf energy of the weld material remains almost un-affected by irradiation, whereas a decrease of 20% is detected for the base metal. Accordingly, the tensile properties of the weld material do not reveal a clear irradiation effect on the yield and ultimate stresses, this in contrast to the base material flow properties. The tensile tests have been analyzed in terms of micromechanical models. A good correlation is found between the standard tests and the micromechanical models, that are able to predict the ductile damage evolution in these materials. Additional information on the ductility behavior of these materials is revealed by this micromechanical analysis

  12. Analysis of radiological parameters associated with decreased fractional anisotropy values on diffusion tensor imaging in patients with lumbar spinal stenosis.

    Science.gov (United States)

    Wang, Xiandi; Wang, Hongli; Sun, Chi; Zhou, Shuyi; Meng, Tao; Lv, Feizhou; Ma, Xiaosheng; Xia, Xinlei; Jiang, Jianyuan

    2018-04-26

    Previous studies have indicated that decreased fractional anisotropy (FA) values on diffusion tensor imaging (DTI) are well correlated with the symptoms of nerve root compression. The aim of our study is to determine primary radiological parameters associated with decreased FA values in patients with lumbar spinal stenosis involving single L5 nerve root. Patients confirmed with single L5 nerve root compression by transforaminal nerve root blocks were included in this study. FA values of L5 nerve roots on both symptomatic and asymptomatic side were obtained. Conventional radiological parameters, such as disc height, degenerative scoliosis, dural sac cross-sectional area (DSCSA), foraminal height (FH), hypertrophic facet joint degeneration (HFJD), sagittal rotation (SR), sedimentation sign, sagittal translation and traction spur were measured. Correlation and regression analyses were performed between the radiological parameters and FA values of the symptomatic L5 nerve roots. A predictive regression equation was established. Twenty-one patients were included in this study. FA values were significantly lower at the symptomatic side comparing to the asymptomatic side (0.263 ± 0.069 vs. 0.334 ± 0.080, P = 0.038). DSCSA, FH, HFJD, and SR were significantly correlated with the decreased FA values, with r = 0.518, 0.443, 0.472 and - 0.910, respectively (P values, and the regression equation is FA = - 0.012 × SR + 0.002 × DSCSA. DSCSA and SR were primary contributors to decreased FA values in LSS patients involving single L5 nerve root, indicating that central canal decompression and segmental stability should be the first considerations in preoperative planning of these patients. These slides can be retrieved under Electronic Supplementary Material.

  13. High temperature fracture of ceramic materials

    International Nuclear Information System (INIS)

    Wiederhorn, S.M.

    1979-01-01

    A review is presented of fracture mechanisms and methods of lifetime prediction in ceramic materials. Techniques of lifetime prediction are based on the science of fracture mechanics. Application of these techniques to structural ceramics is limited by our incomplete understanding of fracture mechanisms in these materials, and by the occurrence of flaw generation in these materials at elevated temperatures. Research on flaw generation and fracture mechanisms is recommended as a way of improving the reliability of structural ceramics

  14. Gate valve performance prediction

    International Nuclear Information System (INIS)

    Harrison, D.H.; Damerell, P.S.; Wang, J.K.; Kalsi, M.S.; Wolfe, K.J.

    1994-01-01

    The Electric Power Research Institute is carrying out a program to improve the performance prediction methods for motor-operated valves. As part of this program, an analytical method to predict the stem thrust required to stroke a gate valve has been developed and has been assessed against data from gate valve tests. The method accounts for the loads applied to the disc by fluid flow and for the detailed mechanical interaction of the stem, disc, guides, and seats. To support development of the method, two separate-effects test programs were carried out. One test program determined friction coefficients for contacts between gate valve parts by using material specimens in controlled environments. The other test program investigated the interaction of the stem, disc, guides, and seat using a special fixture with full-sized gate valve parts. The method has been assessed against flow-loop and in-plant test data. These tests include valve sizes from 3 to 18 in. and cover a considerable range of flow, temperature, and differential pressure. Stem thrust predictions for the method bound measured results. In some cases, the bounding predictions are substantially higher than the stem loads required for valve operation, as a result of the bounding nature of the friction coefficients in the method

  15. Food Packaging Materials

    Science.gov (United States)

    1978-01-01

    The photos show a few of the food products packaged in Alure, a metallized plastic material developed and manufactured by St. Regis Paper Company's Flexible Packaging Division, Dallas, Texas. The material incorporates a metallized film originally developed for space applications. Among the suppliers of the film to St. Regis is King-Seeley Thermos Company, Winchester, Ma'ssachusetts. Initially used by NASA as a signal-bouncing reflective coating for the Echo 1 communications satellite, the film was developed by a company later absorbed by King-Seeley. The metallized film was also used as insulating material for components of a number of other spacecraft. St. Regis developed Alure to meet a multiple packaging material need: good eye appeal, product protection for long periods and the ability to be used successfully on a wide variety of food packaging equipment. When the cost of aluminum foil skyrocketed, packagers sought substitute metallized materials but experiments with a number of them uncovered problems; some were too expensive, some did not adequately protect the product, some were difficult for the machinery to handle. Alure offers a solution. St. Regis created Alure by sandwiching the metallized film between layers of plastics. The resulting laminated metallized material has the superior eye appeal of foil but is less expensive and more easily machined. Alure effectively blocks out light, moisture and oxygen and therefore gives the packaged food long shelf life. A major packaging firm conducted its own tests of the material and confirmed the advantages of machinability and shelf life, adding that it runs faster on machines than materials used in the past and it decreases product waste; the net effect is increased productivity.

  16. Fracture toughness of fibrous composite materials

    Science.gov (United States)

    Poe, C. C., Jr.

    1984-01-01

    Laminates with various proportions of 0 deg, 45 deg, and 90 deg plies were fabricated from T300/5208 and T300/BP-907 graphite/epoxy prepreg tape material. The fracture toughness of each laminate orientation or lay-up was determined by testing center-cracked specimens, and it was also predicted with the general fracture-toughness parameter. The predictions were good except when crack-tip splitting was large, at which time the toughness and strengths tended to be underpredicted. By using predictions, a parametric study was also made of factors that influence fracture toughness. Fiber and matrix properties as well as lay-up were investigated. Without crack-tip splitting, fracture toughness increases in proportion to fiber strength and fiber volume fraction, increases linearly with E(22)/E(11), is largest when the modulus for non-0 deg fibers is greater than that of 0 deg fibers, and is smallest for 0(m)/90(p)(s) lay-ups. (The E(11) and E(22) are Young's moduli of the lamina parallel to and normal to the direction of the fibers, respectively). For a given proportion of 0 deg plies, the most notch-sensitive lay-ups are 0(m)/90(p)(s) and the least sensitive are 0(m)/45(n)(s) and alpha(s). Notch sensitivity increases with the proportion of 0 deg plies and decreases with alpha. Strong, tough matrix materials, which inhibit crack-tip splitting, generally lead to minimum fracture toughness.

  17. Benazepril hydrochloride improves diabetic nephropathy and decreases proteinuria by decreasing ANGPTL-4 expression.

    Science.gov (United States)

    Xue, Lingyu; Feng, Xiaoqing; Wang, Chuanhai; Zhang, Xuebin; Sun, Wenqiang; Yu, Kebo

    2017-10-04

    This study aimed to investigate the effects of benazepril hydrochloride (BH) on proteinuria and ANGPTL-4 expression in a diabetic nephropathy (DN) rat model. A total of 72 Wistar male rats were randomly divided into three groups: normal control (NC), DN group and BH treatment (BH) groups. The DN model was induced by streptozotocin (STZ). Weight, glucose, proteinuria, biochemical indicators and the kidney weight index were examined at 8, 12 and 16 weeks. In addition, ANGPTL-4 protein and mRNA expressions were assessed by immunohistochemistry and qRT-PCR, respectively. Relationships between ANGPTL-4 and biochemical indicators were investigated using Spearman analysis. Weight was significantly lower but glucose levels were significantly higher in both the DN and BH groups than in the NC group (P Benazepril hydrochloride improves DN and decreases proteinuria by decreasing ANGPTL-4 expression.

  18. Supplementary Material

    Indian Academy of Sciences (India)

    mraga

    1. Supplementary Material. A soluble-lead Redox Flow Battery with corrugated graphite sheet and reticulated vitreous carbon as positive and negative current collectors by A Banerjee et al (pp 163-. 170). Figure S1. SEM images for bare substrates: (a) graphite sheet, (b) 20 ppi RVC, (c) 30 ppi. RVC and (d) 45 ppi RVC.

  19. Emerging Materiality

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Breinbjerg, Morten; Pold, Søren

    2009-01-01

    The authors examine how materiality emerges from complex chains of mediation in creative software use. The primarily theoretical argument is inspired and illustrated by interviews with two composers of electronic music. The authors argue that computer mediated activity should not primarily be und...

  20. Atmospheric materiality

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2016-01-01

    experience and, consequently, to the conceptual and methodological shifts in the production of space, and hence in the way we think about materiality. In this context, architectural space is understood as a contingent construction – a space of engagement that appears to us as a result of continuous...

  1. Absorbant materials

    International Nuclear Information System (INIS)

    Quetier, Monique.

    1978-11-01

    Absorbants play a very important part in the nuclear industry. They serve for the control, shut-down and neutron shielding of reactors and increase the capacity of spent fuel storage pools and of special transport containers. This paper surveys the usual absorbant materials, means of obtainment, their essential characteristics relating to their use and their behaviour under neutron irradiation [fr

  2. Dielectric characterization of high-performance spaceflight materials

    Science.gov (United States)

    Kleppe, Nathan; Nurge, Mark A.; Bowler, Nicola

    2015-03-01

    As commercial space travel increases, the need for reliable structural health monitoring to predict possible weaknesses or failures of structural materials also increases. Monitoring of these materials can be done through the use of dielectric spectroscopy by comparing permittivity or conductivity measurements performed on a sample in use to that of a pristine sample from 100 μHz to 3 GHz. Fluctuations in these measured values or of the relaxation frequencies, if present, can indicate chemical or physical changes occurring within the material and the possible need for maintenance/replacement. In this work, we establish indicative trends that occur due to changes in dielectric spectra during accelerated aging of various high-performance polymeric materials: ethylene vinyl alcohol (EVOH), Poly (ether ether ketone) (PEEK), polyphenylene sulfide (PPS), and ultra-high molecular weight polyethylene (UHMWPE). Uses for these materials range from electrical insulation and protective coatings to windows and air- or space-craft parts that may be subject to environmental damage over long-term operation. Samples were prepared by thermal exposure and, separately, by ultraviolet/water-spray cyclic aging. The aged samples showed statistically-significant trends of either increasing or decreasing real or imaginary permittivity values, relaxation frequencies, conduction or the appearance of new relaxation modes. These results suggest that dielectric testing offers the possibility of nondestructive evaluation of the extent of age-related degradation in these materials.

  3. Practical aspects of geological prediction

    International Nuclear Information System (INIS)

    Mallio, W.J.; Peck, J.H.

    1981-01-01

    Nuclear waste disposal requires that geology be a predictive science. The prediction of future events rests on (1) recognizing the periodicity of geologic events; (2) defining a critical dimension of effect, such as the area of a drainage basin, the length of a fault trace, etc; and (3) using our understanding of active processes the project the frequency and magnitude of future events in the light of geological principles. Of importance to nuclear waste disposal are longer term processes such as continental denudation and removal of materials by glacial erosion. Constant testing of projections will allow the practical limits of predicting geological events to be defined. 11 refs

  4. Friction Material Composites Materials Perspective

    CERN Document Server

    Sundarkrishnaa, K L

    2012-01-01

    Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

  5. Improving the Prediction of Prostate Cancer Overall Survival by Supplementing Readily Available Clinical Data with Gene Expression Levels of IGFBP3 and F3 in Formalin-Fixed Paraffin Embedded Core Needle Biopsy Material.

    Directory of Open Access Journals (Sweden)

    Zhuochun Peng

    Full Text Available A previously reported expression signature of three genes (IGFBP3, F3 and VGLL3 was shown to have potential prognostic value in estimating overall and cancer-specific survivals at diagnosis of prostate cancer in a pilot cohort study using freshly frozen Fine Needle Aspiration (FNA samples.We carried out a new cohort study with 241 prostate cancer patients diagnosed from 2004-2007 with a follow-up exceeding 6 years in order to verify the prognostic value of gene expression signature in formalin fixed paraffin embedded (FFPE prostate core needle biopsy tissue samples. The cohort consisted of four patient groups with different survival times and death causes. A four multiplex one-step RT-qPCR test kit, designed and optimized for measuring the expression signature in FFPE core needle biopsy samples, was used. In archive FFPE biopsy samples the expression differences of two genes (IGFBP3 and F3 were measured. The survival time predictions using the current clinical parameters only, such as age at diagnosis, Gleason score, PSA value and tumor stage, and clinical parameters supplemented with the expression levels of IGFBP3 and F3, were compared.When combined with currently used clinical parameters, the gene expression levels of IGFBP3 and F3 are improving the prediction of survival time as compared to using clinical parameters alone.The assessment of IGFBP3 and F3 gene expression levels in FFPE prostate cancer tissue would provide an improved survival prediction for prostate cancer patients at the time of diagnosis.

  6. Study about ion exchange for decreasing the conductivity of water in power plant and refineries

    International Nuclear Information System (INIS)

    Khosravi, M.; Samani; Hajihosseini, N.

    2002-01-01

    Water has been used directly or indirectly for industries, its use would be in factories: such as steam or as a cooler or the product of the industrial material. water is used more than other material in many industries and what ever is obtained as the effect of industrial activities, it is destabilising like waste. By the control of P H and reducing (total dissolved solid) of water or decreasing conductivity of water, we can protect boiler from corrosion. We want to study this article for different method of decreasing (TDS) in order to produce <1μs/cm conductivity. The suitable method which is ion exchange system will be selected

  7. Model sensitivity studies of the decrease in atmospheric carbon tetrachloride

    Directory of Open Access Journals (Sweden)

    M. P. Chipperfield

    2016-12-01

    Full Text Available Carbon tetrachloride (CCl4 is an ozone-depleting substance, which is controlled by the Montreal Protocol and for which the atmospheric abundance is decreasing. However, the current observed rate of this decrease is known to be slower than expected based on reported CCl4 emissions and its estimated overall atmospheric lifetime. Here we use a three-dimensional (3-D chemical transport model to investigate the impact on its predicted decay of uncertainties in the rates at which CCl4 is removed from the atmosphere by photolysis, by ocean uptake and by degradation in soils. The largest sink is atmospheric photolysis (74 % of total, but a reported 10 % uncertainty in its combined photolysis cross section and quantum yield has only a modest impact on the modelled rate of CCl4 decay. This is partly due to the limiting effect of the rate of transport of CCl4 from the main tropospheric reservoir to the stratosphere, where photolytic loss occurs. The model suggests large interannual variability in the magnitude of this stratospheric photolysis sink caused by variations in transport. The impact of uncertainty in the minor soil sink (9 % of total is also relatively small. In contrast, the model shows that uncertainty in ocean loss (17 % of total has the largest impact on modelled CCl4 decay due to its sizeable contribution to CCl4 loss and large lifetime uncertainty range (147 to 241 years. With an assumed CCl4 emission rate of 39 Gg year−1, the reference simulation with the best estimate of loss processes still underestimates the observed CCl4 (overestimates the decay over the past 2 decades but to a smaller extent than previous studies. Changes to the rate of CCl4 loss processes, in line with known uncertainties, could bring the model into agreement with in situ surface and remote-sensing measurements, as could an increase in emissions to around 47 Gg year−1. Further progress in constraining the CCl4 budget is partly limited by

  8. Material Analysis for a Fire Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Alexander; Nemer, Martin B.

    2014-08-01

    This report consolidates technical information on several materials and material classes for a fire assessment. The materials include three polymeric materials, wood, and hydraulic oil. The polymers are polystyrene, polyurethane, and melamine- formaldehyde foams. Samples of two of the specific materials were tested for their behavior in a fire - like environment. Test data and the methods used to test the materials are presented. Much of the remaining data are taken from a literature survey. This report serves as a reference source of properties necessary to predict the behavior of these materials in a fire.

  9. Materials Science

    Science.gov (United States)

    2003-01-01

    The Materials Science Program is structured so that NASA s headquarters is responsible for the program content and selection, through the Enterprise Scientist, and MSFC provides for implementation of ground and flight programs with a Discipline Scientist and Discipline Manager. The Discipline Working Group of eminent scientists from outside of NASA acts in an advisory capacity and writes the Discipline Document from which the NRA content is derived. The program is reviewed approximately every three years by groups such as the Committee on Microgravity Research, the National Materials Advisory Board, and the OBPR Maximization and Prioritization (ReMaP) Task Force. The flight program has had as many as twenty-six principal investigators (PIs) in flight or flight definition stage, with the numbers of PIs in the future dependent on the results of the ReMaP Task Force and internal reviews. Each project has a NASA-appointed Project Scientist, considered a half-time job, who assists the PI in understanding and preparing for internal reviews such as the Science Concept Review and Requirements Definition Review. The Project Scientist also insures that the PI gets the maximum science support from MSFC, represents the PI to the MSFC community, and collaborates with the Project Manager to insure the project is well-supported and remains vital. Currently available flight equipment includes the Materials Science Research Rack (MSRR-1) and Microgravity Science Glovebox. Ground based projects fall into one or more of several categories. Intellectual Underpinning of Flight Program projects include theoretical studies backed by modeling and computer simulations; bring to maturity new research, often by young researchers, and may include preliminary short duration low gravity experiments in the KC-135 aircraft or drop tube; enable characterization of data sets from previous flights; and provide thermophysical property determinations to aid PIs. Radiation Shielding and preliminary In

  10. Magnetocaloric materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeppesen, Stinus

    2008-10-15

    New and improved magnetocaloric materials are one of the cornerstones in the development of room temperature magnetic refrigeration. Magnetic refrigeration has been used since the 1930ies in cryogenic applications, but has since the discovery of room temperature refrigerants received enormous attention. This Ph.D. work has been mainly concerned with developing a new technique to characterize the magnetocaloric effect (MCE) and using this technique in the investigations on new and improved magnetocaloric materials. For this purpose a novel differential scanning calorimeter (DSC) with applied magnetic fields was developed for measuring heat capacity as function of magnetic field. Measurements using the developed DSC demonstrate a very high sensitivity, fast measurements and good agreement with results obtained by other techniques. Furthermore, two material systems have been described in this work. Both systems take basis in the mixed-valence manganite system La{sub 1-x}Ca{sub x}MnO{sub 3} well known from research on colossal magnetoresistance (CMR). The mixed-valence manganite crystallizes in the perovskite structure of general formula ABO{sub 3}. The first material system is designed to investigate the influence of low level Cu doping on the B-site. Six different samples were prepared with over-stoichiometric compositions La{sub 0.67}Ca{sub 0.33}Mn{sub 1.05}Cu{sub x}O{sub 3}, x=0, 1, 2, 3, 4 and 5%. All compositions crystallized well in the same perovskite structure, but the morphology of the samples changed drastically with doping. Investigation on the magnetocaloric properties revealed that small levels of Cu up to around 3% could improve the magnetocaloric performance of the materials. Furthermore, Cu could be used to tune the temperature interval without deteriorating the MCE, which is a much desired characteristic for potential use in magnetic refrigerators. A less comprehensive part of the work has been concerned with the investigation of doping on the A

  11. Materializing Superghosts

    OpenAIRE

    Alexandrov, Victor; Krotov, Dmitry; Losev, Andrei; Lysov, Vyacheslav

    2007-01-01

    We construct the off-shell BV realization of N=1, d=10 SYM with 7 auxillary fields. This becomes possible due to materialized ghost phenomenon. Namely, supersymmetry ghosts are coordinates on a manifold B of 10-dimensional spinors with pure spinors cut out. Auxillary fields are sections of a bundle over B, and supersymmetry transformations are nonlinear in ghosts. By integrating out axillary fields we obtain on-shell supersymmetric BV action with terms quadratic in antifields. Exactly this on...

  12. Material monitoring

    International Nuclear Information System (INIS)

    Kotter, W.; Zirker, L.; Hancock, J.A.

    1995-01-01

    Waste Reduction Operations Complex (WROC) facilities are located at the Idaho National Engineering Laboratory (INEL). The overall goal for the Pollution Prevention/Waste Minimization Unit is to identify and establish the correct amount of waste generated so that it can be reduced. Quarterly, the INEL Pollution Prevention (P2) Unit compares the projected amount of waste generated per process with the actual amount generated. Examples of waste streams that would be addresses for our facility would include be are not limited to: Maintenance, Upgrades, Office and Scrap Metal. There are three potential sources of this variance: inaccurate identification of those who generate the waste; inaccurate identification of the process that generates the waste; and inaccurate measurement of the actual amount generated. The Materials Monitoring Program was proposed to identify the sources of variance and reduce the variance to an acceptable level. Prior to the implementation of the Material Monitoring Program, all information that was gathered and recorded was done so through an informal estimation of waste generated by various personnel concerned with each processes. Due to the inaccuracy of the prior information gathering system, the Material Monitoring Program was established. The heart of this program consists of two main parts. In the first part potential waste generators provide information on projected waste generation process. In the second part, Maintenance, Office, Scrap Metal and Facility Upgrade wastes from given processes is disposed within the appropriate bin dedicated to that process. The Material Monitoring Program allows for the more accurate gathering of information on the various waste types that are being generated quarterly

  13. Thermoelectric Materials

    Science.gov (United States)

    Gao, Peng; Berkun, Isil; Schmidt, Robert D.; Luzenski, Matthew F.; Lu, Xu; Bordon Sarac, Patricia; Case, Eldon D.; Hogan, Timothy P.

    2014-06-01

    Mg2(Si,Sn) compounds are promising candidate low-cost, lightweight, nontoxic thermoelectric materials made from abundant elements and are suited for power generation applications in the intermediate temperature range of 600 K to 800 K. Knowledge on the transport and mechanical properties of Mg2(Si,Sn) compounds is essential to the design of Mg2(Si,Sn)-based thermoelectric devices. In this work, such materials were synthesized using the molten-salt sealing method and were powder processed, followed by pulsed electric sintering densification. A set of Mg2.08Si0.4- x Sn0.6Sb x (0 ≤ x ≤ 0.072) compounds were investigated, and a peak ZT of 1.50 was obtained at 716 K in Mg2.08Si0.364Sn0.6Sb0.036. The high ZT is attributed to a high electrical conductivity in these samples, possibly caused by a magnesium deficiency in the final product. The mechanical response of the material to stresses is a function of the elastic moduli. The temperature-dependent Young's modulus, shear modulus, bulk modulus, Poisson's ratio, acoustic wave speeds, and acoustic Debye temperature of the undoped Mg2(Si,Sn) compounds were measured using resonant ultrasound spectroscopy from 295 K to 603 K. In addition, the hardness and fracture toughness were measured at room temperature.

  14. Hydrogen Storage In Nanostructured Materials

    OpenAIRE

    Assfour, Bassem

    2011-01-01

    Hydrogen is an appealing energy carrier for clean energy use. However, storage of hydrogen is still the main bottleneck for the realization of an energy economy based on hydrogen. Many materials with outstanding properties have been synthesized with the aim to store enough amount of hydrogen under ambient conditions. Such efforts need guidance from material science, which includes predictive theoretical tools. Carbon nanotubes were considered as promising candidates for hydrogen storag...

  15. Material selection and embodied energy

    CSIR Research Space (South Africa)

    Ampofo-Anti, N

    2010-11-01

    Full Text Available mix concrete apron Non reinforced, ready mix concrete strip foundation Non reinforced, ready mix ground floor slab Concrete block Modular, hollow concrete block Solid concrete block Finishes Floor screed Insulated ceiling panel Perlite... Predicting the embodied energy contribution of a single material is however not as easy as green building practices assume. As illustrated by the example in Box 1, the choice of a material implies the choice of integral constituents such as insulation...

  16. Decreased respiratory symptoms in cannabis users who vaporize

    Directory of Open Access Journals (Sweden)

    Barnwell Sara

    2007-04-01

    Full Text Available Abstract Cannabis smoking can create respiratory problems. Vaporizers heat cannabis to release active cannabinoids, but remain cool enough to avoid the smoke and toxins associated with combustion. Vaporized cannabis should create fewer respiratory symptoms than smoked cannabis. We examined self-reported respiratory symptoms in participants who ranged in cigarette and cannabis use. Data from a large Internet sample revealed that the use of a vaporizer predicted fewer respiratory symptoms even when age, sex, cigarette smoking, and amount of cannabis used were taken into account. Age, sex, cigarettes, and amount of cannabis also had significant effects. The number of cigarettes smoked and amount of cannabis used interacted to create worse respiratory problems. A significant interaction revealed that the impact of a vaporizer was larger as the amount of cannabis used increased. These data suggest that the safety of cannabis can increase with the use of a vaporizer. Regular users of joints, blunts, pipes, and water pipes might decrease respiratory symptoms by switching to a vaporizer

  17. Longitudinal effects of increases and decreases in intimate partner aggression.

    Science.gov (United States)

    Hammett, Julia F; Karney, Benjamin R; Bradbury, Thomas N

    2018-04-01

    Interventions aimed at reducing interpartner aggression assume that within-couple declines in aggression enhance individual and relational outcomes, yet reductions in aggression may fail to yield these benefits when other risk-generating mechanisms remain intact. The present study evaluates this possibility by investigating whether naturally observed within-couple changes in aggression are associated with improved individual and relational outcomes in the manner assumed by intervention programs. Drawing upon 4 waves of data collected at 9-month intervals from a community sample of 431 newlywed couples (76% Hispanic) living in low-income neighborhoods, Actor-Partner-Interdependence Modeling (APIM) and Structural Equation Modeling (SEM) indicated that levels of aggression at the outset of marriage had limited associations with later outcomes. Changes in aggression, however, were associated with subsequent marital outcomes, such that decreases in aggression were beneficial and increases in aggression were costly. Individuals who experienced increases in aggression worsened in their observed communication over time and reported greater increases in stress. Reports of stress early in marriage predicted escalations in aggression over time. Thus, helping couples to contain increases in aggression might be particularly consequential for their well-being. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. Soil salinity decreases global soil organic carbon stocks.

    Science.gov (United States)

    Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

    2013-11-01

    Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Effect of mechanical properties on erosion resistance of ductile materials

    Science.gov (United States)

    Levin, Boris Feliksovih

    Solid particle erosion (SPE) resistance of ductile Fe, Ni, and Co-based alloys as well as commercially pure Ni and Cu was studied. A model for SPE behavior of ductile materials is presented. The model incorporates the mechanical properties of the materials at the deformation conditions associated with SPE process, as well as the evolution of these properties during the erosion induced deformation. An erosion parameter was formulated based on consideration of the energy loss during erosion, and incorporates the material's hardness and toughness at high strain rates. The erosion model predicts that materials combining high hardness and toughness can exhibit good erosion resistance. To measure mechanical properties of materials, high strain rate compression tests using Hopkinson bar technique were conducted at strain rates similar to those during erosion. From these tests, failure strength and strain during erosion were estimated and used to calculate toughness of the materials. The proposed erosion parameter shows good correlation with experimentally measured erosion rates for all tested materials. To analyze subsurface deformation during erosion, microhardness and nanoindentation tests were performed on the cross-sections of the eroded materials and the size of the plastically deformed zone and the increase in materials hardness due to erosion were determined. A nanoindentation method was developed to estimate the restitution coefficient within plastically deformed regions of the eroded samples which provides a measure of the rebounding ability of a material during particle impact. An increase in hardness near the eroded surface led to an increase in restitution coefficient. Also, the stress rates imposed below the eroded surface were comparable to those measured during high strain-rate compression tests (10sp3-10sp4 ssp{-1}). A new parameter, "area under the microhardness curve" was developed that represents the ability of a material to absorb impact energy. By

  20. Material Modelling - Composite Approach

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    is successfully justified comparing predicted results with experimental data obtained in the HETEK-project on creep, relaxation, and shrinkage of very young concretes cured at a temperature of T = 20^o C and a relative humidity of RH = 100%. The model is also justified comparing predicted creep, shrinkage......, and internal stresses caused by drying shrinkage with experimental results reported in the literature on the mechanical behavior of mature concretes. It is then concluded that the model presented applied in general with respect to age at loading.From a stress analysis point of view the most important finding...... in this report is that cement paste and concrete behave practically as linear-viscoelastic materials from an age of approximately 10 hours. This is a significant age extension relative to earlier studies in the literature where linear-viscoelastic behavior is only demonstrated from ages of a few days. Thus...