Sample records for reaction conditions employed

  1. Employment status and working conditions

    Goudswaard, A.; Andries, F.


    In the 1990s an increasing number of employees were engaged in non-permanent contract work in the European Union. This can, to a large extent, be explained by an active labour market policy where job creation was the focus, and this type of employment provided a way of meeting the increased demand f


    S. Kovalskaya


    Full Text Available The main products of sclareol (1 Ritter’s reaction in mild conditions are (8R,13R-Labd-14(15-en-8,13-diacetamide (2 (8R,13S-Labd-14(15-en-8,13-diacetamide (3 stereoisomeric on C13 atom and having unrearranged native diol skeleton. We present in the current communication the results of sclareol converting (1 into nitrogen-containing labdanes in the Ritter’s reaction conditions.

  3. Conditioning reaction time: evidence for a process of conditioned automatization.

    Montare, A


    The classical conditioning of the standard, simple reaction time (RT) in 140 college men and women is described. Consequent to an anticipatory instructed conditioning procedure, two experimental and two control groups acquired voluntary, controlled US(light)-URTR (unconditioned reaction-time response) associations which then served as the foundation for subsequent classical conditioning when a novel CS (auditory click) was simultaneously paired with the US. Conditioned reaction-time responses (CRTRs) occurred significantly more often during test trials in the two experimental groups than in the two control groups. Statistical and introspective findings support the notion that observed CRTRs may be products of cognitively unconscious conditioned automatization whereby the conditioning of relatively slow, voluntary, and controlled US-URTR associations leads to the acquisition of relatively fast, involuntary, and automatic CS-CRTR associations.

  4. Employer health insurance and local labor market conditions.

    Marquis, M S; Long, S H


    Theory suggests that an employer's decisions about the amount of health insurance included in the compensation package may be influenced by the practices of other employers in the market. We test the role of local market conditions on decisions of small employers to offer insurance and their dollar contribution to premiums using data from two large national surveys of employers. These employers are more likely to offer insurance and to make greater contributions in communities with tighter labor markets, less concentrated labor purchasers, greater union penetration, and a greater share of workers in big business and a small share in regulated industries. However, our data do not support the notion that marginal tax rates affect employers' offer decision or contributions.

  5. 76 FR 44265 - General Working Conditions in Shipyard Employment; Correction


    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Occupational Safety and Health Administration 29 CFR Part 1910 RIN 1218-AB50 General Working Conditions in... rule on General Working Conditions in Shipyard Employment published in the Federal Register of May...

  6. EU road freight transport sector : work and employment conditions

    Houtman, I.L.D.; Klein Hesselink, D.J.; Bossche, S.N.J. van den; Berg, R. van der; Heuvel, F. van den


    International competition and technological developments have had both positive and negative effects on the road freight transport sector. These changes have significantly influenced work and employment conditions in the sector. As this report highlights, creating more and better jobs while enhancin

  7. Membrane contactor assisted extraction/reaction process employing ionic liquids

    Lin, Yupo J.; Snyder, Seth W.


    The present invention relates to a functionalized membrane contactor extraction/reaction system and method for extracting target species from multi-phase solutions utilizing ionic liquids. One preferred embodiment of the invented method and system relates to an extraction/reaction system wherein the ionic liquid extraction solutions act as both extraction solutions and reaction mediums, and allow simultaneous separation/reactions not possible with prior art technology.

  8. Employment conditions and health inequities: a case study of Brazil.

    Dias, Elizabeth Costa; Oliveira, Roberval Passos de; Machado, Jorge H; Minayo-Gomez, Carlos; Perez, Marco Antonio Gomes; Hoefel, Maria da Graça L; Santana, Vilma Sousa


    This paper was prepared for the Employment Conditions and Health Inequalities Knowledge Network (EMCONET), part of the WHO Commission on the Social Determinants of Health. We describe the Brazilian context of employment conditions, labor conditions and health, their characteristics and causal relationships. The social, political and economic factors that influence these relationships are also presented with an emphasis on social inequalities, and how they are reproduced within the labor market and thereby affect the health and wellbeing of workers. A literature review was conducted in SciELO, LILACS, Google and Google Scholar, MEDLINE and the CAPES Brazilian thesis database. We observed that there are more workers operating in the informal sector than in the formal sector and these former have no social insurance or any other social benefits. Work conditions and health are poor in both informal and formal enterprises since health and safety labor norms are not effective. The involvement of social movements and labor unions in the elaboration and management of workers' health polices and programs with universal coverage, is a promising initiative that is underway nationwide.

  9. Conditions for Conclusion of Open-ended Employment Contract

    Wang Hongyan


    @@ The Law of the People's Republic of China on Employment Contracts (short for Law on Employment Contracts) carried out in 2008 classified the employment cantracts into three types: fixed-term employment contract, open-ended employment contract and employment contract to expire upon completion of a certain job.

  10. A Glycosidation Reaction Employing Montmorillonite K-10 as Catalyst

    Bedell, Brooke L.; Crouch, R. David; Holden, Michael S.; Martinson, Heidi E.


    The large number of biology majors and prehealth students enrolled in Organic Chemistry makes it desirable to have laboratories that involve biologically interesting molecules. Although many laboratory manuals contain sections on carbohydrate chemistry, the experiments are typically limited to esterification or hydrolysis reactions. A recent publication (Toshima, K.; Ishizuka, T.; Matsuo, G.; Nakata, M. Synlett. 1995, 306. ) on the glycosidation of glycals offered a different possibility.

  11. 34 CFR 675.20 - Eligible employers and general conditions and limitation on employment.


    ... employer to pay the non-Federal share of the student earnings. (2) The institution may enter into an... student earnings; and (ii) Required employer costs such as the employer's share of social security or... same position. (Approved by the Office of Management and Budget under control number...

  12. The Commission on Employment Conditions, an ambitious undertaking !

    Staff Association


    Since the beginning of the year, the Commission on Employment Conditions has had much success in the number and ability of its participants. It has mostly worked on salaries, the only compulsory subject of the 2010 five-yearly review. In the framework of this review, the Commission has analysed the results of the comparison carried out by the OECD (see Echo 104 and 105). Through its research and analysis, the Commission has clearly shown that our salaries are lower than those of the comparators. It is there necessary to adjust the salary grid with a salary catch-up and not an increase. In 20 years, no five-yearly review has ended with a significant catch-up. Today it is essential to inform our colleagues that this subject needs to be dealt with and that measures must be taken to finance it, as is the case for restoring the equilibrium of the Pension Fund and Health Insurance schemes. The Commission has established an argumentation to help our fellow delegates talk about the delicate subject of salary catch-...

  13. Employment and employment conditions in the current economic crisis in Croatia

    Goran Vukšić


    Full Text Available The goal of this research is to analyze developments in employment and employment characteristics during the current crisis in Croatia. The main findings can be summarized as follows: (1 The primary (aggregate mode of adjustment to the crisis was a decline in employment. There are, however, considerable differences in adjustment patterns across economic activities. (2 During the crisis, jobs were lost in the, more dynamic, private sector, while the number of jobs in the public sector (entities in state ownership slightly increased. (3 Economic activities with comparatively larger shares of women in employment have experienced fewer employment cuts and the aggregate employment share of women rose during the crisis, especially in activities with a larger share of public sector workers.(4 There has been a declining share of younger workers during the crisis, justifying policy actions to facilitate their employment. (5 Employees with comparatively lower educational attainment face severe challenges in the labor market, which is a longer term trend, not specific to the crisis period. There are indications that this group of employees enjoys a higher level of protection in the public sector. (6 Analysis also shows a rising significance of more flexible forms of employment: increasing shares of fixed term employees (during the last two observed years, and of part time workers. (7 Working hours do not exhibit any strong trends specific to the crisis, except for the diminishing number of overtime hours per worker.

  14. The effect of outside conditions on anaerobic ammonia oxidation reaction

    YANG Min; WANG Shu-bo


    Organic carbon, inorganic carbon, temperature, pH and ORP are all to have a certain influence on the anaerobic ammonia oxidation reaction. We can draw some conclusions on the optimum conditions of anaerobic ammonia oxidation reaction. The optimum temperature of the anaerobic ammonia oxidation reaction is 30-35℃. And the optimum pH of the anaerobic ammonia reaction is 7.5-8.3. The presence of organic matters can affect the anaerobic ammonia reaction, and different organic matters have different influence on it. The concentration of the inorganic carbon also exist great influence on the reaction. High inorganic carbon concentration also can inhibit anaerobic ammonia oxidation reaction.

  15. Transformation of employment conditions in information-network economy

    Anton Viktorovich Kozlov


    Full Text Available The features of information and network economy influence on the nature of employment are being analyzed. With the development of the fifth technological mode, mechanical movement of the labour forces from one industry to another one is impossible. This is prevented by a broad restructuring of the occupational structure of employment, the disappearance of many "old" professions and the emergence of the ones, which require special educational training. There is a growing share of employment mainly in mental labour and decrease of the proportion of persons employed in manual labour, which includes workers of all skill levels. The reduction of productive employment, partly related to labour productivity growth, is offset by its growth in non-manufacturing "computer" occupations - among various administrative support staff servicing computers, creators of peripheral equipment and programmers, operators of local networks etc. New information technologies make it possible to extend flexible forms of employment that do not require steady jobs. In this process, the information economy can provide a number of issues in employment related to the erosion of traditional social and labour relations, weakening of the legal protection of employees in the information business that requires adequate response of the society and the state.

  16. Employing Magnetic Levitation to Monitor Reaction Kinetics and Measure Activation Energy

    Benz, Lauren; Cesafsky, Karen E.; Le, Tran; Park, Aileen; Malicky, David


    This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

  17. Employing Magnetic Levitation to Monitor Reaction Kinetics and Measure Activation Energy

    Benz, Lauren; Cesafsky, Karen E.; Le, Tran; Park, Aileen; Malicky, David


    This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

  18. Latent inhibition of conditioned disgust reactions in rats.

    López, Matías; Gasalla, Patricia; Vega, Mercedes; Limebeer, Cheryl L; Rock, Erin M; Tuerke, Katharine J; Bedard, Holly; Parker, Linda A


    The present experiments, using the latent inhibition (LI) paradigm, evaluated the effect of nonreinforced exposure to saccharin on the acquisition of an LiCl-induced saccharin aversion as measured by conditioned disgust reactions in the taste reactivity test and conditioned taste avoidance in a consumption test. When rats were preexposed to saccharin by bottle exposure (Experiments 1 and 3), LI was evidenced only by conditioned taste avoidance (bottle testing), but not by conditioned disgust reactions (intraoral [IO] testing). On the other hand, when rats were preexposed to saccharin by IO infusion (Experiments 2 and 3), LI was evidenced only by conditioned disgust reactions, but not by conditioned taste avoidance. Experiment 4 showed that LI of conditioned disgust reactions does not appear to be affected by a context shift from preexposure to testing phases. These results show that the expression of LI of both conditioned taste avoidance and conditioned disgust reactions depends critically on a common method of flavor exposure during preexposure and testing.

  19. Optimization of ligation reaction conditions in gene synthesis.

    Theriault, N Y; Carter, J B; Pulaski, S P


    Several phosphorylation, annealing and ligation reaction conditions have been investigated for the enzymatic assembly of genes of interest. The use of longer oligodeoxyribonucleotides (40-60 bases long) also improved the enzymatic reaction. Furthermore, the use of longer oligonucleotides and the elimination of long stretches of G's or C's lowered the mutation rate.

  20. Labor market conditions and employment of the mentally ill.

    Catalano, Ralph; Drake, Robert E.; Becker, Deborah R.; Clark, Robin E.


    BACKGROUND: The mental health services literature includes assertions that workers with mental illness are at earlier risk of unemployment than other workers when the economy contracts. This possibility is important for several reasons. One is that such a phenomenon would support the argument that the lives of mentally ill persons are made unnecessarily stressful by the stigma of mental illness. Another is that the phenomenon could distort comparisons of the effectiveness of programs designed to prepare persons with severe mental illness for work. Despite its importance, the assertion that severely mentally ill workers are at early risk of unemployment has never been empirically tested. AIMS OF THE STUDY: We aim to test the hypothesis that unemployment among persons with severe mental illness (SMI) increases before job loss among other workers. METHODS: We test the hypothesis by applying Granger causality methods to time-series data collected in two communities in the United States (i.e., Concord and Manchester, NH) over 131 weeks beginning on 12 May 1991. RESULTS: We find no relationship between job loss in the labor market and the likelihood that persons with SMI will be unemployed. DISCUSSION: We speculate that persons with SMI participate in the secondary labor market and that their employment status is unlikely to be well described by data gathered in the primary labor market. This implies that widely available measures of labor market status, which are designed to describe the primary labor market, cannot be used to improve the evaluation of programs intended to prepare the mentally ill for work. We also discuss the possibility that persons with SMI may have needs that are better met by the secondary than by the primary labor market. CONCLUSIONS: The intuition that workers with severe mental illness are affected earlier than other workers by labor market contraction may not be correct. We infer that persons with severe mental illness may participate in the

  1. [Conditioned trace reactions of hypothalamic neurons following exposure to vibration].

    Mednikova, Iu S


    Trace reactions were studied in 112 hypothalamic units in rabbits during motor defensive conditioning to time after vibration action of two intensities. A later formation of conditioned trace reactions was observed as compared to the control. Vibration of lesser intensity improved the course of trace processes and slightly increased the number of neurones responding to the conditioned stimulus (45% as against 43% in the control); after a stronger vibration action, conditioned reactions to time were recorded only in 29% of the hypothalamic cells eith a simultaneous diminution of the trace response. It has been assumed that the observed transformations result from changes of the significance of the reinforcing factor in the formation of a motor defensive conditioned reflex after the action of vibration.

  2. Interpolated lattice Boltzmann boundary conditions for surface reaction kinetics.

    Walsh, S D C; Saar, M O


    This paper describes a method for implementing surface reaction kinetics in lattice Boltzmann simulations. The interpolated boundary conditions are capable of simulating surface reactions and dissolution at both stationary and moving solid-fluid and fluid-fluid interfaces. Results obtained with the boundary conditions are compared to analytical solutions for first-order and constant-flux kinetic surface reactions in a one-dimensional half space, as well as to the analytical solution for evaporation from the surface of a cylinder. Excellent agreement between analytical and simulated results is obtained for a wide range of diffusivities, lattice velocities, and surface reaction rates. The boundary model's ability to represent dissolution in binary fluid mixtures is demonstrated by modeling diffusion from a rising bubble and dissolution of a droplet near a flat plate.

  3. Chitosan microgels obtained by on-chip crosslinking reaction employing a microfluidic device

    Zamora-Mora, Vanessa; Velasco, Diego; Hernández, Rebeca; Mijangos, Carmen


    In the present work, we report on the preparation of microgels of chitosan crosslinked with sodium tripolyphosphate (TPP) employing the microfluidics technique (MF). To achieve this, several flow focusing geometries were designed and tested. As a first step, a two-inlet flow focusing geometry was employed to emulsify chitosan and the crosslinking reaction was carried out offchip. This procedure did not allow separating the resulting chitosan microgels due to an incomplete crosslinking reaction. A crosslinking reaction on-chip was studied as an alternative. A four-inlet flow focusing geometrywas designed in which three dispersed phases, chitosan 0.25% (w/v), TPP 0.05% (w/v) and acetic acid 1% (v/v) and an continuous phase mineral oil + Span 80 (3% w/v) were employed. The flow rates for the continuous phase were varied from 6.7 to 11.7 μL/min and chitosan microgels were successfully obtained with average diameters from 68 to 42 μm. The average size of the microgels outside the MF device decreased up to ~21% with respect to their size inside the MF device due to partial expulsion of water from the microgels when complete gelation occurred.


    Xabier eErdocia


    Full Text Available Organosolv lignin, obtained from olive tree pruning under optimised conditions, was subjected to a hydrothermal depolymerisation process catalysed by sodium hydroxide. The depolymerisation of lignin was carried out at 300 ºC using different reaction times (20, 40, 60, 70, 80, 90 and 100 min in order to study the influence of this parameter on lignin depolymerisation. The resulting products (oil and residual lignin were measured and analysed by different techniques (GC/MS, HPSEC and pyrolysis-GC/MS in order to determine their nature and composition. Coke was also formed, at a lower quantity, incompetitive repolymerisation reactions during the lignin hydrothermal treatment. The maximum oil yield and concentration of monomeric phenolic compounds was obtained after80 min of reaction time. The highest reaction time studied (100 min had the worst results with the lowest oil yield and highest coke production.

  5. Palladium(II-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

    Tanveer Mahamadali Shaikh


    Full Text Available A series of general and selective Pd(II-catalyzed Heck reactions were investigated under mild reaction conditions. The first protocol has been developed employing an imidazole-based secondary phosphine oxide (SPO ligated palladium complex (6 as a precatalyst. The catalytic coupling of aryl halides and olefins led to the formation of the corresponding coupled products in excellent yields. A variety of substrates, both electron-rich and electron-poor olefins, were converted smoothly to the targeted products in high yields. Compared with the existing approaches employing SPO–Pd complexes in a Heck reaction, the current strategy features mild reaction conditions and broad substrate scope. Furthermore, we described the coupling of arylboronic acids with olefins, which were catalyzed by Pd(OAc2 and employed N-bromosuccinimide as an additive under ambient conditions. The resulted biaryls have been obtained in moderate to good yields.

  6. 29 CFR 575.8 - Secretary's conditions for employment under the waiver.


    ... 29 Labor 3 2010-07-01 2010-07-01 false Secretary's conditions for employment under the waiver. 575.8 Section 575.8 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS WAIVER OF CHILD LABOR PROVISIONS FOR AGRICULTURAL EMPLOYMENT OF 10 AND 11...

  7. 29 CFR 575.7 - Statutory conditions for employment under the waiver.


    ... 29 Labor 3 2010-07-01 2010-07-01 false Statutory conditions for employment under the waiver. 575.7 Section 575.7 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS WAIVER OF CHILD LABOR PROVISIONS FOR AGRICULTURAL EMPLOYMENT OF 10 AND 11 YEAR OLD MINORS IN...

  8. Employment, Work Conditions, and the Home Environment in Single-Mother Families

    Lleras, Christy


    This study investigates the impact of employment status and work conditions on the quality of the home environment provided by single mothers of preschool-age children. Multivariate analyses were conducted using data from the National Longitudinal Survey of Youth. The results indicate that employment status is not a significant predictor of the…

  9. Employment, Work Conditions, and the Home Environment in Single-Mother Families

    Lleras, Christy


    This study investigates the impact of employment status and work conditions on the quality of the home environment provided by single mothers of preschool-age children. Multivariate analyses were conducted using data from the National Longitudinal Survey of Youth. The results indicate that employment status is not a significant predictor of the…

  10. Inquiry into Problems of Farmers’ Employment under the Condition of Land Transfer


    This paper emphasizes the urgency of solving the problems of farmers’ employment under the condition of land transfer,indicating that solving the problems of farmers’ employment is the necessary requirement of land transfer,the actual requirement of constructing well-off society comprehensively,and the objective requirement of transforming developmental model.The characteristics of the problems of farmers’ employment under the condition of land transfer are as follows:the rural surplus labor forces increase,and the ubiquitous unemployment is urgent;the employment room of farmers is narrow,and the structural unemployment is serious;the ability of farmers’ employment is poor,and recessive unemployment has a large proportion;the situation of farmers’ employment is not so sanguine,and the policy unemployment is frequent.This paper points out the causes of farmers’ employment problems under the situation of land transfer as follows:in terms of analysis of subjective factors,farmers’ self-employment ability is yet to be underpinned;in terms of analysis of objective factors,the relevant mechanism of government is unsound.Finally,corresponding countermeasures and suggestions are put forward as follows:establish the mechanism of farmer traceability analysis under the condition of land transfer;strengthen the training of farmers’ skills;reinforce the publicity and education of farmers’ employment concept;promote the process of urbanization and construct the employment vehicle of farmers;adjust the industrial structure in rural areas and expand the internal employment in rural areas;improve macro regulation and improve the employment environment for farmers.

  11. Tem holder for sample transfer under reaction conditions

    Damsgaard, Christian Danvad; Zandbergen, Henny W.; Wagner, Jakob Birkedal

    and temperature, which usually are far from the operando conditions of e.g. heterogeneous catalysis. Our efforts focus on bridging these gaps by establishing in situ sample transfer between complementary measurement techniques. To fully exploit the capabilities of ETEM complementary experiments...... and characterization techniques are beneficial. Normally, the complementary measurements are done in parallel with experiments separated in time and space [3] or by mimicking a reactor bed by changing the feed gas composition according to reactivity and conversion measured in dedicated catalyst set-ups [4...... (XRD) setup and subsequently successfully transferred under reaction conditions to the ETEM....

  12. Effects of Meteorological Conditions on Reactions to Noise Exposure

    Shepherd, Kevin P. (Technical Monitor); Fields, James M.


    More than 80,000 residents' responses to transportation noise at different times of year provide the best, but imprecise, statistical estimates of the effects of season and meteorological conditions on community response to noise. Annoyance with noise is found to be slightly statistically significantly higher in the summer than in the winter in a seven-year study in the Netherlands. Analyses of 41 other surveys drawn from diverse countries, climates, and times of year find noise annoyance is increased by temperature, and may be increased by more sunshine, less precipitation, and reduced wind speeds. Meteorological conditions on the day of the interview or the immediately preceding days do not appear to have any more effect on reactions than do the conditions over the immediately preceding weeks or months.


    Mihai CHIRILA


    Full Text Available The employment-productivity-salary correlation is essential towards setting up conditions for economic growth andlasting social stability. An influence exists from technological changes, current stage of economic development,peculiarities of labour offer, employers – trade-unions interaction, etc. The analysis covers long-term and short-termcycles. In keeping with specificity of development stages, national economy witnesses an interval of productivitygrowth facilitating maximized employment and a rise in salary too. A lower growth rate indicates difficulties inassimilating new technologies; a higher growth rate generates instability in employing labour. Thus, the exercise ofstrong pressure is shown to exist on economic and technological structures. Likewise, this is what happens whenproductivity goes ahead of the separate analyses of the correlations between employment and productivity, on theone hand, and productivity and salary, on the other.

  14. Developed Hybrid Model for Propylene Polymerisation at Optimum Reaction Conditions

    Mohammad Jakir Hossain Khan


    Full Text Available A statistical model combined with CFD (computational fluid dynamic method was used to explain the detailed phenomena of the process parameters, and a series of experiments were carried out for propylene polymerisation by varying the feed gas composition, reaction initiation temperature, and system pressure, in a fluidised bed catalytic reactor. The propylene polymerisation rate per pass was considered the response to the analysis. Response surface methodology (RSM, with a full factorial central composite experimental design, was applied to develop the model. In this study, analysis of variance (ANOVA indicated an acceptable value for the coefficient of determination and a suitable estimation of a second-order regression model. For better justification, results were also described through a three-dimensional (3D response surface and a related two-dimensional (2D contour plot. These 3D and 2D response analyses provided significant and easy to understand findings on the effect of all the considered process variables on expected findings. To diagnose the model adequacy, the mathematical relationship between the process variables and the extent of polymer conversion was established through the combination of CFD with statistical tools. All the tests showed that the model is an excellent fit with the experimental validation. The maximum extent of polymer conversion per pass was 5.98% at the set time period and with consistent catalyst and co-catalyst feed rates. The optimum conditions for maximum polymerisation was found at reaction temperature (RT 75 °C, system pressure (SP 25 bar, and 75% monomer concentration (MC. The hydrogen percentage was kept fixed at all times. The coefficient of correlation for reaction temperature, system pressure, and monomer concentration ratio, was found to be 0.932. Thus, the experimental results and model predicted values were a reliable fit at optimum process conditions. Detailed and adaptable CFD results were capable


    Mazhak, Iryna


    According to the research carried out by the Sociological Group "Rating" in December 2016, 60% of the respondents were employed, 40% - unemployed. Among the unemployed, one-third (32%) – pensioners, 27% – housekeeping and childcare, 13% – students, 21% – unemployed and looking for work, 6......% - unemployed and not looking for work. When analyzing their working conditions, the majority of the employed respondents mentioned, on the one hand, an absence of vibration, noise, air pollution, minor physical effort, and on the other, comfortable lighting and temperature. Along with that, almost half....... 88% of the respondents were hired workers, 12% – self-employed (businessmen, family business etc.). Higher rate of self-employment was recorded among married individuals, the middle-aged group, and respondents with high income. The majority (89%) of the respondents worked full time, 11% – part time...

  16. An Efficient Protocol for the Oxidative Hydrolysis of Ketone SAMP Hydrazones Employing SeO(2) and H(2)O(2) under Buffered (pH 7) Conditions.

    Smith, Amos B; Liu, Zhuqing; Simov, Vladimir


    An effective oxidative protocol for the liberation of ketones from SAMP hydrazones employing peroxyselenous acid under aqueous buffered conditions (pH 7) has been developed. The procedure proceeds without epimerization of adjacent stereocenters or dehydration, respectively, in representative SAMP alkylation and aldol reaction adducts.

  17. An Efficient Protocol for the Oxidative Hydrolysis of Ketone SAMP Hydrazones Employing SeO2 and H2O2 under Buffered (pH 7) Conditions

    Smith, Amos B.; Liu, Zhuqing; Simov, Vladimir


    An effective oxidative protocol for the liberation of ketones from SAMP hydrazones employing peroxyselenous acid under aqueous buffered conditions (pH 7) has been developed. The procedure proceeds without epimerization of adjacent stereocenters or dehydration, respectively, in representative SAMP alkylation and aldol reaction adducts. PMID:20657727

  18. Work Conditions and the Food Choice Coping Strategies of Employed Parents

    Devine, Carol M.; Farrell, Tracy J.; Blake, Christine E.; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A.


    Objective: How work conditions relate to parents' food choice coping strategies. Design: Pilot telephone survey. Setting: City in the northeastern United States (US). Participants: Black, white, and Hispanic employed mothers (25) and fathers (25) randomly recruited from low-/moderate-income zip codes; 78% of those reached and eligible…

  19. Work Conditions and the Food Choice Coping Strategies of Employed Parents

    Devine, Carol M.; Farrell, Tracy J.; Blake, Christine E.; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A.


    Objective: How work conditions relate to parents' food choice coping strategies. Design: Pilot telephone survey. Setting: City in the northeastern United States (US). Participants: Black, white, and Hispanic employed mothers (25) and fathers (25) randomly recruited from low-/moderate-income zip codes; 78% of those reached and eligible…

  20. Indirect employment effects of new business formation across regions : The role of local market conditions

    Fritsch, M.; Noseleit, F.


    We investigate the effect of local market conditions on the indirect effects of new business formation measured as their impact on employment in incumbents. Based on organizational ecology theory, we derive and test hypotheses about the magnitude of these indirect effects. The indirect effects are l

  1. Programming of employments physical exercises for the improvement of bodily condition of children of midchildhood.

    Sljusarchuk V.V.


    Full Text Available Approaches are considered on forming and realization of maintenance of physical education of students of initial school. The algorithm of programming of maintenance of lessons of physical culture is developed. The program foresees implementation of requirements of general and methodical principles of physical education, positions of theory of adaptation, requirements of the operating program. It is marked that employments must provide for: differentiated going near students, account of interests and to the wishes, motivation to independent employments by physical exercises, to providing of motor high-density. It is recommended to take into account the features of dynamics of indexes of bodily condition of children of different somatotype.

  2. [Economic crisis and employment conditions: gender differences and the response of social and employment policies. SESPAS report 2014].

    Escribà-Agüir, Vicenta; Fons-Martinez, Jaime


    The economic crisis has had an impact across the European Union (EU), but has had a devastating impact on the labor market in Spain, which has become the country within the EU-15 with the worst employment indicators. The situation is worse in younger people, half of whom were unemployed in 2012, with a slightly higher rate in men (54.4%) than in women (51.8%). This high unemployment rate will be even more difficult to redress because of the decrease in public spending on active employment per percentage point of unemployment in 2012 compared with 2007. Furthermore, the decrease in spending on passive employment policies will worsen the health of the unemployed population. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

  3. Impact of reaction conditions on grafting acrylamide onto starch

    We have explored the radical initiated graft polymerization reaction of acrylamide onto starch where the solvent, concentration, temperature and reaction times were varied. We have found that the morphology of the resulting grafted polymer is dramatically different and is dependent on the reaction c...

  4. Nothing ventured, nothing gained! : How and under which conditions employers provide employability-enhancing practices to their older workers

    M. Fleischmann (Maria); F. Koster (Ferry); J.J. Schippers (Joop)


    textabstractEmployability-enhancing practices usually refer to training or courses, but also practices directed towards older workers to sustain their work capability can be embraced by this term. In the context of an ageing population and workforce, older workers’ labour market participation gains

  5. Influence of Reaction Conditions on Methanol Synthesis and WGS Reaction in the Syngas-to-DME Process


    A series of CuO-ZnO catalysts (with different Cu/Zn molar ratios) were prepared, and evaluated under the reaction conditions of syngas-to-dimethyl ether (DME) with three sorts of feed gas and different space velocity. The catalysts were characterized by X-ray diffraction (XRD) and temperatureprogrammed reduction (TPR). The experiment results showed that the reaction conditions of syngas-to-DME process greatly affected the methanol synthesis and WGS reaction. The influence caused by Cu/Zn molar ratio was quite different on the two reactions; increasing of percentage of CO2 in feed gas was unfavorable for catalyst activity, and also inhibited both reactions; enhancement of reaction space velocity heavily influenced the performance of the catalyst, and the benefits were relatively less for methanol synthesis than for the WGS reaction.

  6. Green chemistry: a facile synthesis of polyfunctionally substituted thieno[3,4-c]pyridinones and thieno[3,4-d]pyridazinones under neat reaction conditions.

    Al-Zaydi, Khadijah M; Borik, Rita M; Mekheimer, Ramadan A; Elnagdi, Mohamed H


    A facile, solvent free, ecofriendly approach for the synthesis of pyridine-2,6-diones 4a-d, pyridazinone derivatives 8a-c and thienoazines 6 and 9 is herein described employing neat reaction conditions under both microwave and ultrasound irradiations. This solventless methodology is environmentally benign as it completely eliminates the use of solvent from the reaction procedure.

  7. Medication therapy management and condition care services in a community-based employer setting.

    Johannigman, Mark J; Leifheit, Michael; Bellman, Nick; Pierce, Tracey; Marriott, Angela; Bishop, Cheryl


    A program in which health-system pharmacists and pharmacy technicians provide medication therapy management (MTM), wellness, and condition care (disease management) services under contract with local businesses is described. The health-system pharmacy department's Center for Medication Management contracts directly with company benefits departments for defined services to participating employees. The services include an initial wellness and MTM session and, for certain patients identified during the initial session, ongoing condition care. The initial appointment includes a medication history, point-of-care testing for serum lipids and glucose, body composition analysis, and completion of a health risk assessment. The pharmacist conducts a structured MTM session, reviews the patient's test results and risk factors, provides health education, discusses opportunities for cost savings, and documents all activities on the patient's medication action plan. Eligibility for the condition care program is based on a diagnosis of diabetes, hypertension, asthma, heart failure, or hyperlipidemia or elevation of lipid or glucose levels. Findings are summarized for employers after the initial wellness screening and at six-month intervals. Patients receiving condition care sign a customized contract, establish goals, attend up to four MTM sessions per year, and track their information on a website; employers may offer incentives for participation. When pharmacists recommend adjustments to therapy or cost-saving changes, it is up to patients to discuss these with their physician. A survey completed by each patient after the initial wellness session has indicated high satisfaction. Direct cost savings related to medication changes have averaged $253 per patient per year. Total cost savings to companies in the first year of the program averaged $1011 per patient. For the health system, the program has been financially sustainable. Key laboratory values indicate positive clinical

  8. Employment conditions of blacks in the coal industry, 1900 to 1930

    Fishback, P.V.M.


    Economic historians recently have analyzed black economic welfare mostly in agriculture. The thesis contributes to knowledge of black welfare in nonagricultural employment by analyzing their status in bituminous-coal mining, an industry in which black employment rose throughout the handloading era ending in 1930. Employmen conditions of blacks are compared with those of native whites and immigrants. Using a model of Schumpeterian competition in an environment of racial hostility, the study analyzes the multiple facets of employment packages, as well as differences in the individuals' initial endowments of wealth and skills, acquisition of human capital, and mobility. Discrimination is found to have been a minor factor in the West Virginia coal industry. Piece-rate wages, about which information was relatively easy to gather, were the same for all ethnic groups. The evidence is consistent with the hypothesis that blacks did not receive unequal treatment via assignments in the mine that affected their safety. Lack of managment positions for blacks was the primary form of job segregation.

  9. Acetalization of furfural with zeolites under benign reaction conditions

    Rubio-Caballeroa, Juan Miguel; Shunmugavel, Saravanamurugan; Maireles-Torres, Pedro


    Acetalization is a viable method to protect carbonyl functionalities in organic compounds and offers apotential synthetic strategy for synthesizing derived chemicals. In this work, several families of commer-cial zeolites have been employed as solid acid catalysts in the acetalization of furfural...

  10. Radiative flow of a tangent hyperbolic fluid with convective conditions and chemical reaction

    Hayat, Tasawar; Qayyum, Sajid; Ahmad, Bashir; Waqas, Muhammad


    The objective of present paper is to examine the thermal radiation effects in the two-dimensional mixed convection flow of a tangent hyperbolic fluid near a stagnation point. The analysis is performed in the presence of heat generation/absorption and chemical reaction. Convective boundary conditions for heat and mass transfer are employed. The resulting partial differential equations are reduced into nonlinear ordinary differential equations using appropriate transformations. Series solutions of momentum, energy and concentration equations are computed. The characteristics of various physical parameters on the distributions of velocity, temperature and concentration are analyzed graphically. Numerical values of skin friction coefficient, local Nusselt and Sherwood numbers are computed and examined. It is observed that larger values of thermal and concentration Biot numbers enhance the temperature and concentration distributions.

  11. Application of click chemistry conditions for 5-bromo-2'-deoxyuridine determination through Fenton and related reactions.

    Cappella, Paolo; Pulici, Maurizio; Gasparri, Fabio


    Mixtures of ascorbate and copper used in certain click chemistry experimental conditions act as oxidizing agents, catalyzing the formation of reactive oxygen species through Fenton and related reactions. Hydroxyl radicals act as chemical nucleases, introducing DNA strand breaks that can be exploited for BrdU immunostaining in place of acid denaturation. This procedure is readily applicable to high content analysis and flow cytometry assays, and provides results comparable to click chemistry EdU cycloaddition and classical BrdU immunodetection. Importantly, this approach allows preservation of labile epitopes such as phosphoproteins. This unit describes an optimized method that successfully employs Fenton chemistry for simultaneous detection of phosphoproteins and BrdU in intact cells.

  12. Associations between social vulnerability, employment conditions and hazardous alcohol consumption in Chile.

    Ansoleaga, Elisa; Castillo-Carniglia, Alvaro


    Studies from many different countries have found associations between alcohol use, employment and social context. The aim of this study was to investigate associations between hazardous alcohol consumption (HAC), social vulnerability and employment conditions among Chilean adults. A cross-sectional study, involving analysis of the 2008 National Survey on Drugs in Chile, was conducted on 8316 economically active men and women aged between 18 and 65 years, who completed the alcohol section of the survey. The participants were selected randomly and data collected through face-to-face interviews. Multilevel analysis was used to achieve the study's objectives. The Alcohol Use Disorders Identification Test was used to define HAC. There were no significant associations between HAC and employment status or occupational category when controlling for potential confounders. Using the social services sector as a reference, the adjusted odds ratio (95% confidence interval) of HAC was 2.60 (1.96-3.46) for those who worked in construction, 2.03 (1.43-2.89) in mining, 1.74 in agriculture (1.16-2.63) and in industry (1.26-2.39), 1.73 (1.31-2.28) in trade, 1.67 (1.29-2.16) in other services and 1.42 (1.01-2.00) in transport. There was no association between the socioeconomic status of the participant's neighbourhood and HAC in the fully adjusted model. The perception of neighbourhood security (third quartile of insecurity) was associated with HAC (odds ratio 1.22; 95% confidence interval 1.02-1.46). HAC was independently associated with the participant's economic sector and perception of neighbourhood security in Chilean adults. It is important to perform in-depth analyses of contextual effects on individual alcohol consumption. © 2012 Australasian Professional Society on Alcohol and other Drugs.

  13. Work Conditions and the Food Choice Coping Strategies of Employed Parents

    Devine, Carol M.; Farrell, Tracy J.; Blake, Christine E.; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A.


    Objective How work conditions relate to parents’ food choice coping strategies Design Pilot telephone survey Setting Northeastern U.S. city Participants Black, white, Hispanic employed mothers (25) and fathers (25) randomly recruited from low/moderate income zip codes; 78% of reached and eligible Variables Measure(s) Socio-demographic characteristics; work conditions (hours, shift, schedule, job security, satisfaction, food access); food choice coping strategies (22 behavioral items for managing food in response to work and family demands (i.e.: food prepared at/away from home, missing meals, individualizing meals, speeding up, planning)) Analysis Two-tailed chi-square and Fisher’s exact tests (p=food choice coping strategies. Long hours and non-standard hours and schedules were positively associated among fathers with take-out meals, missed family meals, prepared entrees, and eating while working; and among mothers with restaurant meals, missed breakfast, and prepared entrees. Job security, satisfaction and food access were also associated with gender-specific strategies. Conclusions and Implications Structural work conditions among parents such as job hours, schedule, satisfaction, and food access are associated with food choice coping strategies with importance for dietary quality. Findings have implications for worksite interventions but need examination in a larger sample. PMID:19717121

  14. Information Management in Portugal: education and employment conditions and some prospects

    Maria Cristina Vieira de Freitas


    Full Text Available The Professors Cristina Freitas and Maria da Graça Simões answer questions prepared by teachers from the Faculdade de Informação e Comunicação (Gestão da Informação Undergraduate Degree da Universidade Federal de Goiás - UFG. The questions are related to the educational structure dedicated to the issues of information management in Portugal, the influence of the "Big Data" phenomenon on education and training in the area - including discussions on data governance, the fundation areas of Information Management and the main approaches to information research in the Country. Besides, they discuss the employment conditions (threats and opportunities for professionals in Information Management in Portugal and in Europe [Available Language: Portuguese/Portugal].

  15. Intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione under the Mitsunobu reaction conditions

    Yu Xia Da; Zhang Zhang; Zheng Jun Quan


    A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione (DHPM) to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate (DEAD) and triphenylphosphine (TPP) at room temperature is reported.

  16. The Health and Working Conditions of Women Employed in Child Care.

    Linnan, Laura; Arandia, Gabriela; Bateman, Lori A; Vaughn, Amber; Smith, Natalie; Ward, Dianne


    Over one million women are employed in child care and are among the lowest wage workers in the US. The health and working conditions of 674 child care workers (118 administrators and 556 staff) from 74 centers is described using baseline data from a larger intervention trial. Participants were 39.9 (±13.0) years old; 55.4% African American, 37.1% Caucasian, and 5.3% of Hispanic ethnicity. Seventy-six percent reported having an Associate's degree or less; 42% were classified as at or below poverty (income and job category. Lower income participants were significantly more likely to be current smokers (19.9% vs. 11.7%), drink more sweetened beverages (1.9 vs. 1.5), and report higher depressive symptoms (15.5 vs. 12.6). Administrators worked more hours weekly compared to staff (46.4 vs. 40.6), are less active (100 vs. 126 min/week), more sedentary (501 vs. 477 min/day), and reported higher job demands (13.3 vs. 12.5). Given the numerous health issues and challenging work conditions, we hope our results serve as a call to action for addressing low wages and the work environment as a means of influencing the health and well-being of child care workers.

  17. The Health and Working Conditions of Women Employed in Child Care

    Laura Linnan


    Full Text Available Over one million women are employed in child care and are among the lowest wage workers in the US. The health and working conditions of 674 child care workers (118 administrators and 556 staff from 74 centers is described using baseline data from a larger intervention trial. Participants were 39.9 (±13.0 years old; 55.4% African American, 37.1% Caucasian, and 5.3% of Hispanic ethnicity. Seventy-six percent reported having an Associate’s degree or less; 42% were classified as at or below poverty (<$20,000; and exhibited many health risks such as excess weight, insufficient activity, poor diet, and inadequate sleep. We investigated potential differences by income and job category. Lower income participants were significantly more likely to be current smokers (19.9% vs. 11.7%, drink more sweetened beverages (1.9 vs. 1.5, and report higher depressive symptoms (15.5 vs. 12.6. Administrators worked more hours weekly compared to staff (46.4 vs. 40.6, are less active (100 vs. 126 min/week, more sedentary (501 vs. 477 min/day, and reported higher job demands (13.3 vs. 12.5. Given the numerous health issues and challenging work conditions, we hope our results serve as a call to action for addressing low wages and the work environment as a means of influencing the health and well-being of child care workers.

  18. Nucleophilic Addition Reactions of Nitriles to Nitrones under Mild Silylation Conditions

    Tanino, Keiji; Yoshimura, Fumihiko; Abe, Taiki


    In the presence of triethylsilyl trifluoromethanesulfonate and triethylamine, aliphatic nitriles undergo addition reactions with aldonitrones under non-basic, mild conditions, providing O-tri­ethylsilyl ethers of β-N-hydroxyamino nitriles with high yield. The reaction appears to proceed through formation of an N-silyl ketene imine in situ followed by a Mannich-type reaction.

  19. Presidential Green Chemistry Challenge: 2008 Greener Reaction Conditions Award

    Presidential Green Chemistry Challenge 2008 award winner, Nalco Company, developed 3D TRASAR technology to monitor the condition of cooling water continuously and add chemicals only when needed, saving water and energy.

  20. Regimes of chemical reaction waves initiated by nonuniform initial conditions for detailed chemical reaction models.

    Liberman, M A; Kiverin, A D; Ivanov, M F


    Regimes of chemical reaction wave propagation initiated by initial temperature nonuniformity in gaseous mixtures, whose chemistry is governed by chain-branching kinetics, are studied using a multispecies transport model and a detailed chemical model. Possible regimes of reaction wave propagation are identified for stoichiometric hydrogen-oxygen and hydrogen-air mixtures in a wide range of initial pressures and temperature levels, depending on the initial non-uniformity steepness. The limits of the regimes of reaction wave propagation depend upon the values of the spontaneous wave speed and the characteristic velocities of the problem. It is shown that one-step kinetics cannot reproduce either quantitative neither qualitative features of the ignition process in real gaseous mixtures because the difference between the induction time and the time when the exothermic reaction begins significantly affects the ignition, evolution, and coupling of the spontaneous reaction wave and the pressure wave, especially at lower temperatures. We show that all the regimes initiated by the temperature gradient occur for much shallower temperature gradients than predicted by a one-step model. The difference is very large for lower initial pressures and for slowly reacting mixtures. In this way the paper provides an answer to questions, important in practice, about the ignition energy, its distribution, and the scale of the initial nonuniformity required for ignition in one or another regime of combustion wave propagation.

  1. Platelet reactions to modified surfaces under dynamic conditions.

    Rhodes, N P; Shortland, A P; Rattray, A; Williams, D F


    The influence of surfaces on the reactions of platelets in whole blood under laminar flow was investigated in a cone and plate viscometer. Citrated whole blood was exposed to steel, PMMA and PMMA modified with PEO at low (500 s(-1)) and high (4000 s(-1)) wall shear rates at room temperature for a period of 100 s. Treated blood samples were fixed with paraformaldehyde, stained with a monoclonal antibody for CD41 (platelet GPIIb/IIIa) conjugated with phycoerythrin and analyzed by flow cytometry. The reactions of platelets (microparticle generation and formation of platelet-platelet, platelet-red blood cell and red blood cell-microparticle aggregates) to these environments were quantified. Additionally, the size of platelet-platelet aggregates was assessed. The percentage platelet aggregation and numbers of microparticles generated were independent of surface type at any shear rate. The composition of the aggregates formed was influenced by the surface: at low and high shear rates PMMA caused the generation of platelet-platelet aggregates of the greatest size. The numbers of red blood cell-platelet and red blood cell-microparticle aggregates also varied depending on the surface. Fewer red blood cell-platelet aggregates were formed at higher shear rates, whereas the reverse was true for red blood cell-microparticle aggregates. It is concluded that these variations may help to explain the differential effects of surfaces to the induction of distant thrombotic events: microparticles may be protected from loss from the blood stream by their association with red blood cells at high shear rates.

  2. Conditions on exchange mechanisms for polarization effects in inclusive reactions

    Salin, P


    In the framework of Mueller-Regge phenomenology the conditions under which one could expect to observe polarization effects in the fragmentation region for inclusive relations are investigated. On the basis of kinematical considerations and parity relations only, it is found that this requires exchange of states with mixed naturalities. (9 refs).

  3. Reactions to Ostracism in Adolescents with Autism Spectrum Conditions

    Sebastian, Catherine; Blakemore, Sarah-Jayne; Charman, Tony


    Little is known about how adolescents with autism spectrum conditions (ASC) experience the initial impact of ostracism. This study investigated whether a mild, short-term episode of experimentally induced ostracism (Cyberball) would affect self-reported anxiety, mood, and the extent to which four social needs (self-esteem, belonging, control and…

  4. The Condition of the Turking Class: Are Online Employers Fair and Honest?

    Horton, John


    Online labor markets give people in poor countries direct access to buyers in rich countries. Economic theory and empirical evidence strongly suggest that this kind of access improves human welfare. However, critics claim that abuses are endemic in these markets and that employers exploit unprotected, vulnerable workers. I investigate part of this claim using a randomized, paired survey in which I ask workers in an online labor market (Amazon Mechanical Turk) how they perceive online employers and employers in their host country in terms of honesty and fairness. I find that, on average, workers perceive the collection of online employers as slightly fairer and more honest than offline employers, though the effect is not significant. Views are more polarized in the online employer case, with more respondents having very positive views of the online collection of employers.

  5. Exact and truncated Coriolis coupling calculations for the S(1D)+HD reaction employing the ground adiabatic electronic state.

    Yang, Huan; Han, Keli; Schatz, George C; Smith, Sean C; Hankel, Marlies


    We present exact quantum differential cross sections and exact and estimated integral cross sections and branching ratios for the title reaction. We employ a time-dependent wavepacket method as implemented in the DIFFREALWAVE code including all Coriolis couplings and also an adapted DIFFREALWAVE code where the helicity quantum number and with this the Coriolis couplings have been truncated. Our exact differential cross sections at 0.453 eV total energy, one of the experimental energies, show good agreement with the experimental results for one of the product channels. While the truncated calculation present a significant reduction in the computational effort needed they overestimate the exact integral cross sections.

  6. The Impact of Employment and Self-Rated Economic Condition on the Subjective Well-Being of Older Korean Immigrants.

    Kim, Bum Jung; Lee, Yura; Sangalang, Cindy; Harris, Lesley M


    Extensive research has demonstrated a relationship between socioeconomic factors and health among older adults, yet fewer studies have explored this relationship with older immigrants. This study aims to examine the influence of employment and self-rated economic condition on the subjective well-being of older Korean immigrants in the United States. Data were drawn from a cross-sectional study of 205 older Korean immigrants, aged 65 to 90, in Los Angeles County. Hierarchical regression was employed to explore the independent and interactive effects of employment status and self-rated economic condition. The study found that employment and self-rated economic status were positively associated with subjective well-being. Also, the interaction between employment and self-rated economic status was significantly associated with higher levels of subjective well-being, such that the influence of self-rated economic condition was stronger for unemployed older Korean immigrants compared with those who were employed. This population-based study provides empirical evidence that employment and self-rated economic condition are directly associated with subjective well-being for older Korean immigrants.

  7. Biofilm reactors for industrial bioconversion processes: employing potential of enhanced reaction rates

    Karcher Patrick


    Full Text Available Abstract This article describes the use of biofilm reactors for the production of various chemicals by fermentation and wastewater treatment. Biofilm formation is a natural process where microbial cells attach to the support (adsorbent or form flocs/aggregates (also called granules without use of chemicals and form thick layers of cells known as "biofilms." As a result of biofilm formation, cell densities in the reactor increase and cell concentrations as high as 74 gL-1 can be achieved. The reactor configurations can be as simple as a batch reactor, continuous stirred tank reactor (CSTR, packed bed reactor (PBR, fluidized bed reactor (FBR, airlift reactor (ALR, upflow anaerobic sludge blanket (UASB reactor, or any other suitable configuration. In UASB granular biofilm particles are used. This article demonstrates that reactor productivities in these reactors have been superior to any other reactor types. This article describes production of ethanol, butanol, lactic acid, acetic acid/vinegar, succinic acid, and fumaric acid in addition to wastewater treatment in the biofilm reactors. As the title suggests, biofilm reactors have high potential to be employed in biotechnology/bioconversion industry for viable economic reasons. In this article, various reactor types have been compared for the above bioconversion processes.

  8. The Pt(111)/Electrolyte Interface under Oxygen Reduction Reaction Conditions

    Bondarenko, A.S.; Stephens, Ifan; Hansen, Heine Anton;


    between the adsorbate and Pt surface atoms (0.45−1.15 V vs RHE). An equivalent electric circuit is proposed to model the Pt(111)/electrolyte interface under ORR conditions within the selected potential window. This equivalent circuit reflects three processes with different time constants, which occur...... simultaneously during the ORR at Pt(111). Density functional theory (DFT) calculations were used to correlate and interpret the results of the measurements. The calculations indicate that the coadsorption of ClO4* and Cl* with OH* is unlikely. Our analysis suggests that the two-dimensional (2D) structures formed...

  9. Reaction condition optimization and kinetic investigation of roasting zinc oxide ore using (NH4)2SO4

    Shao, Hong-mei; Shen, Xiao-yi; Sun, Yi; Liu, Yan; Zhai, Yu-chun


    An orthogonal test was used to optimize the reaction conditions of roasting zinc oxide ore using (NH4)2SO4. The optimized reaction conditions are defined as an (NH4)2SO4/zinc molar ratio of 1.4:1, a roasting temperature of 440°C, and a thermostatic time of 60 min. The molar ratio of (NH4)2SO4/zinc is the most predominant factor and the roasting temperature is the second significant factor that governs the zinc extraction. Thermogravimetric-differential thermal analysis was used for (NH4)2SO4 and zinc mixed in a molar ratio of 1.4:1 at the heating rates of 5, 10, 15, and 20 K·min-1. Two strong endothermic peaks indicate that the complex chemical reactions occur at approximately 290°C and 400°C. XRD analysis was employed to examine the transformations of mineral phases during roasting process. Kinetic parameters, including reaction apparent activation energy, reaction order, and frequency factor, were calculated by the Doyle-Ozawa and Kissinger methods. Corresponding to the two endothermic peaks, the kinetic equations were obtained.

  10. Reaction Behaviors of Glycine under Super- and Subcritical Water Conditions

    Alargov, Dimitar K.; Deguchi, Shigeru; Tsujii, Kaoru; Horikoshi, Koki


    The influence of temperature and pressure on the dimerization and decomposition of glycine under simulated hydrothermal system conditions was studied by injecting a glycine solution into water in the sub- and supercritical state. The experiments at five different temperatures of supplied water - 250, 300, 350, 374, and 400 °C - were performed at 22.2 and 40.0 MPa. At 350 °C, experiments under 15.0-40.0 MPa were conducted. Diglycine, triglycine (trace), diketopiperazine, and an unidentified product with a high molecular mass (433 Da) were the main products of oligomerization. The results show that temperature and pressure influence the extent of dimerization and decomposition of glycine. The maximum of dimers formation was observed at 350 and 375 °C at 22.2 and 40.0 MPa, respectively, and coincided with a high rate of glycine decomposition. Glycine, alanine, aspartic acid, as well as other amino acids, were obtained by injecting a mixture of formaldehyde and ammonia. The results support the oligomerization and synthesis of amino acids in a submarine hydrothermal system.

  11. Employment Condition, Economic Deprivation and Self-Evaluated Health in Europe: Evidence from EU-SILC 2009–2012

    Silvia Bacci


    Full Text Available Background: The mixed empirical evidence about employment conditions (i.e., permanent vs. temporary job, full-time vs. part-time job as well as unemployment has motivated the development of conceptual models with the aim of assessing the pathways leading to effects of employment status on health. Alongside physically and psychologically riskier working conditions, one channel stems in the possibly severe economic deprivation faced by temporary workers. We investigate whether economic deprivation is able to partly capture the effect of employment status on Self-evaluated Health Status (SHS. Methods: Our analysis is based on the European Union Statistics on Income and Living Conditions (EU-SILC survey, for a balanced sample from 26 countries from 2009 to 2012. We estimate a correlated random-effects logit model for the SHS that accounts for the ordered nature of the dependent variable and the longitudinal structure of the data. Results and Discussion: Material deprivation and economic strain are able to partly account for the negative effects on SHS from precarious and part-time employment as well as from unemployment that, however, exhibits a significant independent negative association with SHS. Conclusions: Some of the indicators used to proxy economic deprivation are significant predictors of SHS and their correlation with the employment condition is such that it should not be neglected in empirical analysis, when available and further to the monetary income.

  12. In-situ scanning transmission X-ray microscopy of catalytic materials under reaction conditions

    E. Smit; Creemer, J.F.; Zandbergen, H. W.; Weckhuysen, B. M.; Groot, F.M.F. de


    In-situ Scanning X-ray Transmission Microscopy (STXM) allows the measurement of the soft X-ray absorption spectra with 10 to 30 nm spatial resolution under realistic reaction conditions. We show that STXM-XAS in combination with a micromachined nanoreactor can image a catalytic system under relevant reaction conditions, and provide detailed information on the morphology and composition of the catalyst material. The nanometer resolution combined with powerful chemical speciation by XAS and the...

  13. Surface patterning with natural and synthetic polymers via an inverse electron demand Diels-Alder reaction employing microcontact chemistry.

    Roling, Oliver; Mardyukov, Artur; Lamping, Sebastian; Vonhören, Benjamin; Rinnen, Stefan; Arlinghaus, Heinrich F; Studer, Armido; Ravoo, Bart Jan


    Bioorthogonal ligation methods are the focus of current research due to their versatile applications in biotechnology and materials science for post-functionalization and immobilization of biomolecules. Recently, inverse electron demand Diels-Alder (iEDDA) reactions employing 1,2,4,5-tetrazines as electron deficient dienes emerged as powerful tools in this field. We adapted iEDDA in microcontact chemistry (μCC) in order to create enhanced surface functions. μCC is a straightforward soft-lithography technique which enables fast and large area patterning with high pattern resolutions. In this work, tetrazine functionalized surfaces were reacted with carbohydrates conjugated with norbornene or cyclooctyne acting as strained electron rich dienophiles employing μCC. It was possible to create monofunctional as well as bifunctional substrates which were specifically addressable by proteins. Furthermore we structured glass supported alkene terminated self-assembled monolayers with a tetrazine conjugated atom transfer radical polymerization (ATRP) initiator enabling surface grafted polymerizations of poly(methylacrylate) brushes. The success of the surface initiated iEDDA via μCC as well as the functionalization with natural and synthetic polymers was verified via fluorescence and optical microscopy, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), atomic force microscopy (AFM) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).

  14. 77 FR 18 - General Working Conditions in Shipyard Employment; Approval of Information Collection Requirements


    ... Occupational Safety and Health Administration 29 CFR Part 1915 RIN 1218-AB50 General Working Conditions in... information requirements contained in the General Working Conditions Standard under the Paperwork Reduction...- 2222. SUPPLEMENTARY INFORMATION: OSHA published a final rule for General Working Conditions in...

  15. Optimized Reaction Conditions for Amide Bond Formation in DNA-Encoded Combinatorial Libraries.

    Li, Yizhou; Gabriele, Elena; Samain, Florent; Favalli, Nicholas; Sladojevich, Filippo; Scheuermann, Jörg; Neri, Dario


    DNA-encoded combinatorial libraries are increasingly being used as tools for the discovery of small organic binding molecules to proteins of biological or pharmaceutical interest. In the majority of cases, synthetic procedures for the formation of DNA-encoded combinatorial libraries incorporate at least one step of amide bond formation between amino-modified DNA and a carboxylic acid. We investigated reaction conditions and established a methodology by using 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide, 1-hydroxy-7-azabenzotriazole and N,N'-diisopropylethylamine (EDC/HOAt/DIPEA) in combination, which provided conversions greater than 75% for 423/543 (78%) of the carboxylic acids tested. These reaction conditions were efficient with a variety of primary and secondary amines, as well as with various types of amino-modified oligonucleotides. The reaction conditions, which also worked efficiently over a broad range of DNA concentrations and reaction scales, should facilitate the synthesis of novel DNA-encoded combinatorial libraries.

  16. Economic Conditions and Employment Dynamics of Immigrants versus Natives: Who Pays the Costs of the “Great Recession”?


    This paper studies how unemployment and employment durations for immigrants and natives respond differently to changes in the economic conditions due to the 2008 crisis and to the receipt of unemployment benefits when the economy declines. Using administrative data for Spain, we estimate multi-state multi-spell duration models that disentangle unobserved heterogeneity from true duration dependence. Our findings suggest that immigrants are more sensitive to changes in economic conditions, both...

  17. Active sites in Cu-SSZ-13 deNOx catalyst under reaction conditions: a XAS/XES perspective

    Lomachenko, Kirill A.; Borfecchia, Elisa; Bordiga, Silvia; Soldatov, Alexander V.; Beato, Pablo; Lamberti, Carlo


    Cu-SSZ-13 is a highly active catalyst for the NH3-assisted selective catalytic reduction (SCR) of the harmful nitrogen oxides (NOx, x=1, 2). Since the catalytically active sites for this reaction are mainly represented by isolated Cu ions incorporated into the zeolitic framework, element-selective studies of Cu local environment are crucial to fully understand the enhanced catalytic properties of this material. Herein, we highlight the recent advances in the characterization of the most abundant Cu-sites in Cu-SSZ-13 upon different reaction-relevant conditions made employing XAS and XES spectroscopies, complemented by computational analysis. A concise review of the most relevant literature is also presented.

  18. Previous Employment and Job Satisfaction Conditions: The Case of Regional Administration

    Amalia, Myronaki; Nikolaos, Antonakas


    In the present work we study the different dimensions of satisfaction and the way of constitution of satisfaction of an important sample of the employees in the Regional administration of Crete and in their connection with the variable of the previous employment. We found statistically important differences for the components of satisfaction from the life, collaboration in and outside from the department, in the social satisfaction and the variable of the years in the service (labour group with satisfaction than the other previous employment groups. In the other hand the group with many years in the service presents bigger satisfaction than the other groups. Finally, is important to note that the sample present some interesting characteristics.

  19. In-situ Scanning Transmission X-ray Microscopy of catalytic materials under reaction conditions

    de Smit, Emiel; Creemer, J. Fredrik; Zandbergen, Henny W.; Weckhuysen, Bert M.; de Groot, Frank M. F.


    In-situ Scanning X-ray Transmission Microscopy (STXM) allows the measurement of the soft X-ray absorption spectra with 10 to 30 nm spatial resolution under realistic reaction conditions. We show that STXM-XAS in combination with a micromachined nanoreactor can image a catalytic system under relevant reaction conditions, and provide detailed information on the morphology and composition of the catalyst material. The nanometer resolution combined with powerful chemical speciation by XAS and the ability to image materials under realistic conditions opens up new opportunities to study many chemical processes.

  20. In-situ Scanning Transmission X-ray Microscopy of catalytic materials under reaction conditions

    Smit, Emiel de; Weckhuysen, Bert M; Groot, Frank M F de [Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht (Netherlands); Creemer, J Fredrik [DIMES-ECTM, Delft University of Technology, 2600 GB Delft (Netherlands); Zandbergen, Henny W, E-mail: e.desmit@uu.n [Kavli Institute of NanoScience, National Centre for High Resolution Electron Microscopy, Delft University of Technology, 2600 GA Delft (Netherlands)


    In-situ Scanning X-ray Transmission Microscopy (STXM) allows the measurement of the soft X-ray absorption spectra with 10 to 30 nm spatial resolution under realistic reaction conditions. We show that STXM-XAS in combination with a micromachined nanoreactor can image a catalytic system under relevant reaction conditions, and provide detailed information on the morphology and composition of the catalyst material. The nanometer resolution combined with powerful chemical speciation by XAS and the ability to image materials under realistic conditions opens up new opportunities to study many chemical processes.

  1. Three-phase slug flow in microchips can provide beneficial reaction conditions for enzyme liquid-liquid reactions.

    Cech, Jiří; Přibyl, Michal; Snita, Dalimil


    Here, we introduce a solution to low stability of a two-phase slug flow with a chemical reaction occurring at the phase interface in a microfluidic reactor where substantial merging of individual reacting slugs results in the loss of uniformity of the flow. We create a three-phase slug flow by introducing a third fluid phase into the originally two-phase liquid-liquid slug flow, which generates small two-phase liquid slugs separated by gas phase. Introduction of the third phase into our system efficiently prevents merging of slugs and provides beneficial reaction conditions, such as uniform flow pattern along the whole reaction capillary, interfacial area with good reproducibility, and intensive water-oil interface renewal. We tested the three-phase flow on an enzyme hydrolysis of soybean oil and compared the reaction conversion with those from unstable two-phase slug flows. We experimentally confirmed that the three-phase slug flow arrangement provides conversions and pressure drops comparable or even better with two-phase liquid-liquid arrangements.

  2. An Analysis of Sequential Variables in Pavlovian Conditioning Employing Extended and Limited Acquisition Training

    Miller, Ronald Mellado; Capaldi, E. John


    Sequential theory's memory model of learning has been successfully applied in response contingent instrumental conditioning experiments (Capaldi, 1966, 1967, 1994; Capaldi & Miller, 2003). However, it has not been systematically tested in nonresponse contingent Pavlovian conditioning experiments. The present experiments attempted to determine if…

  3. The role and working conditions of Movement Science students employed in sport and recreational facilities: An Italian multicenter study.

    Gallè, Francesca; Di Onofrio, Valeria; Arpesella, Marisa; Bacci, Silvia; Bianco, Antonino; Brandi, Giorgio; Bruno, Stefania; Anastasi, Daniela; Carraro, Elisabetta; Flacco, Maria Elena; Giampaoli, Saverio; Izzotti, Alberto; Leoni, Erica; Bertoncello, Chiara; Minelli, Liliana; Napoli, Christian; Nobile, Carmelo; Pasquarella, Cesira; Liguori, Giorgio; Romano Spica, Vincenzo


    In Italy, students from Movement Science (MS) Degree Courses often work in sport and recreational facilities before graduation. The employment conditions of Movement Science students working in sport/recreational facilities were investigated, and the management and structural features of the facilities were evaluated, including safety policies. Regional differences were also considered. Questionnaires were administered to undergraduate and graduate students (N = 4,217) in 17 Universities. Students' perceptions of the quality of the facilities where they had been employed was evaluated using multivariate analysis. A latent class model with covariates was used to evaluate how variables relating to participants, employment facilities or regions influence their opinions. A high proportion of MS students were employed in sporting facilities (undergraduate level: 33% ; graduate level: 55%), in most cases without any formal employment contracts. Both the structural and hygienic features, as well as the professional knowledge of the staff, were considered good to excellent by the majority of participants (about 70%). Communication of the basic behavioral rules was considered adequate by 61-63% of undergraduate students and 71-75% of graduate students, while nearly half of the participants were dissatisfied with the staff safety training. Correlations between the perceived good structural/hygienic conditions, the presence of regulations and training programs for the staff were investigated. Differences regarding occupational level and safety training among different regions of Italy were also observed. Italian students in Movement Science were easily employed in sport/recreational facilities, but frequently without a formal contract. This is a consequence of the lack of specific regulations in the field of recreational/leisure employment and could have negative implications, especially in terms of safety.

  4. Assessment of existing H2/O2 chemical reaction mechanisms at reheat gas turbine conditions

    Weydahl, Torleif; Seljeskog, Morten; Haugen, Nils Erland L


    This paper provides detailed comparisons of chemical reaction mechanisms of H2 applicable at high preheat temperatures and pressures relevant to gas turbine and particularly Alstom's reheat gas turbine conditions. It is shown that the available reaction mechanisms exhibit large differences in several important elementary reaction coefficients. The reaction mechanisms are assessed by comparing ignition delay and laminar flame speed results obtained from CHEMKIN with available data, however, the amount of data at these conditions is scarce and a recommended candidate among the mechanisms can presently not be selected. Generally, the results with the GRI-Mech and Leeds mechanisms deviate from the Davis, Li, O'Conaire, Konnov and San Diego mechanisms, but there are also significant deviations between the latter five mechanisms that altogether are better adapted to hydrogen. The differences in ignition delay times between the dedicated hydrogen mechanisms (O'Conaire, Li and Konnov) range from approximately a maxim...

  5. Ring Contraction Reaction of 4H-1,3-Oxazin-4-ones under Electrospray Ionization Conditions

    MA,Yuan; LIU,Wei; ZHAO,Yu-Fen


    @@ Ring contraction reactions of heterocyclic compounds under mass ionization conditions are important and interesting phenomenon.[1] It should be very useful to elucidate the fragmentation of some novel heterocyclic compounds and to identify the structures of some effective compounds in a screened library by mass spectrometric method, which is an easy and available method for identification of effective members in a library due to development of LC-MS. Recently several ring contraction reactions have been reported in literatures.

  6. Influence of the reaction conditions on the enzyme catalyzed transesterification of castor oil

    Andrade, Thalles Allan; Errico, Massimiliano; Christensen, Knud Villy


    The identification of the influence of the reaction parameters is of paramount importance when defining a process design. In this work, non-edible castor oil was reacted with methanol to produce a possible component for biodiesel blends, using liquid enzymes as the catalyst. Temperature, alcohol......-to-oil molar ratio, enzyme and added water contents were the reaction parameters evaluated in the transesterification reactions. The optimal conditions, giving the optimal final FAME yield and FFA content in the methyl ester-phase was identified. At 35 °C, 6.0 methanol-to-oil molar ratio, 5 wt% of enzyme and 5...

  7. A stronger necessary condition for the multistationarity of chemical reaction networks.

    Soliman, Sylvain


    Biochemical reaction networks grow bigger and bigger, fed by the high-throughput data provided by biologists and bred in open repositories of models allowing merging and evolution. Nevertheless, since the available data is still very far from permitting the identification of the increasing number of kinetic parameters of such models, the necessity of structural analyses for describing the dynamics of chemical networks appears stronger every day. Using the structural information, notably from the stoichiometric matrix, of a biochemical reaction system, we state a more strict version of the famous Thomas' necessary condition for multistationarity. In particular, the obvious cases where Thomas' condition was trivially satisfied, mutual inhibition due to a multimolecular reaction and mutual activation due to a reversible reaction, can now easily be ruled out. This more strict condition shall not be seen as some version of Thomas' circuit functionality for the continuous case but rather as related and complementary to the whole domain of the structural analysis of (bio)chemical reaction systems, as pioneered by the chemical reaction network theory.


    BĂLĂU MÎNDRU Tudorel


    Full Text Available The leather processing industry is known as an important source of environmental pollution, due to the large amount of waste generated. In this respect there are efforts concerning recovering and capitalizing of these wastes in order to subsequently use them in different applications. This work aimed to obtain collagen forms with convenient features starting from Chamois leather waste resulting from the buffing operation, by alkaline hydrolysis at different temperatures (60°C, 90°C, and 120°C and reaction time (4, 6 and 8 hours, in a solution of 30% NH4OH with a pH=11. The effects of the reaction conditions (temperature and reaction duration on the hydrolysis yield and molecular weight of the extracted polypeptides were investigated. The working version no. 8 (temperature = 1200C, and reaction time = 6h was chosen as optimal for obtaining a protein product suitable from the point of view of hydrolysis yield and molecular weight, respectively. For this sample no. 8, tests for checking physical-chemical characteristics were carried out, and also the influence of the hydrolysis upon certain structural changes caused by the reaction conditions was investigated by IR analysis. The reaction conditions led to obtaining polypeptide mixtures with different molecular weights and polydispersity that can be used as auxiliaries to obtain composite materials or as additives for new building materials.

  9. Transaction component of exogenous factors of influence upon employment under conditions of globalisation of economy

    Glushach Anna V.


    Full Text Available The goal of the article lies in identification of influence of globalisation upon efficiency of financial and loan instruments that ensure regulation and stimulation of employment and the role of transaction costs in these processes. To achieve the goal, the article shows how globalisation processes, which take place in the sphere of the financial sector, influence the real economy and employment of the population, identifies positive and negative sides of this influence. The article conducts analysis of causes and effects of the financial and economic crisis from the point of view of the theory of transaction costs, in the process of which the role of specific types of these costs in the processes that took place was ascertained. In the course of the study the article reveals negative influence of the growing disproportion between the public and private transaction costs of the risks of financial and economic instability, especially in the countries with the transformation economy, and justifies the necessity of stabilising mechanisms of the international financial market with the aim of elimination of the marked transaction disproportions such as introduction of a special tax on financial transactions or establishment of the double currency course: less flexible – for servicing trading operations, and more flexible – for regulation of financial flows. Studies of negative effects of integration processes allowed formation of directions of the state policy, which would prevent dangerous consequences of interference of the foreign capital with the financial sector and would protect the Ukrainian labour market from influence of negative effects of integration processes.

  10. The precise condition of thermal runaway in microwave heating on chemical reaction

    HUANG KaMa; LU Bo


    The precise condition of thermal runaway in microwave heating on chemical reaction with a feedback control system is quantitatively studied. First, the precise condition of thermal runaway in engineering application is derived based on the principle of the feedback control system. Then, the temperature rising rates for 4 different kinds of reaction systems placed in the waveguide and irradiated by micro-wave with different input powers are simulated. Finally, the relationship, which is inattentive so far, between the thermal runaway and the sensor's response time is discussed.

  11. The precise condition of thermal runaway in microwave heating on chemical reaction


    The precise condition of thermal runaway in microwave heating on chemical reaction with a feedback control system is quantitatively studied. First, the precise condition of thermal runaway in engineering application is derived based on the principle of the feedback control system. Then, the temperature rising rates for 4 different kinds of reaction systems placed in the waveguide and irradiated by micro-wave with different input powers are simulated. Finally, the relationship, which is inattentive so far, between the thermal runaway and the sensor’s response time is discussed.

  12. Pybox monolithic miniflow reactors for continuous asymmetric cyclopropanation reaction under conventional and supercritical conditions.

    Burguete, M I; Cornejo, A; García-Verdugo, E; Gil, María J; Luis, S V; Mayoral, J A; Martínez-Merino, V; Sokolova, M


    Supported catalysts having pybox chiral moieties were prepared as macroporous monolithic miniflow systems. These catalysts are based on styrene-divinylbenzene polymeric backbones having different compositions and pybox chiral moieties. Their corresponding ruthenium complexes were tested for the continuous flow cyclopropanation reaction between styrene and ethyldiazoacetate (EDA) under conventional conditions and in supercritical carbon dioxide (scCO2). Ru-Pybox monolithic miniflow reactors not only provided a highly efficient and robust heterogeneous chiral catalyst but also allowed us to develop more environmental reaction conditions without sacrificing the global efficiency of the process.

  13. Kinetics and corrosion products of aqueous nitrate reduction by iron powder without reaction conditions control

    FAN Xiaomeng; GUAN Xiaohong; MA Jun; AI Hengyu


    Although considerable research has been conducted on nitrate reduction by zero-valent iron powder (Fe0), these studies were mostly operated under anaerobic and invariable pH conditions that was unsuitable for practical application.Without reaction conditions (dissolved oxygen or reaction pH) control, this study aimed at subjecting the kinetics of denitrification by microscale Fe0 (160-200 mesh) to analysis the factors affecting the denitrification of nitrate and the composition of iron reductive products coating upon the iron surface.Results of the kinetics study have indicated that a higher initial concentration of nitrate would yield a greater reaction rate constant.Additional test results showed that the reduction rate of nitrate increased with increasing Fe0 dosage.The reaction can be described as a pseudo-first order reaction with respect to nitrate concentration or Fe0 dosage.Experimental results also suggested that nitrate reduction by microscale Fe0 without reaction condition control primarily was an acid-driven surface-mediated process, and the reaction order was 0.65 with respect to hydrogen ion concentration.X-ray diffractometry and X-ray photoelectron spectroscopy indicated that a black coating, consisted of Fe2O3, Fe3O4 and FeO(OH), was formed on the surface of iron grains as an iron corrosion product when the system initial pH was lower than 5.The proportion of FeO(OH) increased as reaction time went on, whereas the proportion of Fe3O4 decreased.

  14. Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

    Francisco Delgado


    Full Text Available Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17, under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO calculations.

  15. A versatile method for the preparation of conjugates of peptides with DNA/PNA/analog by employing chemo-selective click reaction in water

    Gogoi, Khirud; Mane, Meenakshi V.; Kunte, Sunita S.; Kumar, Vaijayanti A.


    The specific 1,3 dipolar Hüisgen cycloaddition reaction known as ‘click-reaction’ between azide and alkyne groups is employed for the synthesis of peptide–oligonucleotide conjugates. The peptide nucleic acids (PNA)/DNA and peptides may be appended either by azide or alkyne groups. The cycloaddition reaction between the azide and alkyne appended substrates allows the synthesis of the desired conjugates in high purity and yields irrespective of the sequence and functional groups on either of the two substrates. The versatile approach could also be employed to generate the conjugates of peptides with thioacetamido nucleic acid (TANA) analog. The click reaction is catalyzed by Cu (I) in either water or in organic medium. In water, ∼3-fold excess of the peptide-alkyne/azide drives the reaction to completion in 2 h with no side products. PMID:17981837

  16. Nonlinear reaction-diffusion systems conditional symmetry, exact solutions and their applications in biology

    Cherniha, Roman


    This book presents several fundamental results in solving nonlinear reaction-diffusion equations and systems using symmetry-based methods. Reaction-diffusion systems are fundamental modeling tools for mathematical biology with applications to ecology, population dynamics, pattern formation, morphogenesis, enzymatic reactions and chemotaxis. The book discusses the properties of nonlinear reaction-diffusion systems, which are relevant for biological applications, from the symmetry point of view, providing rigorous definitions and constructive algorithms to search for conditional symmetry (a nontrivial generalization of the well-known Lie symmetry) of nonlinear reaction-diffusion systems. In order to present applications to population dynamics, it focuses mainly on two- and three-component diffusive Lotka-Volterra systems. While it is primarily a valuable guide for researchers working with reaction-diffusion systems  and those developing the theoretical aspects of conditional symmetry conception,...

  17. Carboxymethylation of Cassava Starch in Different Solvents and Solvent-Water Mixtures: Optimization of Reaction Conditions

    Nwokocha, Louis M.; Ogunmola, Gabiel B.

    The influence of reaction medium on carboxymethylation process was investigated by treating cassava starch with sodium monochloroacetate in different solvents and solvent-water mixtures under alkaline conditions. The amount of carboxyl groups introduced into the starch moiety was determined titrimetrically and used to calculate the Degree of Substitution (DS) and Reaction Efficiency (RE). The results showed that carboxymethylation is significantly affected by the nature of reaction medium at p<0.05. Carboxymethylation in different solvent-water mixtures showed that aqueous 80% n-propanol offered the best medium for carboxymethylation. Optimization of reaction conditions in aqueous 80% n-propanol showed that the best condition for carboxymethylation was at starch-liquor ratio of 1:3, NaOH/reagent molar ratio of 4.0 and reagent-starch molar ratio of 0.35. An increase in temperature was required to effect the reaction at shorter time. At 55°C the highest values of DS and RE achieved in 0.5 h would require three hours to achieve the same values of DS and RE at 45°C.

  18. Review and analysis of high temperature chemical reactions and the effect of non-equilibrium conditions

    Johnson, R. E.


    Chemical reactions at high temperatures have been considered extensively because of their importance to the heating effects on re-entry of space vehicles. Data on these reactions however, are not abundant and even when found there are discrepancies in data collected by various investigators. In particular, data for recombination reactions are calculated from the dissociation reactions or vice versa through the equilibrium constant. This involves the use of the principle of detailed balancing. This principle is discussed in reference to conditions where it is valid as well as to those where it is not valid. Related topics that merit further study or for which applicable information was available are briefly mentioned in an appendix to this report.

  19. Reaction Mechanism of Thiophene on Vanadium Oxides under FCC Operating Conditions

    Wang Peng; Zheng Aiguo; Tian Huiping; Long Jun


    The reaction mechanism of thiophene on vanadium oxides under FCC operating conditions had been preliminary studied using in-situ FT-IR analysis of thiophene and atmospheric pressure continuous fixed-bed reaction, followed by characterization via pyridine adsorption-temperature programmed desorption method, and FT-IR and XPS spectra. The research had discovered that, under 500C thiophene could undergo the redox reaction with V2O5, while being converted into CO, CO2 as well as SO2 with its conversion rate reaching 41.2%. At the same time the oxidation number of vanadium decreased. The existence of a few Bronsted acid centers on V2O5 could lead to an increase of H2S yield among the products derived from the reaction with thiophene.

  20. Aza-Morita-Baylis-Hillman reaction of maleimides with azodicarboxylates under neat conditions

    Subramani Kandhasamy; Kesavan Karthikeyan; Krishnan Ramachandiran; Doraiswamy Muralidharan; Paramasivan Thirumalai Perumal


    Green approach on reaction of diisopropylazodicarboxylate or diethyl azodicarboxylate with maleimides proceeded smoothly under neat condition at 70°C to give the corresponding hydrazine substituted pyrrolidinone as aza-Morita-Baylis-Hillman adducts in moderate to good yields in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) as nitrogen Lewis base.

  1. Aza-Michael reaction of 12-N-carboxamide of (-)-cytisine under high pressure conditions.

    Tsypysheva, Inna P; Lobov, Alexander N; Kovalskaya, Alena V; Petrova, Polina R; Ivanov, Sergey P; Rameev, Shamil A; Borisevich, Sophia S; Safiullin, Rustam L; Yunusov, Marat S


    The first example of aza-Michael reaction of 12-N-carboxamide of quinolizidine alkaloid (-)-cytisine with α,β-unsaturated ketones, dimethyl acetylenedicarboxylate and β-nitrostyrene under high pressure condition has been described. It has been shown that the [4+2]-cycloaddition takes place in the case with N-phenylmaleimide.

  2. Study of the optimal reaction conditions for assay of the mouse alternative complement pathway

    Dijk, H. van; Rademaker, P.M.; Klerx, J.P.A.M.; Willers, J.M.M.


    The optimal reaction conditions for hemolytic assay of alternative complement pathway activity in mouse serum were investigated. A microtiter system was used, in which a number of 7.5×106 rabbit erythrocytes per test well appeared to be optimal. Rabbit erythrocytes were superior as target cells over


    熊岳山; 韦永康


    The sediment reaction and diffusion equation with generalized initial and boundary condition is studied. By using Laplace transform and Jordan lemma , an analytical solution is got, which is an extension of analytical solution provided by Cheng Kwokming James ( only diffusion was considered in analytical solution of Cheng ). Some problems arisen in the computation of analytical solution formula are also analysed.

  4. In-situ scanning transmission X-ray microscopy of catalytic materials under reaction conditions

    de Smit, E.; Creemer, J.F.; Zandbergen, H.W.; Weckhuysen, B.M.; de Groot, F.M.F.


    In-situ Scanning X-ray Transmission Microscopy (STXM) allows the measurement of the soft X-ray absorption spectra with 10 to 30 nm spatial resolution under realistic reaction conditions. We show that STXM-XAS in combination with a micromachined nanoreactor can image a catalytic system under relevant

  5. Optimization of reaction conditions for enzymatic synthesis of palm fatty hydrazides using response surface methodology.

    Tuan Noor Maznee, T I; Hazimah, A H; Wan Zin, W Y


    Optimization of the enzymatic synthesis of palm fatty hydrazide by the response surface methodology (RSM) was conducted using the Design-Expert 6 software. The palm fatty hydrazide was synthesized from refined, bleached and deodorized palm olein (RBDPOo) and neutralized hydrazine monohydrate in the presence of Rhizomucor miehei lipase, Lipozyme RMIM, an immobilized lipase in n-hexane. The reaction conditions such as the percentage of enzyme, reaction temperature, stirring speed and reaction time were selected as independent variables or studied factors, while the amount of crude palm fatty hydrazide obtained was selected as a dependent variable or response. The study was conducted using a central composite design (CCD) at five coded levels and the experimental data were analyzed using a quadratic model. The analysis of variance (ANOVA) indicates that the model was significant at 95% confidence level with Prob>F of 0.0033, where the regression coefficient value, R² was 0.8415 and lack-of-fit of 0.0984. A percentage of enzyme of 6%, a reaction temperature of 40°C, a stirring speed of 350 rpm and a reaction time of 18 h were found to be the optimum conditions for the conversion of RBDPOo into palm fatty hydrazide.

  6. Scaffold oriented synthesis. Part 4: design, synthesis and biological evaluation of novel 5-substituted indazoles as potent and selective kinase inhibitors employing heterocycle forming and multicomponent reactions.

    Akritopoulou-Zanze, Irini; Wakefield, Brian D; Gasiecki, Alan; Kalvin, Douglas; Johnson, Eric F; Kovar, Peter; Djuric, Stevan W


    We report the synthesis and biological evaluation of 5-substituted indazoles as kinase inhibitors. The compounds were synthesized in a parallel synthesis fashion from readily available starting materials employing heterocycle forming and multicomponent reactions and were evaluated against a panel of kinase assays. Potent inhibitors were identified for Gsk3β, Rock2, and Egfr.

  7. Radiolytic reactions of nitro blue tetrazolium under oxidative and reductive conditions: a pulse radiolysis study

    Kovacs, A.; Wojnarovits, L.; Baranyai, M.; Moussa, A.; Othman, I.; McLaughlin, W. L.


    The radiolytic reactions of the ditetrazolium salt nitro blue tetrazolium chloride (NBTCl 2) were studied by pulse radiolysis technique in aqueous solution under reducing and oxidising conditions with the aim of potential dosimetry application. Under reducing conditions the fast formation of the tetrazolinyl radical is observed that is followed by the appearance of monoformazan (MF +), i.e. one of the tetrazolium rings is reduced to formazan. The formation of the water-insoluble diformazan, i.e. the result of the second reduction step was not observed in pulse radiolysis. Formazan formation was not found under oxidative conditions.

  8. Production of Zinc Borate for Pilot-Scale Equipment and Effects of Reaction Conditions on Yield

    Melek BARDAKCI


    Full Text Available In this study, zinc borate (ZB was synthesized by reacting zinc oxide and boric acid in the presence of standard ZB (w/w, in terms of boric acid in order to promote crystallization. The effects of seed, H3BO3/ZnO (boric acid/zinc oxide ratio, reaction time, water volume, reaction temperature and cooling temperature on yield were investigated for pilot-scale equipment. The results indicated that the addition of seed (w/w to a saturated solution of reactants increased the yield of the reaction. The results of reaction yields obtained from either magnetically or mechanically stirred systems were compared. At various reaction times, the optimal yield was 86.78 % in a saturated aqueous solution. The products were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and Thermogravimetric / Differential Thermal Analysis (TG/DTA. The results displayed that ZB was successfully produced under the optimized reaction conditions and the product synthesized had high thermal stability.DOI:

  9. Production of Zinc Borate for Pilot-Scale Equipment and Effects of Reaction Conditions on Yield

    Melek BARDAKCI


    Full Text Available In this study, zinc borate (ZB was synthesized by reacting zinc oxide and boric acid in the presence of standard ZB (w/w, in terms of boric acid in order to promote crystallization. The effects of seed, H3BO3/ZnO (boric acid/zinc oxide ratio, reaction time, water volume, reaction temperature and cooling temperature on yield were investigated for pilot-scale equipment. The results indicated that the addition of seed (w/w to a saturated solution of reactants increased the yield of the reaction. The results of reaction yields obtained from either magnetically or mechanically stirred systems were compared. At various reaction times, the optimal yield was 86.78 % in a saturated aqueous solution. The products were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and Thermogravimetric / Differential Thermal Analysis (TG/DTA. The results displayed that ZB was successfully produced under the optimized reaction conditions and the product synthesized had high thermal stability.DOI:

  10. Kinetics of diamond-silicon reaction under high pressure-high temperature conditions

    Pantea, Cristian

    In this dissertation work, the kinetics of the reaction between diamond and silicon at high pressure-high temperature conditions was investigated. This study was motivated by the extremely limited amount of information related to the kinetics of the reaction in diamond-silicon carbide composites formation. It was found that the reaction between diamond and melted silicon and the subsequent silicon carbide formation is a two-stage process. The initial stage is a result of direct reaction of melted silicon with carbon atoms from the diamond surface, the phase boundary reaction. Further growth of SiC is much more complicated and when the outer surfaces of diamond crystals are covered with the silicon carbide layer it involves diffusion of carbon and silicon atoms through the SiC layer. The reaction takes place differently for the two regions of stability of carbon. In the graphite-stable region, the reaction between diamond and melted silicon is associated with the diamond-to-graphite phase transition, while in the diamond-stable region there is no intermediary step for the reaction. The data obtained at HPHT were fitted by the Avrami-Erofeev equation. It was found that the reaction is isotropic, the beta-SiC grown on different faces of the diamond crystals showing the same reaction rate, and that the controlling mechanism for the reaction is the diffusion. In the graphite-stable region the activation energy, 402 kJ/mol is slightly higher than in the diamond-stable region, 260 kJ/mol, as the reaction between diamond and melted silicon is associated with the diamond-to-graphite phase transition, which has higher activation energy. In the diamond-stable region, the calculated activation energy is higher for micron size diamond powders (≈260 kJ/mol), while for nanocrystalline diamond powders a lower value of 170 kJ/mol was obtained. This effect was attributed to nanocrystalline structure and strained bonds within grain boundaries in SiC formed from nanosize diamond

  11. Analysis of initial reactions of MALDI based on chemical properties of matrixes and excitation condition.

    Lai, Yin-Hung; Wang, Chia-Chen; Chen, Chiu Wen; Liu, Bo-Hong; Lin, Sheng Hsien; Lee, Yuan Tseh; Wang, Yi-Sheng


    This investigation concerns the initial chemical reactions that affect the ionization of matrixes in matrix-assisted laser desorption/ionization (MALDI). The study focuses on the relaxations of photon energy that occur on a comparable time scale to that of ionization, in which the available laser energy is shared and the ionization condition is changed. The relaxations include fluorescence, fragmentation, and nonradiative relaxation from the excited state to the ground state. With high absorption cross section and long excited-state lifetime, photoionization of matrix plays an important role if sufficient laser energy is used. Under other conditions, thermal ionization of the molecule in the ground state is predicted to be one of the important reactions. Evidence of change in the branching ratio of initial reactions with the matrix and the excitation wavelength was obtained with α-cyano-4-hydroxycinnamic acid, sinapinic acid, 2,5-dihydroxybenzoic acid, and 2,4,6-trihydroxyacetophenone. These matrixes are studied by obtaining their mixed crystal absorption spectra, fluorescence properties, laser-induced infrared emission, and product ions. The exact ionization pathway depends on the chemical properties of matrixes and the excitation conditions. This concept may explain the diversity of experimental results observed in MALDI experiments, which provides an insight into the ensemble of chemical reactions that govern the generation of ions.

  12. Should Student Employment Be Subsidized? Conditional Counterfactuals and the Outcomes of Work-Study Participation: Appendices A and B. A CAPSEE Working Paper

    Scott-Clayton, Judith; Minaya, Veronica


    Student employment subsidies are one of the largest types of federal employment subsidies, and one of the oldest forms of student aid. Yet it is unclear whether they help or harm students' long term outcomes. This document contains the appendices to the report "Should Student Employment Be Subsidized? Conditional Counterfactuals and the…

  13. Correlation changes in EEG, conditioned and behavioral reactions with various degrees of oxygen insufficiency

    Agadzhanyan, N. A.; Zakharova, I. N.; Kalyuzhnyy, L. V.; Dvorzhak, I. I.; Moravek, M.; Tsmiral, Y. I.


    The dynamics of change in bioelectric activity of the brain during acute hypoxia are studied for the time that working capacity and active consciousness are preserved, and to establish the correlation between EEG changes and behavioral reactions under oxygen starvation. Changes in body functions and behavioral disturbances are related to the degree of oxygen saturation in the blood, to bioelectric activity of the brain, and to an increase in conditioned reflexes. The capacity for adequate reaction to external signals and for coordinated psychomotor activity after loss of consciousness returns to man after 30 seconds. Repeated effects of hypoxia produce changes in the physiological reactions of the body directed toward better adaptation to changing gaseous environments.

  14. Realistic boundary conditions for stochastic simulations of reaction-diffusion processes

    Erban, R; Erban, Radek


    Many cellular and subcellular biological processes can be described in terms of diffusing and chemically reacting species (e.g. enzymes). Such reaction-diffusion processes can be mathematically modelled using either deterministic partial-differential equations or stochastic simulation algorithms. The latter provide a more detailed and precise picture, and several stochastic simulation algorithms have been proposed in recent years. Such models typically give the same description of the reaction-diffusion processes far from the boundary of the simulated domain, but the behaviour close to a reactive boundary (e.g. a membrane with receptors) is unfortunately model-dependent. In this paper, we study four different approaches to stochastic modelling of reaction-diffusion problems and show the correct choice of the boundary condition for each model. The reactive boundary is treated as partially reflective, which means that some molecules hitting the boundary are adsorbed (e.g. bound to the receptor) and some molecul...

  15. Analysing the Onus Issue in Dismissals Emanating from the Enforcement of Unilateral Changes to Conditions of Employment

    I Tshoose


    Full Text Available The main objective of this article is to analyse the issue of onus emanating from the enforcement of unilateral changes to conditions of employment. At the heart of the controversy that has faced the Labour Appeal Court was how to interpret dismissals that appear to be based on operational requirements, and yet at the same time, such dismissals also appear to have the effect of compelling an employee to accept a demand in respect of a matter of mutual interest between the employer and the employee.The core section in the Labour Relations Act 66 of 1995 relating to disputes of this nature is section 187(1(c of the Act, and the central enquiry to such disputes is whether they are automatically unfair or operationally justifiable. The fine line that determines whether a dismissal is acceptable or not merits an analysis of the overall onus that faces an employer and employee. This analysis is the focus of the article, which deals predominantly with procedural issues. The issue relating to the promotion of collective bargaining will be assessed against the right to dismiss, based on an analysis of the situation in South Africa, and a brief comparison with the situations in the United Kingdom and Canada. Thereafter, recommendations are made to the South African legislature.

  16. Assessing the reaction conditions to mediate the milkfat-soybean oil enzymatic interesterification

    Ariela Veloso de Paula

    Full Text Available Summary A food grade lipase from Rhizopus oryzae immobilized on a hybrid polysiloxane-polyvinyl alcohol matrix (SiO2-PVA was used as the biocatalyst to mediate the interesterification reactions of a blend containing 65% milkfat and 35% soybean oil. All the reactions occurred in an inert nitrogen atmosphere in cylindrical glass reactors (80 mL with 40 g of the milkfat-soybean oil blend. The influence of the following variables was evaluated: biocatalyst loading (250-1500 activity units per gram of blend, biocatalyst moisture content (5-20%, temperature (45-60 °C and incubation time (2-48 h. The reactions were monitored by determining the free fatty acid content, triacylglycerol (TAGs composition in carbon species, and the consistency of the interesterified (IE products. The reaction conditions were set based on the parameters that provided a high interesterification yield and good consistency of the final product within the ideal range (200 to 800 gf cm-2. Hence the best results were obtained using a biocatalyst loading of 500 U g-1 of blend with 10% moisture content at 45 °C for 4 h. Under these conditions the consistency of the interesterified product was 539.7 ± 38 gf cm-2. The results demonstrated the potential of the immobilized lipase to alter the TAGs profile of the milkfat-soybean oil blend, allowing for the production of structured lipids.

  17. Conditions of contract for construction for building and engineering works designed by the employer : general conditions : guidance for the preparation of particular conditions forms of letter of tender, contract agreement and dispute adjudication agreement


    Conditions of Contract for Construction, which are recommended for building or engineering works designed by the Employer or by his representative, the Engineer. Under the usual arrangements for this type of contract, the Contractor constructs the works in accordance with a design provided by the Employer. However, the works may include some elements of Contractor-designed civil, mechanical, electrical and/or construction works.

  18. Study on the reaction kinetics in pulsed RF discharges under RIE conditions

    Baggerman, Jacobus Antonius Gijsbertus


    In the present-day electronics industry, reactive ion etching (RIE) is a technique widely used to etch thin films anisotropically. The subject of this thesis is the determination of (reaction) kinetics of rf discharges under RIE conditions. Special attention is given to determining quantitatively the rise and decay of densities and energy distributions of plasma particles. A production-type RIE reactor was used for all experiments. In chapter 2 the ion density is determined by LIF spectroscopy in a model (N2) discharge under RIE conditions. Chapter 3 concerns energy-flux density measurements on the various parts of the etch reactor in contact with a 30 Pa nitrogen rf discharge. Chapter 4 concerns the etch mechanism of various organic polymers in oxygen and argon of discharges under RIE conditions studied by performing energy-flux density and ion-flux density measurements on the powered electrode. The polymers of interest are a novolac-based photoresist, polyimide and polymethylmethacrylate (PMMA). The density and the reaction kinetics of ground-state methylidyne (CH radical) are determined by LIF in order to determine whether small molecules in addition to atoms are sputtered from the polymer surface. In chapter 5 a model is set up in which diffusion of CH from the substrate into the gas phase and chemical reactions in the gas phase are taken into account.

  19. Reactions of ferrous neuroglobin and cytoglobin with nitrite under anaerobic conditions

    Petersen, Morten Gjerning; Dewilde, Sylvia; Fago, Angela


    Recent evidence suggests that the reaction of nitrite with deoxygenated hemoglobin and myoglobin contributes to the generation of nitric oxide and S-nitrosothiols in vivo under conditions of low oxygen availability. We have investigated whether ferrous neuroglobin and cytoglobin, the two hexacoor......Recent evidence suggests that the reaction of nitrite with deoxygenated hemoglobin and myoglobin contributes to the generation of nitric oxide and S-nitrosothiols in vivo under conditions of low oxygen availability. We have investigated whether ferrous neuroglobin and cytoglobin, the two...... hexacoordinate globins from vertebrates expressed in brain and in a variety of tissues, respectively, also react with nitrite under anaerobic conditions. Using absorption spectroscopy, we find that ferrous neuroglobin and nitrite react with a second-order rate constant similar to that of myoglobin, whereas...... the ferrous heme of cytoglobin does not react with nitrite. Deconvolution of absorbance spectra shows that, in the course of the reaction of neuroglobin with nitrite, ferric Fe(III) heme is generated in excess of nitrosyl Fe(II)-NO heme as due to the low affinity of ferrous neuroglobin for nitric oxide...

  20. Preparation of cationized pine sawdust for nitrate removal: Optimization of reaction conditions.

    Keränen, Anni; Leiviskä, Tiina; Hormi, Osmo; Tanskanen, Juha


    Anion exchange materials were prepared from pine sawdust (Pinus sylvestris, PSD) through cationizing treatment with N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHMAC) in the presence of NaOH. Response surface methodology (RSM) was used to find the optimal reaction conditions. Three factors were chosen: reaction temperature (26-94 °C), reaction time (0.32-3.7 h) and NaOH/CHMAC molar ratio (0.19-2.2). Product yield (%) was used as a response. A quadratic model was fitted to the experimental data. The optimal conditions were: a reaction temperature of 57 °C, a reaction time of 1.8 h and a NaOH/CHMAC molar ratio of 1.32. A maximum nitrogen content of 2.6% was obtained at 60 °C, 3.7 h and a molar ratio of 1.2. The molar ratio had the greatest impact on the response. Regression analysis revealed that over 95% of the variance can be explained by the model. A maximum nitrate sorption capacity of 15.3 ± 1.4 mg N/g was achieved. The effect of CHMAC dose was also studied (a NaOH/CHMAC molar ratio of 1.2): 0.064 mol/g PSD was found to be near the optimum. Nitrate-contaminated groundwater (27.5 mg/l NO3) was treated with CPSD. Doses of 3-6 g/l resulted in 59-71% nitrate reduction.

  1. Photo catalytic reduction of benzophenone on TiO{sub 2}: Effect of preparation method and reaction conditions

    Albiter E, E.; Valenzuela Z, M. A.; Alfaro H, S.; Flores V, S. O.; Rios B, O.; Gonzalez A, V. J.; Cordova R, I., E-mail: mavalenz@ipn.m [IPN, Escuela Superior de Ingenieria Quimica e Industrias Extractivas, Laboratorio de Catalisis y Materiales, Zacatenco, 07738 Mexico D. F. (Mexico)


    The photo catalytic reduction of benzophenone was studied focussing on improving the yield to benzhydrol. TiO{sub 2} was synthesized by means of a hydrothermal technique. TiO{sub 2} (Degussa TiO{sub 2}-P25) was used as a reference. Catalysts were characterized by X-ray diffraction and nitrogen physisorption. The photo catalytic reduction was carried out in a batch reactor at 25 C under nitrogen atmosphere, acetonitrile as solvent and isopropanol as electron donor. A 200 W Xe-Hg lamp ({lambda}= 360 nm) was employed as irradiation source. The chemical composition of the reaction system was determined by HPLC. Structural and textural properties of the synthesized TiO{sub 2} depended on the type of acid used during sol formation step. Using HCl, a higher specific surface area and narrower pore size distribution of TiO{sub 2} was obtained in comparison with acetic acid. As expected, the photochemical reduction of benzophenone yielded benzopinacol as main product, whereas, benzhydrol is only produced in presence of TiO{sub 2} (i.e. photo catalytic route). In general, the hydrothermally synthesized catalysts were less active and with a lower yield to benzhydrol. The optimal reaction conditions to highest values of benzhydrol yield (70-80%) were found at 2 g/L (catalyst loading) and 0.5 m M of initial concentration of benzophenone, using commercial TiO{sub 2}-P25. (Author)

  2. Formation of flavor components by the reaction of amino acid and carbonyl compounds in mild conditions.

    Pripis-Nicolau, L; de Revel, G; Bertrand, A; Maujean, A


    This work describe products of reactions between four alpha-dicarbonyl compounds (diacetyl, pentan-2,3-dione, glyoxal, and methylglyoxal) or two alpha-hydroxy ketones, (acetoine and acetol) and amino acids present in wines. The results shows the formation of odorous products or strong-smelling additives resulting from the Maillard and Strecker reaction in a primarily aqueous medium, at low temperature and low pH ( approximately pH 3.5) of the wine. GC/FID, GC/FPD, GC/NPD and GC/MS techniques were used. The olfactive characteristics of the products are described. In the presence of sulfur amino acids and in particular cysteine, many products were formed with a heterocycle production such as pyrazines and methylpyrazines, methylthiazoles, acetylthiazoles, acetylthiazolines, acetylthiazolidines, trimethyloxazole, and dimethylethyloxazoles. These various compounds present odors of sulfur, cornlike, pungent, nut, popcorn, roasted hazelnut, toasted, roasted, and ripe fruits. The chemical conditions of the model reactions are specified. The influence of temperature and pH on the reactions in the presence of cysteine were also studied.

  3. Optimized extract preparation methods and reaction conditions for improved yeast cell-free protein synthesis.

    Hodgman, C Eric; Jewett, Michael C


    Cell-free protein synthesis (CFPS) has emerged as a powerful platform technology to help satisfy the growing demand for simple, affordable, and efficient protein production. In this article, we describe a novel CFPS platform derived from the popular bio-manufacturing organism Saccharomyces cerevisiae. By developing a streamlined crude extract preparation protocol and optimizing the CFPS reaction conditions we were able to achieve active firefly luciferase synthesis yields of 7.7 ± 0.5 µg mL(-1) with batch reactions lasting up to 2 h. This duration of synthesis is the longest ever reported for a yeast CFPS batch reaction. Furthermore, by removing extraneous processing steps and eliminating expensive reagents from the cell-free reaction, we have increased relative product yield (µg protein synthesized per $ reagent cost) over an alternative commonly used method up to 2000-fold from ∼2 × 10(-4) to ∼4 × 10(-1)  µg $(-1) , which now puts the yeast CPFS platform on par with other eukaryotic CFPS platforms commercially available. Our results set the stage for developing a yeast CFPS platform that provides for high-yielding and cost-effective expression of a variety of protein therapeutics and protein libraries.

  4. Influence of reaction condition on viscosity of polyurethane modified epoxy based on glycerol monooleate

    Triwulandari, Evi; Ramadhan, Mohammad Kemilau; Ghozali, Muhammad


    Polyurethane modified epoxy based on glycerol monooleate (PME-GMO) was synthesized. GMO as polyol for synthesis of PME-GMO was synthesized via Fisher Esterification between oleic acid from palm oil and glycerol by using sulfuric acid as catalyst with time variation i.e. 3, 4, 5 and 6 hours at 160°C. Characterizations of GMO were carried out by analysis of acid number, hydroxyl value and FTIR. The data show that the conversion of oleic acid to ester compound is directly proportional with the increasing of reaction time but the enhancement is not significant after 3 hours. Furthermore, GMO product was used as polyol for modification of epoxy with polyurethane. Modification of epoxy with polyurethane was performed by reacted epoxy, tolonate and GMO simultaneously in one step. In this research, the reaction condition was varied i.e. time reaction (0.5; 1; 1.5; 2; 2.5 hours), composition of polyurethane used (10%, 20% toward epoxy) and rasio of tolonate and GMO (NCO/OH ratio) as component of polyurethane (1.5 and 2.5). Characterization of polyurethane modified epoxy based on glycerol (PME-GMO) was conducted by viscosity and FTIR analysis. The viscosity of PME-GMO increased with increasing of reaction time, polyurethane composition and NCO/OH ratio.


    I. V. Shirolapov


    Full Text Available Abstract. It has been widely accepted that routine psychophysiological stressors may influence immune functioning via their close interactions between nervous, autonomic, endocrine and immune regulatory systems. The aim of this study was to evaluate immune reactions to acute psychophysiological stress in 203 medical students before and after academic exams. The results showed significant decrease of absolute and relative contents CD3+ T cells, natural killer (NK cell subpopulations and T-NK cells (CD3-CD16+CD56+ and CD3+CD16+CD56+, as well as declined NK cell activity were revealed immediately after exams, as compared to initial values for these indices. Moreover, a significant decrease in CD19+ B cells, CD4+ T-helpers and CD8+ T-cytotoxic lymphocyte counts was found after exams, in comparison with parameters assessed under stress-free conditions, but no differences were observed, when compared with pre-examination values. Serum concentrations of IgA, IgM, IgG were within normal physiological limits. Changes in immunological parameters during acute examination-associated stress depend on characteristics of autonomous and hormonal reactions in humans, and, under particular extreme conditions, such psycho-emotional stress may cause general disturbances of immune reactions. We conclude that acute psycho-physiological stress during the exams causes significant changes in some lymphocyte subpopulations, in particular, natural killers.

  6. Ablation characteristics and reaction mechanism of insulation materials under slag deposition condition

    Guan, Yiwen; Li, Jiang; Liu, Yang


    Current understanding of the physical and chemical processes involved in the ablation of insulation materials by highly aluminized solid propellants is limited. The study on the heat transfer and ablation principle of ethylene propylene diene monomer (EPDM) materials under slag deposition condition is essential for future design or modification of large solid rocket motors (SRMs) for launch application. In this paper, the alumina liquid flow pattern and the deposition principle in full-scale SRM engines are discussed. The interaction mechanism between the alumina droplets and the wall are analyzed. Then, an experimental method was developed to simulate the insulation material ablation under slag deposition condition. Experimental study was conducted based on a laboratory-scale device. Meanwhile, from the analysis of the cross-sectional morphology and chemical composition of the charring layer after ablation, the reaction mechanism of the charring layer under deposition condition was discussed, and the main reaction equation was derived. The numerical simulation and experimental results show the following. (i) The alumina droplet flow in the deposition section of the laboratory-scale device is similar to that of a full-scale SRM. (ii) The charring layer of the EPDM insulator displays a porous tight/loose structure under high-temperature slag deposition condition. (iii) A seven-step carbothermal reduction in the alumina is derived and established under high-pressure and high-temperature environment in the SRM combustion chamber. (iv) The analysis using thermodynamic software indicates that the reaction of the alumina and charring layer initially forms Al4C3 during the operation. Then, Al element and Al2OC compound are subsequently produced with the reduction in the release of gas CO as well with continuous environmental heating.

  7. The Pd(0) nanoparticles stabilized by collagen fibres as a recyclable heterogeneous catalyst for the Stille reaction under aerobic condition

    Babak Mohammadi-Aghdam; Siavash Bahari; Rahim Molaei


    The stabilized palladium(0) nanoparticles by collagen fibres was a highly active, air-stable and recyclable heterogeneous catalyst that could be used for the Stille coupling reactions between aryl iodides and organostannanes under aerobic conditions. This method offered the several advantages: high yield under facile reaction condition and easy work-up procedure. The catalyst was easily recovered from the reaction mixture by filtration and reused multiple times without significant reduction or decrease in the activity.

  8. Effect of Ni Loading and Reaction Conditions on Partial Oxidation of Methane to Syngas

    Haitao Wang; Zhenhua Li; Shuxun Tian


    The partial oxidation of methane to synthesis gas is studied in this paper over Ni/Al2O3 catalysts under atmospheric pressure. The effects of Ni loading on the activity and stability of catalysts with 5 mm α-Al2O3 and θ-Al2O3 pellets as supports were measured in a continuous fixed bed reactor. It is found that the optimum Ni loading is 10%. And the effect of reaction conditions on partial oxidation of methane is also studied. The methane conversion and CO selectivity increase with the increase of the reaction temperature and the space velocity on 10%Ni/α-Al2O3 catalysts. The best CH4/O2 mole ratio is 2 for CO selectivity, and the optimum space velocity is 5.4×105 h-1.

  9. Effect of reaction conditions on phenol removal by polymerization and precipitation using Coprinus cinereus peroxidase.

    Masuda, M; Sakurai, A; Sakakibara, M


    The quantitative relationships between removal efficiency of phenol and reaction conditions were investigated using Coprinus cinereus peroxidase. The most effective ratio of hydrogen peroxide to phenol was nearly 1/1 (mol/mol) at an adequate enzyme dose. 12.2 U of the enzyme was needed to remove 1 mg of phenol when our peroxidase preparation was used. At an insufficient peroxidase dose, the optimum pH value was 9.0, and lowering the reaction temperature led to the improvement of removal efficiency. At an excess peroxidase dose, almost 100% removal of phenol was obtained over a wide range of pH (5-9) and temperature (0-60 degrees C). Despite the presence of culture medium components, it was shown that Coprinus cinereus peroxidase had the same phenol polymerization performance as horseradish peroxidase or Arthromyces ramosus peroxidase.

  10. Accelerating process and catalyst development in reforming reactions with high throughput technologies under industrially relevant conditions

    Schunk, S.A.; Bollmann, G.; Froescher, A.; Kaiser, H.; Lange de Oliveira, A.; Roussiere, T.; Wasserschaff, G. [hte Aktiengesellschaft, Heidelberg (Germany); Domke, I. [BASF SE, Ludwigshafen (Germany)


    The generation of hydrogen via reforming of a variety of carbon containing feed-stocks in the presence of water is up to date one of the most versatile technologies for the production of hydrogen and syngas. Although these reforming technologies are in principle well established, understood and commercialized, there are still a number of technological challenges that are not solved up to a satisfactorily degree and there is a constant demand for appropriate answers to the challenges posed. High throughput experimentation can be a valuable tool in helping accelerate the development of suitable solutions on the catalyst and process development side. In order to be able to generate test data that are close or identical to process relevant conditions, hte has developed a new technology portfolio of test technologies named Stage-IV technology. In contrast to earlier developments which address more small scale testing on the basis of catalyst volumes of 1ml up to 10 ml under isothermal conditions, our new technology portfolio offers the advantage of test volumes at sub-pilot scale also realizing reactor dimensions close to technical applications. This does not only ensure a good mimic of the hydrodynamic conditions of the technical scale, but also allows a fingerprinting of features like temperature gradients in the catalyst bed which play a large role for catalyst performance. Apart from catalyst tests with granulates when screening for optimized catalyst compositions, the units are designed to accommodate tests with shaped catalysts. In order to demonstrate how these technologies can accelerate catalyst and process development we have chosen technically challenging application examples: (I) Pre-reforming and reforming of methane based feeds which accelerate coking and catalyst deactivation. Higher reaction pressures, high CO{sub 2} contents in the feedgas (which occur typically in sources like bio-gas or certain types of natural gas), the presence of higher alkanes

  11. Brownian dynamics simulations of an idealized chemical reaction network under spatial confinement and crowding conditions

    Bellesia, Giovanni


    We investigate, via Brownian dynamics simulations, the reaction dynamics of a simple, non-linear chemical network (the Willamowski-Rossler network) under spatial confinement and crowding conditions. Our results show that the presence of inert crowders has a non-nontrivial effect on the dynamics of the network and, consequently, that effective modeling efforts aiming at a general understanding of the behavior of biochemical networks in vivo should be stochastic in nature and based on an explicit representation of both spatial confinement and macromolecular crowding.

  12. Altered vocal fold kinematics in synthetic self-oscillating models that employ adipose tissue as a lateral boundary condition.

    Saidi, Hiba; Erath, Byron D.


    The vocal folds play a major role in human communication by initiating voiced sound production. During voiced speech, the vocal folds are set into sustained vibrations. Synthetic self-oscillating vocal fold models are regularly employed to gain insight into flow-structure interactions governing the phonation process. Commonly, a fixed boundary condition is applied to the lateral, anterior, and posterior sides of the synthetic vocal fold models. However, physiological observations reveal the presence of adipose tissue on the lateral surface between the thyroid cartilage and the vocal folds. The goal of this study is to investigate the influence of including this substrate layer of adipose tissue on the dynamics of phonation. For a more realistic representation of the human vocal folds, synthetic multi-layer vocal fold models have been fabricated and tested while including a soft lateral layer representative of adipose tissue. Phonation parameters have been collected and are compared to those of the standard vocal fold models. Results show that vocal fold kinematics are affected by adding the adipose tissue layer as a new boundary condition.

  13. 29 CFR 570.35 - Hours of work and conditions of employment permitted for minors 14 and 15 years of age.


    ... AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS CHILD LABOR REGULATIONS, ORDERS AND STATEMENTS OF INTERPRETATION Employment of Minors Between 14 and 16 Years of Age (Child Labor Reg. 3) § 570.35 Hours of work... 29 Labor 3 2010-07-01 2010-07-01 false Hours of work and conditions of employment permitted...

  14. Atomic-Scale Observations of Catalyst Structures under Reaction Conditions and during Catalysis.

    Tao, Franklin Feng; Crozier, Peter A


    Heterogeneous catalysis is a chemical process performed at a solid-gas or solid-liquid interface. Direct participation of catalyst atoms in this chemical process determines the significance of the surface structure of a catalyst in a fundamental understanding of such a chemical process at a molecular level. High-pressure scanning tunneling microscopy (HP-STM) and environmental transmission electron microscopy (ETEM) have been used to observe catalyst structure in the last few decades. In this review, instrumentation for the two in situ/operando techniques and scientific findings on catalyst structures under reaction conditions and during catalysis are discussed with the following objectives: (1) to present the fundamental aspects of in situ/operando studies of catalysts; (2) to interpret the observed restructurings of catalyst and evolution of catalyst structures; (3) to explore how HP-STM and ETEM can be synergistically used to reveal structural details under reaction conditions and during catalysis; and (4) to discuss the future challenges and prospects of atomic-scale observation of catalysts in understanding of heterogeneous catalysis. This Review focuses on the development of HP-STM and ETEM, the in situ/operando characterizations of catalyst structures with them, and the integration of the two structural analytical techniques for fundamentally understanding catalysis.

  15. Study of 20O via the (d,p) reaction in inverse kinematics employing the active gas target detector ANASEN

    Santiago-Gonzalez, D.; Wiedenhöver, I.; Baby, L. T.; Koshchiy, E.; Rogachev, G. V.; Blackmon, J. C.; Linhardt, L. E.


    The energetic location of the d3/2-orbital in neutron-rich nuclei is of particular interest as it determines the location of the drip-line in the oxygen isotopes. Its behavior has recently been described as a consequence of three-body forces. Manifestations of such forces are traced through the location of the d3/2 orbital, which closer to stability leads to highly excited states. In order to study the location and fragmentation of this orbital in 20O a beam of the short-lived 19O was produced at the RESOLUT radioactive beam facility of the Florida State University with an intensity of 1 ×105 pps, 65 % purity and 4.11 MeV/u. The chamber of the active gas target detector ANASEN was filled with molecular deuterium gas (D2) which yielded 20O via the 19O (d , p) reaction. The ejected protons were measured with large solid angle coverage and for beam energies between 2.9 and 3.7 MeV/u. Data from the 17O(d , p) 18O reaction was acquired to verify our experimental methods and analysis techniques. We will present the latest advances in the analysis of the 19O(d , p) 20O data and demonstrate the capabilities of ANASEN. Work supported by the National Science Foundation.

  16. Effects of network dissolution changes on pore-to-core upscaled reaction rates for kaolinite and anorthite reactions under acidic conditions

    Kim, Daesang


    We have extended reactive flow simulation in pore-network models to include geometric changes in the medium from dissolution effects. These effects include changes in pore volume and reactive surface area, as well as topological changes that open new connections. The computed changes were based upon a mineral map from an X-ray computed tomography image of a sandstone core. We studied the effect of these changes on upscaled (pore-scale to core-scale) reaction rates and compared against the predictions of a continuum model. Specifically, we modeled anorthite and kaolinite reactions under acidic flow conditions during which the anorthite reactions remain far from equilibrium (dissolution only), while the kaolinite reactions can be near-equilibrium. Under dissolution changes, core-scale reaction rates continuously and nonlinearly evolved in time. At higher injection rates, agreement with predictions of the continuum model degraded significantly. For the far-from-equilibrium reaction, our results indicate that the ability to correctly capture the heterogeneity in dissolution changes in the reactive mineral surface area is critical to accurately predict upscaled reaction rates. For the near-equilibrium reaction, the ability to correctly capture the heterogeneity in the saturation state remains critical. Inclusion of a Nernst-Planck term to ensure neutral ionic currents under differential diffusion resulted in at most a 9% correction in upscaled rates.

  17. Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

    Tor E. Kristensen


    Full Text Available Amino acids, whether natural, semisynthetic or synthetic, are among the most important and useful chiral building blocks available for organic chemical synthesis. In principle, they can function as inexpensive, chiral and densely functionalized starting materials. On the other hand, the use of amino acid starting materials routinely necessitates protective group chemistry, and in reality, large-scale preparations of even the simplest side-chain derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4-dihydroxyphenylalanine (DOPA, many O-acyl side-chain derivatives are directly accessible via a particularly expedient and scalable method not commonly applied until recently. Direct acylation of unprotected hydroxyamino acids with acyl halides or carboxylic anhydrides under appropriately acidic reaction conditions renders possible chemoselective O-acylation, furnishing the corresponding side-chain esters directly, on multigram-scale, in a single step, and without chromatographic purification. Assuming a certain degree of stability under acidic reaction conditions, the method is also applicable for a number of related compounds, such as various amino alcohols and the thiol-functional amino acid cysteine. While the basic methodology underlying this approach has been known for decades, it has evolved through recent developments connected to amino acid-derived chiral organocatalysts to become a more widely recognized procedure for large-scale preparation of many useful side-chain derivatives of hydroxyamino acids and related compounds. Such derivatives are useful in peptide chemistry and drug development, as amino acid amphiphiles for asymmetric catalysis, and as amino acid acrylic precursors for preparation of

  18. Application of a Homogeneous Dodecakis[NCN-Pincer-PdII] Catalyst in a Nanofiltration Membrane Reactor under Continious Reaction Conditions

    Koten, G. van; Dijkstra, H.P.; Ronde, N.; Klink, G.P.M. van; Vogt, D.


    A shape-persistent nanosize dodecakis(NCN-PdII-aqua) complex (4b) was applied as a homogeneous catalyst in the double Michael reaction between methyl vinyl ketone and ethyl -cyanoacetate under continuous reaction conditions in a nanofiltration membrane reactor. Due to its macromolecular dimensions,

  19. Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO{sub 2}

    Galenda, A., E-mail: [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy); Crociani, L.; Habra, N. El; Favaro, M. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy); Natile, M.M. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Dipartimento di Scienze Chimiche, Università di Padova, via F. Marzolo, 1 35131 Padova (Italy); Rossetto, G. [CNR-IENI, Istituto per l’Energetica e le Interfasi, Corso Stati Uniti, 4 35127 Padova (Italy)


    Highlights: • Boron and/or nitrogen-doped TiO{sub 2} for photocatalytic wastewater treatment. • Methyl red degradation/mineralisation as a function of pH, acids and dopants. • Adsorption time influence on photocatalytic process. • Recovery of worn-out catalyst. - Abstract: Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO{sub 2}-based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV–vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage.

  20. Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO2

    Galenda, A.; Crociani, L.; Habra, N. El; Favaro, M.; Natile, M. M.; Rossetto, G.


    Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO2-based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV-vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage.

  1. Iodine-catalyzed disproportionation of aryl-substituted ethers under solvent-free reaction conditions.

    Jereb, Marjan; Vražič, Dejan


    Iodine was demonstrated to be an efficient catalyst for disproportionation of aryl-substituted ethers under solvent-free reaction conditions. Variously substituted 1,1,1',1'-tetraaryldimethyl ethers were transformed into the corresponding diarylketone and diarylmethane derivatives. I2-catalyzed transformation of 4-methoxyphenyl substituted ethers yielded mono- and dialkylated Friedel-Crafts products as well. Treatment of trityl alkyl and trityl benzyl ethers with a catalytic amount of iodine produced triphenylmethane and the corresponding aldehydes and ketones. The electron-donating substituents facilitated the reaction, while the electron-withdrawing groups retarded it; the difference in reactivity is not very high. Such an observation may be in favour of hydride transfer, predominantly from the less electron rich side of the ether with more stable carbocation formation. With the isotopic studies it was established that a substantial portion of the C-H bond scission took place in the rate-determining step, while the carbonyl oxygen atom originated from the starting ether, and not from the air. The transformation took place under air and under argon, and HI was not a functioning catalyst.

  2. Greenhouse Gas Conversion by Homogeneous Salen Catalyst Systems under Very Mild Reaction Condition

    Suh, Hyungsock; Song, Sanghoon; Ahn, Sunghyun; Kim, Taesoon; Kim, Beomsik; Chang, Taesun [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)


    Homogeneous salen catalyt systems were investigated for the conversion of greenhouse gas into cyclic carbonate under room temperature and atmospheric pressure. Salen complexes were more active than salophen complexes. Neither electron withdrawing nor donating group showed lower conversion efficiency. Co-catalysts such as moisture or ammonium salt increased the conversion efficiency dramatically. These results have potential to decrease carbon dioxide emitted from fossil fuel combustions under mild condition. One of the main scientific challenges in the 21st century is the global warming due to the increasing level of carbon dioxide. The consumption of fossil fuels is continue to increase with emitting substantial amount of green house gas. The solution currently considered is capturing and storing of carbon dioxide which compressing carbon dioxide and then storing it into oil wells or under the ocean. The other solution include converting the carbon dioxide into useful chemicals with significant commercial demand, but low chemical reactivity of carbon dioxide restricts the chemical reactions.

  3. Effects of reaction conditions on cellulose structures synthesized in vitro by bacterial cellulose synthases.

    Penttilä, Paavo A; Sugiyama, Junji; Imai, Tomoya


    Cellulose was synthesized by cellulose synthases extracted from the Komagataeibacter xylinus (formerly known as Gluconacetobacter xylinus). The effects of temperature and centrifugation of the reaction solution on the synthesis products were investigated. Cellulose with number-average degree of polymerization (DPn) roughly in the range 60-80 and cellulose II crystal structure was produced under all conditions. The amount of cellulose varied with temperature and centrifugation, and the centrifugation at 2000 × g also slightly reduced the DPn. Cellulose production was maximal around the temperature 35 °C and without centrifugation. At higher temperatures and during centrifugation at 2000 × g the proteins started to denature, causing differences also in the morphology of the cellulosic aggregates, as seen with electron microscopy. These observations serve as a basis for discussions about the factors affecting the structure formation and chain length of in vitro synthesized cellulose.

  4. The nature of lithium battery materials under oxygen evolution reaction conditions.

    Lee, Seung Woo; Carlton, Christopher; Risch, Marcel; Surendranath, Yogesh; Chen, Shuo; Furutsuki, Sho; Yamada, Atsuo; Nocera, Daniel G; Shao-Horn, Yang


    Transition-metal oxide and phosphate materials, commonly used for lithium battery devices, are active as oxygen evolution reaction (OER) catalysts under alkaline and neutral solution conditions. Electrodes composed of LiCoO(2) and LiCoPO(4) exhibit progressive deactivation and activation for OER catalysis, respectively, upon potential cycling at neutral pH. The deactivation of LiCoO(2) and activation of LiCoPO(4) are coincident with changes in surface morphology and composition giving rise to spinel-like and amorphous surface structures, respectively. The amorphous surface structure of the activated LiCoPO(4) is compositionally similar to that obtained from the electrodeposition of cobalt oxide materials from phosphate-buffered electrolyte solutions. These results highlight the importance of a combined structural and electrochemical analysis of the materials surface when assessing the true nature of the OER catalyst.

  5. The estimation of the reaction stimulators influence into the extraction slag conditions

    A. W. Bydałek


    Full Text Available Slag stimulators was analysed used the DTA methods. In the paper a method of determining the reduction capability of slag solutions wasused. The analysis of slag stimulators concertinaing of the chloride and fluoride compositions are showed. There are the oxides complexesused in to the slag composition for the purpose to establish two indicators in reduction processes: EW - indicator showing the direction and intensity of reaction in to the slag composition, and r - indicator of the rate of coal consumption. There are possible and purposeful the construction optimization programme engaging all of the phisics chemical influence the slags in processes of melting metals alloys. The proposed results, ranges of areas on graphs of phase equilibria's, demonstrative on the optimum values, will be verified in laboratory conditions and industrial. The initiation the new data the gathered base will be built in system of open base enabling.

  6. Development of a reaction cell for in-situ/operando studies of surface of a catalyst under a reaction condition and during catalysis.

    Nguyen, Luan; Tao, Franklin Feng


    Tracking surface chemistry of a catalyst during catalysis is significant for fundamental understanding of catalytic performance of the catalyst since it allows for establishing an intrinsic correlation between surface chemistry of a catalyst at its working status and its corresponding catalytic performance. Ambient pressure X-ray photoelectron spectroscopy can be used for in-situ studies of surfaces of different materials or devices in a gas. To simulate the gaseous environment of a catalyst in a fixed-bed a flowing gaseous environment of reactants around the catalyst is necessary. Here, we report the development of a new flowing reaction cell for simulating in-situ study of a catalyst surface under a reaction condition in gas of one reactant or during catalysis in a mixture of reactants of a catalytic reaction. The homemade reaction cell is installed in a high vacuum (HV) or ultrahigh vacuum (UHV) environment of a chamber. The flowing gas in the reaction cell is separated from the HV or UHV environment through well sealings at three interfaces between the reaction cell and X-ray window, sample door and aperture of front cone of an energy analyzer. Catalyst in the cell is heated through infrared laser beam introduced through a fiber optics interfaced with the reaction cell through a homemade feedthrough. The highly localized heating on the sample holder and Au-passivated internal surface of the reaction cell effectively minimizes any unwanted reactions potentially catalyzed by the reaction cell. The incorporated laser heating allows a fast heating and a high thermal stability of the sample at a high temperature. With this cell, a catalyst at 800 °C in a flowing gas can be tracked readily.

  7. REtools: A laboratory program for restriction enzyme work: enzyme selection and reaction condition assistance

    Boulukos Kim E


    Full Text Available Abstract Background Restriction enzymes are one of the everyday tools used in molecular biology. The continuously expanding panel of known restriction enzymes (several thousands renders their optimal use virtually impossible without computerized assistance. Several manufacturers propose on-line sites that assist scientists in their restriction enzyme work, however, none of these sites meet all the actual needs of laboratory workers, and they do not take into account the enzymes actually present in one's own laboratory. Results Using FileMaker Pro, we developed a stand-alone application which can run on both PCs and Macintoshes. We called it REtools, for Restriction Enzyme tools. This program, which references all currently known enzymes (>3500, permits the creation and update of a personalized list of restriction enzymes actually available in one's own laboratory. Upon opening the program, scientists will be presented with a user friendly interface that will direct them to different menus, each one corresponding to different situations that restriction enzyme users commonly encounter. We particularly emphasized the ease of use to make REtools a solution that laboratory members would actually want to use. Conclusion REtools, a user friendly and easily customized program to organize any laboratory enzyme stock, brings a software solution that will make restriction enzyme use and reaction condition determination straightforward and efficient. The usually unexplored potential of isoschizomers also becomes accessible to all, since REtools proposes all possible enzymes similar to the one(s chosen by the user. Finally, many of the commonly overlooked subtleties of restriction enzyme work, such as methylation requirement, unusual reaction conditions, or the number of flanking bases required for cleavage, are automatically provided by REtools.

  8. Chemical and Physical Reactions of Wellbore Cement under CO2 Storage Conditions: Effects of Cement Additives

    Kutchko, B. G.; Strazisar, B. R.; Huerta, N.; Lowry, G. V.; Dzombak, D. A.; Thaulow, N.


    Sequestration of CO2 into geologic formations requires long-term storage and low leakage rates to be effective. Active and abandoned wells in candidate storage formations must be evaluated as potential leakage points. Wellbore integrity is an important part of an overall integrated assessment program being developed at NETL to assess potential risks at CO2 storage sites. Such a program is needed for ongoing policy and regulatory decisions for geologic carbon sequestration. The permeability and integrity of the cement in the well is a primary factor affecting its ability to prevent leakage. Cement must be able to maintain low permeability over lengthy exposure to reservoir conditions in a CO2 injection and storage scenario. Although it is known that cement may be altered by exposure to CO2, the results of ongoing research indicate that cement curing conditions, fluid properties, and cement additives play a significant role in the rate of alteration and reaction. The objective of this study is to improve understanding of the factors affecting wellbore cement integrity for large-scale geologic carbon sequestration projects. Due to the high frequency use of additives (pozzolan) in wellbore cement, it is also essential to understand the reaction of these cement-pozzolan systems upon exposure to CO2 under sequestration conditions (15.5 MPa and 50°C). Laboratory experiments were performed to determine the physical and chemical changes, as well as the rate of alteration of commonly used pozzolan-cement systems under simulated sequestration reservoir conditions, including both supercritical CO2 and CO2-saturated brine. The rate of alteration of the cement-pozzolan systems is considerably faster than with neat cement. However, the alteration of physical properties is much less significant with the pozzolanic blends. Permeability of a carbonated pozzolanic cement paste remains sufficiently small to block significant vertical migration of CO2 in a wellbore. All of the

  9. Should Student Employment Be Subsidized? Conditional Counterfactuals and the Outcomes of Work-Study Participation. A CAPSEE Working Paper

    Scott-Clayton, Judith; Minaya, Veronica


    Student employment subsidies are one of the largest types of federal employment subsidies, and one of the oldest forms of student aid. Yet it is unclear whether they help or harm students' long term outcomes. We present a framework that decomposes overall effects into a weighted average of effects for marginal and inframarginal workers. We then…

  10. Recyclable nickel catalysed Suzuki-Miyaura reaction in the presence of polyethyleneimine under phosphine-free conditions in ethylene glycol

    Nooredin Goudarzian; Mohammad Gholinejad; Parisa Ghahramani


    In this report, Suzuki-Miyaura coupling reaction was performed in the presence of polyethyleneimine (PEI) as ligand, NiCl2·6H2O and K2CO3 in ethylene glycol at 80-100°C under phosphinefree conditions. By this method, structurally different aryl bromides and iodides were reacted with phenylboronic acid and potassium phenyltrifluoroborate. Under these simple reaction conditions a different biaryl derivatives have been prepared in high to excellent yields. Recycling experiments showed that catalyst can be used as recyclable catalyst in the Suzuki-Miyaura cross-coupling reactions.

  11. Kinetics of Hydrogen Radical Reactions with Toluene Including Chemical Activation Theory Employing System-Specific Quantum RRK Theory Calibrated by Variational Transition State Theory.

    Bao, Junwei Lucas; Zheng, Jingjing; Truhlar, Donald G


    Pressure-dependent reactions are ubiquitous in combustion and atmospheric chemistry. We employ a new calibration procedure for quantum Rice-Ramsperger-Kassel (QRRK) unimolecular rate theory within a chemical activation mechanism to calculate the pressure-falloff effect of a radical association with an aromatic ring. The new theoretical framework is applied to the reaction of H with toluene, which is a prototypical reaction in the combustion chemistry of aromatic hydrocarbons present in most fuels. Both the hydrogen abstraction reactions and the hydrogen addition reactions are calculated. Our system-specific (SS) QRRK approach is adjusted with SS parameters to agree with multistructural canonical variational transition state theory with multidimensional tunneling (MS-CVT/SCT) at the high-pressure limit. The new method avoids the need for the usual empirical estimations of the QRRK parameters, and it eliminates the need for variational transition state theory calculations as a function of energy, although in this first application we do validate the falloff curves by comparing SS-QRRK results without tunneling to multistructural microcanonical variational transition state theory (MS-μVT) rate constants without tunneling. At low temperatures, the two approaches agree well with each other, but at high temperatures, SS-QRRK tends to overestimate falloff slightly. We also show that the variational effect is important in computing the energy-resolved rate constants. Multiple-structure anharmonicity, torsional-potential anharmonicity, and high-frequency-mode vibrational anharmonicity are all included in the rate computations, and torsional anharmonicity effects on the density of states are investigated. Branching fractions, which are both temperature- and pressure-dependent (and for which only limited data is available from experiment), are predicted as a function of pressure.

  12. A more robust model of the biodiesel reaction, allowing identification of process conditions for significantly enhanced rate and water tolerance.

    Eze, Valentine C; Phan, Anh N; Harvey, Adam P


    A more robust kinetic model of base-catalysed transesterification than the conventional reaction scheme has been developed. All the relevant reactions in the base-catalysed transesterification of rapeseed oil (RSO) to fatty acid methyl ester (FAME) were investigated experimentally, and validated numerically in a model implemented using MATLAB. It was found that including the saponification of RSO and FAME side reactions and hydroxide-methoxide equilibrium data explained various effects that are not captured by simpler conventional models. Both the experiment and modelling showed that the "biodiesel reaction" can reach the desired level of conversion (>95%) in less than 2min. Given the right set of conditions, the transesterification can reach over 95% conversion, before the saponification losses become significant. This means that the reaction must be performed in a reactor exhibiting good mixing and good control of residence time, and the reaction mixture must be quenched rapidly as it leaves the reactor.

  13. In search of efficient catalysts and appropriate reaction conditions for gas phase nitration of benzene

    Anton P. Koskin


    Full Text Available The present paper is dedicated to the development of a method for the nitrobenzene production using solid acid catalysts, as an alternative to industrial nitration, based on a mixture of concentrated acids. The influence of key parameters of the nitration process (temperature, reagent flow rate, nitrating agent concentration etc. on the conversion of the initial substrate, the degree of decomposition of nitric acid and the quantity of resulting oxygenates was studied. Recommendations for the selection of effective catalytic systems (high content of Brønsted acid sites with Ho < −4, high specific surface and resistance to HNO3 were developed and the best conditions for process reactions (temperature 200 °C, aqueous solution of nitric acid with concentration of 30 wt%, “nitric acid:benzene” ratio = 0.76 were found. A method for regeneration of the catalytic activity without unloading the catalyst was proposed. As an example, MoO3/SiO2 sample was tested in a dual-mode nitration/regeneration process, which allowed us to increase the flow rates of reagents and obtain catalyst efficiency of up to STY = 4.09 g/(gcat ⋅ h. Several of the most promising catalysts (MoO3/SiO2, WO3/ZrO2 and Nafion/support composite for the process were tested in identical conditions.

  14. Selection of reference genes for quantitative reverse-transcription polymerase chain reaction normalization in Brassica napus under various stress conditions.

    Wang, Zheng; Chen, Yu; Fang, Hedi; Shi, Haifeng; Chen, Keping; Zhang, Zhiyan; Tan, Xiaoli


    Data normalization is essential for reliable output of quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) assays, as the unsuitable choice of reference gene(s), whose expression might be influenced by exogenous treatments in plant tissues, could cause misinterpretation of results. To date, no systematic studies on reference genes have been performed in stressed Brassica napus. In this study, we investigated the expression variations of nine candidate reference genes in 40 samples of B. napus leaves subjected to various exogenous treatments. Parallel analyses by geNorm and NormFinder revealed that optimal reference genes differed across the different sets of samples. The best-ranked reference genes were PP2A and TIP41 for salt stress, TIP41 and ACT7 for heavy metal (Cr(6+)) stress, PP2A and UBC21 for drought stress, F-box and SAND for cold stress, F-box and ZNF for salicylic acid stress, TIP41, ACT7, and PP2A for methyl jasmonate stress, TIP41 and ACT7 for abscisic acid stress, and TIP41, UBC21, and PP2A for Sclerotinia sclerotiorum stress. Two newly employed reference genes, TIP41 and PP2A, showed better performances, suggesting their suitability in multiple conditions. To further validate the suitability of the reference genes, the expression patterns of BnWRKY40 and BnMKS1 were studied in parallel. This study is the first systematic analysis of reference gene selection for qRT-PCR normalization in B. napus, an agriculturally important crop, under different stress conditions. The results will contribute toward more accurate and widespread use of qRT-PCR in gene analysis of the genus Brassica.

  15. Hexene catalytic cracking over 30% sapo-34 catalyst for propylene maximization: influence of reaction conditions and reaction pathway exploration

    Z. Nawaz


    Full Text Available Higher olefins are produced as a by product in a number of refinery processes and are one of the potential raw materials to produce propylene. In the present study, FCC model feed compound was considered to explore the olefin cracking features and options to enhance propylene using 30% SAPO-34 zeolite as catalyst in a micro-reactor. The superior selectivity of propylene (73 wt% and higher total olefin selectivity was obtained over 30% SAPO-34 catalyst than over Y or ZSM-5 zeolite catalysts. The thermodynamical constraints were found to be relatively less serious in the case of 1-hexene conversion. Most of the 1-hexene follows a direct cracking pathway to give two propylene molecules, due to weak acid sites and better diffusion opportunities. The higher temperature and short residence time could also suppress the hydrogen transfer reactions. From OPE (olefins performance envelop the products were classified as primary, secondary, or both. Iso-hexene (2-methyl-2-pentene cracking was also analyzed in order to justify a shape selective effect of the SAPO-34 catalyst. A detailed integrated reaction network together with an associated mechanism was proposed and discussed in detail for their fundamental importance in understanding the olefin cracking processes over SAPO-34.

  16. Simplified models of transport and reactions in conditions of CO2 storage in saline aquifers

    Suchodolska, Katarzyna; Labus, Krzysztof


    Simple hydrogeochemical models may serve as tools of preliminary assessment of CO2 injection and sequestraton impact on the aquifer and cap-rocks. In order to create models of reaction and transport in conditions of CO2 injection and storage, the TOUGHREACT simulator, and the Geochemist's Workbench software were applied. The chemical composition of waters for kinetic transport models based on the water - rock equilibrium calculations. Analyses of reaction and transport of substances during CO2 injection and storage period were carried out in three scenarios: one-dimensional radial model, and two-dimensional model of CO2 injection and sequestration, and one-dimensional model of aquifer - cap-rock interface. Modeling was performed in two stages. The first one simulated the immediate changes in the aquifer and insulating rocks impacted by CO2 injection (100 days in case of reaction model and 30 years in transport and reaction model), the second - enabled assessment of long-term effects of sequestration (20000 years). Reactions' quality and progress were monitored and their effects on formation porosity and sequestration capacity in form of mineral, residual and free phase of CO2 were calculated. Calibration of numerical models (including precipitation of secondary minerals, and correction of kinetics parameters) describing the initial stage of injection, was based on the experimental results. Modeling allowed to evaluate the pore space saturation with gas, changes in the composition and pH of pore waters, relationships between porosity and permeability changes and crystallization or dissolution minerals. We assessed the temporal and spatial extent of crystallization processes, and the amount of carbonates trapping. CO2 in mineral form. The calculated sequestration capacity of analyzed formations reached n·100 kg/m3 for the: dissolved phase - CO(aq), gas phase - CO2(g) and mineral phase, but as much as 101 kg/m3 for the supercritical phase - SCCO2. Processes of gas

  17. N,N-Diethyl-1-Tosyl-3-Indoleglyoxylamide as a Dienophile in Diels-Alder Reactions. Hyperbaric vs. Thermal Conditions

    B. Biolatto


    Full Text Available Under high pressure conditions, the Diels-Alder reaction involving N,N-diethyl-1-tosyl-3-indoleglyoxylamide and 1-(N-acetyl-N-propylamino-1,3-butadiene produces a highly functionalized intermediate for the synthesis of Indole Alkaloids, in shorter times and higher yields than under thermal conditions.

  18. Improved polymerase chain reaction conditions for quick diagnostics of Huntington disease.

    Culjković, B; Ruzdijić, S; Rakić, L; Romac, S


    Huntington disease (HD) belongs to a growing list of neurodegenerative disorders (fragile X syndrome [6], myotonic dystrophy [1], spino-bulbar muscular atrophy [2] etc.) characterized by unstable expanded trinucleotide repeats (so-called 'dynamic mutations'). The dynamic mutation causing HD represents the expansion of CAG triplets in the first exon of a gene IT15 (chromosome 4) coding for huntington. This trinucleotide stretch is varying in the range of 11-34 in normal chromosomes and 39-121 in HD chromosomes. The most direct diagnostic approach is to amplify the proximal region of IT15 gene (from patients genomic DNA) by polymerase chain reaction (PCR) and estimate the number of CAG triplets. All protocols published to date are difficult to reproduce because amplification is inefficient giving additional non-specific products. The strategy of our experiment is shown in Fig. 1. We designed one new primer, primer No. 2 (another primer was primer No. 1) and novel PCR conditions. Primer No. 2 is located closer to CAG triplets and its extension is not including the GC rich region. PCR amplified products, using primer Nos. 1 and 2, thus do not include the GC rich region and, therefore, are much more efficiently amplified (compared to the products of amplification with primer Nos. 1 and 3).

  19. Attrition of limestones by impact loading in fluidized beds: The influence of reaction conditions

    Scala, Fabrizio [Istituto di Ricerche sulla Combustione, Consiglio Nazionale delle Ricerche, Napoli (Italy); Salatino, Piero [Istituto di Ricerche sulla Combustione, Consiglio Nazionale delle Ricerche, Napoli (Italy); Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, Napoli (Italy)


    The extent of attrition associated with impact loading was studied for five different limestones pre-processed in fluidized bed under different reaction conditions. The experimental procedure was based on the measurement of the amount and the particle size distribution of the debris generated upon impact of sorbent samples against a target at velocities between 10 and 45 m/s. The effect of calcination, sulfation and calcination/re-carbonation on impact damage was assessed. Fragmentation by impact loading of the limestones was significant and increased with the impact velocity. Lime samples displayed the largest propensity to undergo impact damage, followed by sulfated, re-carbonated and raw limestones. Fragmentation of the sulfated samples followed a pattern typical of the failure of brittle materials. On the other hand, the behaviour of lime samples better conformed to a disintegration failure mode, with extensive generation of very fine fragments. Raw limestone and re-carbonated lime samples followed either of the two patterns depending on the sorbent nature. The extent of particle fragmentation increased after multiple impacts, but the incremental amount of fragments generated upon one impact decreased with the number of successive impacts. (author)

  20. Modeling Time-Dependent Behavior of Concrete Affected by Alkali Silica Reaction in Variable Environmental Conditions

    Alnaggar, Mohammed; Di Luzio, Giovanni; Cusatis, Gianluca


    Alkali Silica Reaction (ASR) is known to be a serious problem for concrete worldwide, especially in high humidity and high temperature regions. ASR is a slow process that develops over years to decades and it is influenced by changes in environmental and loading conditions of the structure. The problem becomes even more complicated if one recognizes that other phenomena like creep and shrinkage are coupled with ASR. This results in synergistic mechanisms that can not be easily understood without a comprehensive computational model. In this paper, coupling between creep, shrinkage and ASR is modeled within the Lattice Discrete Particle Model (LDPM) framework. In order to achieve this, a multi-physics formulation is used to compute the evolution of temperature, humidity, cement hydration, and ASR in both space and time, which is then used within physics-based formulations of cracking, creep and shrinkage. The overall model is calibrated and validated on the basis of experimental data available in the literature. Results show that even during free expansions (zero macroscopic stress), a significant degree of coupling exists because ASR induced expansions are relaxed by meso-scale creep driven by self-equilibriated stresses at the meso-scale. This explains and highlights the importance of considering ASR and other time dependent aging and deterioration phenomena at an appropriate length scale in coupled modeling approaches. PMID:28772829

  1. Influence of the Reaction Conditions on the Enzyme Catalyzed Transesterification of Castor Oil: a possible step in Biodiesel Production

    Andrade, Thalles Allan; Errico, Massimiliano; Christensen, Knud Villy


    The identification of the influence of the reaction parameters is of paramount importance when defining a process design. In this work, non-edible castor oil was reacted with methanol to produce a possible component for biodiesel blends, using liquid enzymes as the catalyst. Temperature, alcohol......-to-oil molar ratio, enzyme and added water contents were the reaction parameters evaluated in the transesterification reactions. The optimal conditions, giving the optimal final FAME yield and FFA content in the methyl ester-phase was identified. At 35 °C, 6.0 methanol-to-oil molar ratio, 5 wt% of enzyme and 5...

  2. Periaqueductal gray c-Fos expression varies relative to the method of conditioned taste aversion extinction employed.

    Mickley, G Andrew; Wilson, Gina N; Remus, Jennifer L; Ramos, Linnet; Ketchesin, Kyle D; Biesan, Orion R; Luchsinger, Joseph R; Prodan, Suzanna


    A conditioned taste aversion (CTA) is acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). Following CTA training, animals will avoid the taste that was previously associated with malaise. This defensive reaction to a learned fear can be extinguished by repeated exposure to the CS alone (CS-only; CSO-EXT). However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). Through the use of an explicitly unpaired extinction procedure (EU-EXT) we have shown that we can speed up extinction and attenuate SR of the CTA. Here we compared and contrasted the ability of CSO and EU extinction procedures to affect c-Fos expression in the periaqueductal gray (PAG). Fluid-deprived Sprague-Dawley rats acquired a strong CTA [via 3 pairings of 0.3% oral saccharin (SAC; the CS) and 81mg/kg i.p. lithium chloride (LiCl; the US)] followed by extinction trials consisting of multiple exposures to either, (a) the CS every-other day (CSO-EXT), or (b) CS and US on alternate days (EU-EXT). A different group of rats did not receive multiple CS exposures and served as a "no extinction" (NE) control. Both extinction procedures resulted in ≥90% reacceptance of SAC (achieving asymptotic extinction). Some of the animals were sacrificed for c-Fos immunohistochemical analysis following asymptotic extinction. Other rats entered a 30-day latency period where they drank water only. These remaining animals were then tested for SR with a final exposure to SAC before being sacrificed for c-Fos immunohistochemistry. As reported previously, rats in the CS-only group exhibited a significant SR of the CTA. However, animals in the EU extinction group reached asymptotic extinction more rapidly than did CSO rats and they did not show SR of the CTA. As compared to rats that retained their CTA, both groups of extinguished rats showed suppression in the number of c-Fos-labeled neurons in all 4 longitudinal columns of

  3. The Comparison Between Ziegler-Natta and Zirconocene Catalyst on Reaction Conditions and Physical Properties of Polymer in Propylene Polymerization

    Lee, S.C.; Nam, Y.G.; Choung, S.J. [Kyunghee University, Suwon (Korea)


    Propylene polymerizations were carried out by using rac-Et(Ind){sub 2}ZrCl{sub 2} (Zirconocene catalyst) and a commercial third generation Ziegler-Natta catalyst in a semibatch reactor. From the polymerization reactions, the optimum reaction conditions and the physical properties of polymers produced from each catalyst system were investigated. The optimum reaction temperatures of rac-Et(Ind){sub 2}ZrCl{sub 2} and Ziegler-Natta catalyst were 50 deg. C, 40 deg. C, respectively. On the basis of the results for the produced polymer particle size distributions and the catalytic activities of polymerization reaction, the reaction temperature should be considered as an important factor for the successful polymerization reactions. Especially, the polymer was conglomerated in the higher reaction temperature. It was found that there was an upper limitation to co-catalyst concentration. Reaction rates and polymer yields rather decreased with increasing the concentration of co-catalyst, i.e., MAO and TEAl affected only polymerization activities, but the PEEB in Ziegler-Natta catalyst system affected isotactic indexes of produced polymer as well as activities. Based on these observations, the production yield seems to exhibit a first order linear relationship to the partial pressure of monomer. (author). 14 refs., 1 tab., 10 figs.

  4. The Aldol Addition and Condensation: The Effect of Conditions on Reaction Pathway

    Crouch, R. David; Richardson, Amie; Howard, Jessica L.; Harker, Rebecca L.; Barker, Kathryn H.


    The reaction of a ketone and an aldehyde in aqueous Na[subscript 2]CO[subscript 2] is described. This experiment is performed in the absence of strong bases or organic solvents and offers the opportunity for students to observe the critical role that reaction temperature and base strength have in determining the product of the base-mediated…

  5. Constrained approximation of effective generators for multiscale stochastic reaction networks and application to conditioned path sampling

    Cotter, Simon L.


    Efficient analysis and simulation of multiscale stochastic systems of chemical kinetics is an ongoing area for research, and is the source of many theoretical and computational challenges. In this paper, we present a significant improvement to the constrained approach, which is a method for computing effective dynamics of slowly changing quantities in these systems, but which does not rely on the quasi-steady-state assumption (QSSA). The QSSA can cause errors in the estimation of effective dynamics for systems where the difference in timescales between the "fast" and "slow" variables is not so pronounced. This new application of the constrained approach allows us to compute the effective generator of the slow variables, without the need for expensive stochastic simulations. This is achieved by finding the null space of the generator of the constrained system. For complex systems where this is not possible, or where the constrained subsystem is itself multiscale, the constrained approach can then be applied iteratively. This results in breaking the problem down into finding the solutions to many small eigenvalue problems, which can be efficiently solved using standard methods. Since this methodology does not rely on the quasi steady-state assumption, the effective dynamics that are approximated are highly accurate, and in the case of systems with only monomolecular reactions, are exact. We will demonstrate this with some numerics, and also use the effective generators to sample paths of the slow variables which are conditioned on their endpoints, a task which would be computationally intractable for the generator of the full system.

  6. Chemical reactions of fission product deposits and iodine transport in primary circuit conditions

    Kalilainen, Jarmo, E-mail: [VTT Technical Research Centre of Finland, P.O. Box 1000, BI7, FI02044 VTT Espoo (Finland); Kärkelä, Teemu; Zilliacus, Riitta; Tapper, Unto; Auvinen, Ari [VTT Technical Research Centre of Finland, P.O. Box 1000, BI7, FI02044 VTT Espoo (Finland); Jokiniemi, Jorma [VTT Technical Research Centre of Finland, P.O. Box 1000, BI7, FI02044 VTT Espoo (Finland); University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland)


    Highlights: • With CsI precursor, 20% of released iodine was in gaseous form in steam flow at 650 °C. • In similar conditions with Mo, gaseous iodine fraction was increased to 38–79%. • Boron trapped most of the caesium and iodine was almost completely released as gas. - Abstract: The objective of this work was to examine the chemical reactions taking place on primary circuit surfaces and their effect on fission product transport in a severe nuclear reactor accident. Especially transport of gaseous and aerosol phase iodine was studied. Caesium iodide (CsI) was used as precursor material for iodine species. Also, effects of molybdenum and boron on transport of iodine were investigated. The experimental work showed that when CsI alone was used as a precursor, as much as 20% of the released iodine was in gaseous form and the rest as aerosol particles. Aerosol particles were most likely CsI. When the amount of hydrogen in the carrier gas was increased, the fraction of gaseous iodine decreased. When Boron was added to the precursor, a glassy caesium borate surface was formed on the crucible. Boron trapped most of the caesium and also a fraction of iodine, causing almost all released iodine to be in gaseous form. When Mo was introduced in the precursor, most of the iodine was again released in gaseous form. Oxidised Mo reacted with caesium releasing iodine from CsI. The effect of Mo on iodine transport depended much on H{sub 2} concentration and was observed to be substantially greater on stainless steel surface. When stainless steel crucible was used, Mo was found in small amounts from aerosol particles, indicating that it was probably released as caesium molybdate or as molybdenum oxide.

  7. Role of ($\\alpha$,n) reactions under $r$-process conditions in neutrino-driven winds revisited

    Mohr, Peter


    Background: The astrophysical $r$-process occurs in an explosive astrophysical event under extremely neutron-rich conditions, leading to (n,$\\gamma$)-($\\gamma$,n) equilibrium along isotopic chains which peaks around neutron separation energies of a few MeV. Nuclei with larger $Z$ are usually produced by $\\beta^-$-decay, but under certain conditions also $\\alpha$-induced reactions may become relevant for the production of nuclei with $Z+2$. Purpose: The uncertainties of the reaction rates of these $\\alpha$-induced reactions are discussed within the statistical model. As an example, $\\alpha$-induced ($\\alpha$,n) and $(\\alpha$,$x$n) reaction cross sections for the neutron-rich $^{86}$Se nucleus are studied in detail. Method: In a first step, the relevance of ($\\alpha$,n) and $(\\alpha$,$x$n) reactions is analyzed. Next the uncertainties are determined from a variation of the $\\alpha$-nucleus potential which is the all-dominant parameter for the astrophysical $Z \\rightarrow Z+2$ reaction rate. Results: It is found...

  8. Optimization of Ethoxylation Reaction Process Conditions%乙氧基化反应工艺条件的优化

    钱梁华; 吕海丽


    对乙氧基化反应机理及反应特点进行了研究,进而分析了催化剂、反应温度、反应压力及传质等因素对乙氧基化反应速率的影响;通过对乙氧基化反应回路换热器热量衡算,对乙氧基化反应工艺条件优化进行了探讨。结果表明:提高反应温度及压力,有利于乙氧基化反应速率的提高;采用冷却水作为换热介质,在换热量不变的情况下,冷却水的用量约为导热油用量的48%,可以起到降耗的作用。%The mechanism and characteristics of ethoxylation reaction were studied,and the effects of influencing factors such as catalyst,reaction temperature,reaction pressure and mass transfer on ethoxylation reaction rate were further analyzed.Based on the heat balance of ethoxylation reaction loop heat exchanger,the optimization of ethoxylation reaction process conditions was discussed.Results showed that increasing the reaction temperature and pressure were beneficial to the improvement of the ethoxylation reaction rate;and the amount of consumption of cooling water is approximate 48% of the conduction oil under the condition of the constant heat transfer if taking the cooling water as heat transfer medium,which could save energy and reduce consumption.

  9. The reaction between iodine and organic coatings under severe PWR accident conditions. An experimental parameter study

    Hellmann, S.; Funke, F.; Greger, G.U.; Bleier, A.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)


    An extensive experimental parameter study was performed on the deposition and on the resuspension kinetics in the reaction system iodine/organically coated surfaces. Both reactions in the gas phase and in the liquid phase were investigated and kinetic rate constants suitable for modelling were derived. Previous experimental studies on the reaction of iodine with organic coated surfaces were mostly limited to temperatures below 100{sup o}C. Thus, this parameter study aims at filling a gap and providing kinetic data on heterogeneous reactions with organic surfaces in the accident-relevant temperature range of 100-160{sup o}C. Two types of laboratory experiments carried out at Siemens/KWU using coatings representative for German power plants (epoxy-tape paint), namely gas phase tests and liquid phase tests. (author) 6 figs., 6 tabs., 5 refs.

  10. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    Elçin Külah; Laurent Marot; Roland Steiner; Andriy Romanyuk; Thomas A Jung; Aneliia Wäckerlin; Ernst Meyer


    .... Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide...

  11. Study of Fe2O3, CuO, ZnO catalyzed efficient Hantzsch reaction under different conditions

    Mohammad Reza Shushizadeh


    Full Text Available 1,4-dihydropyridine derivatives one-pot synthesis under different condition was described. CuO nanoparticle as a catalyst in microwave irradiation (100w gives product with excellent yields (≥87% and short reaction time. No significant difference was observed between the obtained yield by using ZnO and Fe2O3.

  12. Refined transition-state models for proline-catalyzed asymmetric Michael reactions under basic and base-free conditions.

    Sharma, Akhilesh K; Sunoj, Raghavan B


    The stereocontrolling transition state (TS) models for C-C bond formation relying on hydrogen bonding have generally been successful in proline-catalyzed aldol, Mannich, α-amination, and α-aminoxylation reactions. However, the suitability of the hydrogen-bonding model in protic and aprotic conditions as well as under basic and base-free conditions has not been well established for Michael reactions. Through a comprehensive density functional theory investigation, we herein analyze different TS models for the stereocontrolling C-C bond formation, both in the presence and absence of a base in an aprotic solvent (THF). A refined stereocontrolling TS for the Michael reaction between cyclohexanone and nitrostyrene is proposed. The new TS devoid of hydrogen bonding between the nitro group of nitrostyrene and carboxylic acid of proline, under base-free conditions, is found to be more preferred over the conventional hydrogen-bonding model besides being able to reproduce the experimentally observed stereochemical outcome. A DBU-bound TS is identified as more suitable for rationalizing the origin of asymmetric induction under basic reaction conditions. In both cases, the most preferred approach of nitrostyrene is identified as occurring from the face anti to the carboxylic acid of proline-enamine. The predicted enantio- and diastereoselectivities are in very good agreement with the experimental observations.

  13. Merging Photoredox with Palladium Catalysis: Decarboxylative ortho-Acylation of Acetanilides with α-Oxocarboxylic Acids under Mild Reaction Conditions.

    Zhou, Chao; Li, Pinhua; Zhu, Xianjin; Wang, Lei


    A room temperature decarboxylative ortho-acylation of acetanilides with α-oxocarboxylic acids has been developed via a novel Eosin Y with Pd dual catalytic system. This dual catalytic reaction shows a broad substrate scope and good functional group tolerance, and an array of ortho-acylacetanilides can be afforded in high yields under mild conditions.

  14. Fluoro-substituted ketones from nitriles using acidic and basic reaction conditions

    Raja, Erum; Klumpp, Douglas A.


    Fluoro-substituted aliphatic nitriles are shown to undergo the Houben-Hoesch reactions with arenes in CF3SO3H to give fluoro-substituted ketones in good yields. The fluorine substituents appear to enhance the reactivities of the nitriles (and the nitrilium ion intermediates) compared to similar aliphatic nitriles. Fluoro-substituted ketones are also shown to be accessible through the reactions of organometallic reagents and fluoro-substituted nitriles.

  15. Conditional symmetries for systems of PDEs: new definitions and their application for reaction-diffusion systems

    Cherniha, Roman


    New definitions of $Q$-conditional symmetry for systems of PDEs are presented, which generalize the standard notation of non-classical (conditional) symmetry. It is shown that different types of $Q$-conditional symmetry of a system generate a hierarchy of conditional symmetry operators. A class of two-component nonlinear RD systems is examined to demonstrate applicability of the definitions proposed and it is shown when different definitions of $Q$-conditional symmetry lead to the same operators.

  16. Initial reaction between CaO and SO2 under carbonating and non-carbonating conditions

    Rasmussen, Martin Hagsted; Wedel, Stig; Pedersen, Kim H.;


    The initial kinetics of the CaO/SO2 reaction have been investigated for reaction times shorter than 1s and in the temperature interval between 450 and 600°C under both carbonating and non-carbonating conditions (0-20 vol% CO2) to clarify how recirculating CaO influences the emission of SO2 from...... showed that the CaO conversion with respect to SO2 declined when the CO2 concentration was increased. Under all conditions, larger specific surface areas of CaO gave higher reaction rates with SO2. Higher temperatures had a positive effect on the reaction between SO2 and CaO under non...... a modern dry kiln preheater system for cement production. Calcined Faxe Bryozo limestone with a particle size smaller than 400μm was utilized as CaO source. It was shown, both theoretically and experimentally, that the observed reaction rates were influenced by mass transport limitations. The results...

  17. Optimum Conditions for Introducing Free Radical Polymerizable Methacrylate Groups on the MWCNT Surface by Michael Addition Reaction

    Kim, Sunghoon; Park, Seonghwan; Kwon, Jaebeom; Ha, KiRyong [Keimyung University, Daegu (Korea, Republic of)


    In this study, we investigated optimum conditions for the introduction of a lot of free radical polymerizable methacrylate groups on the multi-walled carbon nanotube (MWCNT) surface. Carboxyl groups were introduced first on MWCNT surfaces by treating with a mixture of sulfuric acid and nitric acid with ultrasonic bath for 2 hours, and oxidized MWCNTs were reacted further with thionyl chloride followed by triethylenetetramine (TETA) to introduce amino groups on the oxidized MWCNT surface, to make MWCNT-NH{sub 2}. To introduce free radical polymerizable methacrylate groups on the MWCNT-NH{sub 2}, MWCNT-NH{sub 2} was reacted with 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) by Michael addition reaction. We investigated progress of modification reactions for MWCNT by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). We found maximum degree of Michael addition reactions between AHM and TETA grafted on MWCNT-NH{sub 2} for 10:1 mol ratio and 8 hour reaction time in our reaction conditions.

  18. Study on Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalytic Reaction (V) Screening Catalysts and Optimizing Synthesis Conditions

    张光旭; 吴元欣; 马沛生; 田崎峰; 吴广文; 李定或; 王存文


    Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was La0.62Pb0.38MnO3 and the average diameter could be about 25.4 nm. The optimum conditions for synthesis of DPC with Pd/LaxPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catMyst/phenol mass ratio 1 to 50, pressure 4.5 MPa,volume concentration of O2 25%, reaction temperature 60° and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the batch operation.

  19. The reaction between iodine and silver under severe PWR accident conditions. An experimental parameter study

    Funke, F.; Greger, G.U.; Bleier, A.; Hellmann, S.; Morell, W. [Siemens AG, Power Generation Group, Erlangen (Germany)


    An extensive experimental parameter study was performed on the kinetics in the reaction system I{sub 2}/Ag and I{sup -}/Ag in a laboratory-scale apparatus.Starting with I{sub 2} or I{sup -} solutions and silver powder suspensions, the decrease of soluted I{sub 2} or I{sup -}, respectively, due to fixation on the silver particles, was monitored as function of time using the radioactive tracer I-131. The measured data were analyzed using a model of first order kinetics with respect to the iodine concentration. However, the analysis using first order kinetics had to be performed separately in an early, fast reaction phase and in a late, slow reaction phase. The reason for this unexpected behaviour was not identified. Thus, rate constant, two for each test, were deduced from 14 I{sub 2}/Ag main tests and from 36 I{sup -}/Ag tests. No dependencies of the rate constants were found on the parameters temperature, initial iodine concentration, presence of boric acid, type of silver educt, and pretreatment of the silver educt prior to the tests. However, the stirring of the reaction solution generally enhanced the kinetics highlighting the importance of mass transfer. The I{sup -}/Ag reaction proceeded only if there was no inertization of the reaction solution by sparging with nitrogen. The temperature-independent rate constant for the early, fast I{sub 2}/Ag reaction phase is 2E-5 m/s. However, a smaller rate constant of 6E-6 m/s is recommended for use in source term calculations with IMPAIR, which already contains a first order model. Analogously, the temperature-independent I{sup -}/Ag reaction rate constant is 8E-6 m/s in an early, fast reaction phase. For use in source term calculations, a smaller rate constant of 2E-6 m/s is recommended. The lower bound of the I{sup -}/Ag rate constant was 3E-8 m/s which could be used in very conservative source term calculations. (author) 20 figs., 6 tabs., 15 refs.

  20. Supervisors' attitudes and skills for active listening with regard to working conditions and psychological stress reactions among subordinate workers.

    Mineyama, Sachiko; Tsutsumi, Akizumi; Takao, Soshi; Nishiuchi, Kyoko; Kawakami, Norito


    We investigated whether supervisors' listening attitudes and skills were related to working conditions and psychological stress reactions among their subordinates. The subjects included 41 male supervisors and their immediate subordinates (n=203). The supervisors completed a short version of the Active Listening Attitude Scale (ALAS) consisting of two subscales: Listening Attitude and Listening Skill for Active Listening. The subordinates rated working conditions and their psychological stress reactions using selected scales of the Job Content Questionnaire and the Brief Job Stress Questionnaire. Those subordinates who worked under supervisors with a higher score of Listening Attitude and Listening Skill reported a more favorable psychological stress reaction than those who worked under supervisors with a lower score of Listening Attitude and Listening Skill. Those subordinates who worked under supervisors with a higher score of Listening Skill reported higher worksite support than those who worked under supervisors with a lower score of Listening Skill. Those subordinates who worked under supervisors with a higher score of Listening Attitude reported higher job control than those who worked under supervisors with a lower score of Listening Attitude. A supervisor's listening attitude and skill appeared to affect psychological stress reactions predominantly among male subordinates than among female subordinates. Psychological stress reactions were lower among younger subordinates who worked under supervisors with high listening skill, while no statistically difference was observed among older subordinates. These findings suggest that a supervisor's listening attitude and skill have an effect on working conditions and psychological stress reactions among subordinates and that the effects vary according to the subordinates' sex and age.

  1. A kinetic study of the reaction of ozone with ethylene in a smog chamber under atmospheric conditions

    XU Yongfu; JIA Long; GE Maofa; DU Lin; WANG Gengchen; WANG Dianxun


    Ozone is one of the key species in the processes of atmospheric chemistry, which can be taken as an indicator of oxidation capacity in the troposphere, The reaction of ozone with reactive gases is an important process in the troposphere. Experimental simulation equipment of smog chamber for atmospheric reactions is used to study the reaction of ozone with ethylene in real atmospheric environment with ozone concentrations of 100-200 ppb. The concentrations of ozone and ethylene were monitored during the reaction with the combination of Model 49C-O3 Analyzer and GC-FID. A rate constant of 1.01×10-18 (cm3.mol-1.s-1) was obtained at 286.5 K,under condition of which the half-life of ozone was 88 min. The results obtained from our experiments are in excellent agreement with those reported previously by other researchers under extremely Iow pressure in terms of matrix-isolation technology. This demonstrates that our equipment of smog chamber for atmospheric reactions is reliable, which can be used for further research of the processes of atmospheric reactions.

  2. DNA microarray synthesis by using PDMS molecular stamps (Ⅲ)-- Optimization for the reaction conditions


    Optimization for the technological processes of fabricating oligonucleotide microarray by the molecular stamping method is studied in this note. Three factors that affect the pressing coupling reactions of the nucleosides are focused on: the stability of the chemical activities of the reaction solutions, the contamination of the remain of the reactive nucleotides among the different spots on the chip, and the influence of the capping reaction on the hybridization result. The experiments show that the acetonitrile solution of tetrazole and nucleoside monomer could maintain sufficient reactive activity for more than 10 h. An effective method has been used and proved to eliminate the residual reactive nucleosides on chip with small molecules containing hydroxyl group. Finally, the capping step-- a regular step in the conventional DNA chemical synthesis can be neglected in our on-chip DNA synthetic process, which would not affect its hybridization results.

  3. Reactions of CF3O radicals with selected alkenes and aromatics under atmospheric conditions

    Kelly, C.; Sidebottom, H.W.; Treacy, J.;


    Rate data for the reactions of CF3O radicals with alkenes and aromatic compounds have been determined at 298 K using a relative rate method. The data are analyzed in terms of structure-reactivity relationships, and their importance to the atmospheric chemistry of CF3O discussed.......Rate data for the reactions of CF3O radicals with alkenes and aromatic compounds have been determined at 298 K using a relative rate method. The data are analyzed in terms of structure-reactivity relationships, and their importance to the atmospheric chemistry of CF3O discussed....

  4. Detection of O(3P(J)) atoms formed by reaction, Al+O2--> AlO+O under crossed-beam condition.

    Ishida, Masayuki; Higashiyama, Tomohiko; Matsumoto, Yoshiteru; Honma, Kenji


    The vacuum ultraviolet laser-induced fluorescence technique was employed to detect the oxygen atoms formed by the reaction, Al+O(2)--> AlO+O. The measurements were carried out under the crossed-beam condition at 12.2 kJmol of collision energy. The relative populations of three spin-orbit states of O((3)P(J)) were determined to be 3.8, 1.0, and 0.2 for J=2, 1, and 0, respectively. They show nonstatistical populations, i.e., more population in O((3)P(2)) and less population in O((3)P(0)) than the statistical expectation. These populations were almost identical for two Al beam conditions where the relative concentrations of two spin-orbit states of Al, (2)P(1/2), and (2)P(3/2), are different. These results suggest that the reaction of Al with O(2) proceeds via an intermediate complex where the memory of the initial spin-orbit state is lost. Deviation from the statistical population of O((3)P(J)) implies the occurrence of the interaction among potential surfaces in the exit channel.


    Mohammad Najafi; Vahid Haddadi-Asl


    Different Ziegler-Natta catalysts were employed to polymerize ethylene.To investigate the influences of reaction parameters,namely Al/Ti molar ratio,hydrogen and processing parameters,I.e.ethylene pressure and temperature,a Taguchi experimental design was worked out.An L27 orthogonal array was chosen to take the above-mentioned parameters and relevant interactions into account.Response surface method was the tool used to analyze the experimental design results.Al/Ti,ethylene pressure and temperature were selected as experimental design factors.and catalyst activity and polymerization yield were the response parameters.Increasing pressure,due to an increment in monomer accessibility,and rising Al/Ti,because of higher reduction in the catalysts,cause an increase in both polymerization yield and catalyst activity.Nonetheless,a higher temperature,thanks to reducing ethylene solubility in the slurry medium and partially catalyst destruction.lead to a reduction in both response parameters.A synergistic eflfect was also observed between temperature and pressure.All catalyst activities will reduce in the presence of hydrogen.Molecular weight also shows a decline in the presence of hydrogen as a transfer agent.However,the polydispersity index remains approximately intact.Using SEM,various morphologies,owing to different catalyst morphologies,were seen for the polyethylene.

  6. Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons

    Külah, Elçin; Marot, Laurent; Steiner, Roland; Romanyuk, Andriy; Jung, Thomas A.; Wäckerlin, Aneliia; Meyer, Ernst


    Rare-earth (RE) oxide surfaces are of significant importance for catalysis and were recently reported to possess intrinsic hydrophobicity. The surface chemistry of these oxides in the low temperature regime, however, remains to a large extent unexplored. The reactions occurring at RE surfaces at room temperature (RT) in real air environment, in particular, in presence of polycyclic aromatic hydrocarbons (PAHs), were not addressed until now. Discovering these reactions would shed light onto intermediate steps occurring in automotive exhaust catalysts before reaching the final high operational temperature and full conversion of organics. Here we first address physical properties of the RE oxide, nitride and fluoride surfaces modified by exposure to ambient air and then we report a room temperature reaction between PAH and RE oxide surfaces, exemplified by tetracene (C18H12) on a Gd2O3. Our study evidences a novel effect – oxidation of higher hydrocarbons at significantly lower temperatures (~300 K) than previously reported (>500 K). The evolution of the surface chemical composition of RE compounds in ambient air is investigated and correlated with the surface wetting. Our surprising results reveal the complex behavior of RE surfaces and motivate follow-up studies of reactions between PAH and catalytic surfaces at the single molecule level. PMID:28327642

  7. Population dynamics, information transfer, and spatial organization in a chemical reaction network under spatial confinement and crowding conditions

    Bellesia, Giovanni; Bales, Benjamin B.


    We investigate, via Brownian dynamics simulations, the reaction dynamics of a generic, nonlinear chemical network under spatial confinement and crowding conditions. In detail, the Willamowski-Rossler chemical reaction system has been "extended" and considered as a prototype reaction-diffusion system. Our results are potentially relevant to a number of open problems in biophysics and biochemistry, such as the synthesis of primitive cellular units (protocells) and the definition of their role in the chemical origin of life and the characterization of vesicle-mediated drug delivery processes. More generally, the computational approach presented in this work makes the case for the use of spatial stochastic simulation methods for the study of biochemical networks in vivo where the "well-mixed" approximation is invalid and both thermal and intrinsic fluctuations linked to the possible presence of molecular species in low number copies cannot be averaged out.

  8. Population dynamics, information transfer, and spatial organization in a chemical reaction network under spatial confinement and crowding conditions.

    Bellesia, Giovanni; Bales, Benjamin B


    We investigate, via Brownian dynamics simulations, the reaction dynamics of a generic, nonlinear chemical network under spatial confinement and crowding conditions. In detail, the Willamowski-Rossler chemical reaction system has been "extended" and considered as a prototype reaction-diffusion system. Our results are potentially relevant to a number of open problems in biophysics and biochemistry, such as the synthesis of primitive cellular units (protocells) and the definition of their role in the chemical origin of life and the characterization of vesicle-mediated drug delivery processes. More generally, the computational approach presented in this work makes the case for the use of spatial stochastic simulation methods for the study of biochemical networks in vivo where the "well-mixed" approximation is invalid and both thermal and intrinsic fluctuations linked to the possible presence of molecular species in low number copies cannot be averaged out.

  9. Mass transfer resistance in a liquid-phase microextraction employing a single hollow fiber under unsteady-state conditions.

    Kumrić, Ksenija R; Vladisavljević, Goran T; Đorđević, Jelena S; Jönsson, Jan Åke; Trtić-Petrović, Tatjana M


    In this study, the mass transport resistance in liquid-phase microextraction (LPME) in a single hollow fiber was investigated. A mathematical model has been developed for the determination of the overall mass transfer coefficient based on the acceptor phase in an unsteady state. The overall mass transfer coefficient in LPME in a single hollow fiber has been estimated from time-dependent concentration of extracted analyte in the acceptor phase while maintaining a constant analyte concentration in the donor phase. It can be achieved either using a high volume of donor to acceptor phase ratio or tuning the extraction conditions to obtain a low-enrichment factor, so that the analyte concentration in the sample is not significantly influenced by the mass transfer. Two extraction systems have been used to test experimentally the developed model: the extraction of Lu(III) from a buffer solution and the extraction of three local anesthetics from a buffer or plasma solution. The mass transfer resistance, defined as a reciprocal values of the mass transfer coefficient, was found to be 1.2 × 10(3) cm(-1) min for Lu(III) under optimal conditions and from 1.96 to 3.3 × 10(3) cm(-1) min for the local anesthetics depending on the acceptor pH and the hydrophobicity of the drug.

  10. Tetrahexahedral Pt Nanoparticles: Comparing the Oxygen Reduction Reaction under Transient vs Steady-State Conditions

    Deng, Yu-Jia; Wiberg, Gustav Karl Henrik; Zana, Alessandro


    -state conditions. As a benchmark, the ORR activity is compared with those of polycrystalline Pt and a commercial Pt/C catalyst. The results show that, under transient conditions, the catalytic performance of the THH Pt NPs and Pt/C are approximately the same and about 2 times lower than that of polycrystalline Pt....... However, under steady-state conditions the THH Pt NPs perform considerably better than Pt/C. Under steady-state conditions THH Pt NPs are even slightly more active than polycrystalline Pt...

  11. Acid-mediated reactions under microfluidic conditions: A new strategy for practical synthesis of biofunctional natural products

    Katsunori Tanaka


    Full Text Available Microfluidic conditions were applied to acid-mediated reactions, namely, glycosylation, reductive opening of the benzylidene acetal groups, and dehydration, which are the keys to the practical synthesis of N-glycans and the immunostimulating natural product, pristane. A distinctly different reactivity from that in conventional batch stirring was found; the vigorous micromixing of the reactants with the concentrated acids is critical especially for the “fast” reactions to be successful. Such a common feature might be due to the integration of all favorable aspects of microfluidic conditions, i.e., efficient mixing, precise temperature control, and the easy handling of the reactive intermediate by controlling the residence time. The microfluidic reactions cited in this review indicate the need to reinvestigate the traditional or imaginary reactions which have so far been performed and evaluated only in batch apparatus, and therefore they could be recognized as a new strategy in synthesizing natural products of prominent biological activity in a “practical” and a “industrial” manner.

  12. Improvement of PCR reaction conditions for site-directed mutagenesis of big plasmids

    Bogdan MUNTEANU; Mario BRAUN; Kajohn BOONROD


    QuickChange mutagenesis is the method of choice for site-directed mutagenesis (SDM) of target sequences in a plasmid.It can be applied successfully to small plasmids (up to 10 kb).However,this method cannot efficiently mutate bigger plasmids.Using KOD Hot Start polymerase in combination with high performance liquid chromatography (HPLC) purified primers,we were able to achieve SDM in big plasmids (up to 16 kb) involving not only a single base change but also multiple base changes.Moreover,only six polymerase chain reaction (PCR) cycles and 0.5 μl of polymerase (instead of 18 PCR cycles and 1.0 μl of enzyme In the standard protocol) were sufficient for the reaction.

  13. Study of the effects of the reaction conditions on the modification of clays with polyelectrolytes and silanes.

    de la Orden, M U; Arranz, J; Lorenzo, V; Pérez, E; Martínez Urreaga, J


    New organically modified clays have been obtained from sodium montmorillonite, using either a cationic polyelectrolyte (polyethylenimine) or a novel homemade bisphenol-A silane as modifiers. The modification processes have been carried out in different reaction media, in order to study the effects on the properties of the modified clays of several reaction parameters, such as the pH of the polyethylenimine solution or the nature of the solvent used in the silanization. The obtained clays were characterized using X-ray diffraction, thermogravimetric analysis, and FTIR spectroscopy. Clays modified with polyelectrolyte or silane show significant increases in the basal spacing. The properties of polyelectrolyte-modified clays depend on the pH of the treating solution. The increase in the basal spacing of polyelectrolyte-modified clays varies only slightly with the pH; however, this reaction parameter clearly determines the total amount of polyelectrolyte introduced in the clay. The properties and applications of silane-modified clays are strongly dependent on the presence of water in the reaction media used for the silanization. These results have been explained by considering that the reaction conditions determine the nature and the amount of material intercalated into the clay.

  14. Controlling thermo-reversibility of gelatin gels through a peroxidase-catalyzed reaction under mild conditions for mammalian cells.

    Sakai, Shinji; Moriyama, Kousuke; Kawakami, Koei


    A variety of cross-linking methods is used for obtaining gelatin gels having a tolerance to thermo-reversible gel-sol transition at physiological temperature. In this paper, we investigated the applicability of horseradish peroxidase-catalyzed cross-linking of tyrosine residues originally contained in native gelatin molecules for preparing such gelatin gels. The gelatin gels obtained through exposure to the enzymatic reaction showed a higher resistance to thermo-reversibility at 37°C than gels obtained through a thermally-induced gelation alone. In addition, the resistance property to thermo-reversible gel-sol transition was tunable by controlling enzymatic reaction conditions: higher peroxidase concentration and thermally-induced pre-gelation accomplished by cooling the gelatin solution prior to the enzymatic reaction produced gels with higher resistance to thermo-reversibility. Fibroblast cells enclosed in the gelatin gels obtained through the enzymatic reaction with thermally-induced pre-gelation showed 93% viability. These results demonstrate the feasibility of peroxidase-catalyzed reaction for obtaining gelatin gels having a tolerance to thermo-reversible gel-to-sol transition at physiological temperature toward applications in biomedical and biopharmaceutical fields.

  15. Reaction of benzeneselenol with tri- and tetrachloroethylenes under conditions of phase-transfer catalysis

    Martynov, A.V.; Mirskova, A.N.; Kalikhman, I.D.; Voronkov, M.G.


    The reaction of benzeneselenol with trichloroethylene in concentrated sodium hydroxide solution, catalyzed by ammonium salts, leads to Z-phenyl /alpha/,/beta/-dichlorovinyl selenide with an equimolar ratio of the catalyst and the selenol or to a mixture of the Z and E isomers with a ratio of 1:10. In addition to the expected trichlorovinyl selenide PhSeCCl=CCl/sub 2/, the analogous reaction with tetrachloroethylene also gives a mixture of the Z and E isomers of /alpha/-/beta/-dichlorovinyl selenides, and in addition, 1,2-bis(phenylseleno)-1,2-dichloroethylene PhSeCCl = CClSePh. If trialkylbenzylammonium chlorides R/sub 3/PhCH/sub 2/N/sup +/Cl/sup /minus// are used as catalyst, phenyl benzyl selenide PhSeCH/sub 2/Ph is formed as a side product. The results of the reaction in the case of trichloroethylene are explained by the addition of the selenolate ion to the CCl/identical to/CCl, generated from the trichloroethylene in situ, and isomerization of the initially formed Z-phenyl /alpha/,/beta/-dichlorovinyl selenide to the thermodynamically more stable E isomer. In the case of tetrachloroethylene they are explained by the usual addition-elimination mechanism with the formation of trichlorovinyl selenide, accompanied by reductive dechlorination of the CCl/sub 2/-CCl/sub 2/ to CHCl=CCl/sub 2/ by the selenolate and subsequent reaction of the selenolate with CHCl=CCl/sub 2/.

  16. Reaction norm model to describe environmental sensitivity across first lactation in dairy cattle under tropical conditions.

    Bignardi, Annaiza Braga; El Faro, Lenira; Pereira, Rodrigo Junqueira; Ayres, Denise Rocha; Machado, Paulo Fernando; de Albuquerque, Lucia Galvão; Santana, Mário Luiz


    Reaction norm models have been widely used to study genotype by environment interaction (G × E) in animal breeding. The objective of this study was to describe environmental sensitivity across first lactation in Brazilian Holstein cows using a reaction norm approach. A total of 50,168 individual monthly test day (TD) milk yields (10 test days) from 7476 complete first lactations of Holstein cattle were analyzed. The statistical models for all traits (10 TDs and for 305-day milk yield) included the fixed effects of contemporary group, age of cow (linear and quadratic effects), and days in milk (linear effect), except for 305-day milk yield. A hierarchical reaction norm model (HRNM) based on the unknown covariate was used. The present study showed the presence of G × E in milk yield across first lactation of Holstein cows. The variation in the heritability estimates implies differences in the response to selection depending on the environment where the animals of this population are evaluated. In the average environment, the heritabilities for all traits were rather similar, in range from 0.02 to 0.63. The scaling effect of G × E predominated throughout most of lactation. Particularly during the first 2 months of lactation, G × E caused reranking of breeding values. It is therefore important to include the environmental sensitivity of animals according to the phase of lactation in the genetic evaluations of Holstein cattle in tropical environments.

  17. Employment of single-diode model to elucidate the variations in photovoltaic parameters under different electrical and thermal conditions

    Hameed, Shilan S.; Aziz, Fakhra; Sulaiman, Khaulah; Ahmad, Zubair


    In this research work, numerical simulations are performed to correlate the photovoltaic parameters with various internal and external factors influencing the performance of solar cells. Single-diode modeling approach is utilized for this purpose and theoretical investigations are compared with the reported experimental evidences for organic and inorganic solar cells at various electrical and thermal conditions. Electrical parameters include parasitic resistances (Rs and Rp) and ideality factor (n), while thermal parameters can be defined by the cells temperature (T). A comprehensive analysis concerning broad spectral variations in the short circuit current (Isc), open circuit voltage (Voc), fill factor (FF) and efficiency (η) is presented and discussed. It was generally concluded that there exists a good agreement between the simulated results and experimental findings. Nevertheless, the controversial consequence of temperature impact on the performance of organic solar cells necessitates the development of a complementary model which is capable of well simulating the temperature impact on these devices performance. PMID:28793325

  18. Influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of acidic, neutral and basic polysaccharides.

    Wang, Qing-Chi; Zhao, Xia; Pu, Jiang-Hua; Luan, Xiao-Hong


    Monosaccharide composition analysis is important for structural characterization of polysaccharides. To investigate the influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of polysaccharides, we chose alginate, starch, chitosan and chondroitin sulfate as representative of acidic, neutral, basic and complex polysaccharides to compare the release degree of monosaccharides under different hydrolytic conditions. The hydrolysis stability of 10 monosaccharide standards was also explored. Results showed that the basic sugars were hard to release but stable, the acidic sugars (uronic acids) were easy to release but unstable, and the release and stability of neutral sugars were in between acidic and basic sugars. In addition, the hydrolysis process was applied to monosaccharide composition analysis of Hippocampus trimaculatus polysaccharide and the appropriate hydrolytic condition was accorded with that of the above four polysaccharides. Thus, different hydrolytic conditions should be used for the monosaccharide composition analysis of polysaccharides based on their structural characteristics.

  19. Sign conditions for injectivity of generalized polynomial maps with applications to chemical reaction networks and real algebraic geometry

    Müller, Stefan; Feliu, Elisenda; Regensburger, Georg


    We give necessary and sufficient conditions in terms of sign vectors for the injectivity of families of polynomials maps with arbitrary real exponents defined on the positive orthant. Our work relates and extends existing injectivity conditions expressed in terms of Jacobian matrices and determin...... and determinants. In the context of chemical reaction networks with power-law kinetics, our results can be used to preclude as well as to guarantee multiple positive steady states. In the context of real algebraic geometry, our results reveal the first ......We give necessary and sufficient conditions in terms of sign vectors for the injectivity of families of polynomials maps with arbitrary real exponents defined on the positive orthant. Our work relates and extends existing injectivity conditions expressed in terms of Jacobian matrices...

  20. Elimination of carbon vacancies in 4H-SiC employing thermodynamic equilibrium conditions at moderate temperatures

    Ayedh, H. M.; Svensson, B. G. [University of Oslo, Department of Physics/Center for Materials Science and Nanotechnology, P.O. Box 1048 Blindern, N-0316 Oslo (Norway); Nipoti, R. [Consiglio Nazionale delle Ricerche, Istituto di Microelettronica e Microsistemi, Sezione di Bologna (CNR-IMM of Bologna), I-40129 Bologna (Italy); Hallén, A. [Royal Institute of Technology, School of Information and Communication Technology (ICT), SE-164 40 Kista-Stockholm (Sweden)


    The carbon vacancy (V{sub C}) is a major point defect in high-purity 4H-SiC epitaxial layers limiting the minority charge carrier lifetime. In layers grown by chemical vapor deposition techniques, the V{sub C} concentration is typically in the range of 10{sup 12 }cm{sup −3}, and after device processing at temperatures approaching 2000 °C, it can be enhanced by several orders of magnitude. In the present study, both as-grown layers and a high-temperature processed one have been annealed at 1500 °C and the V{sub C} concentration is demonstrated to be strongly reduced, exhibiting a value of only a few times 10{sup 11 }cm{sup −3} as determined by deep-level transient spectroscopy measurements. The value is reached already after annealing times on the order of 1 h and is evidenced to reflect thermodynamic equilibrium under C-rich ambient conditions. The physical processes controlling the kinetics for establishment of the V{sub C} equilibrium are estimated to have an activation energy below ∼3 eV and both in-diffusion of carbon interstitials and out-diffusion of V{sub C}'s are discussed as candidates. This concept of V{sub C} elimination is flexible and readily integrated in a materials and device processing sequence.

  1. Fibrous nano-silica (KCC-1)-supported palladium catalyst: Suzuki coupling reactions under sustainable conditions

    Fihri, Aziz


    Noble amines recycled: Fibrous high-surface-area nano-silica functionalized with aminopropyl groups and loaded with well-dispersed Pd nanoparticles is evaluated for the Suzuki coupling of aromatic halides. It is active for the reaction of a range of aryl bromides and iodides as well as chlorides with aryl boronic acids in good to excellent yields. The catalyst can be recovered and reused for a number of cycles with negligible loss in activity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Investigation of reaction conditions on morphology and optical properties of Zinc Oxide Nanorods

    Almodarresiyeh, H. A.; Abakshonok, A. V.; Agabekov, V. E.; Eryomin, A. N.; Shahab, S. N.


    Zinc oxide nanoparticles (ZnO NPs) were synthesized by precipitation method in the presence of various polymers. Rod shaped ZnO NPs (length ~ 1 micron) were obtained at 70 °C in a reaction medium containing 10-20 mM of zinc nitrate hexahydrate (Zn(NO3)2·6H2O), 0.05-0.1 mg/ml of polyethylenimine (PEI) and 20 mM of hexamethylenetetramine (HMT). Properties of ZnO NPs were characterized by fluorescence, UV-visible spectroscopy, atomic force and transmission electron microscopy.

  3. Solubility and Reaction Rates of Aluminum Solid Phases Under Geothermal Conditions

    Benezeth, P.; Palmer, D.A.; Wesolowski, D.J.; Anovitz, L.M.


    Experimental studies involving equilibrium solubility and dissolution/precipitation rates were initiated on aluminum hydroxide phases prevalent under geothermal reservoir conditions. A large capacity, hydrogen-electrode concentration cell (HECC) was constructed specifically for this purpose.

  4. Safety analysis of switching between reductive and oxidative conditions in a reaction coupling reverse flow reactor.

    van Sint Annaland, M.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria


    A new reverse flow reactor is developed where endothermic reactants (propane dehydrogenation) and exothermic reactants (fuel combustion) are fed sequentially to a monolithic catalyst, while periodically alternating the inlet and outlet positions. Upon switching from reductive to oxidative conditions

  5. Housing conditions influence cortical and behavioural reactions of sheep in response to videos showing social interactions of different valence.

    Vögeli, Sabine; Wolf, Martin; Wechsler, Beat; Gygax, Lorenz


    Mood, as a long-term affective state, is thought to modulate short-term emotional reactions in animals, but the details of this interplay have hardly been investigated experimentally. Apart from a basic interest in this affective system, mood is likely to have an important impact on animal welfare, as bad mood may taint all emotional experience. In the present study about mood - emotion interaction, 29 sheep were kept under predictable, stimulus-rich or unpredictable, stimulus-poor housing conditions, to induce different mood states. In an experiment, the animals were confronted with video sequences of social interactions of conspecifics showing agonistic interactions, ruminating or tolerantly co-feeding as stimuli of different valences. Emotional reactions were assessed by measuring frontal brain activity using functional near-infrared spectroscopy and by recording behavioral reactions. Attentiveness of the sheep decreased from videos showing agonistic interactions to ruminating sheep to those displaying co-feeding sheep. Seeing agonistic interactions was also associated with a deactivation of the frontal cortex, specifically in animals living under predictable, stimulus-rich housing conditions. These sheep generally showed less attentiveness and locomotor activity and they had their ears in a forward position less often and in a backward position more often than the sheep from the unpredictable, stimulus-poor conditions. Housing conditions influenced how the sheep behaved, which can either be thought to be mediated by mood or by the animals' previous experience with stimulus-richness in their housing conditions. Frontal cortical activity may not depend on valence only, but also on the perceptual channel through which the stimuli were perceived.

  6. Influences of reaction conditions on methane decomposition over non-supported Ni catalyst

    Wei Zhang; Qingjie Ge; Hengyong Xu


    Effects of reaction temperature and methane gas hourly space velocity (GHSV) on methane decomposition over non-supported Ni catalyst havebeen investigated in this work.Methane molecules activation,Ni particles growth and nano-carbon diffusion were the main factors influencing methane decomposition stability of non-supported Ni.The results of methane decomposition activity test on the non-supported Ni catalyst showed that the prepared non-supported Ni could exhibit a good methane decomposition performance with 273 gC/gNi and 2667 molH2/molNi at 500 ℃ and 45000 mL/(gcat·h).Scanning electron microscope (SEM),X-ray powder diffraction (XRD) and temperature-programmed oxidation (TPO) have been carried out to characterize the used catalysts.The deposited carbon was carbon nanofibers,among which graphitic carbon formation increased with the reaction time of methane decomposition.Ni particle size was not the decisive factor during the carbon growing stage.

  7. Palladium-Catalyzed α-Arylation of Zinc Enolates of Esters: Reaction Conditions and Substrate Scope

    Hama, Takuo; Ge, Shaozhong; Hartwig, John F.


    The intermolecular α-arylation of esters by palladium-catalyzed coupling of aryl bromides with zinc enolates of esters is reported. Reactions of three different types of zinc enolates have been developed. α-Arylation of esters occurs in high yields with isolated Reformatsky reagents, with Reformatsky reagents generated from α-bromo esters and activated zinc, and with zinc enolates generated by quenching lithium enolates of esters with zinc chloride. The use of zinc enolates, instead of alkali metal enolates, greatly expands the scope of the arylation of esters. The reactions occur at room temperature or at 70 °C with bromoarenes containing cyano, nitro, ester, keto, fluoro, enolizable hydrogen, hydroxyl or amino functionality and with bromopyridines. The scope of esters encompasses acyclic acetates, propionates, and isobutyrates, α-alkoxyesters, and lactones. The arylation of zinc enolates of esters was conducted with catalysts bearing the hindered pentaphenylferrocenyl di-tert-butylphosphine (Q-phos) or the highly reactive dimeric Pd(I) complex {[P(t-Bu)3]PdBr}2. PMID:23931445

  8. Preparation and characterization of HypoGel-supported Pd nanocatalysts for Suzuki reaction under mild conditions

    Kin Hong Liew; Wan Zurina Samad; Norazzizi Nordin; Poh Lee Loh; Joon Ching Juan; Mohd Ambar Yarmo; Badrul Hisham Yahaya; Rahimi M. Yusop


    A new heterogeneous catalyst composed of Pd nanoparticles immobilized within a HypoGel resin has been prepared in the absence of any ligands using an extensive cross-linking method. This new-ly developed nanocatalyst was characterized by N2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy and inductively coupled plasma-mass spec-trometer (ICP-MS) techniques. TEM and XRD results revealed that the Pd nanoparticles were well dispersed with diameters in the range of 4–12 nm, and an average size of about 8 nm. The cross-linked Pd catalyst demonstrated excellent catalytic activity towards the synthesis of a series of biaryl compounds by the reaction of various aryl halides (e.g., bromides andiodides) with phenyl-boronic acid in the presence of tetrabutylammonium bromide. ICP-MS analysis indicated that there was only 0.25% weight loss of Pd (0.55 ± 0.02 ppm) from the supported catalyst after the first cycle reaction. Furthermore, the catalyst showed excellent reusability (up to five uses) with consistently high levels of catalytic activity following its recovery by filtration.

  9. Palladium-catalyzed α-arylation of zinc enolates of esters: reaction conditions and substrate scope.

    Hama, Takuo; Ge, Shaozhong; Hartwig, John F


    The intermolecular α-arylation of esters by palladium-catalyzed coupling of aryl bromides with zinc enolates of esters is reported. Reactions of three different types of zinc enolates have been developed. α-Arylation of esters occurs in high yields with isolated Reformatsky reagents, with Reformatsky reagents generated from α-bromo esters and activated zinc, and with zinc enolates generated by quenching alkali metal enolates of esters with zinc chloride. The use of zinc enolates, instead of alkali metal enolates, greatly expands the scope of the arylation of esters. The reactions occur at room temperature or at 70 °C with bromoarenes containing cyano, nitro, ester, keto, fluoro, enolizable hydrogen, hydroxyl, or amino functionality and with bromopyridines. The scope of esters encompasses acyclic acetates, propionates, and isobutyrates, α-alkoxyesters, and lactones. The arylation of zinc enolates of esters was conducted with catalysts bearing the hindered pentaphenylferrocenyl di-tert-butylphosphine (Q-phos) or the highly reactive dimeric Pd(I) complex {[P(t-Bu)3]PdBr}2.

  10. Polymerization of Acetonitrile via a Hydrogen Transfer Reaction from CH3 to CN under Extreme Conditions.

    Zheng, Haiyan; Li, Kuo; Cody, George D; Tulk, Christopher A; Dong, Xiao; Gao, Guoying; Molaison, Jamie J; Liu, Zhenxian; Feygenson, Mikhail; Yang, Wenge; Ivanov, Ilia N; Basile, Leonardo; Idrobo, Juan-Carlos; Guthrie, Malcolm; Mao, Ho-Kwang


    Acetonitrile (CH3 CN) is the simplest and one of the most stable nitriles. Reactions usually occur on the C≡N triple bond, while the C-H bond is very inert and can only be activated by a very strong base or a metal catalyst. It is demonstrated that C-H bonds can be activated by the cyano group under high pressure, but at room temperature. The hydrogen atom transfers from the CH3 to CN along the CH⋅⋅⋅N hydrogen bond, which produces an amino group and initiates polymerization to form a dimer, 1D chain, and 2D nanoribbon with mixed sp(2) and sp(3) bonded carbon. Finally, it transforms into a graphitic polymer by eliminating ammonia. This study shows that applying pressure can induce a distinctive reaction which is guided by the structure of the molecular crystal. It highlights the fact that very inert C-H can be activated by high pressure, even at room temperature and without a catalyst.

  11. Structural Rearrangement of Au-Pd Nanoparticles under Reaction Conditions: An ab Initio Molecular Dynamics Study.

    Xu, Cong-Qiao; Lee, Mal-Soon; Wang, Yang-Gang; Cantu, David C; Li, Jun; Glezakou, Vassiliki-Alexandra; Rousseau, Roger


    The structure, composition, and atomic distribution of nanoalloys under operating conditions are of significant importance for their catalytic activity. In the present work, we use ab initio molecular dynamics simulations to understand the structural behavior of Au-Pd nanoalloys supported on rutile TiO2 under different conditions. We find that the Au-Pd structure is strongly dependent on the redox properties of the support, originating from strong metal-support interactions. Under reducing conditions, Pd atoms are inclined to move toward the metal/oxide interface, as indicated by a significant increase of Pd-Ti bonds. This could be attributed to the charge localization at the interface that leads to Coulomb attractions to positively charged Pd atoms. In contrast, under oxidizing conditions, Pd atoms would rather stay inside or on the exterior of the nanoparticle. Moreover, Pd atoms on the alloy surface can be stabilized by hydrogen adsorption, forming Pd-H bonds, which are stronger than Au-H bonds. Our work offers critical insights into the structure and redox properties of Au-Pd nanoalloy catalysts under working conditions.

  12. Glyoxal uptake on ammonium sulphate seed aerosol: reaction products and reversibility of uptake under dark and irradiated conditions

    M. M. Galloway


    Full Text Available Chamber studies of glyoxal uptake onto neutral ammonium sulphate aerosol were performed under dark and irradiated conditions to gain further insight into processes controlling glyoxal uptake onto ambient aerosol. Organic fragments from glyoxal dimers and trimers were observed within the aerosol under dark and irradiated conditions; glyoxal oligomer formation and overall organic growth were found to be reversible under dark conditions. Analysis of high-resolution time-of-flight aerosol mass spectra provides evidence for irreversible formation of carbon-nitrogen (C-N compounds in the aerosol. These compounds are likely to be imidazoles formed by reaction of glyoxal with the ammonium sulphate seed. To the authors' knowledge, this is the first time C-N compounds resulting from condensed phase reactions with ammonium sulphate seed have been detected in aerosol. Organosulphates were not detected under dark conditions. However, active oxidative photochemistry, similar to that found in cloud processing, was found to occur within aerosol during irradiated experiments. Organosulphates, carboxylic acids, and organic esters were identified within the aerosol. Our study suggests that both C-N compound formation and photochemical processes should be considered in models of secondary organic aerosol formation via glyoxal.

  13. Evaluation under diverse conditions of a differential host reaction scale to Tomato yellow leaf curl virus in tomato



    Full Text Available Tomato yellow leaf curl virus (TYLCV is the most widespread virus species causing Tomato yellow leaf curl disease. Accurate methods for assessment of resistance are requisite in breeding programs. Researchers at the Volcani Center (Israel developed a scale of differential TYLCV reactions in seven non-segregating tomato host lines, with virus responses ranging from susceptible to highly resistant. In the present work, this scale has been evaluated with inoculation and assessment methods routinely used by two different research groups, in Spain and Cuba. Different TYLCV isolates, inoculation methods, plant ages, and environmental conditions were compared. Symptom scores of the tomato lines were generally lower in the conditions assayed in both locations than those originally described. Reaction ranking order of the standard tomato lines was more similar to the original description in the assays carried out in Spain. However, response of the lines to TYLCV obtained in both locations did not correspond to scale grades for most of the conditions. A large difference between symptom scores in the susceptible and the resistant lines was observed, with the range in the resistant lines being narrow. These results indicate that the number of standard lines used could be reduced, selecting the most susceptible and the most resistant lines, and one with intermediate resistance. All the factors evaluated affected symptom development. This highlights the importance of establishing a standard inoculation method, experimental conditions, evaluation period and appropriate resistance evaluation criteria, to ensure precise evaluation of genotype responses.

  14. The necessary and sufficient conditions of therapeutic personality change: Reactions to Rogers' 1957 article.

    Samstag, Lisa Wallner


    Carl Rogers' article (see record 2007-14639-002) on the necessary and sufficient conditions for personality change has had a significant impact on the field of psychotherapy and psychotherapy research. He emphasized the client as arbiter of his or her own subjective experience and tested his hypothesized therapist-offered conditions of change using recorded sessions. This aided in demystifying the therapeutic process and led to a radical shift in the listening stance of the therapist. I briefly outline my views regarding the influence of the ideas presented in this work, describe the intellectual and cultural context of the times, and discuss a number of ways in which the therapist-offered conditions for psychological transformation are neither necessary nor sufficient. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  15. Preparation of different amides via Ritter reaction from alcohols and nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) under solvent-free conditions

    Maryam-Sadat Shakeri; Hassan Tajik; Khodabakhsh Niknam


    A number of methods have been proposed for the modification of the Ritter reaction. However, many of these methods involve the use of strongly acidic conditions, stoichiometric amounts of reagents, harsh reaction conditions and extended reaction times. Therefore, the development of mild, efficient, convenient and benign reagents for the Ritter reaction is desirable. In this research, we have developed a clean and environmentally friendly protocol for the synthesis of amides by using different benzylic or tertiary alcohols and different nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) as catalyst under solvent-free conditions in high yields.

  16. Illegal employment

    Jana Mervartová


    Full Text Available Since 2007 Labour Code contains the definition of dependent work, which can be carried out only in labour-law relations. The Amendment to Labour Code from 2012 makes the definition more precise, when it stipulates essential elements of dependent work and designates the others as conditions, under which dependent work should be carried out. The Amendment to Employment Act changes the definition of illegal work. Illegal work is a performance of dependent work by natural person except for labour-law relation, or if natural person – foreigner carries out work in conflict with issued permission to employment or without this permission. Since 2012 sanctions for illegal work were increased. Labour inspection is entitled to impose sanctions, in case of foreigners it is Customs Office. For control purposes employer is obliged to have copies of documents at the workplace proving the existence of labour-law relation. Goal of controls and high fines is to limit illegal employment of citizens of Czech Republic and foreigners as well. Illegal work has unfavourable economic impact on state budget. It comes to extensive tax evasions and also to evasions within health insurance and social security. If a concluded commercial-law relation meets the attributes of dependent work, then it stands for a concealed legal relationship. Tax Office can subsequently assess an income tax to businessman. Labour-law relationship enjoys a higher legal protection than commercial-law relationship; nonetheless it is not suitable to limit liberty of contract in cases when it is not unambiguously a dependent activity.

  17. Effect of reaction conditions on film morphology of polyaniline composite membranes for gas separation

    Blinova, Natalia V.


    Composite membranes combining polyaniline as an active layer with a polypropylene support have been prepared using an in situ deposition technique. The protonated polyaniline layer with a thickness in the range of 90-200 nm was prepared using precipitation, dispersion, or emulsion polymerization of aniline with simultaneous deposition on top of the porous polypropylene support, which was immersed in the reaction mixture. Variables such as temperature, concentration of reagents, presence of steric stabilizers, surfactants, and heteropolyacid were found to control both the formation and the quality of the polyaniline layers. Both morphology and thickness of the layers were characterized using scanning electron microscopy. Selective separation of carbon dioxide from its mixture with methane is used to illustrate potential application of these composite membranes. © 2012 Wiley Periodicals, Inc.

  18. Identification of alterations in the Jacobian of biochemical reaction networks from steady state covariance data at two conditions.

    Kügler, Philipp; Yang, Wei


    Model building of biochemical reaction networks typically involves experiments in which changes in the behavior due to natural or experimental perturbations are observed. Computational models of reaction networks are also used in a systems biology approach to study how transitions from a healthy to a diseased state result from changes in genetic or environmental conditions. In this paper we consider the nonlinear inverse problem of inferring information about the Jacobian of a Langevin type network model from covariance data of steady state concentrations associated to two different experimental conditions. Under idealized assumptions on the Langevin fluctuation matrices we prove that relative alterations in the network Jacobian can be uniquely identified when comparing the two data sets. Based on this result and the premise that alteration is locally confined to separable parts due to network modularity we suggest a computational approach using hybrid stochastic-deterministic optimization for the detection of perturbations in the network Jacobian using the sparsity promoting effect of [Formula: see text]-penalization. Our approach is illustrated by means of published metabolomic and signaling reaction networks.

  19. An Environmentally-Friendly and Catalytic Procedure for Mukaiyama Aldol Reaction Using Organic Catalyst DBU under Solvent Free Conditions

    SHEN,Zhi-Liang; JI,Shun-Jun; LOH,Teck Peng


    @@ Recently, methods based exclusively on organic catalysts have become of major significance in synthetic chemistry.Mukaiyama-aldol reaction, as one of the most important and frequently utilized methods for C-C bond formation, is well documented in literatures recently. A variety of reagents, particularly metal-containing Lewis acids or bases, are known to promote the nucleophilic process. However, many of the reported strategies might have the following limitations from environmental viewpoints: (1) the use of metal-containing catalyst. Some of the catalysts are air or moisture sensitive (such as lithium amide), and crucial reaction conditions are needed; Some of the catalysts derived from poisonous metal (for example: SnCl4, SmI2 etc.) may cause harmful influence on humane body and environment; (2) the use of organic solvent (such as DMF, CH2Cl2 etc.) may bring about environmental pollution and solvent waste.

  20. Quantitative changes in proteins responsible for flavonoid and anthocyanin biosynthesis in strawberry fruit at different ripening stages: A targeted quantitative proteomic investigation employing multiple reaction monitoring.

    Song, Jun; Du, Lina; Li, Li; Kalt, Wilhelmina; Palmer, Leslie Campbell; Fillmore, Sherry; Zhang, Ying; Zhang, ZhaoQi; Li, XiHong


    To better understand the regulation of flavonoid and anthocyanin biosynthesis, a targeted quantitative proteomic investigation employing LC-MS with multiple reaction monitoring was conducted on two strawberry cultivars at three ripening stages. This quantitative proteomic workflow was improved through an OFFGEL electrophoresis to fractionate peptides from total protein digests. A total of 154 peptide transitions from 47 peptides covering 21 proteins and isoforms related to anthocyanin biosynthesis were investigated. The normalized protein abundance, which was measured using isotopically-labeled standards, was significantly changed concurrently with increased anthocyanin content and advanced fruit maturity. The protein abundance of phenylalanine ammonia-lyase; anthocyanidin synthase, chalcone isomerase; flavanone 3-hydroxylase; dihydroflavonol 4-reductase, UDP-glucose:flavonoid-3-O-glucosyltransferase, cytochrome c and cytochrome C oxidase subunit 2, was all significantly increased in fruit of more advanced ripeness. An interaction between cultivar and maturity was also shown with respect to chalcone isomerase. The good correlation between protein abundance and anthocyanin content suggested that a metabolic control point may exist for anthocyanin biosynthesis. This research provides insights into the process of anthocyanin formation in strawberry fruit at the level of protein concentration and reveals possible candidates in the regulation of anthocyanin formation during fruit ripening. To gain insight into the molecular mechanisms contributing to flavonoids and anthocyanin biosynthesis and regulation of strawberry fruit during ripening is challenging due to limited molecular biology tools and established hypothesis. Our targeted proteomic approach employing LC-MS/MS analysis and MRM technique to quantify proteins in relation to flavonoids and anthocyanin biosynthesis and regulation in strawberry fruit during fruit ripening is novel. The identification of peptides

  1. Employment conditions and health inequities: a case study of Brazil Condições de emprego e iniquidades em saúde: um estudo de caso no Brasil

    Elizabeth Costa Dias


    Full Text Available This paper was prepared for the Employment Conditions and Health Inequalities Knowledge Network (EMCONET, part of the WHO Commission on the Social Determinants of Health. We describe the Brazilian context of employment conditions, labor conditions and health, their characteristics and causal relationships. The social, political and economic factors that influence these relationships are also presented with an emphasis on social inequalities, and how they are reproduced within the labor market and thereby affect the health and wellbeing of workers. A literature review was conducted in SciELO, LILACS, Google and Google Scholar, MEDLINE and the CAPES Brazilian thesis database. We observed that there are more workers operating in the informal sector than in the formal sector and these former have no social insurance or any other social benefits. Work conditions and health are poor in both informal and formal enterprises since health and safety labor norms are not effective. The involvement of social movements and labor unions in the elaboration and management of workers' health polices and programs with universal coverage, is a promising initiative that is underway nationwide.Este trabalho descreve aspectos das condições de trabalho e emprego e suas relações com a saúde, no contexto brasileiro, enfatizando as desigualdades sociais relacionadas com a inserção no mercado de trabalho, tendo sido desenvolvido como contribuição ao documento da rede "Employment Conditions and Health Inequalities Knowledge Network (EMCONET - WHO Commission on Social Determinants of Health". A pesquisa bibliográfica foi realizada no SciELO, LILACS, Google, Google Scholar, MEDLINE e no banco de teses da CAPES. No Brasil, o número de trabalhadores inseridos no setor informal supera o daqueles no setor formal. As informações sobre adoecimento e morte relacionados ao trabalho não estão disponíveis para o conjunto da população economicamente ativa. As condi

  2. Finite Difference Method for Reaction-Diffusion Equation with Nonlocal Boundary Conditions

    Jianming Liu; Zhizhong Sun


    In this paper, we present a numerical approach to a class of nonlinear reactiondiffusion equations with nonlocal Robin type boundary conditions by finite difference methods. A second-order accurate difference scheme is derived by the method of reduction of order. Moreover, we prove that the scheme is uniquely solvable and convergent with the convergence rate of order two in a discrete L2-norm. A simple numerical example is given to illustrate the efficiency of the proposed method.

  3. Optimal asset structure of a bank - bank reactions to stressful market conditions

    Hałaj, Grzegorz


    The aim of the paper is to propose a model of banks' asset portfolios to account for the strategic and optimising behavior of banks under adverse economic conditions. In the proposed modelling framework, banks are assumed to respond in an optimising manner to changes in their economic environment (e.g. interest rate and credit risk shocks, funding disruptions, etc.). The modelling approach is based on the risk-return optimal program in which banks aim at a particular composition of their asse...

  4. Prevalence and Associated Cost and Utilization of Multiple Chronic Conditions in the Outpatient Setting among Adult Members of an Employer-Based Health Plan.

    Rezaee, Michael E; Pollock, Martha


    Patients with multiple chronic conditions (MCCs) are a significant concern for the US health care system. MCC patients represent an increasing proportion of the US population and are associated with increased health care cost and utilization, and poor quality of care. Research that has been conducted on MCC patients to date has been at the national level using large data sets, such as Medicare and Medicaid claims and the National Inpatient Sample. These studies have produced research evidence that may be of little utility to individual employer-based health plans given the inherent differences in the patient populations they serve. This study analyzed evaluation and management claims for patients ages 18 years and older (n=632,477) from the Beaumont Employee Health Plan (BEHP), a regional health insurance provider serving Beaumont Health System employees and their families across Southeastern Michigan. The study found that individuals with MCCs are associated with increased cost and visits, and decreased time between appointments in the outpatient setting. Despite decreasing prevalence of MCCs over the study period, substantial increases in cost and visits, and a decrease in time between appointments was observed for MCC patients. Asthma and chronic back pain were uniquely identified as additional primary targets for disease management programs for employer-based health plans. These findings speak to the value of studying MCCs at the employer-based health plan level, where population-specific MCCs can be identified for meaningful intervention and management. Significant opportunity exists for employer-based health plans to study, prevent, and manage MCCs among adult patients.

  5. Lipid Synthesis Under Hydrothermal Conditions by Fischer- Tropsch-Type Reactions

    McCollom, Thomas M.; Ritter, Gilles; Simoneit, Bernd R. T.


    Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated on Mars and elsewhere as well). Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems. Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid. Optimum synthesis occurs in stainless steel vessels by heating at 175 °C for 2-3 days and produces lipid compounds ranging from C2 to >C35 which consist of n-alkanols, n- alkanoic acids, n-alkenes, n-alkanes and alkanones. The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO. Both carbon sources yield the same lipid classes with essentially the same ranges of compounds. The synthesis reactions were confirmed by using 13C labeled precursor acids.

  6. Optimisation of the reaction conditions for the production of cross-linked starch with high resistant starch content.

    Kahraman, Kevser; Koksel, Hamit; Ng, Perry K W


    The optimum reaction conditions (temperature and pH) for the preparation of cross-linked (CL) corn and wheat starches with maximum resistant starch (RS) content were investigated by using response surface methodology (RSM). According to the preliminary results, five levels were selected for reaction temperature (38-70 °C) and pH (10-12) in the main study. RS contents of the CL corn and wheat starch samples increased with increasing temperature and pH, and pH had a greater influence on RS content than had temperature. The maximum RS content (with a maximum p value of 0.4%) was obtained in wheat starch cross-linked at 38 °C and pH 12. In the case of CL corn starch, the optimum condition was 70 °C and pH 12. CL corn and wheat starch samples were also produced separately under the optimum conditions and their RS contents were 80.4% and 83.9%, respectively. These results were also in agreement with the values predicted by RSM.

  7. A VUV photoionization study of the multichannel reaction of phenyl radicals with 1,3-butadiene under combustion relevant conditions.

    Golan, Amir; Ahmed, Musahid; Mebel, Alexander M; Kaiser, Ralf I


    We studied the reaction of phenyl radicals (C(6)H(5)) with 1,3-butadiene (H(2)CCHCHCH(2)) exploiting a high temperature chemical reactor under combustion-like conditions (300 Torr, 873 K). The reaction products were probed in a supersonic beam by utilizing VUV radiation from the Advanced Light Source and by recording the experimental PIE curves at mass-to-charge ratios of m/z = 130 (C(10)H(10)(+)), 116 (C(9)H(8)(+)), and 104 (C(8)H(8)(+)). Our data suggest that the atomic hydrogen (H), methyl (CH(3)), and vinyl (C(2)H(3)) losses are open with estimated branching ratios of about 86 ± 4%, 8 ± 2%, and 6 ± 2%, respectively. The isomer distributions were probed further by fitting the experimentally recorded PIE curves with a linear combination of the PIE curves of individual C(10)H(10), C(9)H(8), and C(8)H(8) isomers. These fits indicate the formation of three C(10)H(10) isomers (trans-1,3-butadienylbenzene, 1,4-dihydronaphthalene, 1-methylindene), three C(9)H(8) isomers (indene, phenylallene, 1-phenyl-1-methylacetylene), and a C(8)H(8) isomer (styrene). A comparison with results from recent crossed molecular beam studies of the 1,3-butadiene-phenyl radical reaction and electronic structure calculations suggests that trans-1,3-butadienylbenzene (130 amu), 1,4-dihydronaphthalene (130 amu), and styrene (104 amu) are reaction products formed as a consequence of a bimolecular reaction between the phenyl radical and 1,3-butadiene. 1-Methylindene (130 amu), indene (116 amu), phenylallene (116 amu), and 1-phenyl-1-methylacetylene (116 amu) are synthesized upon reaction of the phenyl radical with three C(4)H(6) isomers: 1,2-butadiene (H(2)CCCH(CH(3))), 1-butyne (HCCC(2)H(5)), and 2-butyne (CH(3)CCCH(3)); these C(4)H(6) isomers can be formed from 1,3-butadiene via hydrogen atom assisted isomerization reactions or via thermal rearrangements of 1,3-butadiene involving hydrogen shifts in the high temperature chemical reactor.

  8. On Positive Solutions of Some System of Reaction-Diffusion Equations with Nonlocal Initial Conditions

    Walker, Christoph


    The paper focuses on positive solutions to a coupled system of parabolic equations with nonlocal initial conditions. Such equations arise as steady-state equations in an age-structured predator-prey model with diffusion. By using global bifurcation techniques, we describe the structure of the set of positive solutions with respect to two parameters measuring the intensities of the fertility of the species. In particular, we establish co-existence steady-states, i.e. solutions which are nonnegative and nontrivial in both components.

  9. Stability and Bifurcation in a Delayed Reaction-Diffusion Equation with Dirichlet Boundary Condition

    Guo, Shangjiang; Ma, Li


    In this paper, we study the dynamics of a diffusive equation with time delay subject to Dirichlet boundary condition in a bounded domain. The existence of spatially nonhomogeneous steady-state solution is investigated by applying Lyapunov-Schmidt reduction. The existence of Hopf bifurcation at the spatially nonhomogeneous steady-state solution is derived by analyzing the distribution of the eigenvalues. The direction of Hopf bifurcation and stability of the bifurcating periodic solution are also investigated by means of normal form theory and center manifold reduction. Moreover, we illustrate our general results by applications to the Nicholson's blowflies models with one- dimensional spatial domain.

  10. The research of neurospecific proteins and lysosomal peptidehydrolases in frontal neocortex during forming conditioned reaction of active avoiding of rats

    Vyatkin O. K.


    Full Text Available Dynamics of the activity of neuronal cell adhesion molecule (NCAM and lysosomal cysteine cathepsins B, L, H was researched in frontal neocortex of rat brain during forming a conditioned reaction of active avoiding. The quantitative estimation of NCAM content in the neocortex membrane fraction was carried on by ELISA in 3, 7, 14 and 21 days after starting animals’ training. The dynamics correlation between the NCAM content increasing and cysteine cathepsins activity was obtained, especially for aminopeptidase cathepsin H during the process of memory engram forming in frontal neocortex of rat brain.

  11. Process optimization of deposition conditions of PbS thin films grown by a successive ionic layer adsorption and reaction (SILAR) method using response surface methodology

    Yücel, Ersin; Yücel, Yasin; Beleli, Buse


    In this study, lead sulfide (PbS) thin films were synthesized by a successive ionic layer adsorption and reaction (SILAR) method with different pH, dipping time and dipping cycles. Response surface methodology (RSM) and central composite design (CCD) were successfully used to optimize the PbS films deposition parameters and understand the significance and interaction of the factors affecting the film quality. 5-level-3-factor central composite design was employed to evaluate the effects of the deposition parameters (pH, dipping time and dipping cycles) on the response (the optical band gap of the films). Data obtained from RSM were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation. The optimal conditions for the PbS films deposition have been found to be: pH of 9.1, dipping time of 10 s and dipping cycles of 10 cycles. The predicted band gap of PbS film was 2.13 eV under the optimal conditions. Verification experiment (2.24 eV) confirmed the validity of the predicted model. The film structures were characterized by X-ray diffractometer (XRD). Morphological properties of the films were studied with a scanning electron microscopy (SEM). The optical properties of the films were investigated using a UV-visible spectrophotometer.

  12. Biodiesel production from various oils under supercritical fluid conditions by Candida antartica lipase B using a stepwise reaction method.

    Lee, Jong Ho; Kwon, Cheong Hoon; Kang, Jeong Won; Park, Chulhwan; Tae, Bumseok; Kim, Seung Wook


    In this study, we evaluate the effects of various reaction factors, including pressure, temperature, agitation speed, enzyme concentration, and water content to increase biodiesel production. In addition, biodiesel was produced from various oils to establish the optimal enzymatic process of biodiesel production. Optimal conditions were determined to be as follows: pressure 130 bar, temperature 45 degrees C, agitation speed 200 rpm, enzyme concentration 20%, and water contents 10%. Among the various oils used for production, olive oil showed the highest yield (65.18%) upon transesterification. However, when biodiesel was produced using a batch system, biodiesel conversion yield was not increased over 65%; therefore, a stepwise reaction was conducted to increase biodiesel production. When a reaction medium with an initial concentration of methanol of 60 mmol was used and adjusted to maintain this concentration of methanol every 1.5 h during biodiesel production, the conversion yield of biodiesel was 98.92% at 6 h. Finally, reusability was evaluated using immobilized lipase to determine if this method was applicable for industrial biodiesel production. When biodiesel was produced repeatedly, the conversion rate was maintained at over 85% after eight reuses.

  13. Role of choline and glycine betaine in the formation of N,N-dimethylpiperidinium (mepiquat) under Maillard reaction conditions.

    Bessaire, Thomas; Tarres, Adrienne; Stadler, Richard H; Delatour, Thierry


    This study is the first to examine the role of choline and glycine betaine, naturally present in some foods, in particular in cereal grains, to generate N,N-dimethylpiperidinium (mepiquat) under Maillard conditions via transmethylation reactions involving the nucleophile piperidine. The formation of mepiquat and its intermediates piperidine - formed by cyclisation of free lysine in the presence of reducing sugars - and N-methylpiperidine were monitored over time (240°C, up to 180 min) using high-resolution mass spectrometry in a model system comprised of a ternary mixture of lysine/fructose/alkylating agent (choline or betaine). The reaction yield was compared with data recently determined for trigonelline, a known methylation agent present naturally in coffee beans. The role of choline and glycine betaine in nucleophilic displacement reactions was further supported by experiments carried out with stable isotope-labelled precursors (¹³C- and deuterium-labelled). The results unequivocally demonstrated that the piperidine ring of mepiquat originates from the carbon chain of lysine, and that either choline or glycine betaine furnishes the N-methyl groups. The kinetics of formation of the corresponding demethylated products of both choline and glycine betaine, N,N-demethyl-2-aminoethanol and N,N-dimethylglycine, respectively, were also determined using high-resolution mass spectrometry.

  14. Cortisol reaction in success and failure condition in endogenous depressed patients and controls.

    Croes, S; Merz, P; Netter, P


    The authors studied differences in cortisol response to controllable and uncontrollable stress and its relationship to Seligman's theory of learned helplessness in hospitalized unipolar depressed patients (11 nontreated, acutely depressed; 11 treated patients) and 11 age and sex matched controls hospitalized for traumatic surgery. Control and lack of control were achieved by induction of success and failure in a simple number addition test and applied in balanced order on 2 consecutive days. Saliva cortisol samples were collected before and after the test. No group differences in baseline cortisol levels were observed. Cortisol increased after uncontrollable and decreased after controllable stress in control patients, whereas cortisol decreased after both conditions in the acutely depressed group and less so in the treated group, although they were as emotionally upset after failure as controls. Thus, the normally observed ability of the neuroendocrine system to discriminate between controllable and uncontrollable stress deteriorates with increasing severity of depression.

  15. Reaction of tangerines genotypes to Elsinoe fawcettii under natural infection conditions

    Marcelo Claro de Souza


    Full Text Available A citrus scab disease, caused by Elsinoe fawcettii, is currently found in all citrus areas throughout Brazil. Thatbeing, given the importance of this casual agent, the behavior of tangerines and hybrids influenced by this pathogen wasevaluated under natural infection conditions. This study was performed with plants around 15 years old without irrigation;100 fruits of three plants were collected during harvest season, using a grade scale varying from 0 (absence of symptoms to6 (severe symptoms the level of disease severity was determined. Among the cultivars, citrus scab resistance was observedin Citrus deliciosa, C. tangerina, C. nobilis; a mandarin hybrid (C. nobilis x C. deliciosa and a satsuma hybrid (C. unshiu xC. sinensis. Among

  16. Complex Fertilizer Production from the Residue in Producing Furfural Using Straw: Study on the Additives and Reaction Conditions


    The complex additives which contain (ω) 4%~6% phosphoric acid, 4%~6% calcium triplesuperphosphate, 80%~90% calcium phosphate, 2%~3% calcium carbonate, 2%~4% sodiumhydrosuphite, 2%~4% ferric sulfate and 2%~4% aluminum sulfate were used to produce furfural bystraw hydrolysis with sulfuric acid. The effect of reaction conditions on residue acidity and furfuralproductivity were investigated. The experimental results showed that the suitable conditions are sulfuricacid concentration 16% (ω), the added sulfuric acid amounting to 6% of all raw materials, the weightratio of liquid to solid 2:1, the content of additives in straw 6%, temperature 100~130°C and reactiontime of 2 h, under which the productivity of furfural was 9.6% of rice straw and 10.5% of wheat strawrespectively(or 80%~85% of the theoretical value), meanwhile the residue became a compound fertilizer.

  17. Correlation of Impact Conditions, Interface Reactions, Microstructural Evolution, and Mechanical Properties in Kinetic Spraying of Metals: A Review

    Kim, Jaeick; Lee, Changhee


    In the past, most studies into kinetic spraying technology focused on basic research, but a large portion of current research is devoted to industrial applications of the technology. To advance, however, studies about industrial applications of kinetic spraying require profound understanding of the scientific foundations of the kinetic spray process. Nevertheless, no one has yet provided a well-organized summary of the correlations among impact conditions, interface reactions, microstructural evolution, and mechanical properties across the whole field of kinetic spraying technology. This paper provides such an overview of these correlations for kinetic spraying of metals. For each correlation, the interactions between the given conditions and the material properties of the metal feedstock powder are the most influential. These interactions are so complicated that it is difficult to systematically classify all cases into certain types. Nonetheless, we try to explain and summarize the critical factors and their roles in each relationship.

  18. QuadraPure-Supported Palladium Nanocatalysts for Microwave-Promoted Suzuki Cross-Coupling Reaction under Aerobic Condition

    Kin Hong Liew


    Full Text Available Cross-linked resin-captured palladium (XL-QPPd was readily prepared by simple physical adsorption onto the high loading QuadraPure macroporous resin and a subsequent reduction process. To enhance the mechanical stability, entrapped palladium nanocatalysts were cross-linked with succinyl chloride. Both transmission electron microscopy images and X-ray diffraction analysis revealed that the palladium nanoparticles were well dispersed with diameters ranging in 4–10 nm. The catalyst performed good catalytic activity in microwave-promoted Suzuki cross-coupling reactions in water under aerobic condition with mild condition by using various aryl halides and phenylboronic acid. In addition, the catalyst showed an excellent recyclability without significant loss of catalytic activity.

  19. Correlation of Impact Conditions, Interface Reactions, Microstructural Evolution, and Mechanical Properties in Kinetic Spraying of Metals: A Review

    Kim, Jaeick; Lee, Changhee


    In the past, most studies into kinetic spraying technology focused on basic research, but a large portion of current research is devoted to industrial applications of the technology. To advance, however, studies about industrial applications of kinetic spraying require profound understanding of the scientific foundations of the kinetic spray process. Nevertheless, no one has yet provided a well-organized summary of the correlations among impact conditions, interface reactions, microstructural evolution, and mechanical properties across the whole field of kinetic spraying technology. This paper provides such an overview of these correlations for kinetic spraying of metals. For each correlation, the interactions between the given conditions and the material properties of the metal feedstock powder are the most influential. These interactions are so complicated that it is difficult to systematically classify all cases into certain types. Nonetheless, we try to explain and summarize the critical factors and their roles in each relationship.

  20. CO2 hydrogenation to methanol on supported Au catalysts under moderate reaction conditions: support and particle size effects.

    Hartadi, Yeusy; Widmann, Daniel; Behm, R Jürgen


    The potential of metal oxide supported Au catalysts for the formation of methanol from CO2 and H2 under conditions favorable for decentralized and local conversion, which could be concepts for chemical energy storage, was investigated. Significant differences in the catalytic activity and selectivity of Au/Al2 O3 , Au/TiO2 , AuZnO, and Au/ZrO2 catalysts for methanol formation under moderate reaction conditions at a pressure of 5 bar and temperatures between 220 and 240 °C demonstrate pronounced support effects. A high selectivity (>50 %) for methanol formation was obtained only for Au/ZnO. Furthermore, measurements on Au/ZnO samples with different Au particle sizes reveal distinct Au particle size effects: although the activity increases strongly with the decreasing particle size, the selectivity decreases. The consequences of these findings for the reaction mechanism and for the potential of Au/ZnO catalysts for chemical energy storage and a "green" methanol technology are discussed.

  1. Adaptive locomotor training on an end-effector gait robot: evaluation of the ground reaction forces in different training conditions.

    Tomelleri, Christopher; Waldner, Andreas; Werner, Cordula; Hesse, Stefan


    The main goal of robotic gait rehabilitation is the restoration of independent gait. To achieve this goal different and specific patterns have to be practiced intensively in order to stimulate the learning process of the central nervous system. The gait robot G-EO Systems was designed to allow the repetitive practice of floor walking, stair climbing and stair descending. A novel control strategy allows training in adaptive mode. The force interactions between the foot and the ground were analyzed on 8 healthy volunteers in three different conditions: real floor walking on a treadmill, floor walking on the gait robot in passive mode, floor walking on the gait robot in adaptive mode. The ground reaction forces were measured by a Computer Dyno Graphy (CDG) analysis system. The results show different intensities of the ground reaction force across all of the three conditions. The intensities of force interactions during the adaptive training mode are comparable to the real walking on the treadmill. Slight deviations still occur in regard to the timing pattern of the forces. The adaptive control strategy comes closer to the physiological swing phase than the passive mode and seems to be a promising option for the treatment of gait disorders. Clinical trials will validate the efficacy of this new option in locomotor therapy on the patients.

  2. Synthesis of Pd(0) nanocatalyst using lignin in water for the Mizoroki-Heck reaction under solvent-free conditions.

    Marulasiddeshwara, M B; Kumar, P Raghavendra


    Palladium(0) nanospheres with an average size of 1-5 nm were synthesized and stabilized by lignin in water without any reducing agent. The lignin supported palladium(0) nanoparticles (lignin@Pd-NPs) were characterized by UV-vis., FT-IR, SEM, TEM, HRICP-AES, EDX and PXRD. Absence of the peak at 430 nm in UV-vis., spectrum confirmed the reduction of Pd(II) to Pd(0). The five characteristic peaks at (111), (200), (220), (311) and (222) corresponding to the 2θ values 40°, 46.7°, 67.9°, 81.9° and 86.9°, respectively, appeared in PXRD spectrum indicated the crystallographic planes of Pd(0) with fcc structure. The Pd(0) loaded on lignin was 0.0467 mmol/g determined by HRICP-AES and 0.89% (w/w) by EDX. The performance of lignin@Pd-NPs catalyst have been investigated for the Mizoroki-Heck CC bond formation reactions between n-butyl propene-2-enoate and halobenzenes and substituted halobenzenes in polar to highly polar solvents as well as under solvent-free conditions in the presence of organic or inorganic bases. The lignin@Pd-NPs was found to be a highly efficient catalyst to yield the desired products of up to 94% under solvent-free conditions in short reaction times. The catalyst was heterogeneous and hence recovered by filtration and reused several times in the subsequent batches of the same reaction.

  3. Gender role stereotype and poor working condition pose obstacles for female doctors to stay in full-time employment: alumnae survey from two private medical schools in Japan.

    Izumi, Miki; Nomura, Kyoko; Higaki, Yuko; Akaishi, Yu; Seki, Masayasu; Kobayashi, Shizuko; Komoda, Takayuki; Otaki, Junji


    The shortage of physicians has become a serious problem in Japan. It has been pointed out that an increase in the number of female doctors may contribute to the aggravation of this shortage because it is known that women work fewer hours than male doctors. Here, we investigated how many female doctors had ever resigned from a full-time position, and elucidated the reasons why female doctors find it difficult to stay in full-time employment. An alumnae survey of 2 private medical schools was conducted in 2007. A self-administered questionnaire was sent to 1423 graduates and 711 responded with informed consent (response rate, 50%; mean age, 39 years). Overall, 55% of the respondents had previously resigned from full-time employment, of which 90% resigned within 10 years of graduating from medical school. The difficulty in balancing work, childbirth and child rearing (45%) were the top 2 reasons for resignation, followed by physical problems (12%) and long working hours (8%). Among those who resigned, only 33% returned to full-time employment. Women who had at least 1 child were only 30% of those who had never resigned and 84% of those who had previously resigned. The majority of study subjects, regardless of experience of resignation (88%), agreed that women should continue to work even after childbirth. In conclusion, the results of this study suggested that many female doctors resigned from a full-time position within 10 years of graduating from medical school, largely because of the gender role stereotype and poor working conditions.

  4. Optimum Operating Conditions for Epoxidation Reaction of Jojoba and Castor Oils

    El-Adly R. A


    Full Text Available The goal of this paper is to determine the best set of parameters such as, glacial acetic acid to ethylenic unsaturation mole ratio (acid/ethylene, hydrogen peroxide to ethylenic unsaturation mole ratio (H2O2/ethylene and temperature on epoxidation conversion based on experimental results, with respect to time. The effect of these parameters has been studied in a separate set of experiments. Their ranges were as follows: 0.2-0.8Wt%, 0.75-3Wt%, and 40oC-80oC respectively. Six models have been introduced to indicate the effect of these three variables on conversion for both jojoba and castor oil, and the prediction abilities of the resultant models were tested. Regression analysis is used to extract the introduced non linear models. In addition, two new correlations have been introduced to incorporate all the studied variables and their effect on conversion simultaneously for both jojoba and castor oil. An optimization program has been introduced to determine the optimum operating conditions for maximum conversion for both jojoba and castor oil. The study shows that, the maximum conversion for epoxidized jojoba oil (66% could be achieved at acid/ethylene ratio: 0.4, H2O2/ethylene ratio: 1.44; temp: 66.5 and time is 8hr. While the maximum conversion for epoxidized castor oil (53.24% could be achieved at acid/ethylene ratio: 0.37; H2O2/ethylenes ratio: 1.32; temp: 61 and time is 8hr. the model results are strongly agreed with the experimental results.

  5. Correlation of Growth and Surface Properties of Poly(\\(p\\-xylylenes to  Reaction Conditions

    Andreas Reichel


    Full Text Available Parylene, a non-critical, non-toxic layer material, which is not only a candidate for low-\\(K\\ dielectrics, but also well suited for long-term applications in the human body, has been deposited by (plasma-enhanced chemical vapor deposition of the monomeric species. To that end, a specially-designed reactor exhibiting a cracker tube at its entrance, which serves as the upstream control, and a cooling trap in front of the downstream control has been applied. The process of polymerization has been traced and is explained by evaporating the dimeric species followed by dissociation in the cracker at elevated temperatures and, eventually, to the coating of the polymeric film in terms of thermodynamics. Alternatively, the process of dissociation has been accomplished applying a microwave plasma. In both cases, the monomerization is controlled by mass spectrometry. The window for surface polymerization could be clearly defined in terms of a factor of dilution by an inert gas for the chemical vapor deposition (CVD case and in the case of plasma-enhanced chemical vapor deposition (PECVD, additionally by the power density. The characterization of the layer parameters has been carried out by several analytical tools: scanning electron microscopy and atomic force microscopy to determine the surface roughness and density and depth of voids in the film, which influence the layer capacitance and deteriorate the breakdown voltage, a bulk property. The main issue is the conduct against liquids between the two borders' hydrophilic and hydrophobic conduct, but also the super-hydrophobic character, which is the condition for the Lotus effect. The surface tension has been evaluated by contact angle measurements. Fourier-transform infrared spectroscopy has proven the conservation of all of the functional groups during polymerization.

  6. Investigation of influence of hypomagnetic conditions closely similar to interplanetary magnetic filed on behavioral and vegetative reactions of higher mammals

    Krivova, Natalie; Trukhanov, Kiril; Zamotshina, Tatyana; Zaeva, Olga; Khodanovich, Marina; Misina, Tatyana; Tukhvatulin, Ravil; Suhko, Valery

    To study the influence of long being under reduced magnetic field on behavioral and vegetative reactions of higher mammals the white rat males were put into the 700-1000 times reduced geomagnetic field (50-70 nT) for 25 days. Such field was obtained by using automatic compensation of the horizontal and vertical components of the GMF at a frequencies up to 10 Hz by means of solenoids of the experimental magnetic system. Control animals were located in the same room under usual laboratory GMF conditions (52 uT). Two days before the experiment the behavioral reactions were studied in the "open field" by means of a set of tests, characterizing the level of emotionality, moving and orientational-investigative activities of the animals under conditions of unimpeded behavior. 60 white underbred rat males with the initial body mass of 200 g were divided into three clusters. Animals with average indices were selected for the experiment. We have judged behavioral reaction disturbances of the rats under hypomagnetic conditions using videotape recordings carried out in the entire course of the chronic experiment. According to the obtained results during the period of maximum activity (from 230 to 330 a.m.) the number of interrelations between the individuals increased appreciably for experimental rats including interrelations with aggressive character. This was real during all 25 days of observation. We observed a certain dynamics of this index differed from that of the control group. We have also analyzed the final period of observation from the 21th to the 25th days. In this period we studied the 24 hours' dynamics of interrelations which were noted during 5 minutes in every hour around the clock. In the control group the number of interrelation was at a constantly low level. For experimental animals the number of interrelations was higher in the night hours than in the day ones. Moreover it exceeded the similar indexes observed from the 1st to the 20th day. For example from

  7. Characterization of a Pressure-Fed LOX/LCH4 Reaction Control System Under Simulated Altitude and Thermal Vacuum Conditions

    Atwell, Matthew J.; Melcher, John C.; Hurlbert, Eric A.; Morehead, Robert L.


    A liquid oxygen, liquid methane (LOX/LCH4) reaction control system (RCS) was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under simulated altitude and thermal vacuum conditions. The RCS is a subsystem of the Integrated Cryogenic Propulsion Test Article (ICPTA) and was initially developed under Project Morpheus. Composed of two 28 lbf-thrust and two 7 lbf-thrust engines, the RCS is fed in parallel with the ICPTA main engine from four propellant tanks. 40 tests consisting of 1,010 individual thruster pulses were performed across 6 different test days. Major test objectives were focused on system dynamics, and included characterization of fluid transients, manifold priming, manifold thermal conditioning, thermodynamic vent system (TVS) performance, and main engine/RCS interaction. Peak surge pressures from valve opening and closing events were examined. It was determined that these events were impacted significantly by vapor cavity formation and collapse. In most cases the valve opening transient was more severe than the valve closing. Under thermal vacuum conditions it was shown that TVS operation is unnecessary to maintain liquid conditions at the thruster inlets. However, under higher heat leak environments the RCS can still be operated in a self-conditioning mode without overboard TVS venting, contingent upon the engines managing a range of potentially severe thermal transients. Lastly, during testing under cold thermal conditions the engines experienced significant ignition problems. Only after warming the thruster bodies with a gaseous nitrogen purge to an intermediate temperature was successful ignition demonstrated.

  8. Liquid Phase Hydrogenation of Benzalacetophenone:Effect of Solvent,Catalyst Support,Catalytic Metal and Reaction Conditions%Liquid Phase Hydrogenation of Benzalacetophenone: Effect of Solvent, Catalyst Support, Catalytic Metal and Reaction Conditions

    Achim STOLLE; Christine SCHMOGER; Bernd ONDRUSCHKA; Werner BONRATH; Thomas F. KELLER; Klaus D. JANDT


    Innovative catalysts based on a “porous glass” support material were developed and investigated for the reduction of benzalacetophenone.The easy preparation conditions and possibility to use different metals (e.g.Pd,Pt,Rh) for impregnation gave a broad variety of these catalysts.Hydrogenation experiments with these supported catalysts were carried out under different hydrogen pressures and temperatures.Porous glass catalysts with Pd as the active component gave chemoselective hydrogenation of benzalacetophenone,while Pt- and Rh-catalysts tended to further reduce the carbonyl group,especially at elevated hydrogen pressures and temperatures.Kinetic analysis of the reactions revealed these had zero order kinetics,which was independent of the type of porous glass support and solvent used.

  9. Synthesis of carbodiimides by I2/CHP-mediated cross-coupling reaction of isocyanides with amines under metal-free conditions.

    Zhu, Tong-Hao; Wang, Shun-Yi; Tao, Yang-Qing; Ji, Shun-Jun


    An I2/CHP-mediated cross-coupling reaction of isocyanides with readily accessible amines via C-N formation is described for carbodiimide synthesis in moderate to excellent yields. This represents a metal-free strategy for a coupling reaction of isocyanides with amines, and it provides an efficient approach for symmetric and unsymmetric functionalized carbodiimide derivative synthesis under mild conditions.

  10. Real-Time Optical Monitoring of Flow Kinetics and Gas Phase Reactions Under High-Pressure OMCVD Conditions

    Dietz, N.; McCall, S.; Bachmann, K. J.


    This contribution addresses the real-time optical characterization of gas flow and gas phase reactions as they play a crucial role for chemical vapor phase depositions utilizing elevated and high pressure chemical vapor deposition (HPCVD) conditions. The objectives of these experiments are to validate on the basis of results on real-time optical diagnostics process models simulation codes, and provide input parameter sets needed for analysis and control of chemical vapor deposition at elevated pressures. Access to microgravity is required to retain high pressure conditions of laminar flow, which is essential for successful acquisition and interpretation of the optical data. In this contribution, we describe the design and construction of the HPCVD system, which include access ports for various optical methods of real-time process monitoring and to analyze the initial stages of heteroepitaxy and steady-state growth in the different pressure ranges. To analyze the onset of turbulence, provisions are made for implementation of experimental methods for in-situ characterization of the nature of flow. This knowledge will be the basis for the design definition of experiments under microgravity, where gas flow conditions, gas phase and surface chemistry, might be analyzed by remote controlled real-time diagnostics tools, developed in this research project.

  11. In(OTf)3-Catalyzed Synthesis of Functionalized 1,5-Benzodiazepines from o-Phenylenediamine and Alkyl Propiolates under Solvent-Free Reaction Conditions%In(OTf)3-Catalyzed Synthesis of Functionalized 1,5-Benzodiazepines from o-Phenylenediamine and Alkyl Propiolates under Solvent-Free Reaction Conditions

    吴海生; 杨进; 王磊


    A simple, environmental-friendly, and practical method for the synthesis of benzodiazepine derivatives through a reaction of substituted o-phenylenediamines with alkyl propiolates has been developed. The reactions generated the 1,5-benzodiazepines in good to excellent yields in the presence of catalytic amount of In(OTf)3 under sol- vent-free reaction conditions.

  12. Direct ethanol fuel cell (DEFC): Electrical performances and reaction products distribution under operating conditions with different platinum-based anodes

    Rousseau, S.; Coutanceau, C.; Lamy, C.; Leger, J.-M. [Laboratoire de Catalyse en Chimie Organique, -Equipe Electrocatalyse- UMR-CNRS 6503, Universite de Poitiers, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex (France)


    Ethanol electro-oxidation at different Pt-based electrodes was investigated in a single direct ethanol fuel cell (DEFC) in terms of reaction product distribution depending on the anode catalyst. In DEFC experiments, only three reaction products were detected using HPLC: acetaldehyde (AAL), acetic acid (AA) and CO{sub 2}. The addition of tin to platinum increases the activity of the catalyst by several order of magnitude and the electrical performance of the DEFC are greatly enhanced from a few mWcm{sup -2} to 30mWcm{sup -2} at 80{sup o}C, with Pt/C and Pt-Sn/C catalysts, respectively. Moreover, at Pt-Sn/C and Pt-Sn-Ru/C the formation of CO{sub 2} and AAL is lowered whereas the formation of AA is increased in comparison to what happens at a Pt/C catalyst. The addition of Ru to Pt-Sn only leads to enhance the electrical performance of the DEFC, i.e. the activity of the catalyst, but does not modify the product distribution. Very good stability in the open circuit voltage of the DEFC (close to 0.75V) was observed over a period of 2 weeks at 90{sup o}C, the cell undergoing start-run-stop cycles each day. Good stability under operating conditions at a given current density was also observed over 6h. (author)

  13. Optimization of preparation conditions of Fe-Co nanoparticles in low-temperature CO oxidation reaction by taguchi design method

    Abolfazl Biabani; Mehran Rezaei; Zohreh Fattah


    Mixed iron-cobalt oxide (Co/Fe molar ratio=1/5) are prepared using a simple co-precipitation procedure and studied for the catalytic oxidation of carbon monoxide.In particular,the effects of a range of preparation variables such as pH value when precipitation,aging temperature,precipitation agent type and aging time are investigated on the catalytic performance of synthesized Fe-Co oxides in CO oxidation reaction.In addition,the preparation factors were optimized by Taguchi design method.The optimized sample was characterized by XRD,N2 adsorption/desorption,TEM and TGA/DTA techniques.The results reveal that the optimized sample shows a mesoporous structure with a narrow pore size distribution centered in the range of 2-7 nm.The sample prepared under optimized conditions has high activity and stability toward removal of carbon monoxide at lower temperatures.It is shown that different preparation variables influence the catalytic performance of Fe-Co oxide in CO oxidation reaction.

  14. Synthesis of cellulose triacetate from cotton cellulose by using NIS as a catalyst under mild reaction conditions.

    El Nemr, Ahmed; Ragab, Safaa; El Sikaily, Amany; Khaled, Azza


    This research discusses the acetylation of cotton cellulose with acetic anhydride without solvents. The acetylation was done in the presence of different amounts of N-Iodosuccinimide (NIS) as a catalyst; this took place under mild reaction conditions. The extent of acetylation was measured by the weight percent gain (WPG) that varied from 24.71 to 71.83%. Cotton cellulose acetates, with the degree of substitution (DS) that ranged from 0.89 to 2.84, were prepared in one step. The cellulose triacetate, with a degree of substitution (DS) 2.84, was obtained. The WPG and DS were easily controlled by changing the reaction duration (1-5h), and the concentration of the catalyst (0.05 g, 0.075 g and 0.10 g for 1g of cellulose) in 25 ml of acetic anhydride. NIS was recognized as a novel and more successful catalyst for the acetylation of hydroxyl groups in cotton cellulose. Formation of the acetates and the calculation of the degree of substitution were performed by FT-IR, Raman, and (1)H NMR.


    Aslan, E.; Bulut, N. [Department of Physics, Firat University, 23169 Elazig (Turkey); Castillo, J. F.; Banares, L.; Aoiz, F. J. [Departamento de Quimica Fisica I, Facultad de Ciencias Quimicas (Unidad Asociada CSIC), Universidad Complutense de Madrid, 28040 Madrid (Spain); Roncero, O., E-mail: [Instituto de Fisica Fundamental, CSIC, C/Serrano 123, E-28006 Madrid (Spain)


    The dynamics and kinetics of the H{sup +} + LiH reaction have been studied using a quantum reactive time-dependent wave packet (TDWP) coupled-channel quantum mechanical method on an ab initio potential energy surface at conditions of the early universe. The total reaction probabilities for the H{sup +} + LiH(v = 0, j = 0) {yields} H{sup +} {sub 2} + Li process have been calculated from 5 Multiplication-Sign 10{sup -3} eV up to 1 eV for total angular momenta J from 0 to 110. Using a Langevin model, integral cross sections have been calculated in that range of collision energies and extrapolated for energies below 5 Multiplication-Sign 10{sup -3} eV. The calculated rate constants are found to be nearly independent of temperature in the 10-1000 K interval with a value of Almost-Equal-To 10{sup -9} cm{sup 3} s{sup -1}, which is in good agreement with estimates used in evolutionary models of the early universe lithium chemistry.

  16. Stress response in Pectobacterium atrosepticum SCRI1043 under starvation conditions: adaptive reactions at a low population density.

    Petrova, Olga; Gorshkov, Vladimir; Daminova, Amina; Ageeva, Marina; Moleleki, Lucy N; Gogolev, Yuri


    The adaptive reactions of plant pathogenic bacterium Pectobacterium atrosepticum SCRI1043 under starvation conditions were studied. The main emphasis was given to the peculiarities of stress responses depending on the bacterial population densities. When bacteria were subjected to starvation at high population densities (10(7)-10(9) CFU ml(-1)), their adaptive reactions conformed to the conventional conception of bacterial adaptation related to autolysis of part of the population, specific modification of cell ultrastructure, activation of expression of stress responsive genes and acquiring cross protection against other stress factors. In contrast, at low initial population densities (10(3)-10(5) CFU ml(-1)), as described in our recent work, the cell density increased due to multiple cell division despite the absence of exogenous growth substrate. Here we present data that demonstrate that such unconventional behavior is part of a stress response, which provides increased stress tolerance while retaining virulence. Cell morphology and gene expression in high- and low-cell-density starving Pba cultures were compared. Our investigation demonstrates the existence of alternative adaptive strategies enabling pathogenic bacteria to cope with a variety of stress factors, including starvation, especially necessary when residing outside of their host.

  17. Effects of Thermal Radiation and Chemical Reaction on MHD Free Convection Flow past a Flat Plate with Heat Source and Convective Surface Boundary Condition



    Full Text Available This paper analyzes the radiation and chemical reaction effects on MHD steady two-dimensional laminar viscous incompressible radiating boundary layer flow over a flat plate in the presence of internal heat generation and convective boundary condition. It is assumed that lower surface of the plate is in contact with a hot fluid while a stream of cold fluid flows steadily over the upper surface with a heat source that decays exponentially. The Rosseland approximation is used to describe radiative heat transfer as we consider optically thick fluids. The governing boundary layer equations are transformed into a system of ordinary differential equations using similarity transformations, which are then solved numerically by employing fourth order Runge-Kutta method along with shooting technique. The effects of various material parameters on the velocity, temperature and concentration as well as the skin friction coefficient, the Nusselt number, the Sherwood number and the plate surface temperature are illustrated and interpreted in physical terms. A comparison of present results with previously published results shows an excellent agreement.

  18. Optimization of reaction conditions for enzymatic viscosity reduction and hydrolysis of wheat arabinoxylan in an industrial ethanol fermentation residue

    Sørensen, H.R.; Pedersen, S.; Meyer, Anne Boye Strunge


    of enzyme-catalyzed hydrolysis of arabinoxylan, beta-glucan, and cellulose. In designed response surface experiments, the optimal enzyme reaction conditions with respect to pH and temperature of the vinasse, the vinasse supernatant (mainly soluble material), and the vinasse sediment (mainly insoluble...... substances) varied from pH 5.2-6.4 and 41-49 degrees C for arabinose release and from pH 4.9-5.3 and 42-46 degrees C for xylose release. Even though only limited hydrolysis of the arabinoxylan in the vinasse sediment fraction was obtained, the results indicated that the same enzyme activities acted...... on the arabinoxylan in the different vinasse fractions irrespective of the state of solubility of the substrate material. The levels of liberated arabinose and xylose increased with increased dry matter concentration during enzymatic hydrolysis in the vinasse and the vinasse supernatant, but at the same time...

  19. Stationary Conditions of the Electron Density Along the Reaction Path: Connection with Conceptual DFT and Information Theory.

    Gonzalez, Carlos A; Squitieri, Emilio; Franco, Hector J; Rincon, Luis C


    The Kohn-Sham density functional theory (DFT) formalism has been used to investigate the influence of the stationary behavior of the electron density (ρ(r⃗;s)) along a minimum energy path on the corresponding stationary conditions observed in the total potential energy of the reactive system, information theory measures (Shannon information entropy and Onicescu information energy), and chemical reactivity indexes (the chemical hardness). The theoretical treatment presented in this work, combined with DFT calculations on 3 different test reactions: Ḣ' + H2, Ḣ' + CH4 and H(-) + CH4, suggest that for any reactive system, properties that can be cast as a functional of the electron density, must exhibit stationary points along the IRC path modulated by the corresponding stationary behavior of the electron density.

  20. Fischer-Tropsch diesel production over calcium-promoted Co/alumina catalyst: Effect of reaction conditions

    A.R. de la Osa; A. De Lucas; A. Romero; J.L. Valverde; P. Sanchez [University of Castilla-La Mancha, Ciudad Real (Spain). Chemical Engineering Department


    The effects of reaction conditions on the Fischer-Tropsch activity and product distribution of an alkali-earth metal promoted cobalt based catalyst were studied. The influence of the promoter on the reducibility and cobalt particle size was studied by different techniques, including N{sub 2} adsorption, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption and acid-base titrations. Experiments were carried out on a bench-scale fixed bed reactor and catalysts were prepared by incipient wetness impregnation. It was observed that addition of a small amount of calcium oxide as a promoter (0.6 wt.%) improved the cobalt oxide reducibility and reduced the formation of cobalt-aluminate species. A positive correlation between basicity and particle size was observed. In terms of FTS results, CO conversion and C{sub 5}{sup +} selectivity were found to be enhanced by the addition of this promoter. It was important to note that the addition of calcium shifted the distribution to mainly C{sub 16}-C{sub 18} hydrocarbons fraction, which could be greatly considered for a diesel formulation. Furthermore, the variation of the reaction conditions seemed to influence product distribution in a lesser extent than unpromoted catalyst. Also, a displacement of hydrocarbon distribution to higher molecular weight with decreasing space velocity and temperature was observed. Moreover, the addition of calcium to the cobalt based catalyst was found to greatly maintain selectivity to C{sub 5}{sup +} for a wide range of H{sub 2}/CO molar ratios. 60 refs., 10 figs., 5 tabs.

  1. Health-Related Quality of Life in leukemia Survivors of Allogeneic Hematopoietic Stem Cell Transplantation Employing the Mexican Reduced-Intensity Conditioning.

    González-Ramírez, Mónica P; Miravete-Lagunes, Karla; Gómez-de-León, Andrés; Ponce-de-León, Sergio; Tenorio-Rojo, Andrea P; Martagón-Herrera, Nora A; Hernández-Reyes, Jesús A; García-Villasenor, Arturo; Burguette, Esteban; Vallejo-Villalobos, María Fernanda; Ruiz-Delgado, Guillermo J; Gómez-Almaguer, David; Ruiz-Argüelles, Guillermo J


    Quality of life (QOL) is an important consideration in the counseling, implementation, and post-treatment management of arduous treatments for life-threatening conditions such as allogeneic hematopoietic cell transplantation (allo-HCT). To analyze the QOL of leukemia patients allografted with the Mexican reduced-intensity conditioning regimen in two Mexican academic medical centers. By means of the quality metric short form 36 version 2 to measure generic health concepts, relevant QOL was analyzed in leukemia patients who underwent allo-HCT using reduced-intensity conditioning on an outpatient basis at either the Centro de Hematología y Medicina Interna de Puebla of the Clínica Ruiz or the Hematology Service of the Internal Medicine Department of the Hospital "Dr. José Eleuterio González" of the Universidad Autónoma de Nuevo León, and who had survived more than 12 months after the allograft, who could be approached, who were in a continued complete remission (with or without graft-versus-host disease), and who were willing to respond to the questionnaire. Thirty-five patients fulfilling these requirements were included, and a sex- and age-matched group of 35 reference subjects was also studied. Allografted patients were found to have a slightly better mental component summary than the reference subjects (53.23 vs. 48.66 points; p = 0.01), whereas the physical component summary did not show a difference (54.53 vs. 52.05 points; p = 0.59). Most of the differences between allografted individuals and reference subject controls were not significant. Despite several sources of bias, these data suggest that allografted individuals employing the Mexican reduced-intensity conditioning regimen enjoy a health-related QOL life similar to that of reference subjects, adding another advantage of this method of conducting stem cell allografts. However, more work needs to be done to elucidate the impact of reduced-intensity conditioning on post allo-HCT QOL.

  2. The influence of mass-transport conditions on the ethanol oxidation reaction (EOR) mechanism of Pt/C electrocatalysts.

    Bach Delpeuch, Antoine; Jacquot, Marjorie; Chatenet, Marian; Cremers, Carsten


    This study aims to provide further understanding of the influence of different parameters that control mass-transport (the revolution rate of the rotating disk electrode and the potential scan rate) on the ethanol oxidation reaction (EOR). The experiments were conducted on a home-made carbon-supported 20 wt% Pt/C electrocatalyst, synthesized using a modified polyol method, and characterized in terms of physicochemical properties by thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The EOR at the thin active layer of this electrocatalyst was characterized using both differential electrochemical mass spectrometry (DEMS) in a flow cell configuration and the rotating disc electrode (RDE). The results demonstrate that operating under stationary conditions (low scan rate and high RDE speed) hinders complete ethanol electrooxidation into CO2 and favors the poisoning of the electrocatalyst surface by hydroxide and strong ethanol adsorbates. As such, the EOR appears to be more efficient and faster under dynamic conditions than in near steady-state.

  3. Reaction of Basaltic Materials under High-Fidelity Venus Surface Conditions using the Glenn Extreme Environment Rig: First Results

    Radoman-Shaw, Brandon; Harvey, Ralph; Costa, Gustavo; Nakley, Leah Michelle; Jacobson, Nathan S.


    Both historical and current investigations of Venus suggest that atmosphererock interactions play a critical role in the evolution of its atmosphere and crust. We have begun a series of systematic experiments designed to further our understanding of atmosphere-driven weathering and secondary mineralization of basaltic materials that may be occurring on Venus today. Our experiments expose representative igneous phases (mineral, glasses and rocks) to a high-fidelity simulation of Venus surface conditions using the NASA Glenn Extreme Environment Rig (GEER) located at the NASA Glenn Research Center in Cleveland, Ohio. GEER is a very large (800L) vessel capable of producing a long-term, high fidelity simulation of both the physical conditions (750 K and 92 bar) and atmospheric chemistry (down to the ppb-level) asso-ciated with the Venusian surface. As of this writing we have just finished the first of several planned experiments: a 42-day exposure of selected mineral, rocks and volcanic glasses. Our goal is to identify and prioritize the reactions taking place and better our understanding of their importance in Venus' climate history.

  4. The effect of Al on thermal stability and kinetics of decomposition of MgH{sub 2} prepared by mechanochemical reaction at different conditions

    Ershova, O.G.; Dobrovolsky, V.D., E-mail:; Solonin, Y.M.; Khyzhun, O.Y.; Koval, A.Y.


    This work is directed at decreasing decomposition temperature of MgH{sub 2}. In accordance with the theoretical predictions, hydride of solid solution of Al in Mg should decompose at lower temperature compared to that of MgH{sub 2}, and numerous experiments indicate that thermodynamic stability of the hydride depends on methods and conditions of its synthesis. Therefore, the goal of this article is to study the possibility of obtaining the hydride of solid solution of aluminum in magnesium by different technological approaches. Three mechanical composite alloys derived by the different approaches are studied employing the X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermodesorption spectroscopy (TDS) methods. XRD Rietveld analysis reveals that the hydrogenation of a Mg + 10 wt% Al powder by means of reactive milling in the hydrogen atmosphere as well as hydrogenation of the powder from the gaseous phase after milling the powder for 20 h in the argon atmosphere leads to formation of aluminum-free MgH{sub 2} hydride and the Mg{sub 17}Al{sub 12} phase. Our TDS studies (at P{sub H2} = 0.1 MPa) indicate that additives of 10 wt% Al to magnesium do not lead to decreasing the decomposition temperature of MgH{sub 2} prepared by mechanochemical reaction at the different conditions. - Highlights: • Three mechanical alloys with 10% wt. Al additives to Mg have been synthesized. • Hydrogen-sorption properties and thermal stability of the alloys are studied at 1 bar H{sub 2}. • Al additives to Mg do not influence decomposition temperature of MgH{sub 2} phase of the alloys. • Al additives do not improve kinetics of process of hydrogen desorption from MgH{sub 2} phase.

  5. Penicillin allergy: anti-penicillin IgE antibodies and immediate hypersensitivity skin reactions employing major and minor determinants of penicillin.

    Chandra, R K; Joglekar, S A; Tomas, E


    300 children considered to have had adverse reactions to penicillin were examined. Informed consent was obtained from the parents. Skin tests were conducted by the scratch/prick and intradermal techniques, using benzylpenicilloyl polylysine conjugate and a mixture of minor determinants of penicillin. Specific anti-penicillin IgE antibodies were estimated by the radioallergosorbent test. There was a good correlation between the two methods. The overall frequency of positive tests was 19%. 11 c...

  6. [Optimization of reaction conditions and methodological investigation on microtox-based fast testing system for traditional Chinese medicine injection].

    Gao, Hong-Li; Li, Xiao-Rong; Yan, Liang-Chun; Zhao, Jun-Ning


    Vibrio fischeri CS234 was used to establish and optimize microtox assay system, laying a foundation for the application of this method in comprehensive acute toxicity test of traditional Chinese medicine (TCM) injections. Firstly, the Plackett-Burman method was carried out to optimize the factors which would affect Vibrio fischeri CS234 luminescence. Secondly, ZnSO4•7H2O was chosen as reference substance to establish its reaction system with quality control samples. The optimal luminescence conditions were achieved as follows: ①At a temperature of (15±1) ℃, Vibrio fischeri CS234 lyophilized powders were balanced for 15 min, then, 1 mL resuscitation fluid was added and blended for 10 min. 100 μL bacteria suspension was taken to measure the initial luminescence intensity, and then 1 mL resuscitation fluid or test sample was immediately added; after reaction for 10 min, corresponding luminescence intensity was measured again. Resuscitation diluent, osmotic pressure regulator and ZnSO4•7H2O stock solution showed no interference to the determination of Vibrio fischeri CS234 luminescence intensity, so this method was of good specificity. The within-and between-batch precisions of quality controls and the lower limit of quantification (LLOQ) samples were testing needs of the vast majority of traditional Chinese medicine injections. The Vibrio fischeri strain CS234 assay system was specific, stable, sensitive, accurate and adaptable after optimization, so it was suitable for the comprehensive acute toxicity assessment of TCM injections. Copyright© by the Chinese Pharmaceutical Association.

  7. Microwave-Accelerated Organic Reactions

    LU; TaJung


    The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.  ……

  8. Microwave-Accelerated Organic Reactions

    LU TaJung


    @@ The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.

  9. Engaging Employers?

    Hillier, Yvonne


    A key factor in the successful development of workplace learning is employer engagement (Leitch, 2006; DfES, 2007). However, despite numerous approaches by government in the United Kingdom to bring together employers, providers and learners so that economic success is generated by a skilled and flexible workforce, there continue to be challenges…

  10. Industry Employment

    Occupational Outlook Quarterly, 2012


    This article illustrates projected employment change by industry and industry sector over 2010-20 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment for which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  11. The Conditions and Influencing Factors for Complete Reaction in Asymmetry Redox Reaction%不对称型氧化还原反应进行完全的条件及影响因素

    刘凯; 李冬霞; 彭敏


    以能斯特方程为基础,推导出不对称型氧化还原反应进行完全的判别式,并进一步探讨了影响该类反应进行完全的相关因素.对于给定的反应,主要受条件电动势和反应物浓度的影响.对主体物质微粒数减少的反应,宜在较高浓度下进行;反之,则宜在较低浓度下进行.%Discriminant for complete reaction in asymmetric redox reactions was deduced on the basis of Nernst equation, based on which a further exploration was made into the correlative factors that might affect the complete reaction of an asymmetric redox reaction. For a given reaction, the principal influences come from the conditional electromotive force and reactant concentrations; for reactions in which the particles of subjectival substance of the reaction decrease in number, the reactions are better conducted in high concentrations; otherwise, low concentrations are preferred.

  12. Penicillin allergy: anti-penicillin IgE antibodies and immediate hypersensitivity skin reactions employing major and minor determinants of penicillin.

    Chandra, R K; Joglekar, S A; Tomas, E


    300 children considered to have had adverse reactions to penicillin were examined. Informed consent was obtained from the parents. Skin tests were conducted by the scratch/prick and intradermal techniques, using benzylpenicilloyl polylysine conjugate and a mixture of minor determinants of penicillin. Specific anti-penicillin IgE antibodies were estimated by the radioallergosorbent test. There was a good correlation between the two methods. The overall frequency of positive tests was 19%. 11 children showed cutaneous reactivity only to the minor determinants mixture. Positive results were found more often in those with accelerated adverse reactions, particularly anaphylaxis, serum sickness, angio-oedema, or urticaria. The validity of penicillin-negative results was confirmed by drug challenge in 56 subjects, only 2 of whom showed a slight skin rash. Of 5 patients with positive tests, inadvertent administration of penicillin produced accelerated urticaria in all. 14 of 42 children with positive tests had lost hypersensitivity to penicillin one year later. In a separate group of 50 children with a history of adverse response to ampicillin, the overall frequency of positive tests was 12%; 38% showed evidence of recent E-B virus infection. It was concluded that penicillin allergy is often overdiagnosed. The diagnosis can be reliably confirmed by skin tests using major and minor determinants of benzylpenicillin and by the radioallergosorbent test; such hypersensitivity is not permanent.

  13. Employing CO2 as reaction medium for in-situ suppression of the formation of benzene derivatives and polycyclic aromatic hydrocarbons during pyrolysis of simulated municipal solid waste.

    Lee, Jechan; Choi, Dongho; Tsang, Yiu Fai; Oh, Jeong-Ik; Kwon, Eilhann E


    This study proposes a strategic principle to enhance the thermal efficiency of pyrolysis of municipal solid waste (MSW). An environmentally sound energy recovery platform was established by suppressing the formation of harmful organic compounds evolved from pyrolysis of MSW. Using CO2 as reaction medium/feedstock, CO generation was enhanced through the following: 1) expediting the thermal cracking of volatile organic carbons (VOCs) evolved from the thermal degradation of the MSWs and 2) directly reacting VOCs with CO2. This particular influence of CO2 on pyrolysis of the MSWs also led to the in-situ mitigation of harmful organic compounds (e.g., benzene derivatives and polycyclic aromatic hydrocarbons (PAHs)) considering that CO2 acted as a carbon scavenger to block reaction pathways toward benzenes and PAHs in pyrolysis. To understand the fundamental influence of CO2, simulated MSWs (i.e., various ratios of biomass to polymer) were used to avoid any complexities arising from the heterogeneous matrix of MSW. All experimental findings in this study suggested the foreseeable environmental application of CO2 to energy recovery from MSW together with disposal of MSW. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Tailoring Synthesis Conditions of Carbon Xerogels towards Their Utilization as Pt-Catalyst Supports for Oxygen Reduction Reaction (ORR

    María Jesús Lázaro


    Full Text Available Carbon xerogels characterized by different textural, structural and chemical properties were synthesized and used as supports for Pt catalysts for the application in polymer electrolyte fuel cells. Synthesis conditions were varied in order to synthesize carbon xerogels following the sol-gel method. These included the reactants ratio (precursor/formaldehyde, the catalyst concentration (precursor/catalyst ratio and type (basic and acid, the precursor type (resorcinol and pyrogallol and the solvent (aqueous or acetone based. Stoichiometric mixtures of resorcinol and formaldehyde yielded well polymerized gels and highly developed structures. Slow gelation, favored by the presence of acetone as solvent in the sol and low catalyst concentration, resulted in higher polymerization extent with a highly mesoporous or even macroporous texture and more ordered structure, as evidenced by XPS and Raman spectroscopy. Small Pt particles of ca. 3.5 nm were obtained by using carbon xerogels characterized by an ordered surface structure. The specific activity towards the oxygen reduction reaction, i.e., the limiting catalytic process in low temperature fuel cells, is significantly favored by highly ordered carbon xerogels due to a metal-support enhanced interaction. Nevertheless, surface defects favor the distribution of the metallic particles on the surface of carbon, which in the end influences the effectiveness of the catalyst. Accelerated degradation tests were conducted to evaluate catalyst stability under potential cycling conditions. The observed decay of performance was considerably lower for the catalysts based on ordered carbon xerogels stabilizing Pt particles in a higher extent than the other xerogels and the commercial carbon black support.

  15. CO2 Reaction with Hydrated Class H Well Cement under Geologic Sequestration Conditions: Effects of Flyash Admixtures

    Kutchko, Barbara G. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering; Strazisar, Brian R. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Huerta, Nicolas [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Univ. of Texas, Austin, TX (United States); Lowry, Gregory V. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering; Dzombak, David A. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering; Thaulow, Niels [RJ Lee Group, Inc., Monroeville, PA (United States)


    The rate and mechanism of reaction of pozzolan-amended Class H cement exposed to both supercritical CO2 and CO2-saturated brine were determined under geologic sequestration conditions to assess the potential impact of cement degradation in existing wells on CO2 storage integrity. The pozzolan additive chosen, Type F flyash, is the most common additive used in cements for well sealing in oil-gas field operations. The 35:65 and 65:35 (v/v) pozzolancement blends were exposed to supercritical CO2 and CO2-saturated brine and underwent cement carbonation. Extrapolation of the carbonation rate for the 35:65 case suggests a penetration depth of 170-180 mm far both the CO2-saturated brine and supercritical CO2 after 30 years. Despite alteration in both pozzolan systems, the reacted cement remained relatively impermeable to fluid flow after exposure to brine solution saturated with CO2, with values well below the American Petroleum Institute recommended maximum well cement permeability of 200 mu D. Analyses of 50:50 pozzolan-cement cores from a production well in a sandstone reservoir exhibited carbonation and low permeability to brine solution saturated with CO2, which are consistent with our laboratory findings.

  16. CO{sub 2} reaction with hydrated class H well cement under geologic sequestration conditions: effects of flyash admixtures

    Barbara G. Kutchko; Brian R. Strazisar; Nicolas Huerta; Gregory V. Lowry; David A. Dzombak; Niels Thaulow [United States Department of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory


    The rate and mechanism of reaction of pozzolan-amended Class H cement exposed to both supercritical CO{sub 2} and CO{sub 2}-saturated brine were determined under geologic sequestration conditions to assess the potential impact of cement degradation in existing wells on CO{sub 2} storage integrity. The pozzolan additive chosen, Type F flyash, a by-product of coal combustion, is the most common additive used in cements for well sealing in oil-gas field operations. The 35:65 and 65:35 (v/v) pozzolan-cement blends were exposed to supercritical CO{sub 2} and CO{sub 2}-saturated brine and underwent cement carbonation. Extrapolation of the carbonation rate for the 35:65 case suggests a penetration depth of 170-180 mm for both the CO{sub 2}-saturated brine and supercritical CO{sub 2} after 30 years. Despite alteration in both pozzolan systems, the reacted cement remained relatively impermeable to fluid flow after exposure to brine solution saturated with CO{sub 2}, with values well below the American Petroleum Institute recommended maximum well cement permeability of 200 {mu}D. Analyses of 50:50 pozzolan-cement cores from a production well in a sandstone reservoir exhibited carbonation and low permeability to brine solution saturated with CO{sub 2}, which are consistent with our laboratory findings. 16 refs., 4 figs., 1 tab.

  17. CO2 reaction with hydrated class H well cement under geologic sequestration conditions: effects of flyash admixtures.

    Kutchko, Barbara G; Strazisar, Brian R; Huerta, Nicolas; Lowry, Gregory V; Dzombak, David A; Thaulow, Niels


    The rate and mechanism of reaction of pozzolan-amended Class H cement exposed to both supercritical CO2 and CO2-saturated brine were determined under geologic sequestration conditions to assess the potential impact of cement degradation in existing, wells on CO2 storage integrity. The pozzolan additive chosen, Type F flyash, is the most common additive used in cements for well sealing in oil-gas field operations. The 35:65 and 65:35 (v/v) pozzolan-cement blends were exposed to supercritical CO2 and CO2-saturated brine and underwent cement carbonation. Extrapolation of the carbonation rate for the 35:65 case suggests a penetration depth of 170-180 mm for both the CO2-saturated brine and supercritical CO2 after 30 years. Despite alteration in both pozzolan systems, the reacted cement remained relatively impermeable to fluid flow after exposure to brine solution saturated with CO2, with values well below the American Petroleum Institute recommended maximum well cement permeability of 200 microD. Analyses of 50: 50 pozzolan-cement cores from a production well in a sandstone reservoir exhibited carbonation and low permeability to brine solution saturated with CO2, which are consistent with our laboratory findings.

  18. Synthesis of different-sized silver nanoparticles by simply varying reaction conditions with leaf extracts of Bauhinia variegata L.

    Kumar, V; Yadav, S K


    Green synthesis of nanoparticles is one of the crucial requirements in today's climate change scenario all over the world. In view of this, leaf extract (LE) of Bauhinia variegata L. possessing strong antidiabetic and antibacterial properties has been used to synthesise silver nanoparticles (SNP) in a controlled manner. Various-sized SNP (20-120 nm) were synthesised by varying incubation temperature, silver nitrate and LE concentrations. The rate of SNP synthesis and their size increased with increase in AgNO(3) concentration up to 4 mM. With increase in LE concentration, size and aggregation of SNP was increased. The size and aggregation of SNP were also increased at temperatures above and below 40°C. This has suggested that size and dispersion of SNP can be controlled by varying reaction components and conditions. Polarity-based fractionation of B. variegata LE has suggested that only water-soluble fraction is responsible for SNP synthesis. Fourier transform infrared spectroscopy analysis revealed the attachment of polyphenolic and carbohydrate moieties to SNP. The synthesised SNPs were found stable in double distilled water, BSA and phosphate buffer (pH 7.4). On the contrary, incubation of SNP with NaCl induced aggregation. This suggests the safe use of SNP for various in vivo applications.

  19. Structural Evolution under Reaction Conditions of Supported (NH43HPMo11VO40 Catalysts for the Selective Oxidation of Isobutane

    Fangli Jing


    Full Text Available When using heteropolycompounds in the selective oxidation of isobutane to methacrolein and methacrylic acid, both the keeping of the primary structure (Keggin units and the presence of acidic sites are necessary to obtain the desired products. The structural evolution of supported (NH43HPMo11VO40 (APMV catalysts under preliminary thermal oxidizing and reducing treatments was investigated. Various techniques, such as TGA/DTG (Thermo-Gravimetric Analysis/Derivative Thermo-Gravimetry, H2-TPR (Temperature Programed Reduction, in situ XRD (X-Ray Diffraction and XPS (X-ray Photoelectron Spectroscopy, were applied. It was clearly evidenced that the thermal stability and the reducibility of the Keggin units are improved by supporting 40% APMV active phase on Cs3PMo12O40 (CPM. The partial degradation of APMV takes place depending on temperature and reaction conditions. The decomposition of ammonium cations (releasing NH3 leads to the formation of vacancies favoring cationic exchanges between vanadium coming from the active phase and cesium coming from the support. In addition, the vanadium expelled from the Keggin structure is further reduced to V4+, species, which contributes (with Mo5+ to activate isobutane. The increase in reducibility of the supported catalyst is assumed to improve the catalytic performance in comparison with those of unsupported APMV.

  20. Reference genes for quantitative real-time polymerase chain reaction studies in soybean plants under hypoxic conditions.

    Nakayama, T J; Rodrigues, F A; Neumaier, N; Marcelino-Guimarães, F C; Farias, J R B; de Oliveira, M C N; Borém, A; de Oliveira, A C B; Emygdio, B M; Nepomuceno, A L


    Quantitative real-time polymerase chain reaction (RT-qPCR) is a powerful tool used to measure gene expression. However, because of its high sensitivity, the method is strongly influenced by the quality and concentration of the template cDNA and by the amplification efficiency. Relative quantification is an effective strategy for correcting random and systematic errors by using the expression level of reference gene(s) to normalize the expression level of the genes of interest. To identify soybean reference genes for use in studies of flooding stress, we compared 5 candidate reference genes (CRGs) with the NormFinder and GeNorm programs to select the best internal control. The expression stability of the CRGs was evaluated in root tissues from soybean plants subjected to hypoxic conditions. Elongation factor 1-beta and actin-11 were identified as the most appropriate genes for RT-qPCR normalization by both the NormFinder and GeNorm analyses. The expression profiles of the genes for alcohol dehydrogenase 1, sucrose synthase 4, and ascorbate peroxidase 2 were analyzed by comparing different normalizing combinations (including no normalization) of the selected reference genes. Here, we have identified potential genes for use as references for RT-qPCR normalization in experiments with soybean roots growing in O2-depleted environments, such as flooding-stressed plants.

  1. Agency employment

    Tomčíková, Ilona


    - Agency Employment For my thesis topic, I have chosen "Agency Employment". It's a relatively young institute, which was incorporated into our legal system only on October 1st, 2004. I believe that Agency Employment topic can be always considered current and positive, because it allows us to flexibly react to the needs of the job market. Since the topic is very broad, the goal of this paper is not a detailed analysis of all aspects of this institute, but only a few of them that I consider to ...

  2. Poly(vinyl chloride)-supported Pd(II) complex as an efficient catalyst for Heck and Cu-free Sonogashira reactions under aerobic conditions

    Mohammad Bakherad; Ali Keivanloo; Shahrzad Samangooei


    A novel poly(vinyl chloride)-supported Pd complex was found to be a highly active catalyst for the Heck and Sonogashira reactions of aryl halides under aerobic conditions. The complex is thermally stable, and can be easily recovered and reused. The catalyst was recycled for the Heck and So-nogashira reactions for five runs without appreciable loss of its catalytic activity, and with negligible metal leaching.

  3. An Unexpected Green and Facile Synthesis of 2,6-Diaryl-4-styrylpyridines via Multi-component Reactions in Microwave-assisted Solvent-free Conditions

    SHI Feng; ZHANG Ge; ZHOU Dianxiang; MA Ning; ZHANG Yajie; CHEN Rongshun; TU Shujiang


    An unexpected green and facile synthesis of 2,6-diaryl-4-styryipyridines was realized via microwave-assisted multi-component reactions of 3-arylacrylaldehyde oximes,l-arylethanones and ammonium acetate in solvent-free conditions.This protocol has the prominent advantages of environmental-friendliness,short reaction time,high yields,low cost,easy operation as well as broad scope of applicability.

  4. Effects of reaction conditions on hydrogen production and carbon nanofiber properties generated by methane decomposition in a fixed bed reactor using a NiCuAl catalyst

    Suelves, I.; Pinilla, J.L.; Lazaro, M.J.; Moliner, R. [Instituto de Carboquimica CSIC, Miguel Luesma Castan, 4, 50015 Zaragoza (Spain); Palacios, J.M. [Instituto de Catalisis y Petroleoquimica, CSIC, Cantoblanco, Marie Curie 2, 28049 Madrid (Spain)


    In this paper, the results obtained in the catalytic decomposition of methane in a fixed bed reactor using a NiCuAl catalyst prepared by the fusion method are presented. The influences of reaction temperature and space velocity on hydrogen concentration in the outlet gases, as well as on the properties of the carbon produced, have been investigated. Reaction temperature and the space velocity both increase the reaction rate of methane decomposition, but also cause an increase in the rate of catalyst deactivation. Under the operating conditions used, the carbon product is mainly deposited as nanofibers with textural properties highly correlated with the degree of crystallinity. (author)

  5. Optimization of reaction conditions to fabricate nano-silver using Couroupita guianensis Aubl. (leaf & fruit) and its enhanced larvicidal effect

    Vimala, R. T. V.; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal


    Currently bioactive principles of plants and their nanoproducts have been extensively studied in agriculture and medicine. In this study Couroupita guianensis Aubl. leaf and fruit extracts were selected for rapid and cost-effective synthesis of silver nanoparticles (leaf-LAgNPs and fruit-FAgNPs). Various physiological conditions such as temperature, pH, concentration of metal ions, stoichiometric proportion of reaction mixture and reaction time showed influence on the size, dispersity and synthesis rate of AgNPs. Generation of AgNPs was initially confirmed with the surface plasmon vibrations at 420 nm in UV-visible spectrophotometer. The results recorded from X-ray diffractometer (XRD) and Transmission electron microscope (TEM) supports the biosynthesis of cubic crystalline LAgNPs & FAgNPs with the size ranges between 10-45 nm and 5-15 nm respectively. Surface chemistry of synthesized AgNPs was studied with Fourier transform infrared spectroscopy (FTIR), it reveals that water soluble phenolic compounds present in the extracts act as reducing and stabilizing agent. Leaf, fruit extracts and synthesized AgNPs were evaluated against IV instar larvae of Aedes aegypti (Diptera; Culicidae). Furthermore, different extracts and synthesized AgNPs showed dose dependent larvicidal effect against A. aegypti after 24 h of treatment. Compare to all extracts such as ethyl acetate (leaf; LC50 - 44.55 ppm and LC90 - 318.39 ppm & fruit; LC50 - 49.96 ppm and LC90 - 568.84 ppm respectively) and Methanol (leaf; LC50 - 85.75 ppm and LC90 - 598.63 ppm & fruit; LC50 - 67.78 ppm and LC90 - 714.45 ppm respectively) synthesized AgNPs showed extensive mortality rate (LAgNPs; LC50 - 2.1 ppm and LC90 - 5.59 ppm & FAgNPs; LC50 - 2.09 ppm and LC90 - 5.7 ppm). Hence, this study proves that C. guianensis is a potential bioresource for stable, reproducible nanoparticle synthesis (AgNPs) and also can be used as an efficient mosquito control agent.

  6. Determining the conditions for changes of the three-phase reaction type in a V‒Zr‒Cr system

    Lutsyk, V. I.; Vorob'eva, V. P.; Shodorova, S. Ya.


    A 3D computer model of the T- x- y diagram for a V-Zr-Cr system is constructed, in which the possibilities of both two- and three-polymorphic modifications of compound ZrCr2 participating in invariant reactions is considered. The temperature and concentration borders of eutectic-peritectic transitions in the three-phase regions on the corresponding surfaces of two-phase reactions are determined (upon degeneration of a three-phase reaction into a two-phase reaction in the presence of the third phase).

  7. Recycling of plastic materials employing zeolite and MCM-41 materials

    Ortega, D.; L. Noreña; Aguilar, J; I. Hernández; Ramírez, V.


    We report on the catalytic and the thermal decomposition of low density polyethylene resulting in several fuel products (LP gas, gasoline, gas oil). We built a continuos, fixed-bed reaction system. We employed Ga-MCM-41, Al-MCM-41, commercial FCC Y zeolite (fresh and equilibrium) and natural mordenite as catalysts. We set the following reaction conditions: 450 °C reaction temperature, constant feed flow and 30 min reaction time at atmospheric pressure. We analyzed the gas and liquid products ...

  8. conditions

    M. Venkatesulu


    Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.

  9. β-Alanine-DBU" A Highly Efficient Catalytic System forKnoevenageI-Doebner Reaction under Mild Conditionsβ-Alanine-DBU" A Highly Efficient Catalytic System forKnoevenageI-Doebner Reaction under Mild Conditions

    祝令建; 雷宁; 缪震元; 盛春泉; 庄春林; 姚建忠; 张万年


    A mild and efficient Knoevenagel-Doebner reaction from malonic acid and a wide range of aldehydes was catalyzed by a catalytic system consisting offlalanine and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), affording the corresponding (E)-a,fl-unsaturated carboxylic acids in good to excellent yields and with high stereoselectivity. The advantage of the method is that the reaction could proceed smoothly at ambient temperature so that it can tolerate a variety of functional groups and avoid unnecessary side reactions.

  10. Reactions of sulfur- and phosphorus-substituted fluoroalkylating silicon reagents with imines and enamines under acidic conditions.

    Kosobokov, Mikhail D; Dilman, Alexander D; Struchkova, Marina I; Belyakov, Pavel A; Hu, Jinbo


    Nucleophilic fluoroalkylation reactions of imines and enamines with α-phenylthio, α-phenylsulfonyl, and α-diethylphosphoryl substituted fluorinated silanes have been investigated. The reactions are promoted by hydrofluoric acid generated in situ from potassium hydrodifluoride and trifluoroacetic acid. Sulfur reagents worked well with both imines and enamines, whereas phosphorus reagent efficiently coupled only with enamines.

  11. Employer Branding

    Frimann, Søren; Mønsted, Bolette Rye


    Employer branding er både for den private og den offentlige sektor blevet en måde, de kan imødekomme ændrede arbejdsmarkedsvilkår og organisatoriske udfordringer i en postmoderne og globaliseret verden. Den aktuelle finanskrise har skabt nye udfordringer for organisationer i deres bestræbelser på...... at tiltrække- og fastholde attraktive medarbejdere. Men hvilken betydning har det, når Grundfos siger ”Mennesket er i fokus”, og hvad siger ”mangfoldighed” om Københavns Kommune som arbejdsplads i relation til employer branding? Er der egentlig sammenhæng mellem tankerne bag employer branding og de eksternt...... kommunikerede employer brandprodukter. Eller bliver det unikke ved arbejdspladserne ersattet af buzzwords uden substans og inddragelse af ansatte og interessenter? Artiklen har til formål at vurdere disse spørgsmål på baggrund af analyser af to cases med employer branding....

  12. Employer Branding

    Frimann, Søren; Mønsted, Bolette Rye


    Employer branding er både for den private og den offentlige sektor blevet en måde, de kan imødekomme ændrede arbejdsmarkedsvilkår og organisatoriske udfordringer i en postmoderne og globaliseret verden. Den aktuelle finanskrise har skabt nye udfordringer for organisationer i deres bestræbelser på...... at tiltrække- og fastholde attraktive medarbejdere. Men hvilken betydning har det, når Grundfos siger ”Mennesket er i fokus”, og hvad siger ”mangfoldighed” om Københavns Kommune som arbejdsplads i relation til employer branding? Er der egentlig sammenhæng mellem tankerne bag employer branding og de eksternt...... kommunikerede employer brandprodukter. Eller bliver det unikke ved arbejdspladserne ersattet af buzzwords uden substans og inddragelse af ansatte og interessenter? Artiklen har til formål at vurdere disse spørgsmål på baggrund af analyser af to cases med employer branding....

  13. Molecular studies of model surfaces of metals from single crystals to nanoparticles under catalytic reaction conditions. Evolution from prenatal and postmortem studies of catalysts.

    Somorjai, Gabor A; Aliaga, Cesar


    Molecular level studies of metal crystal and nanoparticle surfaces under catalytic reaction conditions at ambient pressures during turnover were made possible by the use of instruments developed at the University of California at Berkeley. Sum frequency generation vibrational spectroscopy (SFGVS), owing to its surface specificity and sensitivity, is able to identify the vibrational features of adsorbed monolayers of molecules. We identified reaction intermediates, different from reactants and products, under reaction conditions and for multipath reactions on metal single crystals and nanoparticles of varying size and shape. The high-pressure scanning tunneling microscope (HP-STM) revealed the dynamics of a catalytically active metallic surface by detecting the mobility of the adsorbed species during catalytic turnover. It also demonstrated the reversible and adsorbate-driven surface restructuring of platinum when exposed to molecules such as CO and ethylene. Ambient pressure X-ray photoelectron spectroscopy (AP-XPS) detected the reversible changes of surface composition in rhodium-palladium, platinum-palladium, and other bimetallic nanoparticles as the reactant atmosphere changed from oxidizing to reducing. It was found that metal nanoparticles of less than 2 nm in size are present in higher oxidation states, which alters and enhances their catalytic activity. The catalytic nanodiode (CND) confirmed that a catalytic reaction-induced current flow exists at oxide-metal interfaces, which correlates well with the reaction turnover.

  14. Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

    Klaas Mennecke


    Full Text Available The preparation of monolithic polyionic supports which serve as efficient heterogeneous supports for palladium(0 nanoparticles is described. These functionalized polymers were incorporated inside a flow reactor and employed in Suzuki–Miyaura and Heck cross couplings under continuous flow conditions.

  15. Synthesis of New Pentacyclo[,6.03,10.05,9]undecane-8,11-dione (PCU Cyanosilylated Derivatives Using Sulphated Zirconia and Hydrotalcite as Catalysts in Microwave-Assisted Reactions under Solvent Free Conditions

    Juan Navarrete-Bolaños


    Full Text Available A comparison was made of the effectiveness of the functionalization reactions of pentacyclo[,6.03,10.05,9]undecane-8,11-dione (PCU using sulphated zirconia in protection-deprotection reactions and Mg/Al hydrotalcite in a cyanosilylation reaction, under classical thermal conditions and imposing microwave radiation; improved yields and reaction times were considered.

  16. Determination of the in vivo NAD:NADH ratio in Saccharomyces cerevisiae under anaerobic conditions, using alcohol dehydrogenase as sensor reaction.

    Bekers, K M; Heijnen, J J; van Gulik, W M


    With the current quantitative metabolomics techniques, only whole-cell concentrations of NAD and NADH can be quantified. These measurements cannot provide information on the in vivo redox state of the cells, which is determined by the ratio of the free forms only. In this work we quantified free NAD:NADH ratios in yeast under anaerobic conditions, using alcohol dehydrogenase (ADH) and the lumped reaction of glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase as sensor reactions. We showed that, with an alternative accurate acetaldehyde determination method, based on rapid sampling, instantaneous derivatization with 2,4 diaminophenol hydrazine (DNPH) and quantification with HPLC, the ADH-catalysed oxidation of ethanol to acetaldehyde can be applied as a relatively fast and simple sensor reaction to quantify the free NAD:NADH ratio under anaerobic conditions. We evaluated the applicability of ADH as a sensor reaction in the yeast Saccharomyces cerevisiae, grown in anaerobic glucose-limited chemostats under steady-state and dynamic conditions. The results found in this study showed that the cytosolic redox status (NAD:NADH ratio) of yeast is at least one order of magnitude lower, and is thus much more reduced, under anaerobic conditions compared to aerobic glucose-limited steady-state conditions. The more reduced state of the cytosol under anaerobic conditions has major implications for (central) metabolism. Accurate determination of the free NAD:NADH ratio is therefore of importance for the unravelling of in vivo enzyme kinetics and to judge accurately the thermodynamic reversibility of each redox reaction.

  17. Effect of reaction conditions and kinetic study on the Fischer-Tropsch synthesis over fused Co-Ni/Al2 O3 catalyst

    P.Nikparsa; A.A Mirzaei; H.Atashi


    Co-Ni/Al2O3 catalyst was prepared by the fusion method and used in Fischer-Tropsch synthesis (FTS). The catalysts were characterized by means of nitrogen sorption and scanning electron microscopy. The effect of some reaction conditions such as temperature, pressure and H2/CO feed ratio on the catalytic performance of Co-Ni/Al2O3 in CO hydrogenation was investigated in a fixed-bed reactor. The results indicate that the optimum reaction conditions are 250℃, 0. 3 MPa, H2/CO feed ratio of 2. 0, and GHSV of 3 000 h-1 . Kinetically, the reaction rate was correlated with the Langmuir-Hinshelwood-Hougen-Watson type models. The activation energy for the best fitted model is 88. 41 kJ/mol, suggesting that the intra-particle mass transport is not significant.

  18. The catalytic effect of water, water dimers and water trimers on H2S + (3)O2 formation by the HO2 + HS reaction under tropospheric conditions.

    Zhang, Tianlei; Yang, Chen; Feng, Xukai; Kang, Jiaxin; Song, Liang; Lu, Yousong; Wang, Zhiyin; Xu, Qiong; Wang, Wenliang; Wang, Zhuqing


    In this article, the reaction mechanisms of H2S + (3)O2 formation by the HO2 + HS reaction without and with catalyst X (X = H2O, (H2O)2 and (H2O)3) have been investigated theoretically at the CCSD(T)/6-311++G(3df,2pd)//B3LYP/6-311+G(2df,2p) level of theory, coupled with rate constant calculations by using conventional transition state theory. Our results show that in the presence of catalyst X (X = H2O, (H2O)2 and (H2O)3) into the channel of H2S + (3)O2 formation, the reactions between the SH radical and HO2(H2O)n (n = 1-3) complexes are more favorable than the corresponding reactions of the HO2 radical with HS(H2O)n (n = 1-3) complexes due to the lower barrier of the former reactions and the higher concentrations of HO2(H2O)n (n = 1-3) complexes. Meanwhile, the catalytic effect of water, water dimers and water trimers is mainly taken from the contribution of a single water vapor molecule, since the total effective rate constant of HO2H2O + HS and H2OHO2 + HS reactions was, respectively, larger by 7-9 and 9-12 orders of magnitude than that of SH + HO2(H2O)2 and SH + HO2(H2O)3 reactions. Besides, the enhancement factor of water vapor is only 0.37% at 240 K, while at high temperatures, such as 425 K, the positive water vapor effect is enhanced up to 38.00%, indicating that at high temperatures the positive water effect is obvious under atmospheric conditions. Overall, these results show how water and water clusters catalyze the gas phase reactions under atmospheric conditions.


    Microwave-assisted reaction of 2'-hydroxychalcones in the presence of DBU resulted in the formation of hitherto unknown dimers by conjugate addition of the intermediate cyclic ketone to the starting enone.

  20. Primers and polymerase chain reaction conditions for DNA barcoding teleost fish based on the mitochondrial cytochrome b and nuclear rhodopsin genes

    Sevilla, R.G.; Diez, A.; Noren, M.; Mouchel, O.; Jerome, M.; Verrez-Bagnis, V.; Pelt-Heerschap, van H.M.L.


    This report describes a set of 21 polymerase chain reaction primers and amplification conditions developed to barcode practically any teleost fish species according to their mitochondrial cytochrome b and nuclear rhodopsin gene sequences. The method was successfully tested in more than 200 marine

  1. Highly efficient synthesis of β-amino esters via Mannich-type reaction under solvent-free conditions using ZnCl2 catalyst

    Xue Ming Chen; Xing Shu Li; Albert S.C. Chan


    β-Amino esters were synthesized via ZnCl2-catalyzed Mannich-type reaction of imines and malonate esters under solvent-free conditions in 6 min.The β-amino ester was converted into the corresponding aspartic acid derivatives.

  2. Primers and polymerase chain reaction conditions for DNA barcoding teleost fish based on the mitochondrial cytochrome b and nuclear rhodopsin genes

    Sevilla, R.G.; Diez, A.; Noren, M.; Mouchel, O.; Jerome, M.; Verrez-Bagnis, V.; Pelt-Heerschap, van H.M.L.


    This report describes a set of 21 polymerase chain reaction primers and amplification conditions developed to barcode practically any teleost fish species according to their mitochondrial cytochrome b and nuclear rhodopsin gene sequences. The method was successfully tested in more than 200 marine fi

  3. Synthesis of 1-amidoalkyl-2-naphthols based on a three-component reaction catalyzed by boric acid as a solid heterogeneous catalyst under solvent-free conditions

    Zahed Karimi-Jaberi


    Full Text Available An efficient method for the preparation of 1-amidoalkyl-2-naphthols has been described using a multi-component, one-pot condensation reaction of 2-naphthol, aldehydes and amides in the presence of boric acid under solvent-free conditions.DOI:

  4. CO oxidation on PtSn nanoparticle catalysts occurs at the interface of Pt and Sn oxide domains formed under reaction conditions

    Michalak, William D.


    The barrier to CO oxidation on Pt catalysts is the strongly bound adsorbed CO, which inhibits O2 adsorption and hinders CO2 formation. Using reaction studies and in situ X-ray spectroscopy with colloidally prepared, monodisperse ∼2 nm Pt and PtSn nanoparticle catalysts, we show that the addition of Sn to Pt provides distinctly different reaction sites and a more efficient reaction mechanism for CO oxidation compared to pure Pt catalysts. To probe the influence of Sn, we intentionally poisoned the Pt component of the nanoparticle catalysts using a CO-rich atmosphere. With a reaction environment comprised of 100 Torr CO and 40 Torr O2 and a temperature range between 200 and 300 C, Pt and PtSn catalysts exhibited activation barriers for CO2 formation of 133 kJ/mol and 35 kJ/mol, respectively. While pure Sn is readily oxidized and is not active for CO oxidation, the addition of Sn to Pt provides an active site for O2 adsorption that is important when Pt is covered with CO. Sn oxide was identified as the active Sn species under reaction conditions by in situ ambient pressure X-ray photoelectron spectroscopy measurements. While chemical signatures of Pt and Sn indicated intermixed metallic components under reducing conditions, Pt and Sn were found to reversibly separate into isolated domains of Pt and oxidic Sn on the nanoparticle surface under reaction conditions of 100 mTorr CO and 40 mTorr O2 between temperatures of 200-275 C. Under these conditions, PtSn catalysts exhibited apparent reaction orders in O2 for CO 2 production that were 0.5 and lower with increasing partial pressures. These reaction orders contrast the first-order dependence in O 2 known for pure Pt. The differences in activation barriers, non-first-order dependence in O2, and the presence of a partially oxidized Sn indicate that the enhanced activity is due to a reaction mechanism that occurs at a Pt/Sn oxide interface present at the nanoparticle surface. © 2014 Published by Elsevier Inc.

  5. Unsteady MHD Mixed Convection Slip Flow of Casson Fluid over Nonlinearly Stretching Sheet Embedded in a Porous Medium with Chemical Reaction, Thermal Radiation, Heat Generation/Absorption and Convective Boundary Conditions.

    Ullah, Imran; Bhattacharyya, Krishnendu; Shafie, Sharidan; Khan, Ilyas


    Numerical results are presented for the effect of first order chemical reaction and thermal radiation on mixed convection flow of Casson fluid in the presence of magnetic field. The flow is generated due to unsteady nonlinearly stretching sheet placed inside a porous medium. Convective conditions on wall temperature and wall concentration are also employed in the investigation. The governing partial differential equations are converted to ordinary differential equations using suitable transformations and then solved numerically via Keller-box method. It is noticed that fluid velocity rises with increase in radiation parameter in the case of assisting flow and is opposite in the case of opposing fluid while radiation parameter has no effect on fluid velocity in the forced convection. It is also seen that fluid velocity and concentration enhances in the case of generative chemical reaction whereas both profiles reduces in the case of destructive chemical reaction. Further, increase in local unsteadiness parameter reduces fluid velocity, temperature and concentration. Over all the effects of physical parameters on fluid velocity, temperature and concentration distribution as well as on the wall shear stress, heat and mass transfer rates are discussed in detail.

  6. A two-step reaction scheme leading to singlet carbene species that can be detected under matrix conditions for the reaction of Zr(3F) with either CH3F or CH3CN.

    Torres, Ana E; Castro, Guadalupe; Pablo-Pedro, Ricardo; Colmenares, Fernando


    The results obtained from CASSCF-MRMP2 calculations are used to rationalize the singlet complexes detected under matrix-isolation conditions for the reactions of laser-ablated Zr((3)F) atoms with the CH3F and CH3CN molecules, without invoking intersystem crossings between electronic states with different multiplicities. The reaction Zr((3)F) + CH3 F evolves to the radical products ZrF· + ·CH3. This radical asymptote is degenerate to that emerging from the singlet channel of the reactants Zr((1)D) + CH3 F because they both exhibit the same electronic configuration in the metal fragment. Hence, the caged radicals obtained under cryogenic-matrix conditions can recombine through triplet and singlet paths. The recombination of the radical species along the low-multiplicity channel produces the inserted structures H3C-Zr-F and H2C=ZrHF experimentally detected. For the Zr((3)F) + CH3 CN reaction, a similar two-step reaction scheme involving the radical fragments ZrNC· + ·CH3 explains the presence of the singlet complexes H C-Zr-NC and H2 C=Zr(H)NC revealed in the IR-matrix spectra upon UV irradiation.

  7. Universal reaction mechanism of boronic acids with diols in aqueous solution: kinetics and the basic concept of a conditional formation constant.

    Furikado, Yuki; Nagahata, Tomomi; Okamoto, Takuya; Sugaya, Tomoaki; Iwatsuki, Satoshi; Inamo, Masahiko; Takagi, Hideo D; Odani, Akira; Ishihara, Koji


    To establish a detailed reaction mechanism for the condensation between a boronic acid, RB(OH)2, and a diol, H2L, in aqueous solution, the acid dissociation constants (Ka(BL)) of boronic acid diol esters (HBLs) were determined based on the well-established concept of conditional formation constants of metal complexes. The pKa values of HBLs were 2.30, 2.77, and 2.00 for the reaction systems, 2,4-difluorophenylboronic acid and chromotropic acid, 3-nitrophenylboronic acid and alizarin red S, and phenylboronic acid and alizarin red S, respectively. A general and precise reaction mechanism of RB(OH)2 with H2L in aqueous solution, which can serve as a universal reaction mechanism for RB(OH)2 and H2L, was proposed on the basis of (a) the relative kinetic reactivities of the RB(OH)2 and its conjugate base, that is, the boronate ion, toward H2L, and (b) the determined pKa values of HBLs. The use of the conditional formation constant, K', based on the main reaction: RB(OH)2 + H2L (K1)⇌ RB(L)(OH)(-) + H3O(+) instead of the binding constant has been proposed for the general reaction of uncomplexed boronic acid species (B') with uncomplexed diol species (L') to form boronic acid diol complex species (esters, BL') in aqueous solution at pH 5-11: B' + L' (K')⇌ BL'. The proposed reaction mechanism explains perfectly the formation of boronic acid diol ester in aqueous solution. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Temperature waves in chemical reaction-diffusion-heat conduction systems with two ends respectively subject to Dirichlet and no-flux conditions


    Taking the Lindemann model as a sample system in which there exist chemical reactions, diffusion and heat conduction, we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous two-variable system with one end subject to Dirichlet conditions, while the other end no-flux conditions. Furthermore, the conditions for the emergence of temperature waves are found out by the linear stabiliy analysis and verified by a diagram for successive steps of evolution of spatial profile of temperature during a period that is plotted by numerical simulations on a computer. Without doubt, these results are in favor of the heat balance in chemical reactor designs.

  9. In situ monitoring of the acetylene decomposition and gas temperature at reaction conditions for the deposition of carbon nanotubes using linear Raman scattering.

    Reinhold-López, Karla; Braeuer, Andreas; Popovska, Nadejda; Leipertz, Alfred


    To understand the reaction mechanisms taking place by growing carbon nanotubes via the catalytic chemical vapor deposition process, a strategy to monitor in situ the gas phase at reaction conditions was developed applying linear Raman spectroscopy. The simultaneous determination of the gas temperature and composition was possible by a new strategy of the evaluation of the Raman spectra. In agreement to the well-known exothermic decomposition of acetylene, a gas temperature increase was quantified when acetylene was added to the incident flow. Information about exhaust gas recirculation and location of the maximal acetylene conversion was derived from the composition measurements.

  10. Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

    Hai Yang Liu; Kun Wang; Hai Yan Fu; Mao Lin Yuan; Hua Chen; Rui Xiang Li


    Amide, which is derived from proline and is inexpensive and air-stable, has been synthesized and characterized by 1H NMR,13C NMR, and MS. It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction. In the Pd/amide catalytic system, aryl bromides can be coupled with phenylboronic acid in ethanol/water (1:2;v/v) in excellent yields even with a low Pd loading of 0.01 mol%. Moreover, the scope of the reaction is broad, and a wide variety of functional groups are tolerant.

  11. A reaction cell with sample laser heating for in situ soft X-ray absorption spectroscopy studies under environmental conditions.

    Escudero, Carlos; Jiang, Peng; Pach, Elzbieta; Borondics, Ferenc; West, Mark W; Tuxen, Anders; Chintapalli, Mahati; Carenco, Sophie; Guo, Jinghua; Salmeron, Miquel


    A miniature (1 ml volume) reaction cell with transparent X-ray windows and laser heating of the sample has been designed to conduct X-ray absorption spectroscopy studies of materials in the presence of gases at atmospheric pressures. Heating by laser solves the problems associated with the presence of reactive gases interacting with hot filaments used in resistive heating methods. It also facilitates collection of a small total electron yield signal by eliminating interference with heating current leakage and ground loops. The excellent operation of the cell is demonstrated with examples of CO and H2 Fischer-Tropsch reactions on Co nanoparticles.

  12. How Pragmatic Interpretations Arise from Conditionals: Profiling the Affirmation of the Consequent Argument with Reaction Time and EEG Measures

    Bonnefond, Mathilde; Van der Henst, Jean-Baptiste; Gougain, Marion; Robic, Suzanne; Olsen, Matthew D.; Weiss, Oshri; Noveck, Ira


    Conditional reasoning consists in combining a conditional premise with a categorical premise and inferring a conclusion from them. Two well-known conditional arguments are Modus Ponens (MP: "If P then Q; P//"therefore Q), which is logically valid and Affirmation of the Consequent (AC: "If P then Q; Q//"therefore "P"), which is not. The latter is…

  13. Reaction and transport in wellbore interfaces under CO2 storage conditions: Experiments simulating debonded cement-casing interfaces

    Wolterbeek, T.K.T.; Peach, C.J.; Spiers, C.J.


    Debonding-defects at the interfaces between wellbore casing and cement are widely recognized as providing potential pathways for CO2 escape from geological storage systems. This study addresses how chemical reaction between CO2, cement and steel may affect the transport properties of such defects un


    The use of coliform plate count data to assess stream sanitary and ecological condition is limited by the need to store samples at 4oC and analyze them within a 24-hour period. We are testing LH-PCR as an alternative tool to assess the bacterial load of streams, offering a cost ...

  15. Irregular response of nanofluid flow subject to chemical reaction and shape parameter in the presence of variable stream conditions

    R. Kandasamy


    Full Text Available The problem of boundary layer of nanofluid flow which results from the stretching of a flat surface has been investigated numerically. The model includes the effects of Brownian motion, magnetic effect, non-linear velocity, variable thickness, thermophoresis, chemical reaction, porous medium, shape, thickness and heat source. The Partial differential equations are converted to ordinary deferential equations to solve analytically using shooting technique. The velocity, temperature and concentration profiles are discussed in detail for all parameters.

  16. Highly efficient oxidation of alcohols using Oxone(R) as oxidant catalyzed by ruthenium complex under mild reaction conditions

    Zi Qiang Lei; Jian Qiang Wang; Peng Hua Yan


    Aromatic and alkyl alcohols were oxidized to the corresponding aldehydes or ketones at room temperature with high conversion and selectivity using Oxone (2KHSO5·KHSO4·K2SO4) as oxidant catalyzed by ruthenium complex Quin-Ru-Quin (where Quin = 8-hydroxyquinoline). The reaction time is very short and the preparation of complex is simple. 2008 Zi Qiang Lei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  17. Effect of calcination temperature and reaction conditions on methane partial oxidation using lanthanum-based perovskite as oxygen donor

    DAI Xiaoping; YU Changchun; LI Ranjia; WU Qiong; SHI Kaijiao; HAO Zhengping


    We investigated the effect of calcination temperature, reaction temperature, and different amounts of replenished lattice oxygen on the partial oxidation of methane (POM) to synthesis gas using perovskite-type LaFeO3 oxide as oxygen donor instead of gaseous oxygen, which was prepared by the sol-gel method, and the oxides were characterized by XRD, TG/DTA, and BET. The results indicated that the particle size increased with the calcination temperature increasing, while BET and CH4 conversion declined with the calcination temperature increasing using LaFeO3 oxide as oxygen donor in the absence of gaseous oxygen. CO selectivity remained at a high level such as above 92%, and increased slightly as the calcination temperature increased. Exposure of LaFeO3 oxides to methane atmosphere enhanced the oxygen migration of in the bulk with time online owing to the loss of lattice oxygen and reduction of the oxidative stated Fe ion simultaneously. The high reaction temperature was favorable to the migration of oxygen species from the bulk toward the surface for the synthesis gas production with high CO selectivity. The product distribution and evolution for POM by sequential redox reaction was determined by amounts of replenished lattice oxygen with gaseous oxygen. The optimal process should decline the total oxidation of methane, and increase the selectivity of partial oxidation of methane.

  18. A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests

    Markus Dietrich; Dieter Rauch; Adrian Porch; Ralf Moos


    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experimen...

  19. An efficient and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles via Zn-mediated barbier-type reaction under aqueous conditions



    A robust and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles from isatins is described. This method introduces an ecofriendly, un-activated Zn dust, solid NH₄Cl and substrates under aqueous conditions, which has produced the product in moderate to good yields. Without using column chromatography, majority of the compounds were isolated in analytically pure form. The progress of the reaction could be visualized by naked eye.

  20. Microwave-Assisted Condensation Reactions of Acetophenone Derivatives and Activated Methylene Compounds with Aldehydes Catalyzed by Boric Acid under Solvent-Free Conditions.

    Brun, Elodie; Safer, Abdelmounaim; Carreaux, François; Bourahla, Khadidja; L'helgoua'ch, Jean-Martial; Bazureau, Jean-Pierre; Villalgordo, Jose Manuel


    We here disclosed a new protocol for the condensation of acetophenone derivatives and active methylene compounds with aldehydes in the presence of boric acid under microwave conditions. Implementation of the reaction is simple, healthy and environmentally friendly owing to the use of a non-toxic catalyst coupled to a solvent-free procedure. A large variety of known or novel compounds have thus been prepared, including with substrates bearing acid or base-sensitive functional groups.

  1. Microwave-Assisted Condensation Reactions of Acetophenone Derivatives and Activated Methylene Compounds with Aldehydes Catalyzed by Boric Acid under Solvent-Free Conditions

    Elodie Brun


    Full Text Available We here disclosed a new protocol for the condensation of acetophenone derivatives and active methylene compounds with aldehydes in the presence of boric acid under microwave conditions. Implementation of the reaction is simple, healthy and environmentally friendly owing to the use of a non-toxic catalyst coupled to a solvent-free procedure. A large variety of known or novel compounds have thus been prepared, including with substrates bearing acid or base-sensitive functional groups.

  2. Co-formation of hydroperoxides and ultra-fine particles during the reactions of ozone with a complex VOC mixture under simulated indoor conditions

    Fan, Z.H.; Weschler, Charles J.; Han, IK


    in the O-3/23 VOCs system. The present study confirmed the findings of a previous study carried out in a real-world office and generated new findings regarding co-formation of UFP. Through a comparative analysis of H2O2* yields under different reaction conditions, this study demonstrates that VOCs co......) under simulated indoor conditions. The VOC mixture contained 23 compounds, including two terpenes (d-limonene and alpha-pinene), two unsaturated alkenes (1-decene and 1-octene), and 19 other saturated organic compounds. These compounds are commonly found in indoor air but their concentrations were...

  3. Effects of operating conditions on compositional characteristics and reaction kinetics of liquid derived by delayed coking of nigerian petroleum residue

    O. O. Bello


    Full Text Available The thermal upgrading of Nigerian petroleum residue was studied at relatively low pressure in a delayed coking reactor system. In this work, the intent was to investigate the effects of process variables such as reaction temperature (200(0C to 600(0C, reaction time (0 to 120min, additive concentration loading and additive-to-residue ratio on the amounts and quality of organic liquid product (OLP. The liquid products derived from the delayed coking process were characterized by means of instrumental analysis of gas-liquid chromatography. Results obtained from the analyses of the OLP revealed an upward trend of the conversion process and the selectivity of the aromatic compounds with additive-to-residue ratio (ARR and increase in temperature. This led to maximum yield of 37.2% achieved with ARR of 5 compared to 31% achieved with ordinary thermal conversion. The selectivity for aromatic hydrocarbons was maximum at 83.1wt% the selectivity towards aromatics and aliphatic hydrocarbons were highest for methanol-potassium hydroxide and methanol respectively. In all additive system cases, maximum OLP was produced at an optimum reaction temperature of 370(0C in the delayed coking reactor and at higher residence time. The gaseous product consisted of carbon monoxide and carbon dioxide and C1 - C6 hydrocarbons, which amounted to about 20 to 30 wt% of liquid distillate. The information obtained in this study show that the organic liquid products are amenable to characterization procedure and provided the basis for the identification of processes for upgrading Nigerian petroleum residue and such other starting materials such as bitumen or fossil fuel coal liquids.

  4. Rapid and efficient copper-catalyzed Finkelstein reaction of (hetero)aromatics under continuous-flow conditions.

    Chen, Mao; Ichikawa, Saki; Buchwald, Stephen L


    A general, rapid, and efficient method for the copper-catalyzed Finkelstein reaction of (hetero)aromatics has been developed using continuous flow to generate a variety of aryl iodides. The described method can tolerate a broad spectrum of functional groups, including N-H and O-H groups. Additionally, in lieu of isolation, the aryl iodide solutions were used in two distinct multistep continuous-flow processes (amidation and Mg-I exchange/nucleophilic addition) to demonstrate the flexibility of this method.

  5. Dynamic of bioelectric activity back hypothalamus changes in conditions of pyroxan application on the background of stress-reaction developmen

    T. G. Chaus


    Full Text Available The dynamic of changes of capacity of electroencephalogram’s rhythms back hypothalamus at animals of control group and group in stress conditions in parallel with rats who on a background of stress development accepted pyroxan is analyzed. The submitted results have shown influence of a pharmacological preparation pyroxan on bioelectric activity of back hypothalamus in stress conditions that restoration of electric activity under action of this preparation was more shown at 3 weeks of its application.

  6. Evidence for an unorthodox firing sequence employed by the Berlin Painter : deciphering ancient ceramic firing conditions through high-resolution material characterization and replication

    Cianchetta, I.; Trentelman, K.; Maish, J.; Saunders, D.; Foran, B.; Walton, M.; Sciau, Ph.; Wang, T.; Pouyet, E.; Cotte, M.; Meirer, F.; Liu, Y.; Pianetta, P.; Mehta, A.


    XANES spectroscopy was used to complement the results previously obtained with Raman spectroscopy by the same group to determine the firing conditions used in the production of a single vessel painted by the Berlin Painter in the 5th century B.C. The vessel, part of the collection of the J. Paul Get

  7. KPP reaction-diffusion systems with loss inside a cylinder: convergence toward the problem with Robin boundary conditions

    Giletti, Thomas


    We consider in this paper a reaction-diffusion system under a KPP hypothesis in a cylindrical domain in the presence of a shear flow. Such systems arise in predator-prey models as well as in combustion models with heat losses. Similarly to the single equation case, the existence of a minimal speed c* and of traveling front solutions for every speed c > c* has been shown both in the cases of heat losses distributed inside the domain or on the boundary. Here, we deal with the accordance between the two models by choosing heat losses inside the domain which tend to a Dirac mass located on the boundary. First, using the characterizations of the corresponding minimal speeds, we will see that they converge to the minimal speed of the limiting problem. Then, we will take interest in the convergence of the traveling front solutions of our reaction-di?usion systems. We will show the convergence under some assumptions on those solutions, which in particular can be satis?ed in dimension 2.

  8. Measurement of six degrees of freedom head kinematics in impact conditions employing six accelerometers and three angular rate sensors (6aω configuration).

    Kang, Yun-Seok; Moorhouse, Kevin; Bolte, John H


    The ability to measure six degrees of freedom (6 DOF) head kinematics in motor vehicle crash conditions is important for assessing head-neck loads as well as brain injuries. A method for obtaining accurate 6 DOF head kinematics in short duration impact conditions is proposed and validated in this study. The proposed methodology utilizes six accelerometers and three angular rate sensors (6aω configuration) such that an algebraic equation is used to determine angular acceleration with respect to the body-fixed coordinate system, and angular velocity is measured directly rather than numerically integrating the angular acceleration. Head impact tests to validate the method were conducted using the internal nine accelerometer head of the Hybrid III dummy and the proposed 6aω scheme in both low (2.3 m/s) and high (4.0 m/s) speed impact conditions. The 6aω method was compared with a nine accelerometer array sensor package (NAP) as well as a configuration of three accelerometers and three angular rate sensors (3aω), both of which have been commonly used to measure 6 DOF kinematics of the head for assessment of brain and neck injuries. The ability of each of the three methods (6aω, 3aω, and NAP) to accurately measure 6 DOF head kinematics was quantified by calculating the normalized root mean squared deviation (NRMSD), which provides an average percent error over time. Results from the head impact tests indicate that the proposed 6aω scheme is capable of producing angular accelerations and linear accelerations transformed to a remote location that are comparable to that determined from the NAP scheme in both low and high speed impact conditions. The 3aω scheme was found to be unable to provide accurate angular accelerations or linear accelerations transformed to a remote location in the high speed head impact condition due to the required numerical differentiation. Both the 6aω and 3aω schemes were capable of measuring accurate angular displacement while the

  9. OD(X/sup 2/II) and SD(X/sup 2/II) from reactions of D atoms with OCS under bulk and precursor geometry limited conditions

    Haeusler, D.; Rice, J.; Wittig, C.


    Reactions of D atoms with OCS were studied by 193-nm pulsed laser photolysis of DBr as a nearly monoenergetic D-atom source. Nascent OD(X/sup 2/II) and SD(X/sup 2/II) rotational, vibrational, spin-orbit, and ..lambda..-doublet populations were obtained under single-collision bulk conditions at 300 K. The SD channel is favored energetically ( H = -43 +/- 13 and 230 +/- 13 kJ mol/sup -1/ for the SD and OD channels, respectively) and is the dominant pathway ((SD)/(OD) = 5 +/- 2). Nascent OD(X/sup 2/II) products were also obtained from a precursor geometry limited (PGL) reaction by using the weakly bound van der Waals complex SCO-DBr. The OD(X/sup 2/II) rotational distributions are the same for both bulk and PGL conditions and can be reproduced by using a statistical model. Due to experimental difficulties, SD(X/sup 2/II) distributions could not be obtained under PGL conditions. The SD(X/sup 2/II) distribution obtained under bulk conditions is very nonstatistical, suggesting that this species is not formed via a long-lived DSCO intermediate complex in which vibrational energy is randomized.

  10. Reactions of Laser Ablated Metal Plasma with Molecular Alcohol Beams: Dependence of the Produced Cluster Ion Species on the Beam Condition

    NIU Dong-Mei; LI Hai-Yang; ZHANG Shu-Dong


    The gas phase reactions of metal plasma with alcohol clusters were studied by time of flight mass spectrometry(TOFMS) using laser ablation-molecular beam (LAMB) method. The significant dependence of the product cluster ions on the molecular beam conditions was observed. When the plasma acted on the low density parts of the pulsed molecular beam, the metal-alcohol complexes M+An (M=Cu, Al, Mg, Ni and A=C2H5OH, CH3OH) were the dominant products, and the sizes of product ion clusters were smaller. While the plasma acted on the high density part of the beam, however, the main products turned to be protonated alcohol clusters H+An and, as the reactions of plasma with methanol were concerned, the protonated water-methanol complexes H3O+(CH3OH)n with a larger size(n≤ 12 for ethanol and n≤24 for methanol). Similarly, as the pressure of the carrier helium gas was varied from1 × 105 to 5 × 105 Pa, the main products were changed from M+An to H+An and the sizes of the clusters also increased. The changes in the product clusters were attributed to the different formation mechanism of the output ions,that is, the M+An ions came from the reaction of metal ion with alcohol clusters, while H+An mainly from collisional reaction of electron with alcohol clusters.

  11. [Adaptive reactions of lipid metabolism in native and alien female representatives of Tofalaria population living under extreme environmental conditions].

    Kolesnikova, L I; Darenskaya, M A; Grebenkina, L A; Dolgikh, M I; Semenova, N V


    Peculiarities of the state of lipid metabolism and of processes of lipid peroxidation--the antioxidant protection have been considered in female representatives of the native and alien population of Tofalaria in the age aspects. The obtained data indicate specificity of changes of level of parameters lipid metabolism not only in response to duration of effect of climatic factors, but also depending on belonging to different ethnic groups. Thus, in girls of the natural population of Tofalaria there is noted activation of adaptational-compensatory processes as compared with the alien ones, which is expressed as a significant decrease of atherogenic blood fractions and the general activation of the system of antioxidant protection. However, with age, in both ethnic groups a change of character of reactions of lipid peroxidation and lipid metabolism is noted, which is more expressed in the alien population.

  12. Efficient transfer hydrogenation reaction Catalyzed by a dearomatized PN 3P ruthenium pincer complex under base-free Conditions

    He, Lipeng


    A dearomatized complex [RuH(PN 3P)(CO)] (PN 3PN, N′-bis(di-tert-butylphosphino)-2,6-diaminopyridine) (3) was prepared by reaction of the aromatic complex [RuH(Cl)(PN 3P)(CO)] (2) with t-BuOK in THF. Further treatment of 3 with formic acid led to the formation of a rearomatized complex (4). These new complexes were fully characterized and the molecular structure of complex 4 was further confirmed by X-ray crystallography. In complex 4, a distorted square-pyramidal geometry around the ruthenium center was observed, with the CO ligand trans to the pyridinic nitrogen atom and the hydride located in the apical position. The dearomatized complex 3 displays efficient catalytic activity for hydrogen transfer of ketones in isopropanol. © 2011 Elsevier B.V. All rights reserved.

  13. Dynamic transformation of small Ni particles during methanation of CO2 under fluctuating reaction conditions monitored by operando X-ray absorption spectroscopy

    Mutz, B.; Carvalho, H. W. P.; Kleist, W.; Grunwaldt, J.-D.


    A 10 wt.-% Ni/Al2O3 catalyst with Ni particles of about 4 nm was prepared and applied in the methanation of CO2 under dynamic reaction conditions. Fast phase transformations between metallic Ni, NiO and NiCO3 were observed under changing reaction atmospheres using operando X-ray absorption spectroscopy (XAS). Removing H2 from the feed gas and, thus, simulating a H2 dropout during the methanation reaction led to oxidation of the active sites. The initial reduced state of the Ni particles could not be recovered under methanation atmosphere (H2/CO2 = 4); this was only possible with an effective reactivation step applying H2 at increased temperatures. Furthermore, the cycling of the gas atmospheres resulted in a steady deactivation of the catalyst. Operando XAS is a powerful tool to monitor these changes and the behavior of the catalyst under working conditions to improve the understanding of the catalytic processes and deactivation phenomena.

  14. Transformation of hydroxycarbonate green rust into crystalline iron (hydr)oxides: Influences of reaction conditions and underlying mechanisms

    Wang, Xiaoming; Liu, Fan; Tan, W.; Feng, Xionghan; Koopal, L.K.


    Green rusts (GRs) are found as intermediate products between FeII hydroxides and FeIII oxyhydroxides in various anoxic environments. The transformation of hydroxycarbonate green rust GR1(CO32-) by air oxidation at different conditions and the underlying mechanisms were investigated using X-ray diffr

  15. Propane Dehydrogenation over a Commercial Pt-Sn/Al2O3 Catalyst for Isobutane Dehydrogenation: Optimization of Reaction Conditions

    Farnaz Tahriri Zangeneh; Saeed Sahebdelfar; Mohsen Bahmani


    The applicability of a commercial Pt-Sn/Al2O3 isobutane dehydrogenation catalyst in dehydrogenation of propane was studied.Catalyst performance tests were carried out in a fixed-bed quartz reactor under different operating conditions.Generally,as the factors improving propane conversion decrease the propylene selectivity,the optimal operating condition to maximize propylene yield is expected.The optimal condition was obtained by the experimental design method.The investigated parameters were temperature,hydrogen/hydrocarbon (H2/HC) ratio and space velocity,being changed in three levels.Constrains such as the susceptibility of the catalyst components to sintering or phase transformation were also taken into account.Activity,selectivity and stability of the catalyst were considered as the measured response factors,while the space-time-yield (STY) was considered as the variable to be optimized due to its commercial interest.A STY of 16 mol·kg-1·h-1 was achieved under the optimal conditions of T=620 ℃,H2/HC =0.6 and,weight hourly space velocity (WHSV) =2.2 h-1.Single carbon-carbon bond rupture was found to be the main route for the formation of lower hydrocarbon byproducts.

  16. [Acoustic evoked driving reactions in the EEG and their conditioning related to the personality factor extraversion-introversion (author's transl)].

    Haidmayer, I; Schulter, G


    Clicks were delivered in trains of 2,5 s duration at click repetition rates of 5 or 8/s to provoke rhythmical activity in the vertex-EEG ('driving response') and to condition the driving response to neutral stimuli in a discrimination paradigm. The Eysenck Personality Inventory was administered to define an independent personality variable, i.e. extraversion-introversion; the interaction of background activity, driving and conditioned driving response with the personality dimension was analyzed. In the background EEG there was a significant difference in the absolute power of the fast alpha-band between introverts and extraverts. Driving was only observed in the fundamental frequency of acoustic stimulation, not in the first harmonic. There was no interaction between driving response and extraversion-introversion or resting EEG activity. Classical conditioning of the driving response was successful with introverts only. Results were interpreted within the framework of Eysenck's personality theory. The possibility to study neurophysiological correlates of memory processes in humans by means of conditioned driving responses is discussed.

  17. Impact of Flight Enthalpy, Fuel Simulant, and Chemical Reactions on the Mixing Characteristics of Several Injectors at Hypervelocity Flow Conditions

    Drozda, Tomasz G.; Baurle, Robert A.; Drummond, J. Philip


    The high total temperatures or total enthalpies required to duplicate the high-speed flight conditions in ground experiments often place stringent requirements on the material selection and cooling needs for the test articles and intrusive flow diagnostic equipment. Furthermore, for internal flows, these conditions often complicate the use of nonintrusive diagnostics that need optical access to the test section and interior portions of the flowpath. Because of the technical challenges and increased costs associated with experimentation at high values of total enthalpy, an attempt is often made to reduce it. This is the case for the Enhanced Injection and Mixing Project (EIMP) currently underway in the Arc-Heated Scramjet Test Facility at the NASA Langley Research Center. The EIMP aims to investigate supersonic combustion ramjet (scramjet) fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships between mixing performance and losses relevant to flight Mach numbers greater than 8. The experiments will consider a "direct-connect" approach and utilize a Mach 6 nozzle to simulate the combustor entrance flow of a scramjet engine. However, while the value of the Mach number is matched to that expected at the combustor entrance in flight, the maximum value of the total enthalpy for these experiments is limited by the thermal-structural limits of the uncooled experimental hardware. Furthermore, the fuel simulant is helium, not hydrogen. The use of "cold" flows and non-reacting mixtures of fuel simulants for mixing experiments is not new and has been extensively utilized as a screening technique for scramjet fuel injectors. In this study, Reynolds-averaged simulations are utilized (RAS) to systematically verify the implicit assumptions used by the EIMP. This is accomplished by first performing RAS of mixing for two injector configurations at planned nominal experimental

  18. 5 CFR 315.704 - Conversion to career employment from indefinite or temporary employment.


    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Conversion to career employment from... MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Conversion to Career or Career-Conditional Employment From Other Types of Employment § 315.704 Conversion to career employment...

  19. Analyses of photoinitiated H+CO 2 reactions: Gas phase single-collision conditions and CO 2HBr adducts

    Wittig, C.; Engel, Y. M.; Levine, R. D.


    Analyses of data obtained under single-collision bulk conditions and from CO 2HBr complexes suggest that with complexes ≈80% of the OHproduct accrues via a mechanism wherein repulsive entrance-channel interactions enhance Br-HOCO † c.m. kinetic energy at the expense of HOCO † internal energy. Resonances are described in which H is localized between Br and OCO until the reactive window opens.

  20. A possibility of parallel and anti-parallel diffraction measurements on neutron diffractometer employing bent perfect crystal monochromator at the monochromatic focusing condition

    Yong Nam Choi; Shin Ae Kim; Sung Kyu Kim; Sung Baek Kim; Chang-Hee Lee; Pivel Mikula


    In a conventional diffractometer having single monochromator, only one position, parallel position, is used for the diffraction experiment (i.e. detection) because the resolution property of the other one, anti-parallel position, is very poor. However, a bent perfect crystal (BPC) monochromator at monochromatic focusing condition can provide a quite flat and equal resolution property at both parallel and anti-parallel positions and thus one can have a chance to use both sides for the diffraction experiment. From the data of the FWHM and the / measured on three diffraction geometries (symmetric, asymmetric compression and asymmetric expansion), we can conclude that the simultaneous diffraction measurement in both parallel and anti-parallel positions can be achieved.

  1. A multi-scale model of the oxygen reduction reaction on highly active graphene nanosheets in alkaline conditions

    Vazquez-Arenas, Jorge; Ramos-Sanchez, Guadalupe; Franco, Alejandro A.


    A multi-scale model based on a mean field approach, is proposed to describe the ORR mechanism on N-GN catalysts in alkaline media. The model implements activation energies calculated with Density Functional Theory (DFT) at the atomistic level, and scales up them into a continuum framework describing the cathode/electrolyte interface at the mesoscale level. The model also considers mass and momentum transports arising in the region next to the rotating electrode for all ionic species and O2; correction of potential drop and electrochemical double-layer capacitance. Most fitted parameters describing the kinetics of ORR elementary reactions are sensitive in the multi-scale model, which results from the incorporation of activation energies using the mean field method, unlike single-scale modelling Errors in the deviations from activation energies are found to be moderate, except for the elementary step (2) related to the formation of O2ads, which can be assigned to the inherent DFT limitations. The consumption of O2ads to form OOHads is determined as the rate-determining step as a result of its highest energy barrier (163.10 kJ mol-1) in the system, the largest error obtained for the deviation from activation energy (28.15%), and high sensitivity. This finding is confirmed with the calculated surface concentration and coverage of electroactive species.


    NICA-BADEA Delia


    Full Text Available The paper considers this issue matters as of interference noise of the ordinary activity of the population owing to its cause and its presence in all departments of life. Noise pollution is a major problem in all countries where we are witnessing a phenomenon of magnification levels of noise having effects more or less aggressive about comfort and even health. Are presented arguments relating to the characterization of noise as a risk factor in the induction of pathologies such as: auditory disorders, hypertension, ischemic heart disease aggravation, discomfort, sleep disorders and decreasing school performance in children. For the evaluation and management of ambient noise has developed a study aimed at assessing the state of comfort and subjective reactions of residents in order to fundamentarii measures for reducing the levels of exposure and prevention of the effects of population exposed to noise in the street. In areas with heavy traffic confirm the existence of risk perception of 56% of the people who accuse the discomfort caused by noise in homes during the day and during the night rate is 40%. The age groups most affected are 51-65 years and over 65 years old, because they spend most of the time period in the home.

  3. Employment relations, flexibility and risk

    Jensen, Carsten Strøby

    Employment relations literature often distinguishes between social democratic/corporatist models of employment relations and liberal models of employment relations as they are seen as opposite or at least different ways of organizing labor markets. They are often characterized as having very...... different risk profiles in terms of relationships between employees, employers, and the state. Low levels of labor market regulation very often characterize the liberal models of employment relations as we know them from, for instance, the USA and the UK. This means that employment conditions are very often...... insecure and that the burden of unemployment risk mostly lies with the employees rather than the employer. Corporatist – or social democratic – employment relations models are, in contrast to the liberal models, often characterized by stricter regulation of the labor market and by high standards...

  4. Optimisation of ICPMS collision/reaction cell conditions for the simultaneous removal of argon based interferences of arsenic and selenium in water samples.

    Darrouzès, Jérôme; Bueno, Maïté; Lespès, Gaëtane; Holeman, Michel; Potin-Gautier, Martine


    The optimisation of ICPMS collision/reaction cell conditions for the simultaneous analysis of arsenic and selenium is described. A mixture of 3.8mL min(-1) of H(2) and 0.5mL min(-1) of He was found to be suitable for the removal of both ArAr(+) and ArCl(+) interferences. Detection limits down to 30ng (element) L(-1) in total analysis, and between 81 and 230ng (element) L(-1) in speciation analysis were achieved in chloride matrix (1gL(-1) NaCl). After validation, the method was applied to commercially available mineral waters.

  5. The Impact of Non-Enzymatic Reactions and Enzyme Promiscuity on Cellular Metabolism during (Oxidative) Stress Conditions.

    Piedrafita, Gabriel; Keller, Markus A; Ralser, Markus


    Cellular metabolism assembles in a structurally highly conserved, but functionally dynamic system, known as the metabolic network. This network involves highly active, enzyme-catalyzed metabolic pathways that provide the building blocks for cell growth. In parallel, however, chemical reactivity of metabolites and unspecific enzyme function give rise to a number of side products that are not part of canonical metabolic pathways. It is increasingly acknowledged that these molecules are important for the evolution of metabolism, affect metabolic efficiency, and that they play a potential role in human disease-age-related disorders and cancer in particular. In this review we discuss the impact of oxidative and other cellular stressors on the formation of metabolic side products, which originate as a consequence of: (i) chemical reactivity or modification of regular metabolites; (ii) through modifications in substrate specificity of damaged enzymes; and (iii) through altered metabolic flux that protects cells in stress conditions. In particular, oxidative and heat stress conditions are causative of metabolite and enzymatic damage and thus promote the non-canonical metabolic activity of the cells through an increased repertoire of side products. On the basis of selected examples, we discuss the consequences of non-canonical metabolic reactivity on evolution, function and repair of the metabolic network.

  6. Model predictions of realgar precipitation by reaction of As(III) with synthetic mackinawite under anoxic conditions

    Gallegos, T.J.; Han, Y.-S.; Hayes, K.F.


    This study investigates the removal of As(III) from solution using mackinawite, a nanoparticulate reduced iron sulfide. Mackinawite suspensions (0.1-40 g/L) effectively lower initial concentrations of 1.3 ?? 10 -5 M As(III) from pH 5-10, with maximum removal occurring under acidic conditions. Based on Eh measurements, it was found that the redox state of the system depended on the mackinawite solids concentration and pH. Higher initial mackinawite concentrations and alkaline pH resulted in a more reducing redox condition. Given this, the pH edge data were modeled thermodynamically using pe (-log[e-]) as a fitting parameter and linear pe-pH relationships within the range of measured Eh values as a function of pH and mackinawite concentration. The model predicts removal of As(III) from solution by precipitation of realgar with the formation of secondary oxidation products, greigite or a mixed-valence iron oxide phase, depending on pH. This study demonstrates that mackinawite is an effective sequestration agent for As(III) and highlights the importance of incorporating redox into models describing the As-Fe-S-H2O system. ?? 2008 American Chemical Society.

  7. Authenticity in Employment Relations

    Tackney, Charles Thomas

    This research takes up the concept of authenticity as a criterion variable for theology of the workplace analysis, a domain which explores employment parameters in light of religious teaching on the social question at national, organizational or firm-specific levels. Following a review of the con......This research takes up the concept of authenticity as a criterion variable for theology of the workplace analysis, a domain which explores employment parameters in light of religious teaching on the social question at national, organizational or firm-specific levels. Following a review...... of the concept in Western culture, philosophy, and management studies, Religious Society of Friends (Quaker) and Roman Catholic social teachings are investigated for positively correlative data to help develop the criterion variable. From the literature review of concept and historical data in both traditions......, it becomes possible to specify employment relations parameters between the indirect and direct employer and employees in a manner that will ensure working conditions consistent with these traditions, substantially enhancing the prospect of authenticity in employment relations. This theology of the workplace...

  8. Experimental Investigation of Augmented Spark Ignition of a LO2/LCH4 Reaction Control Engine at Altitude Conditions

    Kleinhenz, Julie; Sarmiento, Charles; Marshall, William


    The use of nontoxic propellants in future exploration vehicles would enable safer, more cost-effective mission scenarios. One promising green alternative to existing hypergols is liquid methane (LCH4) with liquid oxygen (LO2). A 100 lbf LO2/LCH4 engine was developed under the NASA Propulsion and Cryogenic Advanced Development project and tested at the NASA Glenn Research Center Altitude Combustion Stand in a low pressure environment. High ignition energy is a perceived drawback of this propellant combination; so this ignition margin test program examined ignition performance versus delivered spark energy. Sensitivity of ignition to spark timing and repetition rate was also explored. Three different exciter units were used with the engine s augmented (torch) igniter. Captured waveforms indicated spark behavior in hot fire conditions was inconsistent compared to the well-behaved dry sparks. This suggests that rising pressure and flow rate increase spark impedance and may at some point compromise an exciter s ability to complete each spark. The reduced spark energies of such quenched deliveries resulted in more erratic ignitions, decreasing ignition probability. The timing of the sparks relative to the pressure/flow conditions also impacted the probability of ignition. Sparks occurring early in the flow could trigger ignition with energies as low as 1 to 6 mJ, though multiple, similarly timed sparks of 55 to 75 mJ were required for reliable ignition. Delayed spark application and reduced spark repetition rate both correlated with late and occasional failed ignitions. An optimum time interval for spark application and ignition therefore coincides with propellant introduction to the igniter.

  9. 合成乙酰水杨酸的反应条件的探讨%Research of Reaction Conditions about Acetylsalicylic Acid Synthesized

    李娅生; 刘大勇; 王九; 王昱航; 陈强; 付富生


    对乙酰水杨酸“老药新用”的应用现状以及应用前景进行了详细的分析。比较了目前市场上乙酰水杨酸各种合成方法的优劣,设计了适合于工业化的较佳的合成路线,考察了原料物质的量之比、催化剂用量、反应温度、反应时间对反应收率的影响,进一步优化了合成工艺。经过实验数据的处理与分析,采用O-酰基化反应合成乙酰水杨酸的适宜条件为:无水环境下,对甲苯磺酸为催化剂,n(水杨酸):n(乙酸酹)=1:2.0:反应温度为85℃和反应时间为30rain时,乙酰水杨酸的收率高于97%。所得样品符合《中国药典》和《美国药典》中乙酰水杨酸的质量要求,能够用于合成乙酰水杨酸。%Acetylsalicylic acid "new use for an old drug" application status and application prospect were analyzed in detail. Compared with the present market of acetylsalicylic acid synthesis methods advantages and disadvantages. Design suitable for industrialization of better synthetic route. The effect of raw material ratio, the dosage of catalyst, reaction temperature, reaction time on the yield of the reaction, further optimization of the synthesis technology. Through the experimental data processing and analysis, the O acylation reaction conditions for synthesis of acetyl salicylic acid: without water environment, concentrated 4-Toluene sulfonic acid as catalyst, n(salicylic acid) " n(acetic anhydride)=l : 2.0; when the reaction temperature of 85 ℃ and reaction time of 30 min, acetyl salicylic acid yield were higher than 97 %. The sample meets acetylsalicylic acid quality requirements of"Chinese Pharmacopoeia" and "with the United States Pharmacopoeia", can be used for the synthesis of acetyl salicylic acid.

  10. A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests

    Markus Dietrich


    Full Text Available The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR of nitrogen oxides (NOX depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia.

  11. A laboratory test setup for in situ measurements of the dielectric properties of catalyst powder samples under reaction conditions by microwave cavity perturbation: set up and initial tests.

    Dietrich, Markus; Rauch, Dieter; Porch, Adrian; Moos, Ralf


    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia.

  12. New Insight into the Hydrogen Evolution Reaction under Buffered Near-Neutral pH Conditions: Enthalpy and Entropy of Activation

    Shinagawa, Tatsuya


    Electrochemical conversion of thermodynamically stable chemicals of water and carbon dioxide is regarded as a core technology for achieving sustainability in our society. In both cases, the electrochemical hydrogen evolution reaction (HER) is a key reaction, particularly at near-neutral pH. This study addresses the kinetic aspects of the HER in buffered near-neutral pH conditions using a variety of electrode materials (W, Ni, Pt, Au, and Cu) over a wide temperature range (299–346 K). When the overall performance was summarized with respect to the binding energy of the reaction intermediate species, a classic volcano-shaped relationship was obtained. Interestingly, the temperature sensitivity analysis disclosed that smaller activation energies did not always lead to higher performance in 1.5 mol L–1 K-phosphate solution (pH 5.8). Detailed analysis of the temperature- and potential-dependent parameters revealed that smaller activation energies coincided with smaller values of the pre-exponential factor in the Arrhenius’ equation (associated with the entropy of activation). Due to the trade-off relationship of enthalpy–entropy compensation in the current system, the conventional approach of mixing elements of lower and higher binding energies to the intermediate species failed: even though Ni–Cu showed lower apparent activation energy, its activity toward the HER was between that of Ni and Cu due to the lowered entropy of activation. This study demonstrates the unrevealed fundamental aspects of the HER in buffered near-neutral condition, which contributes to the rational development of efficient energy and material conversion systems.

  13. Treatment of arsenic in acid wastewater and river sediment by Fe@Fe2O3 nanobunches: The effect of environmental conditions and reaction mechanism.

    Tang, Lin; Feng, Haopeng; Tang, Jing; Zeng, Guangming; Deng, Yaocheng; Wang, Jiajia; Liu, Yani; Zhou, Yaoyu


    High concentration of arsenic in acid wastewater and polluted river sediment caused by metallurgical industry has presented a great environmental challenge for decades. Nanoscale zero valent iron (nZVI) can detoxify arsenic-bearing wastewater and groundwater, but the low adsorption capacity and rapid passivation restrict its large-scale application. This study proposed a highly efficient arsenic treatment nanotechnology, using the core-shell Fe@Fe2O3 nanobunches (NBZI) for removal of arsenic in acid wastewater with cyclic stability and transformation of arsenic speciation in sediment. The adsorption capacity of As(III) by NBZI was 60 times as high as that of nanoscale zero valent iron (nZVI) at neutral pH. Characterization of the prepared materials after reaction revealed that the contents of As(III) and As(V) were 65% and 35% under aerobic conditions, respectively, which is the evidence of oxidation included in the reaction process apart from adsorption and co-precipitation. The presence of oxygen was proved to improve the adsorption ability of the prepared NBZI towards As(III) with the removal efficiency increasing from 68% to 92%. In order to further enhance the performance of NBZI-2 in the absence of oxygen, a new Fenton-Like system of NBZI/H2O2 to remove arsenic under the anoxic condition was also proposed. Furthermore, the removal efficiency of arsenic in acid wastewater remained to be 78% after 9 times of cycling. Meanwhile, most of the mobile fraction of arsenic in river sediment was transformed into residues after NBZI treatment for 20 days. The reaction mechanism between NBZI and arsenic was discussed in detail at last, indicating great potential of NBZI for the treatment of arsenic in wastewater and sediment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Conditional differences in mean reaction time explain effects of response congruency, but not accuracy, on posterior medial frontal cortex activity.

    Joshua eCarp


    Full Text Available According to the conflict-monitoring model of cognitive control, the posterior medial frontal cortex (pMFC plays an important role in detecting conflict between competing motor responses. Consistent with this view, pMFC activity is greater in high-conflict trials (e.g., incongruent trials and errors than in low-conflict trials (e.g., congruent trials and correct responses of distractor interference tasks. However, in both low- and high-conflict trials, pMFC activity increases linearly with RT. Thus, heightened pMFC activity in high-conflict trials may simply reflect the fact that mean RT is longer in high-conflict than in low-conflict trials. To investigate this hypothesis, we reanalyzed data from a previously published fMRI study in which participants performed an event-related version of the multi-source interference task (MSIT. Critically, after controlling for conditional differences in mean RT, effects of response congruency on pMFC activity were eliminated; in contrast, effects of response accuracy on pMFC activity remained robust. These findings indicate that effects of response congruency on pMFC activity may index any of several processes whose recruitment increases with time on task (e.g., sustained attention. However, effects of response accuracy reflect processes unique to error trials. We conclude that effects of response accuracy on pMFC activity provide stronger support for the conflict-monitoring model than effects of response congruency.

  15. Rational inattention and employer learning

    Habermalz, Steffen


    Research on employer learning has provided important insights into the dynamic process that determines individual wages, especially during the early part of a worker's career. However, the recent evidence on the absence of employer learning for college graduates by Arcidiacono et al. (2008) and results that economic conditions at labor market entry have persistent effects on wages (for example Oreopoulos et al. (2008)) cast doubt on the model's validity. This paper extends the employer learni...

  16. A rapid method for the differentiation of yeast cells grown under carbon and nitrogen-limited conditions by means of partial least squares discriminant analysis employing infrared micro-spectroscopic data of entire yeast cells

    Kuligowski, Julia; Quintás, Guillermo; Herwig, Christoph; Lendl, Bernhard


    This paper shows the ease of application and usefulness of mid-IR measurements for the investigation of orthogonal cell states on the example of the analysis of Pichia pastoris cells. A rapid method for the discrimination of entire yeast cells grown under carbon and nitrogen-limited conditions based on the direct acquisition of mid-IR spectra and partial least squares discriminant analysis (PLS-DA) is described. The obtained PLS-DA model was extensively validated employing two different validation strategies: (i) statistical validation employing a method based on permutation testing and (ii) external validation splitting the available data into two independent sub-sets. The Variable Importance in Projection scores of the PLS-DA model provided deeper insight into the differences between the two investigated states. Hence, we demonstrate the feasibility of a method which uses IR spectra from intact cells that may be employed in a second step as an in-line tool in process development and process control along Quality by Design principles. PMID:22967595

  17. Evaluating Employability Skills: Employer and Student Perceptions

    Saunders, Venetia; Zuzel, Katherine


    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  18. Evaluating Employability Skills: Employer and Student Perceptions

    Saunders, Venetia; Zuzel, Katherine


    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  19. Monitoring Employment Conditions of Military Spouses


    elements into nonoverlapping groups, called strata, and then selecting a simple random sample from each stratum” ( Scheaffer et al., 1996, p. 125). 22...73,46096&_dad=itc&_schema=PORTAL¤t_ id= (as of April 25, 2006). Scheaffer , Richard L., William Mendenhall III, and R

  20. Insight into chemoselectivity of nitroarene hydrogenation: A DFT-D3 study of nitroarene adsorption on metal surfaces under the realistic reaction conditions

    Zhang, Lidong; Cao, Xiao-Ming; Hu, P.


    The adsorption of nitrobenzene and 4-nitrostyrene on the Pt(111) and the Au(111) surfaces under the general reaction condition of nitroarene catalytic hydrogenation is investigated utilizing periodic density functional theory calculations with the Grimme's empirical three-body dispersion correction to understand the influence of adsorption configurations on chemoselectivity of nitroarene compound hydrogenation. It is found that at the low coverage both nitrobenzene and 4-nitrostyrene tend to adsorb paralleling to the Pt(111) and the Au(111) surfaces. Based on the crystal orbital Hamilton population analysis, it is found that the chemical bonding between nitro group and Pt(111) surface is weak. The adsorption configurations of nitrobenzene and 4-nitrostyrene are determined by the chemisorption strength of phenyl group and vinyl group. Under the reaction condition, the 1/9 ML nitrobenzene and 4/9 ML hydrogen atom can be coadsorbed while the 1/6 ML 4-nitrostyrene and 1/3 ML hydrogen atom can be coadsorbed on Pt(111). With the increase of the coverage, nitrobenzene still remains its paralleled adsorption configuration while the adsorption configuration of 4-nitrostyrene is switched to the tilted adsorption configuration through vinyl group without the chemisorption of phenyl and nitro group on Pt(111). In addition, the competitive adsorption with hydrogen will not change the adsorption configuration of nitrobenzene and 4-nitrostyrene under the reaction condition. On Au(111), the physical adsorption strength determines the adsorption configuration. The paralleled adsorption with the shortest average distance between the adsorbate and Au(111) surface is preferred. At the paralleled adsorption configuration, the chemoselectivities of the hydrogenation on these functional groups are similar if only in terms of geometric configuration. However, the hydrogenation on nitro group encounters the problem of steric hindrance at the tilted adsorption configuration through vinyl

  1. Ca(NO3)2·4H2O-catalysed Biginelli Reaction: One-pot Synthesis of 1,2,3,4-Tetrahydropyrimidin-2-ones/pyrimidine-2-thiones under Solvent-free Conditions

    DEBACHE Abdelmadjid; BOULCINA Raouf; TAFER Radia; BELFAITAH Ali; RHOUATI Salah; CARBONI Bertrand


    The synthesis of 1,2,3,4-dihydropyrimidinone/thione derivatives was achieved in good to excellent yields using calcium(Ⅱ)nitrate as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes,β-keto compounds and urea or thiourea.The reaction was carried out under solvent-free condi-tions.

  2. Efficient automated one-step synthesis of 2-[{sup 18}F]fluoroethylcholine for clinical imaging: optimized reaction conditions and improved quality controls of different synthetic approaches

    Asti, Mattia [Nuclear Medicine Department, Santa Maria Nuova Hospital, Reggio Emilia (Italy)], E-mail:; Farioli, Daniela; Iori, Michele; Guidotti, Claudio; Versari, Annibale; Salvo, Diana [Nuclear Medicine Department, Santa Maria Nuova Hospital, Reggio Emilia (Italy)


    [{sup 18}F]-labelled choline analogues, such as 2-[{sup 18}F]fluoroethylcholine ({sup 18}FECH), have suggested to be a new class of choline derivatives highly useful for the imaging of prostate and brain tumours. In fact, tumour cells with enhanced proliferation rate usually exhibit an improved choline uptake due to the increased membrane phospholipids biosynthesis. The aim of this study was the development of a high yielding synthesis of {sup 18}FECH. The possibility of shortening the synthesis time by reacting all the reagents in a convenient and rapid one-step reaction was specially considered. Methods: {sup 18}FECH was synthesized by reacting [{sup 18}F]fluoride with 1,2-bis(tosyloxy)ethane and N,N-dimethylaminoethanol. The synthesis was carried out using both a one- and a two-step reaction in order to compare the two procedures. The effects on the radiochemical yield and purity by using different [{sup 18}F]fluoride phase transfer catalysts, reagents amounts and purification methods were assessed. Quality controls on the final products were performed by means of radio-thin-layer chromatography, gas chromatography and high-performance liquid chromatography equipped with conductimetric, ultraviolet and radiometric detectors. Results: In the optimized experimental conditions, {sup 18}FECH was synthesized with a radiochemical yield of 43{+-}3% and 48{+-}1% (not corrected for decay) when the two-step or the one-step approach were used, respectively. The radiochemical purity was higher than 99% regardless of the different synthetic pathways or purification methods adopted. The main chemical impurity was due to N,N-dimethylmorpholinium. The identity of this impurity in {sup 18}FECH preparations was not previously reported. Conclusion: An improved two-step and an innovative one-step reaction for synthesizing {sup 18}FECH in a high yield were reported. The adaptation of a multistep synthesis to a single step process, opens further possibilities for simpler and more

  3. MHD Heat and Mass Transfer of Chemical Reaction Fluid Flow over a Moving Vertical Plate in Presence of Heat Source with Convective Surface Boundary Condition

    B. R. Rout


    Full Text Available This paper aims to investigate the influence of chemical reaction and the combined effects of internal heat generation and a convective boundary condition on the laminar boundary layer MHD heat and mass transfer flow over a moving vertical flat plate. The lower surface of the plate is in contact with a hot fluid while the stream of cold fluid flows over the upper surface with heat source and chemical reaction. The basic equations governing the flow, heat transfer, and concentration are reduced to a set of ordinary differential equations by using appropriate transformation for variables and solved numerically by Runge-Kutta fourth-order integration scheme in association with shooting method. The effects of physical parameters on the velocity, temperature, and concentration profiles are illustrated graphically. A table recording the values of skin friction, heat transfer, and mass transfer at the plate is also presented. The discussion focuses on the physical interpretation of the results as well as their comparison with previous studies which shows good agreement as a special case of the problem.

  4. Influence of reaction conditions and the char separation system on the production of bio-oil from radiata pine sawdust by fast pyrolysis

    Park, Hyun Ju; Park, Young-Kwon; Kim, Joo Sik [Faculty of Environmental Engineering, University of Seoul, 90 Jeonnong-Dong, Dondaemun-Gu, Seoul 130-743 (Korea)


    Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system. (author)

  5. Role of the Support and Reaction Conditions on the Vapor-Phase Deoxygenation of m-Cresol over Pt/C and Pt/TiO2 Catalysts

    Griffin, Michael B.; Ferguson, Glen A.; Ruddy, Daniel A.; Biddy, Mary J.; Beckham, Gregg T.; Schaidle, Joshua A.


    The catalytic deoxygenation of biomass fast pyrolysis vapors offers a promising route for the sustainable production of liquid transportation fuels. However, a clear understanding of the mechanistic details involved in this process has yet to be achieved, and questions remain regarding the role of the catalyst support and the influence of reaction conditions. In order to gain insight into these questions, the deoxygenation of m-cresol was investigated over Pt/C and Pt/TiO2 catalysts using experimental and computational techniques. The performance of each catalyst was evaluated in a packed-bed reactor under two conditions (523 K, 2.0 MPa and 623 K, 0.5 MPa), and the energetics of the ring hydrogenation, direct deoxygenation, and tautomerization mechanisms were calculated over hydrogen-covered Pt(111) and oxygen vacancies on the surface of TiO2(101). Over Pt(111), ring hydrogenation to 3-methylcyclohexanone and 3-methylcyclohexanol was found to be the most energetically favorable pathway. Over TiO2(101), tautomerization and direct deoxygenation to toluene were identified as additional energetically favorable routes. These calculations are consistent with the experimental data, in which Pt/TiO2 was more active on a metal site basis and exhibited higher selectivity to toluene at 623 K relative to Pt/C. On the basis of these results, it is likely that the reactivity of Pt/TiO2 and Pt/C is driven by the metallic phase at 523 K, while contributions from the TiO2 support enhance deoxygenation at 623 K. These results highlight the synergistic effects between hydrogenation catalysts and reducible metal oxide supports and provide insight into the reaction pathways responsible for their enhanced deoxygenation performance.

  6. Influence of Electronic Factors on “Solvent-Free and Catalyst-Free Biginelli Reaction

    Tanay Pramanik


    Full Text Available A series of Biginelli condensation were carried out employing urea, ethyl acetoacetate with a series of different derivatives of benzaldehyde. A green synthetic procedure was followed for performing the Biginelli reactions. The reaction conditions were found to be different for electron rich and electron deficient benzaldehydes. So the electronic effect has shown a significant impact on the reaction condition of the Biginelli condensation.

  7. Allergic Reactions

    ... round, they may be caused by exposure to indoor allergens such as dust mites, indoor molds or pets. Urticaria, or hives, is characterized ... home. Video: What is an allergic reaction? » Utility navigation Donate Annual meeting Browse your conditions Check pollen ...

  8. Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.

    Pasquier, Louis-César; Mercier, Guy; Blais, Jean-François; Cecchi, Emmanuelle; Kentish, Sandra


    Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions. In this work, finely ground and heat-treated serpentinite [Mg3Si2O5(OH)4] extracted from mining residues was reacted with a 18.2 vol % CO2 gas stream at moderate global pressures to investigate the effect on CO2 solubility and Mg leaching. Serpentinite dissolution rates were also measured to define the rate-limiting step. Successive batches of gas were contacted with the same serpentinite to identify surface-limiting factors using scanning electron microscopy (SEM) analysis. Investigation of the serpentinite carbonation reaction mechanisms under conditions close to a direct flue gas treatment showed that increased dissolution rates could be achieved relative to prior work, with an average Mg dissolution rate of 3.55 × 10(-11) mol cm(-2) s(-1). This study provides another perspective of the feasibility of applying a mineral carbonation process to reduce industrial greenhouse gas (GHG) emissions from large emission sources.

  9. An unusual decarboxylative Maillard reaction between L-DOPA and D-glucose under biomimetic conditions: factors governing competition with Pictet-Spengler condensation.

    Manini, P; d'Ischia, M; Prota, G


    In 0.1 M phosphate buffer at pH 7.4 and 37 degrees C, the tyrosine metabolite L-3,4-dihydroxyphenylalanine (L-DOPA) reacts smoothly with D-glucose to afford, besides diastereoisomeric tetrahydroisoquinolines 1 and 2 by Pictet-Spengler condensation, a main product shown to be the unexpected decarboxylated Amadori compound N-(1-deoxy-D-fructos-1-yl)-dopamine (3). Under similar conditions, dopamine gave only tetrahydroisoquinoline products 4 and 5, whereas L-tyrosine gave exclusively the typical Amadori compound 6. Fe(3+) and Cu(2+) ions, which accumulate in relatively high levels in parkinsonian substantia nigra, both inhibited the formation of 3. Cu(2+) ions also inhibited the formation of 1 and 2 to a similar degree, whereas Fe(3+) ions increased the yields of 1 and 2. Apparently, the formation of 3 would not be compatible with a simple decarboxylation of the initial Schiff base adduct, but would rather involve the decarboxylative decomposition of a putative oxazolidine-5-one intermediate assisted by the catechol ring. These results report the first decarboxylative Maillard reaction between an amino acid and a carbohydrate under biomimetic conditions and highlight the critical role of transition metal ions in the competition with Pictet-Spengler condensation.

  10. Employer's investments in hospital workers' employability and employment opportunities

    van Harten, E.J.; Knies, E.; Leisink, P.L.M.


    Purpose – The purpose of this paper is to examine the relationship between employer’s investments (through job characteristics and managerial support) and employees’ employment opportunities, with employability, conceptualized as perceived up-to-date expertise and willingness to change, as a mediati

  11. Acceleration of Organic Reactions Using Microwave

    Lu Ta-Jung


    The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted direct amide formation from carboxylic acid and amine, the hydrolysis of biopolymers, and nucleophilic aromatic substitution reaction. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.

  12. 水产品中红霉素残留测定过程中衍生反应条件的优化研究%Study on optimization of derivatization reaction conditions during determination of erythromycin residues

    惠芸华; 于欢; 于慧娟


    Objective To investigate the conditions of derivatization reaction during the process of erythromycin determination in aquatic products. Methods The reaction temperature, reaction time, FMOC-CL quantity and reaction system were studied to optimize the derivatization reaction. Results The results showed that the best derivatization reaction conditions of erythromycin were as follows: the derivatization reaction temperature was 45℃, the reaction time was 1 h, and the amount of FMOC-CL was 50μg under the reaction system of Vacetonitrile:VKH2PO4=2:1. Conclusion The derivatization reaction condition was suitable for the established experiment.%目的:对水产品中红霉素残留量测定过程中衍生反应的条件进行探讨和研究。方法为了使衍生反应达到最佳化,对影响反应的温度、时间、FMOC-CL的量、反应体系进行了研究。结果红霉素的最佳衍生条件是反应温度45℃、反应时间1 h、50μg FMOC-CL、反应体系V 乙腈:VKH2PO4=2:1。结论该衍生反应条件优化得比较成功,适用于所建立的实验方法。

  13. Mitsunobu Reactions Catalytic in Phosphine and a Fully Catalytic System.

    Buonomo, Joseph A; Aldrich, Courtney C


    The Mitsunobu reaction is renowned for its mild reaction conditions and broad substrate tolerance, but has limited utility in process chemistry and industrial applications due to poor atom economy and the generation of stoichiometric phosphine oxide and hydrazine by-products that complicate purification. A catalytic Mitsunobu reaction using innocuous reagents to recycle these by-products would overcome both of these shortcomings. Herein we report a protocol that is catalytic in phosphine (1-phenylphospholane) employing phenylsilane to recycle the catalyst. Integration of this phosphine catalytic cycle with Taniguchi's azocarboxylate catalytic system provided the first fully catalytic Mitsunobu reaction.

  14. Readiness for employment: perceptions of mental health service users.

    Prior, Susan; Maciver, Donald; Forsyth, Kirsty; Walsh, Mike; Meiklejohn, Alison; Irvine, Linda


    Work is good for both physical and mental health, and access to work is a basic human right. People with mental health conditions want to work and with the right support can work but are often excluded from the workplace. We explored factors influencing individual's perceptions of their readiness for employment. Participants' narratives focused particularly on personal causation and it's inter-reactions with other aspects of volition, habituation and the environment and highlight a number of key areas, which are discussed in relation to service provision. Sheltered workshops offer support and some structure and routine but may limit an individual's readiness for employment. Services should be evidence based and focused on real work opportunities which fit with individual's interests and values. Occupational therapy theory offers a unique and valuable perspective in understanding perceptions of readiness for employment and occupational therapists offer valid and useful assessments and interventions for vocational rehabilitation.

  15. A Numerical Handling of the Boundary Conditions Imposed by the Skull on an Inhomogeneous Diffusion-Reaction Model of Glioblastoma Invasion Into the Brain: Clinical Validation Aspects

    Georgios S Stamatakos


    Full Text Available A novel explicit triscale reaction-diffusion numerical model of glioblastoma multiforme tumor growth is presented. The model incorporates the handling of Neumann boundary conditions imposed by the cranium and takes into account both the inhomogeneous nature of human brain and the complexity of the skull geometry. The finite-difference time-domain method is adopted. To demonstrate the workflow of a possible clinical validation procedure, a clinical case/scenario is addressed. A good agreement of the in silico calculated value of the doubling time (ie, the time for tumor volume to double with the value of the same quantity based on tomographic imaging data has been observed. A theoretical exploration suggests that a rough but still quite informative value of the doubling time may be calculated based on a homogeneous brain model. The model could serve as the main component of a continuous mathematics-based glioblastoma oncosimulator aiming at supporting the clinician in the optimal patient-individualized design of treatment using the patient’s multiscale data and experimenting in silico (ie, on the computer.

  16. Comportamento de variedades paulistas de algodoeiro em solo infestado pelo fungo causador da murcha verticilar Comparative reactions of some cotton varieties to Verticillium wilt in field conditions

    Edivaldo Cia


    Full Text Available Foi estudado o comportamento de variedades paulistas de algodoeiro em terreno infestado pelo fungo causador da "murcha de Verticillium", no Estado de São Paulo. As variedades IAC RM3 e IAC RM4, resistentes à Fusariose, destacaram-se em produção e apresentaram as menores porcentagens de plantas com sintomas externos da doença estudada. Os resultados sugerem que tais variedades constituem também fontes genéticas de resistência à murcha verticilar.A study was made on the reactions of the cotton varieties commonly cultivated in the State of São Paulo (Brazil to Verticillium wilt under field conditions. The effects of the disease were evaluated by determining the percentages of plants showing the symptoms of the Verticilliumwilt and by measuring the yield of each variety. The Fusarium resistant varieties IAC RM3 and IAC RM4 gave the highest yields and the lowest percentages of plants infected by Verticilliumwilt. It is suggested that these varieties might represent sources of resistance to Verticillium wilt.

  17. Monopoly, employment and wages


    This paper shows that monopoly in the capital equipment market results in higher productivity and wages but lower employment in comparison with the benchmark of competition. The combined effect on workers' welfare is negative, for expected earnings (defined as the product of the probability of employment and the wage earned when employed) are lowered. Indeed, low skill workers suffer relatively greater declines in employment and expected earnings. Furthermore, the employment and expected earn...

  18. Behavior of reaction mixtures under microwave conditions: Use of sodium salts in microwave-induced N-[[sup 18]F]fluoroalkylations of aporphine and tetralin derivatives

    Zijlstra, S.; de Groot, T.J.; Kok, L.P.; Visser, G.M.; Vaalburg, W. (Univ. Hospital, Oostersingel, Groningen (Netherlands) Univ. of Groningen (Netherlands))


    In the present study, the authors have examined the behavior of reaction mixtures in a microwave field and the use of sodium salts to manipultate reaction rates. Three potential dopamine D[sub 2] agonists 2-[N-(3-[[sup 18]F]fluoropropyl)-N-[(4-fluorophenyl)ethyl]amino]-5-methoxytetralin (2), 6-(2-[[sup 18F

  19. Preventing Alkyne-Alkyne (i.e., Glaser) Coupling Associated with the ATRP Synthesis of Alkyne-Functional Polymers/Macromonomers and for Alkynes under Click (i.e., CuAAC) Reaction Conditions.

    Leophairatana, Porakrit; Samanta, Sanjoy; De Silva, Chathuranga C; Koberstein, Jeffrey T


    Alkyne-functional polymers synthesized by ATRP exhibit bimodal molecular weight distributions indicating the occurrence of some undesirable side reaction. By modeling the molecular weight distributions obtained under various reaction conditions, we show that the side reaction is alkyne-alkyne (i.e., Glaser) coupling. Glaser coupling accounts for as much as 20% of the polymer produced, significantly compromising the polymer functionality and undermining the success of subsequent click reactions in which they are used. Glaser coupling does not occur during ATRP but during postpolymerization workup upon first exposure to air. Two strategies are reported that effectively eliminate these coupling reactions without the need for a protecting group for the alkyne-functional initiator: (1) maintaining low temperature post-ATRP upon exposure to air followed by immediate removal of copper catalyst; (2) adding excess reducing agents post-ATRP which prevent the oxidation of Cu(I) catalyst required by the Glaser coupling mechanism. Post-ATRP Glaser coupling was also influenced by the ATRP synthesis ligand used. The order of ligand activity for catalyzing Glaser coupling was: linear bidentate > tridentate > tetradentate. We find that Glaser coupling is not problematic in ARGET-ATRP of alkyne-terminated polymers because a reducing agent is present during polymerization, however the molecular weight distribution is broadened compared to ATRP due to the presence of oxygen. Glaser coupling can also occur for alkynes held under CuAAC reaction conditions but again can be eliminated by adding appropriate reducing agents.

  20. Synthesis of new pentacyclo[,6).0(3,10).0(5,9)]undecane-8,11-dione (PCU) cyanosilylated derivatives using sulphated zirconia and hydrotalcite as catalysts in microwave-assisted reactions under solvent free conditions.

    Guerra-Navarro, Nahí Adriana; Palacios-Grijalva, Laura Nadxieli; Angeles-Beltrán, Deyanira; Negrón-Silva, Guillermo E; Lomas-Romero, Leticia; González-Zamora, Eduardo; Gaviño-Ramírez, Rubén; Navarrete-Bolaños, Juan


    A comparison was made of the effectiveness of the functionalization reactions of pentacyclo[,6).0(3,10).0(5,9)]undecane-8,11-dione (PCU) using sulphated zirconia in protection-deprotection reactions and Mg/Al hydrotalcite in a cyanosilylation reaction, under classical thermal conditions and imposing microwave radiation; improved yields and reaction times were considered.

  1. Employment and winter construction

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig


    possibilities exist for reducing seasonal variation in employment? In addition to a literature review related to winter construction, European and national employment and meteorological data were studied. Finally, ministerial acts, ministerial orders or other public policy documents related to winter...

  2. The Propensity for Schedule-Induced Polydipsia is Related to Differences in Conditioned Avoidance Behaviour and in Defense Reactions in a Defeat Test

    Dantzer, R.; Terlouw, C.; Tazi, A.; Koolhaas, J.M.; Bohus, B.; Koob, G.F.; Moal, M. le


    In line with previous research showing that animals predisposed to develop schedule-induced polydipsia when submitted to intermittent distribution of food show differential behavioural and neurochemical characteristics, the present experiments investigated the nature of defense reactions to aversive

  3. Piper-betle-shaped nano-S-catalyzed synthesis of 1-amidoalkyl-2-naphthols under solvent-free reaction condition: a greener "nanoparticle-catalyzed organic synthesis enhancement" approach.

    Das, Vijay K; Borah, Madhurjya; Thakur, Ashim J


    Nano-S prepared by an annealing process showed excellent catalytic activity for the synthesis of 1-amidoalkyl-2-naphthols under solvent-free reaction condition at 50 °C. The catalyst could be reused up to the fifth cycle without loss in its action. The green-ness of the present protocol was also measured using green metrics drawing its superiority.

  4. Cu(OAc)2/Pyrimidines-Catalyzed Cross-coupling Reactions of Aryl Iodides and Activated Aryl Bromides with Alkynes under Aerobic, Solvent-free and Palladium-free Conditions

    XIE Ye-Xiang; DENG Chen-Liang; PI Shao-Feng; LI Jin-Heng; YIN Du-Lin


    Excellent results have been achieved in the Cu(OAc)2-catalyzed Sonogashira cross-couplings of aryl iodides and activated aryl bromides utilizing TBAF (tetrabutylammonium fluoride) as the base and 4,6-dimethoxypyrimidin-2-amine as the ligand. It is noteworthy that the reaction is conducted under aerobic, solvent-free and palladium-free conditions.

  5. An efficient and convenient synthesis of N-substituted amides under heterogeneous condition using Al(HSO4)3 via Ritter reaction

    Elnaz Karimian; Batool Akhlaghinia; Sara S E Ghodsinia


    An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. Thecatalyst which is an air-stable, cost-effective solid acid could be readily recycled by filtration and reused four times without any significant loss of its activity.

  6. Graduate Identity and Employability

    Hinchliffe, Geoffrey William; Jolly, Adrienne


    This paper develops the concept of graduate identity as a way of deepening the understanding of graduate employability. It does this through presenting research in which over 100 employers in East Anglia were asked to record their perceptions of graduates in respect of their employability. The findings suggest a composite and complex graduate…

  7. Institutionalized Employer Collective Action

    Ibsen, Christian Lyhne; Navrbjerg, Steen Erik


    Recent studies show that employer associations continue to exist in new ways despite internationalisation of the economy, liberalisation of markets and the decline of trade unions. This paradox raises two questions regarding EOs in today’s labour markets: Which employers join employer association...

  8. Isotope exchange reactions involving HCO+ with CO: A theoretical approach

    Mladenović, M.; Roueff, E.


    Aims: We aim to investigate fractionation reactions involved in the 12C/13C, 16O/18O, and 17O balance. Methods: Full-dimensional rovibrational calculations were used to compute numerically exact rovibrational energies and thermal equilibrium conditions to derive the reaction rate coefficients. A nonlinear least-squares method was employed to represent the rate coefficients by analytic functions. Results: New exothermicities are derived for 30 isotopic exchange reactions of HCO+ with CO. For each of the reactions, we provide the analytic three-parameter Arrhenius-Kooij formula for both the forward reaction and backward reaction rate coefficients, that can further be used in astrochemical kinetic models. Rotational constants derived here for the 17O containing forms of HCO+ may assist detection of these cations in outer space.

  9. MOF catalysis of Fe(II)-to-Fe(III) reaction for an ultrafast and one-step generation of the Fe2O3@MOF composite and uranium(vi) reduction by iron(ii) under ambient conditions.

    Xiong, Yang Yang; Li, Jian Qiang; Yan, Chang Sheng; Gao, Heng Ya; Zhou, Jian Ping; Gong, Le Le; Luo, Ming Biao; Zhang, Le; Meng, Pan Pan; Luo, Feng


    Herein, we demonstrate that Zn-MOF-74 enables the ultrafast and one-step generation of the Fe2O3@MOF composite once Zn-MOF-74 contacts with FeSO4 solution. This unique reaction can be further applied in catalysis of U(vi) reduction by Fe(ii) under ambient conditions. The results provide a highly renovated strategy for U(vi) reduction by Fe(ii) just under ambient conditions, which completely subvert all established methods about U(vi) reduction by Fe(ii) in which O2- and CO2-free conditions are absolutely required.

  10. Interfacial thiol-isocyanate reactions for functional nanocarriers: a facile route towards tunable morphologies and hydrophilic payload encapsulation.

    Kuypers, Sören; Pramanik, Sumit Kumar; D'Olieslaeger, Lien; Reekmans, Gunter; Peters, Martijn; D'Haen, Jan; Vanderzande, Dirk; Junkers, Thomas; Adriaensens, Peter; Ethirajan, Anitha


    Functional nanocarriers were synthesized using an in situ inverse miniemulsion polymerization employing thiol-isocyanate reactions at the droplet interface to encapsulate hydrophilic payloads. The morphology of the nanocarriers is conveniently tunable by varying the reaction conditions and the dispersions are easily transferable to the aqueous phase.

  11. Green synthesis of Pd/CuO nanoparticles by Theobroma cacao L. seeds extract and their catalytic performance for the reduction of 4-nitrophenol and phosphine-free Heck coupling reaction under aerobic conditions.

    Nasrollahzadeh, Mahmoud; Sajadi, S Mohammad; Rostami-Vartooni, Akbar; Bagherzadeh, Mojtaba


    We report the green synthesis of palladium/CuO nanoparticles (Pd/CuO NPs) using Theobroma cacao L. seeds extract and their catalytic activity for the reduction of 4-nitrophenol and Heck coupling reaction under aerobic conditions. The catalyst was characterized using the powder XRD, TEM, EDS, UV-vis and FT-IR. This method has the advantages of high yields, elimination of surfactant, ligand and homogeneous catalysts, simple methodology and easy work up. The catalyst can be recovered from the reaction mixture and reused several times without any significant loss of catalytic activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions.

    Nesselberger, Markus; Ashton, Sean J; Wiberg, Gustav K H; Arenz, Matthias


    We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.

  13. Low-energy photodisintegration of {sup 9}Be and {alpha}+{alpha}+n<->{sup 9}Be+{gamma} reactions at astrophysical conditions

    Efros, V.D. [Rossijskij Nauchnyj Tsentr ``Kurchatovskij Inst.``, Moscow (Russian Federation); Oberhummer, H. [Institut fuer Kernphysik, Wiedner Hauptstrasse 8--10, TU Wien, A--1040, Vienna (Austria); Pushkin, A. [Department of Mathematical Physics, Lund Institute of Technology, P.O. Box, 118 S--221 00 Lund (Sweden); Thompson, I.J. [Department of Physics, University of Surrey, Guildford GU2 5XH (United Kingdom)


    A semi-microscopic model for the low-energy photodisintegration of the {sup 9}Be nucleus is constructed, and the experimental data are analyzed with its help. The older radioactive isotope data are supported by this analysis. The theoretical photodisintegration cross section is derived. The astrophysical rates for the reaction {alpha}+{alpha}+n{yields}{sup 9}Be +{gamma} and the reverse photodisintegration of {sup 9}Be are calculated. The new reaction rate for {alpha}+{alpha}+n{yields}{sup 9}Be +{gamma} is compared with previous estimations. (orig.) With 3 figs., 1 tab., 30 refs.

  14. Urticaria and Allergy-Mediated Conditions.

    Jafilan, Lena; James, Charis


    Urticaria is a common condition that involves pruritic, raised skin wheals. Although urticaria is a benign, self-limiting condition, it may cause frustration for patients, often because of its chronicity and its tendency to recur. It can also be a life-threatening allergic reaction. Diagnosis is made clinically. It affects 20% of the general population. The first-line treatment for nonremitting cases includes H-1anti-histamines. However, other therapies may be employed. Other allergy-mediated skin conditions include angioedema, contact dermatitis, and atopic dermatitis. Diagnosis is clinical, and management focuses on prevention, avoiding triggers, and treating the itching and inflammation that accompany these conditions.

  15. Influence of catalytic activity and reaction conditions on the product distribution in coal liquefaction; Sekitan ekikayu no seiseibutsu bunpu ni taisuru shokubai kassei oyobi hanno joken no eikyo

    Hasuo, H.; Sakanishi, K.; Mochida, I. [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study


    The NiMo sulfide supported on Ketjen Black (KB) was more effective and yielded lighter oil products containing light fractions with their boiling point below 300{degree}C during the two stage liquefaction combining low temperature and high temperature hydrogenation the conventional NiMo/alumina catalyst and FeS2 catalyst. Although the NiMo/alumina yielded increased oil products during the two stage liquefaction, the lighter oil fractions did not increase and the heavier fractions increased mainly. This suggests that the hydrogenation of aromatic rings and successive cleavage of the rings are necessary for producing the light oil, which is derived from the sufficient hydrogenation of aromatic rings using catalysts. For the two stage reaction with NiMo/KB catalyst, it was considered that sufficient hydrogen was directly transferred to coal molecules at the first stage of the low temperature reaction, which promoted the solubilization of coal and the successive hydrogenation at the high temperature reaction. Thus, high activity of the catalyst must be obtained. It is expected that further high quality distillates can be produced through the optimization of catalysts and solvents at the two stage reaction. 1 ref., 4 figs., 1 tab.


    Ольга Валентиновна Шохова


    Full Text Available The article is devoted to the problem of emotional response in children with developmental disorders in subject-communicative activity . The characteristic of the particularities of emotional reaction in children with divelopmental disorders is given. The author proves that it is necessary to develop emotional response as the base for further social adaptation of children with multiple disorders in development; mechanisms of formation of emotional reaction in communicative activity are described: contents, methods used for multiple diorders. Experimental data has proved the effectiveness of pedagogical thechnology on forming of emotional reaction in subject-communicative activity. Corrective and development work used in this technology is based on principles of integrity, complexness; the interralated series of thematical studies is organized intended for develoment of motor, sensor, communicative and emotional sphere in different activities of children. All this facilitate gradual interiorization of emotional reactions, their automatization in communicative activity.DOI:

  17. Cu catalyzed oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran and 2,5-furandicarboxylic acid under benign reaction conditions

    Hansen, Thomas S.; Sádaba, Irantzu; Garcia, Eduardo;


    containing promoters (NCPs) to obtain excellent yields. In acetonitrile a 95% DFF yield was obtained after 24h with ambient pressure of dioxygen at room temperature in the presence of different NCPs, which – to our knowledge – is the best result reported thus far for this reaction. The use of NCPs made...

  18. Aldehyde-alcohol reactions catalyzed under mild conditions by chromium(III) terephthalate metal organic framework (MIL-101) and phosphotungstic acid composites.

    Bromberg, Lev; Hatton, T Alan


    Porous materials based on chromium(III) terephthalate metal organic frameworks (MIL-101) and their composites with phosphotungstic acid (PTA) were studied as heterogeneous acid catalysts in aldehyde-alcohol reactions exemplified by acetaldehyde-phenol (A-P) condensation and dimethylacetal formation from benzaldehyde and methanol (B-M reaction). The MIL-101 was synthesized solvothermically in water, and the MIL101/PTA composite materials were obtained by either impregnation of the already prepared MIL-101 porous matrix with phosphotungstic acid solution or by solvothermic treatment of aqueous mixtures of Cr(NO(3))(3), and terephthalic and phosphotungstic acids. The MIL101/PTA materials appeared to be effective catalysts for both A-P and B-M reactions occurring at room temperature, with half-lives ranging from 0.5 h (A-P) to 1.5-2 h (B-M) and turnover numbers over 600 for A-P and over 2900 for the B-M reaction, respectively. A synergistic effect of the strong acidic moieties (PTA) addition to mildly acidic Brønsted and Lewis acid cites of the MIL-101 was observed with the MIL101/PTA composites. The ability of the PTA and MIL101/PTA materials to strongly absorb and condense acetaldehyde vapors was discovered, with the MIL101/PTA absorbing over 10-fold its dry weight of acetaldehyde condensate at room temperature. The acetaldehyde was converted rapidly to crotonaldehyde and higher-molecular-weight compounds while in contact with MIL-101 and MIL101/PTA materials. The stability of the MIL-101 and MIL101/PTA catalysts was assessed within four cycles of the 1-day alcohol-aldehyde reactions in terms of the overall catalyst recovery, PTA or Cr content, and reaction rate constants in each cycle. The loss of the catalyst over 4 cycles was approximately 10 wt % for all tested catalysts due to the incomplete recovery and minute dissolution of the components. The reaction rates in all cycles remained unchanged and the catalyst losses stopped after the third cycle. The developed

  19. Information Literacy and Employability

    O'Keeffe, Colin


    Information Literacy (IL) and its relationship to third level graduates’ employability has gained more attention in recent years. This article examines how IL has evolved from skills initially associated with academic libraries into a key workplace skill set of the knowledge economy. It outlines the challenges interviewees encounter when selling IL to employers, how IL can be utilised when preparing for upcoming interviews and suggests a distinction between workplace IL and employability IL. ...

  20. Reaction mechanism and optimal conditions for preparation of high-quality vanadium oxide films by organic sol-gel for optoelectronic applications

    Sun, Minghui; Wen, Yuejiang; Xu, Xiangdong; Wang, Meng; He, Qiong; Jiang, Yadong; Dai, Zelin; Gu, Yu; Chen, Zhegeng


    Although vanadium oxides (VO x ) are important functional materials for academic research and industrial applications, the reaction mechanism of VO x prepared by organic sol-gel remains unclear. In order to investigate this mechanism, VO x organic sols were reacted at different temperatures, by which various VO x thin films were prepared. The products were systematically characterized by infrared spectroscopy, Raman spectroscopy, UV-vis spectroscopy, thermogravimetric analysis, scanning electron microscopy, x-ray diffraction, and a high resistance meter. Results reveal that vanadium alkoxides are created through an alcoholysis reaction of V2O5 powder and isobutyl alcohol, and then a condensation reaction of the vanadium alkoxides leads to the formation of VO x networks. The as-prepared sols are strongly temperature-dependent, causing different chemical structures and physical properties for the resulting VO x films. Particularly, a moderate temperature of 110 °C prompts both alcoholysis and condensation reactions, and thus the VO x films that are produced by the sol reacted at 110 °C possess a low resistivity of 23 Ω cm, a high temperature coefficient resistance (TCR) of  -3.2% K-1, and a low average transmittance of 54% in 580-1100 nm, compared with those prepared by the sols reacted at lower or higher temperatures. Therefore, 110 °C is a desirable sol temperature for producing VO x films serving as high-quality bolometric materials for uncooled infrared detectors. This work discloses not only the reaction mechanism of VO x films prepared by organic sol-gel, but also the route to yield desirable VO x films for optoelectronic applications.

  1. General Outside Employment

    Montgomery County of Maryland — This dataset contains all outside employment requests held by employees of Montgomery County (excluding uniformed police officer) approved by the Ethics Commission...

  2. 提高女大学生就业能力的必要性及价值分析%Social Exclusion Condition Investigation in Female College Students' Employment Process

    张亚强; 梁彦红


    To understand the current employment status of female students, this paper analyzed the main reason for "the difficult employment" and social exclusion of female college students, and put forward relevant countermeasures. In the survey on female college students' employment, it found that the girls were more difficult to get a job than boys and the biggest harder that girls faced was sex discrimination and social exclusion. Government departments, the employer and the schools should adopt positive improvement measures to help female college students' employment and reduce social exclusion.%为把握了解当前女大学生的就业现状,分析女大学生“就业难”和社会排挤的主要原因,研究分析并提出相关对策建议,我们对某高校女大学生就业情况进行问卷调查.调查中我们发现就业过程中确实存在女生比男生更难就业,女生就业面临的最大困难就是性别歧视和社会排挤.政府部门、用人单位与学校应采用积极的改进措施帮助女大学生就业和减少社会排挤.

  3. Employment condition analysis and countermeasures discussion of vocational nursing profession in professional college%高职教育护理专业毕业生就业状况分析与对策

    鲍文慧; 连燕舒; 汪平


    Objective After the survey and analysis of graduate employment in our senior high vocational school nursing profession,the writer wants to explore and enhance graduate employment competitive strength,establish correct career values,accurate positioning and provide effective measures to improve the employment rate.Methods According to the collected data of dispatch system of Jiangsu province college graduates' employment management information system ( online),Excel and SPSS 11.0 software are used to analyze the employment situation of nursing students graduating from 2008 to 2010 in our school.Results There has great difference in the first employment rate of nursing students graduating from 2008 to 2010 Final employment rate makes no difference.The continuous three-year employment proportion at or above the county hospital has been increasing.They are 69.8%,77.6%,78.4% respectively.The number of graduates going back to work in the northern regions in Jiangsu province gradually declines.Conclusions The employment rate in our college is quite high and employment quality better.To maintain and improve nursing professional employment,great efforts should be made to strengthen the cultivation of students' employment competitiveness and improve their overall quality.%目的 对江苏建康职业学院高职护理专业毕业生就业状况进行调查分析,探讨增强毕业生就业竞争力,树立正确就业观,准确定位,提高就业率的有效措施.方法 根据江苏省高校毕业生就业管理信息系统(网络版)派遣系统数据进行资料收集,采用Excel和SPSS 11.0软件对江苏建康职业学院2008届~ 2010届护理专业毕业生就业情况进行统计分析.结果 2008届~2010届护理专业毕业生初次就业率差异具有统计学意义,最终就业率差异无统计学意义;3届毕业生在县级以上医院就业人数比例逐年升高,分别为69.8%、77.6%和78.4%;生源地在苏北地区的毕业生回当地

  4. Diamond Synthesis Employing Nanoparticle Seeds

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)


    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  5. Supported Employment in Spain.

    Verdugo, Miguel Angel; Borja, F.; de Urries, Jordan; Bellver, Fernando; Martinez, Salvador


    Supported employment is growing in Spain, assisted by models from other countries and national legislation. The Spanish Association of Supported Employment is providing a framework for program development. The field must deal with the lack of systematic evaluation and with funding problems. (SK)

  6. Employment Challenges in Kenya

    Dr Kazungu

    that improving the productivity of the informal sector with a well balanced mix of ... The agreements aimed at increasing employment levels by at least ... promotion and improvement in labour market information systems. .... Other wage employment dynamics in Kenya reveal inequities in access to ..... core policy priority.

  7. Listening to Employers

    Machalski, Jan; Riley, Alison; Aubrey, Karl


    Various government initiatives have highlighted the importance of employer engagement in schools, further education and higher education. However, speaking as a team of lecturers in HE the authors have found that there is a tension between the perceptions of government and those of employers. Clearly, it would be a good thing if, particularly in…

  8. Investor Sentiment and Employment

    M. Montone (Maurizio); R.C.J. Zwinkels (Remco)


    markdownabstract__Abstract__ We find that investor sentiment should affect a firm's employment policy in a world with moral hazard and noise traders. Consistent with the model's predictions, we show that higher sentiment among US investors leads to: (1) higher employment growth worldwide; (2) lower

  9. Maine's Employability Skills Program

    McMahon, John M.; Wolffe, Karen E.; Wolfe, Judy; Brooker, Carrie


    This Practice Report describes the development and implementation of the "Maine Employability Skills Program," a model employment program developed by the Maine Division for the Blind and Visually Impaired (DBVI). The program was designed to support the efforts of the chronically unemployed or underemployed. These consumers were either…

  10. Employment and Training Programs.

    Minnesota State Office of the Legislative Auditor, St. Paul. Program Evaluation Div.

    This report examines the effectiveness of employment and training programs in Minnesota and discusses the impact of the 1985 Jobs Bill state legislation. Chapter 1 provides an introduction to Minnesota's programs and to studies of employment and training programs conducted nationwide. Chapter 2 studies the use of Job Training Partnership Act funds…

  11. Mn(2+)-mediated homogeneous Fenton-like reaction of Fe(III)-NTA complex for efficient degradation of organic contaminants under neutral conditions.

    Li, Yifan; Sun, Jianhui; Sun, Sheng-Peng


    In this work, we report a novel Mn(2+)-mediated Fenton-like process based on Fe(III)-NTA complex that is super-efficient at circumneutral pH range. Kinetics experiments showed that the presence of Mn(2+) significantly enhanced the effectiveness of Fe(III)-NTA complex catalyzed Fenton-like reaction. The degradation rate constant of crotamiton (CRMT), a model compound, by the Fe(III)- NTA_Mn(2+) Fenton-like process was at least 1.6 orders of magnitude larger than that in the absence of Mn(2+). Other metal ions such as Ca(2+), Mg(2+), Co(2+) and Cu(2+) had no impacts or little inhibitory effect on the Fe(III)-NTA complex catalyzed Fenton-like reaction. The generation of hydroxyl radical (HO) and superoxide radical anion (O2(-)) in the Fe(III)-NTA_Mn(2+) Fenton-like process were suggested by radicals scavenging experiments. The degradation efficiency of CRMT was inhibited significantly (approximately 92%) by the addition of HO scavenger 2-propanol, while the addition of O2(-) scavenger chloroform resulted in 68% inhibition. Moreover, the results showed that other chelating agents such as EDTA- and s,s-EDDS-Fe(III) catalyzed Fenton-like reactions were also enhanced significantly by the presence of Mn(2+). The mechanism involves an enhanced generation of O2(-) from the reactions of Mn(2+)-chelates with H2O2, indirectly promoting the generation of HO by accelerating the reduction rate of Fe(III)-chelates to Fe(II)- chelates. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Study on Mai l lard Reaction Conditions of Mushroom Hydrolysate%香菇水解液的美拉德反应条件研究

    顾宗珠; 沈健; 王瑶


    Take mushroom enzymatic solution and glucose as main substrate to prepare Maillard reac-tion products.Through single factor and orthogonal experiments,the effect of microwave heating on the browning degree of Maillard reaction is investigated.The results show that the degree of brown-ing is optimal when glucose addition amount is 10%,the initial pH value of mushroom hydrolysate is adjusted to 9,the heating time is 4 min,and the microwave power is 800 W.The reaction product with sensory evaluation has unique flavor of sauce.%以香菇酶解液和葡萄糖为主要底物制备美拉德反应产物。通过单因素和正交实验,考察了微波加热对美拉德反应褐变程度的影响。结果表明:葡萄糖添加量为10%,香菇水解液初始 pH 值调整为9,加热时间为4 min,微波功率为800 W时褐变程度最佳。感官评价反应产物具有独特的酱香味。

  13. Studies in Reaction to Disability. XII: Structure of Attitudes toward the Physically Disabled; Disability Factor Scales--Amputation, Blindness, Cosmetic Conditions.

    Siller, Jerome; And Others

    To describe and to develop instruments to measure attitudes toward amputees, the blind, and those with cosmetic conditions, three groups of subjects responded to one of three large pools of items tapping attitudes toward the three disability conditions. Three new groups of about 500 subjects of diverse demographic characteristics were given one of…

  14. Establishment and Optimization of RSAP-PCR Reaction Conditions in Pleurotus ostreatus%侧耳RSAP-PCR体系的建立和优化

    潘祖桐; 宋慧; 刘麒; 李胜南; 李媛媛; 刘晓龙


    In this study, single factor and orthogonal experiments were used to establish and optimize the RSAP - PCR reaction system of Pleurotus ostreatus. Then, experiment tests were done to check the stability of the RSAP - PCR reaction system using a different pair of primers. Finally, a 25 μL optimized reaction system was obtained: 30 ng DNA, 2.0 μL 10 × PCR buffer, Mg2+ 2.5 mmol/L, dNTPs 0.25 mmol/L, Primers 0.32 μmol/L, Taq DNA polymerase 2 U, ddH2O 13.2 μL.%采用单因素试验和正交设计相结合进行了侧耳(Pleurotus ostreatus)RSAP-PCR反应体系的建立和优化,并对优化后体系的稳定性进行了验证.讨论了Mg2+浓度、dNTPs浓度、引物浓度、Taq聚合酶用量和模板DNA含量对侧耳RSAP-PCR反应的影响,最终得出总体积为25μL的反应体系:30 ng模板DNA,2.0 μL 10倍PCR buffer,Mg2+ 2.5 mmol/L,dNTPs o.25 mmol/L,引物0.32 μmol/L,Taq DNA聚合酶2U,ddH2O 13.2 μL.

  15. Retail Employment Trends


    Robert Walters, one of the world’s leading professional specialist recruitment consultancies, has recently released a report on employment opportunities in China’s consumer goods retail industry in the first half of this year. Excerpts follow:

  16. The development and experimental validation of a reduced ternary kinetic mechanism for the auto-ignition at HCCI conditions, proposing a global reaction path for ternary gasoline surrogates

    Machrafi, Hatim; Cavadias, Simeon; Amouroux, Jacques [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France)


    To acquire a high amount of information of the behaviour of the Homogeneous Charge Compression Ignition (HCCI) auto-ignition process, a reduced surrogate mechanism has been composed out of reduced n-heptane, iso-octane and toluene mechanisms, containing 62 reactions and 49 species. This mechanism has been validated numerically in a 0D HCCI engine code against more detailed mechanisms (inlet temperature varying from 290 to 500 K, the equivalence ratio from 0.2 to 0.7 and the compression ratio from 8 to 18) and experimentally against experimental shock tube and rapid compression machine data from the literature at pressures between 9 and 55 bar and temperatures between 700 and 1400 K for several fuels: the pure compounds n-heptane, iso-octane and toluene as well as binary and ternary mixtures of these compounds. For this validation, stoichiometric mixtures and mixtures with an equivalence ratio of 0.5 are used. The experimental validation is extended by comparing the surrogate mechanism to experimental data from an HCCI engine. A global reaction pathway is proposed for the auto-ignition of a surrogate gasoline, using the surrogate mechanism, in order to show the interactions that the three compounds can have with one another during the auto-ignition of a ternary mixture. (author)

  17. Deficiency of employability capacity

    Pelse I.


    Full Text Available Young unemployed people have comprised one of the significantly largest groups of the unemployed people in Latvia in recent years. One of the reasons why young people have difficulty integrating into the labour market is the “expectation gap” that exists in the relations between employers and the new generation of workers. Employers focus on capacity-building for employability such individual factors as strength, patience, self-discipline, self-reliance, self-motivation, etc., which having a nature of habit and are developed in a long-term work socialization process, which begins even before the formal education and will continue throughout the life cycle. However, when the socialization is lost, these habits are depreciated faster than they can be restored. Currently a new generation is entering the labour market, which is missing the succession of work socialization. Factors, such as rising unemployment and poverty in the background over the past twenty years in Latvia have created a very unfavourable employability background of “personal circumstances” and “external factors”, which seriously have impaired formation of the skills and attitudes in a real work environment. The study reveals another paradox – the paradox of poverty. Common sense would want to argue that poverty can be overcome by the job. However, the real state of affairs shows that unfavourable coincidence of the individual, personal circumstances and external factors leads to deficit of employability capacity and possibility of marked social and employment deprivation.

  18. Degradation of {gamma}-HCH spiked soil using stabilized Pd/Fe{sup 0} bimetallic nanoparticles: Pathways, kinetics and effect of reaction conditions

    Singh, Ritu [Ecotoxicology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Raebareli Road, Lucknow 226 025, UP (India); Misra, Virendra, E-mail: [Ecotoxicology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Mudiam, Mohana Krishna Reddy [Analytical Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Chauhan, Lalit Kumar Singh [Petroleum Toxicology Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001, UP (India); Singh, Rana Pratap [Department of Environmental Science, Babasaheb Bhimrao Ambedkar University, Raebareli Road, Lucknow 226 025, UP (India)


    Highlights: Black-Right-Pointing-Pointer This study explores the potential of CMC-Pd/nFe{sup 0} to degrade {gamma}-HCH in spiked soil. Black-Right-Pointing-Pointer Sorption-desorption characteristics and partitioning of {gamma}-HCH is investigated. Black-Right-Pointing-Pointer Three degradation pathways has been proposed and discussed. Black-Right-Pointing-Pointer {gamma}-HCH degradation mechanism and kinetics is elucidated. Black-Right-Pointing-Pointer Activation energy reveals that {gamma}-HCH degradation is a surface mediated reaction. - Abstract: This study investigates the degradation pathway of gamma-hexachlorocyclohexane ({gamma}-HCH) in spiked soil using carboxymethyl cellulose stabilized Pd/Fe{sup 0} bimetallic nanoparticles (CMC-Pd/nFe{sup 0}). GC-MS analysis of {gamma}-HCH degradation products showed the formation of pentachlorocyclohexene, tri- and di-chlorobenzene as intermediate products while benzene was formed as the most stable end product. On the basis of identified intermediates and final products, degradation pathway of {gamma}-HCH has been proposed. Batch studies showed complete {gamma}-HCH degradation at a loading of 0.20 g/L CMC-Pd/nFe{sup 0} within 6 h of incubation. The surface area normalized rate constant (k{sub SA}) was found to be 7.6 Multiplication-Sign 10{sup -2} L min{sup -1} m{sup -2}. CMC-Pd/nFe{sup 0} displayed {approx}7-fold greater efficiency for {gamma}-HCH degradation in comparison to Fe{sup 0} nanoparticles (nFe{sup 0}), synthesized without CMC and Pd. Further studies showed that increase in CMC-Pd/nFe{sup 0} loading and reaction temperature facilitates {gamma}-HCH degradation, whereas a declining trend in degradation was noticed with the increase in pH, initial {gamma}-HCH concentration and in the presence of cations. The data on activation energy (33.7 kJ/mol) suggests that {gamma}-HCH degradation is a surface mediated reaction. The significance of the study with respect to remediation of {gamma}-HCH contaminated soil using

  19. Musical taste, employment, education, and global region.

    North, Adrian C; Davidson, Jane W


    Sociologists have argued that musical taste should vary between social groups, but have not considered whether the effect extends beyond taste into uses of music and also emotional reactions to music. Moreover, previous research has ignored the culture in which participants are located. The present research employed a large sample from five post-industrial global regions and showed that musical taste differed between regions but not according to education and employment; and that there were three-way interactions between education, employment, and region in the uses to which participants put music and also their typical emotional reactions. In addition to providing partial support for existing sociological theory, the findings highlight the potential of culture as a variable in future quantitative research on taste.

  20. Reaction Qualifications Revisited

    Lippert-Rasmussen, Kasper


    of merit. Specifically, it preserves symmetry between negative evaluations of antimeritocratic bases of selection and negative evaluations of qualifications rooted in comparable antimeritocratic reactions. So if employers should not select among applicants on the basis of their (the employers') racial...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... reaction-qualifications are entirely irrelevant from the point of view of merit, the view expounded here implies that the ideal of meritocracy and the norm of non-discrimination are less closely tied than theorists like Andrew Mason and David Miller believe.  ...

  1. Application of quinoxaline based diimidazolium salt in palladium catalyzed cross-coupling reactions

    Mujahuddin M Siddiqui; Mohammed Waheed; Sajad A Bhat; Maravanji S Balakrishna


    The reaction of 2,3-bis(bromomethyl)quinoxaline with imidazole afforded the quinoxaline bridged diimidazolium salt (1) in good yield. Diimidazolium salt (1) in conjunction with Pd(OAc)2 was employed as a catalyst for C–C cross-coupling reactions. The diimidazolium salt was found to be efficient in catalyzing Suzuki-Miyaura cross-coupling reaction in ethanol under ambient conditions. Moderate to good selectivity of the trans product was observed in the Heck cross-coupling reaction. The molecular structure of 1 was confirmed by single crystal X-ray diffraction study.

  2. An alkaline one-pot reaction to synthesize luminescent Eu-BTC MOF nanorods, highly pure and water-insoluble, under room conditions

    Medina-Velazquez, D. Y.; Alejandre-Zuniga, B. Y.; Loera-Serna, S.; Ortiz, E. M.; Morales-Ramirez, A. de J.; Garfias-Garcia, E.; Garcia-Murillo, A.; Falcony, C.


    The increasing demand for optoelectronic devices requires the development of luminescent materials with high luminescence efficiency and low energy demands, and the metalorganic frameworks (MOFs) with lanthanides ions offer great potential in this area. The metalorganic materials provide properties of flexibility, low density, low-cost methods of synthesis, and insolubility in water, which gives them an advantage over traditional phosphors. In this study, a benzenetricarboxylate ligand (BTC) with a Eu3+ MOF was synthesized, and its structural and luminescent properties were measured. The metalorganic compound was generated in a one-pot reaction from europium nitrate and trimesic acid precursors. Through characterization by X-ray diffraction powder, infrared spectroscopy, SEM structural characterization, and luminescent spectroscopy, the formation of Europium benzenetricarboxylate (Eu-BTC) MOF nanorods was tested and the calculated value was in the range of 30-60 nm. A red luminescent emission with high intensity was observed for all the procedures.

  3. The Calculation of the Steam Turbine Governing Stage Enthalpy Drop and Reaction Degree in Off-design Condition%汽轮机调节级变工况时焓降和反动度的计算

    李清; 黄竹青; 王运民; 李亮; 张伦柱


    The calculation of enthalpy drop and reaction degree is an important content and basis of the calculation for governing stage in off-design condition. The calculation method of the steam turbine governing stage enthalpy drop and reaction degree in off-design condition is introduced in this paper, and a instance calculating of a power plant - N600 - 16.67 -538 / 538 -1 steam turbine in Hunan province is simulated by MATLAB software. Finally,the changing curves of governing stage enthalpy drop and reaction degree is drawn according to the calculation results. The results from the research have an important value in theory and application.%调节级焓降和反动度的计算是调节级变工况计算的基础和重要内容.介绍了汽轮机调节级变工况时焓降和反动度的计算方法,并以湖南某电厂N600-16.67 -538/538 -Ⅰ型汽轮机为例,应用MATLAB语言编制计算软件进行了实例计算,根据计算结果绘制了调节级焓降和反动度的变化曲线.研究成果具有重要的理论意义和应用价值.

  4. Experimental Demonstrations in Teaching Chemical Reactions.

    Hugerat, Muhamad; Basheer, Sobhi


    Presents demonstrations of chemical reactions by employing different features of various compounds that can be altered after a chemical change occurs. Experimental activities include para- and dia-magnetism in chemical reactions, aluminum reaction with base, reaction of acid with carbonates, use of electrochemical cells for demonstrating chemical…

  5. Synthesis of naphthoxazinone derivatives using silica-bonded -sulfonic acid as catalyst under solvent-free conditions

    Khodabakhsh Niknam; Parisa Abolpour


    Silica-bonded -sulfonic acid is employed as a recyclable catalyst for the synthesis of naphthoxazinone derivatives from the reaction of -naphthol, aromatic aldehydes and urea at 150°C under solvent-free conditions. The heterogeneous catalyst was recycled for five runs after the reaction of -naphthol, benzaldehyde and urea without losing its catalytic activity.

  6. Reaction mechanisms and kinetics of processing glucose, xylose and glucose-xylose mixtures under hot compressed water conditions for predicting bio-crude composition

    Grigoras, Ionela; Toor, Saqib Sohail; Rosendahl, Lasse Aistrup

    Mechanisms for bio-crude formation during the conversion of glucose, xylose and glucose-xylose mixtures as biomass model compounds under hot compressed water conditions are investigated. Studies in literature have shown that the diverse products formed at the early stages of glucose or xylose con...

  7. Revisiting the Reaction Between Diaminomaleonitrile and Aromatic Aldehydes: a Green Chemistry Approach

    Francisco León


    Full Text Available The reaction between diaminomaleonitrile (DAMN and aldehydes and the resulting monoimines are well known. Since the standard reaction conditions involve the use of toxic solvents (typically methanol, we have sought to apply green chemistry principles to this reaction by either using water as the solvent without any catalysts or employing “solvent-free” conditions. The monoimines derived from DAMN are of interest as precursors for obtaining different heterocyclic systems and linear polymers. The methodologies used have significant advantages with regards to cost and environmental considerations.

  8. Equilibrium coverage of OHad in correlation with platinum catalyzed fuel cell reactions in HClO4

    Deng, Yujia; Arenz, Matthias; Wiberg, Gustav Karl Henrik


    We employ a recently developed stripping protocol to examine the equilibrium coverage of oxygenated species and their influence on the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR). In particular we aim to distinguish between dynamic and steady state conditions and est...

  9. Advancing intercultural competency: Canadian engineering employers' experiences with immigrant engineers

    Friesen, Marcia; Ingram, Sandra


    This paper explores Canadian engineering employers' perceptions of and experiences with internationally educated engineers (recent immigrants to Canada) employed in their organisations for varying lengths of time. Qualitative data were collected from employers using focus group methodology. Findings reflected employers' observations of culturally different behaviours and characteristics in their internationally educated employees, employers' reactions to cultural differences ranging from negative attributions to tolerance, and the implementation of largely ad hoc intra-organisational strategies for managing cultural differences in employer-employee relationships. Findings exposed the lack of corporate intercultural competency in the Canadian engineering profession. Equity and gatekeeping implications are discussed.

  10. Implementing public employment policy

    Larsen, Flemming; Bredgaard, Thomas

    disciplining of the unemployed (work first) (cf.Bredgaard & Larsen, 2005; Sol & Westerweld, 2005). It is, however, remarkable that in the research field there seems to be a division of labour so that changes in public administration and changes in the substance of employment policies are dealt with separately...... an intended policy shift, there seems to be very little public discussion about them. Far-reaching policy changes become politically invisible and de-politicized. Our empirical case is the contracting out of the public employment services in Australia, the Netherlands and Denmark. The main question is what...... happens to public employment policies when they are contracted out to various non-public (for-profit and non-profit) agencies. The data consist of in-depth interviews with key respondents in the three countries, observations at service delivery agencies, and desk studies of existing research....

  11. Implementing public employment policy

    Larsen, Flemming; Bredgaard, Thomas

    disciplining of the unemployed (work first) (cf.Bredgaard & Larsen, 2005; Sol & Westerweld, 2005). It is, however, remarkable that in the research field there seems to be a division of labour so that changes in public administration and changes in the substance of employment policies are dealt with separately....... But there is an interesting question to investigate here: whether and if so how, NPM-inspired reforms are related to changes in employment policy towards a work-first approach? Are changes in public management systems created as deliberate policy changes, or do they bring about more indirect and unintended policy changes...... an intended policy shift, there seems to be very little public discussion about them. Far-reaching policy changes become politically invisible and de-politicized. Our empirical case is the contracting out of the public employment services in Australia, the Netherlands and Denmark. The main question is what...

  12. 反应条件对磷酸铁粒度分布的影响%Effects of reaction conditions on the size distribution of iron phosphate

    骆艳华; 佘世杰; 曹卫国; 潘峰


    The process parameters of preparing iron phosphate in ethanol system were optimized by the method of or-thogonal experiment.The results showed that the influencing order of the parameters affecting the particle size distribu-tion of iron phosphate was ethanol addition rate,reaction temperature and stirring speed.The ethanol adding speed was the key factor to influence the size distribution of iron phosphate.When the addition of ethanol was 40 L/min,the reac-tion temperature was 90℃and the stirring speed was 60 r/min,the d50 of iron phosphate was 0.73μm.When the addi-tion of ethanol was 10 L/min,the reaction temperature was 50℃ and the stirring speed was 120 r/min,the d50 of iron phosphate was 2.10μm.The physical-chemical indicators of iron phosphate were charaterized by SEM,BET and XRF. When d50 was 0.73μm,the BET of iron phosphate was larger than 60 m2/g.When d50 was 2.10μm,the BET of iron phosphate was approximately 45 m2/g.The molar ratio of P and Fe of two kinds of iron phosphate was about 1∶1 .The content of sulfur was relatively high,when the particle size of iron phosphate was smaller.%采用正交实验方法对乙醇体系中制备磷酸铁的工艺参数进行了优化分析,研究结果表明影响磷酸铁粒度分布的工艺参数主次顺序依次为乙醇的加入速度、反应温度和搅拌速度,且乙醇的加入速度是影响磷酸铁粒度分布的关键因素。当乙醇的加入速度为40 L/min,反应温度为90℃,搅拌速度为60 r/min时,制备磷酸铁的d50为0.73μm;当乙醇的加入速度为10 L/min,反应温度为50℃,搅拌速度为120 r/min时,制备的磷酸铁的d50为2.10μm。通过对磷酸铁进行SEM、BET和XRF分析,当d50为0.73μm时,比表面积大于60 m2/g;当d50为2.10μm时,比表面积约为45 m2/g,两种磷酸铁的磷铁物质的量比近似为1∶1,当磷酸铁的粒度较细时,其杂质硫含量相对较高。

  13. Characterization of recombinant nitrile-specifier proteins (NSPs) of Arabidopsis thaliana: dependency on Fe(II) ions and the effect of glucosinolate substrate and reaction conditions.

    Kong, Xiang Yi; Kissen, Ralph; Bones, Atle M


    Glucosinolates are plant secondary metabolites that are part of a plant defence system against pathogens and pests, the myrosinase-glucosinolate system, in which glucosinolates get activated by enzymic degradation through thioglucoside glucohydrolases called myrosinases. Epithiospecifier protein (ESP) and nitrile-specifier proteins (NSPs) divert myrosinase-catalyzed hydrolysis of a given glucosinolate from the formation of isothiocyanate to that of epithionitrile and/or nitrile. As the biological activity of glucosinolate hydrolysis products varies considerably, a detailed characterization of these specifier proteins is of utmost importance to understand their biological role. Therefore, the Arabidopsis thaliana AtNSP1, AtNSP2 and AtNSP5 and a supposed ancestor protein AtNSP-like1 were expressed in Escherichia coli and the activity of the purified recombinant proteins was tested in vitro on three highly different glucosinolates and compared to that of purified AtESP. As previously reported, only AtESP showed epithiospecifier activity on 2-propenylglucosinolate. We further confirmed that purified AtNSP1, AtNSP2 and AtNSP5, but not the ancestor AtNSP-like1 protein, show nitrile-specifier activity on 2-propenylglucosinolate and benzylglucosinolate. We now show for the first time that in vitro AtNSP1, AtNSP2 and AtNSP5 are able to generate nitrile from indol-3-ylmethylglucosinolate. We also tested the effect of different Fe(II) ion concentrations on the nitrile-specifier activity of purified AtNSP1, AtNSP2 and AtNSP5 on 2-propenylglucosinolate and benzylglucosinolate. AtNSP-related nitrile production was highly dependent on the presence of Fe(II) ions in the reaction assay. In the absence of added Fe(II) ions nitriles were only detected when benzylglucosinolate was incubated with AtNSP1. While AtNSP1 also exhibited overall higher nitrile-specifier activity than AtNSP2 and AtNSP5 at a given Fe(II) ion concentration, the pattern of nitrile formation in relation to Fe

  14. Implementing the employability agenda

    Lee, Donna; Snaith, Holly Grace; Foster, Emma


    This article draws on research commissioned by the Higher Education Academy (HEA) and conducted during 2013. It interrogates the ways in which the employability agenda has been fed through to the level of individual politics departments. The project was particularly concerned with establishing...... whether, and how, colleagues in politics and international relations (IR) had taken ownership of student employability at the level of the curriculum. In the article, the key findings of the research are summarised. There is also discussion of the (sometimes troubling) professional implications...

  15. Employment certificates on HRT

    HR Department


    As part of the ongoing drive to simplify and streamline administrative procedures and processes, the IT and HR Departments have made employment certificates available on a self-service basis on the HRT application, in the main menu under "My self services". All members of the personnel can thus obtain a certificate of employment or association, in French or in English, for the present or past contractual period. The HR Department’s Records Office remains responsible for issuing any special certificates that might be required. IT-AIS (Administrative Information Services) HR-SPS (Services, Procedures & Social) Records Office – Tel. 73700

  16. Governing EU employment policy

    Sørensen, Eva; Triantafillou, Peter; Damgaard, Bodil


    In the European Union (EU), employment policy is a prerogative of the member states. Therefore the EU's ability to govern in this area depends on its capability to involve national governments and relevant stakeholders in a collaborative effort to formulate and implement shared policy objectives....... Drawing an analytical distinction between cooperation, coordination and collaboration, the article analyses the formulation and implementation of EU employment policies. It concludes that while the formulation of policy objectives and the discussion of national policy approaches do involve elements...

  17. Comparison of D1´- and D1-containing PS II reaction centre complexes under different environmental conditions in Synechocystis sp. PCC 6803.

    Crawford, Tim S; Hanning, Kyrin R; Chua, Jocelyn P S; Eaton-Rye, Julian J; Summerfield, Tina C


    In oxygenic photosynthesis, the D1 protein of Photosystem II is the primary target of photodamage and environmental stress can accelerate this process. The cyanobacterial response to stress includes transcriptional regulation of genes encoding D1, including low-oxygen-induction of psbA1 encoding the D1´ protein in Synechocystis sp. PCC 6803. The psbA1 gene is also transiently up-regulated in high light, and its deletion has been reported to increase ammonium-induced photoinhibition. Therefore we investigated the role of D1´-containing PS II centres under different environmental conditions. A strain containing only D1´-PS II centres under aerobic conditions exhibited increased sensitivity to ammonium chloride and high light compared to a D1-containing strain. Additionally a D1´-PS II strain was outperformed by a D1-PS II strain under normal conditions; however, a strain containing low-oxygen-induced D1´-PS II centres was more resilient under high light than an equivalent D1 strain. These D1´-containing centres had chlorophyll a fluorescence characteristics indicative of altered forward electron transport and back charge recombination with the donor side of PS II. Our results indicate D1´-PS II centres are important in the reconfiguration of thylakoid electron transport in response to high light and low oxygen. © 2016 John Wiley & Sons Ltd.

  18. The role of Fe and redox conditions in olivine carbonation rates: An experimental study of the rate limiting reactions at 90 and 150 °C in open and closed systems

    Saldi, Giuseppe D.; Daval, Damien; Morvan, Gilles; Knauss, Kevin G.


    The mechanisms and rates of olivine carbonation reactions have been the object of a number of studies, but the thermodynamic limitations and the kinetics of the elementary processes that control the overall reaction are still poorly understood and characterized. The main objective of this study is to probe the effect of Fe on the measured rates of olivine carbonation and its role in the formation of Si-rich surface layers, which can significantly inhibit olivine dissolution and limit the extent of the carbonation reaction. A series of batch and flow-through reactor experiments was conducted in pure water at 90 and 150 °C and under a CO2 partial pressure of 100 and 200 bar, using both a natural sample of Fe-bearing olivine (Fo88) and a synthetic sample of pure forsterite (Fo100). Experimental results show that Fe plays an ambivalent role in the carbonation rates of olivine. On one hand, the presence of Fe favors the formation of Fe-Si-rich protective layers at the interface between olivine and aqueous solution, slowing down the dissolution reaction and limiting the extent of carbonation, whereas pure silica coatings have little to no inhibiting effect on measured carbonation rates. On the other hand, Fe enhances olivine to carbonate conversion rates at low degrees of supersaturation, by promoting the formation of fast precipitating Mg-Fe carbonate solid solutions. The passivating properties of Fe-Si-rich layers originate from the strong Fe(III)-Si interaction and are linked to the permanence of oxidizing conditions in the aqueous fluid. As a consequence, under reducing conditions, olivine carbonation rates can be significantly increased by higher extents of dissolution and by the formation of ferroan magnesites (Mg,Fe)CO3, which nucleate faster than the pure Mg end-member. Forsterite and olivine carbonation reactions can be hindered by the formation of secondary Mg sheet-silicates but, at the conditions studied, the formation of such silicate phases was observed to

  19. Molecular Simulations of RNA 2’-O-Transesterification Reaction Models in Solution

    Radak, Brian K.; Harris, Michael E.; York, Darrin M.


    We employ quantum mechanical/molecular mechanical umbrella sampling simulations to probe the free energy surfaces of a series of increasingly complex reaction models of RNA 2’-O-transesterification in aqueous solution under alkaline conditions. Such models are valuable for understanding the uncatalyzed processes underlying catalytic cleavage of the phosphodiester backbone of RNA, a reaction of fundamental importance in biology. The chemically reactive atoms are modeled by the AM1/d-PhoT quant...

  20. A Stochastic Employment Problem

    Wu, Teng


    The Stochastic Employment Problem(SEP) is a variation of the Stochastic Assignment Problem which analyzes the scenario that one assigns balls into boxes. Balls arrive sequentially with each one having a binary vector X = (X[subscript 1], X[subscript 2],...,X[subscript n]) attached, with the interpretation being that if X[subscript i] = 1 the ball…

  1. Employment Relations in Denmark

    Madsen, Jørgen Steen; Due, Jesper Jørgen; Andersen, Søren Kaj


    Jørgen Steen Madsen, Jesper Due og Søren Kaj Andersen har skrevet et kapitel om udviklingen i dansk arbejdsmarkedsregulering til bogen International and Comparative Employment Relations, redigeret af Greg Bamber, Russell Lansbury og Nick Wailes. Bogen indeholder bidrag, der præsenterer og...

  2. Industrialisation, Exports and Employment.

    Sabolo, Yves


    After reviewing trends in industrial production, exports, and employment in the Third World since 1960, the author discusses industrialization strategies based on the local processing of raw materials for export. Such processing has proved to be a major factor in job creation. (Author/SK)

  3. Challenging Scandinavian employment relations

    Ibsen, Christian Lyhne; Larsen, Trine Pernille; Madsen, Jørgen Steen


    and employment relations in the Danish, Norwegian and Swedish public sector. In this paper, we argue that although differences exist across the Scandinavian countries, it is evident that they have managed to adopt and implement NPM-inspired reforms without dismantling their universal welfare services and strong...

  4. Learning Disabilities and Employment.

    Gerber, Paul J., Ed.; Brown, Dale S., Ed.

    This book provides information on preparing individuals with learning disabilities for the challenges of employment and outlines the rights of those with learning disabilities in the workplace. Introductory chapters in Part 1 include: "Life after School: Challenges in the Workplace" (Paul J. Gerber); "The New Economy in the 21st…

  5. Employer Engagement in Education

    Mann, Anthony; Dawkins, James


    The subject of this paper is employer engagement in education as it supports the learning and progression of young people through activities including work experience, job shadowing, workplace visits, career talks, mock interviews, CV workshops, business mentoring, enterprise competitions and the provision of learning resources. Interest has grown…

  6. Shifting employment revisited

    Cremers, Jan; Gramuglia, Alessia


    The CLR-network examined in 2006 the phenomenon of undeclared labour, with specific regard to the construction sector. The resulting study, Shifting Employment: undeclared labour in construction (Shifting-study hereafter), gave evidence that this is an area particularly affected by undeclared activi

  7. Employability through covenants

    Korver, T.; Oeij, P.R.A.


    How can a sustainable employment insurance system be guaranteed as a major element of the ESM? First a summary overview of the Lisbon targets and their impact on the policies of and in the member states of the European Union is given. Then follow data and problems associated with the target of enhan

  8. Vietnamese Students Employability Skills

    Tuan, Nguyen Minh


    This paper attempts to investigate if the International University (IU) students' core competencies can meet the requirements set by employers, what are the differences in core competencies in final year students (or undergraduates), and how they view themselves compared with ex-students after one or two years in working environment, how…

  9. Atherton–Todd reaction: mechanism, scope and applications

    Stéphanie S. Le Corre


    Full Text Available Initially, the Atherton–Todd (AT reaction was applied for the synthesis of phosphoramidates by reacting dialkyl phosphite with a primary amine in the presence of carbon tetrachloride. These reaction conditions were subsequently modified with the aim to optimize them and the reaction was extended to different nucleophiles. The mechanism of this reaction led to controversial reports over the past years and is adequately discussed. We also present the scope of the AT reaction. Finally, we investigate the AT reaction by means of exemplary applications, which mainly concern three topics. First, we discuss the activation of a phenol group as a phosphate which allows for subsequent transformations such as cross coupling and reduction. Next, we examine the AT reaction applied to produce fire retardant compounds. In the last section, we investigate the use of the AT reaction for the production of compounds employed for biological applications. The selected examples to illustrate the applications of the Atherton–Todd reaction mainly cover the past 15 years.

  10. Biological characterization of ingredients in OPLC-BioArena-greenhouse-system. Unique reactions of endogenous HCHO and O{sub 3} in in vitro and in vivo conditions

    Tyihak, Ernoe; Moricz, Agnes M.; Ott, Peter G.; Katay, Gyoergy [Hungarian Academy of Sciences, Budapest (Hungary). Centre for Agricultural Research; Mincsovics, Emil [OPLC-NIT Ltd., Budapest (Hungary); Corvinus Univ., Budapest (Hungary). Dept. of Genetics and Plant Breeding


    In the case of two ''old medicines'', the extension of the results from the in vitro BioArena studies was successfully solved for in vivo (greenhouse) conditions. These preliminary results of in vitro and in vivo studies confirmed the unique role and function of HCHO and O{sub 3} in the antibiotic effect of these two chemical substances, and in the basal and induced resistance. In the future, for the characterization of known and new active substances, in vitro and in vivo biological studies will be recommended in addition to chemical and physical characterization. (orig.)

  11. Reaction of 1,2,3,4-Diepoxybutane with 2′-Deoxyguanosine: Initial Products and Their Stabilities and Decomposition Patterns under Physiological Conditions

    Zhang, Xin-Yu; Elfarra, Adnan A.


    1,2,3,4-Diepoxybutane (DEB), an in vivo metabolite of 1,3-butadiene (BD), is a carcinogen and a potent mutagen. Previously, DEB was shown to react with 2′-deoxyguanosine (dG) under physiological conditions to produce seven major nucleoside adducts resulting from alkylation at the N1- (P8 and P9), N7- (P5 and P5′) and both the N1- and N2-positions of dG to form six-membered (P4-1 and P4-2) and seven-membered fused ring systems (P6), respectively (Zhang and Elfarra, Chem. Res. Toxicol. 2003, 16...

  12. Sn-PILC: A novel Efficient and Recyclable Catalyst for One-pot Three Component Povarov’s Inverse-electron-demand Hetero Diels-Alder Reaction for a Facile Synthesis of Tetrahydropyranoquinoline Derivatives under Neat Conditions

    Megha Rai


    Full Text Available The Povarov’s inverse-electron-demand hetero Diels–Alder one-pot three components reaction of aromatic aldehyde, aromatic amine with DHF has been developed using Sn-PILC as a catalyst under a neat condition which may helpful to society to get pharmacologically more active compounds. In the present study a novel series of tetrahydroquinoline 4(a-f were synthesized and characterized by IR, 1HNMR, 13CNMR, Mass spectral analysis and elemental analysis. The synthetic details and characterization results are discussed. DOI:

  13. Establishment of the best reaction condition for the M protein genes of porcine epidemic diarrhoea virus in RT-PCR%PEDV膜蛋白基因RT-PCR最适反应条件的确立

    乔宪凤; 熊忠良; 华文君; 郑新民


    以猪流行性腹泻病毒(PEDV)的RNA为模板,探讨了影响猪流行性腹泻病毒(PEDV)的RT-PCR反应的各种因素,确立了RT-PCR的最适反应条件。%RNA of porcine epidemic diarrhoea virus was used as template. The article discussed all kinds of factors affected porcine epidemic diarrhoea virus in RT-PCR and established its best reaction condition.

  14. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    Zhao, Yujun


    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction\\'s stereoselectivity. © 2012 The Royal Society of Chemistry.

  15. Synthesis of functionalized benzofurans by iodocyclization reaction of alkynylanisoles

    Carlise Frota


    Full Text Available Benzofurans are important synthetic building blocks present in a high number of biologically active natural products, pursuing several medicinal properties. In this context, there is an increasing interest in developing efficient syntheses for this class of compounds. Accordingly, we present in this work our preliminary results involving the iodocyclization reaction of 2-iodo-6-alkynylanisoles, employing molecular iodine under mild conditions, leading to the formation of highly functionalized benzofurans, potential precursors of pharmaceuticals and functional materials.

  16. Excess water generation during reaction-inducing intrusion of granitic melts into ultramafic rocks at crustal P-T conditions in the Sør Rondane Mountains of East Antarctica

    Uno, Masaoki; Okamoto, Atsushi; Tsuchiya, Noriyoshi


    Arc magmas are one of the main sources of aqueous geofluids in the crust, and the movement of fluids above magma chambers has been geophysically imaged. Here, we constrain the water budget (i.e., supply, consumption and release of H2O) in these areas above magma chamber by examining the hydration caused by crust-melt reactions in the Sør Rondane Mountains of East Antarctica. The study area contains a phlogopite-pargasite-peridotite unit that has been intruded by numerous granitic dikes, creating hydration reaction zones at the dike-peridotite boundary. These reactions occurred at 0.5 GPa and 700 °C, corresponding to middle crustal conditions, and generated a series of reaction zones with distance from the granitic dikes as follows: (i) granitic dike, (ii) pargasite-actinolite zone, (iii) tremolite-phlogopite zone, (iv) anthophyllite-phlogopite zone, (v) phlogopite-olivine-orthopyroxene zone, and (vi) unaltered pargasite-phlogopite peridotite. The presence of amphiboles with a preferred orientation perpendicular to the dike margins and an absence of Cr-rich magnetite indicate that the pargasite-actinolite zone [zone (ii)] grew from the dike margins as a result of the dike reacting with the host rock, with an initial melt/rock boundary located between zones (ii) and (iii). The H2O contents of reaction zones (ii)-(v) are higher than the content in the hosting pargasite-phlogopite peridotite, suggesting that the intrusion of the dike was associated with hydration reactions. Geochemical analysis along a profile through the reaction zones indicates Mg and Fe depletion, and Si enrichment in zones (iii)-(iv), and Ca depletion and K enrichment in zones (iv)-(v) relative to the hosting pargasite-phlogopite peridotite. In contrast, zone (ii) is characterized by Ca, Fe, and Mg enrichments relative to the granitic dike. These observations suggest that the reaction zone sequence was formed by the elemental transfer between granitic dike and parasite-phlogopite peridotite: Ca

  17. In situ formation of the amino sugars 1-amino-1-deoxy-fructose and 2-amino-2-deoxy-glucose under Maillard reaction conditions in the absence of ammonia.

    Nashalian, Ossanna; Yaylayan, Varoujan A


    Replacing amino acids with their binary metal complexes during the Maillard reaction can initiate various processes, including the oxidative degradation of their glucose conjugates, generating 1-amino-1-deoxy-fructose and its derivatives. These reactive amino sugars are not easily accessible under Maillard reaction conditions and are only formed in the presence of ammonia. To explore the generality of this observation and to study in particular the ability of fructose to generate glucosamine, the amino acid-metal complexes were heated in aqueous solutions with three aldohexoses and two ketohexoses at 110°C for 2 h and the dry residues were analysed by ESI/qTOF/MS/MS. All the sugars generated relatively intense ions at [M+H](+) 180 (C6H14NO5); those ions originating from ketohexoses exhibited MS/MS fragmentations identical to glucosamine and those originating form aldohexoses showed ions identical to fructosamine. Furthermore, the amino sugars were found to form fructosazine, react with other sugars and undergo dehydration reactions.

  18. Ligand discrimination in the reaction of nitrones with [PtCl2(PhCN)2]. Selective formation of mono-oxadiazoline and mixed bis-oxadiazoline complexes under thermal and microwave conditions.

    Desai, Bimbisar; Danks, Timothy N; Wagner, Gabriele


    [2+3] Cycloaddition of nitrones to the nitrile ligands in the complexes cis- or trans-[PtCl2(PhCN)2] occurs under ligand differentiation and allows for selective synthesis of complexes of the type cis- or trans-[PtCl2(oxadiazoline)(PhCN)]. Microwave irradiation enhances the reaction rates of the cycloaddition considerably and further favours the selectivity towards the mono-cycloadduct with respect to thermal conditions, because the first cycloaddition is accelerated to a higher extent than the second one. Reaction of the trans-substituted mono-oxadiazoline complexes with a nitrone different from the one used for the first cycloaddition step gives access to mixed bis-oxadiazoline compounds of the composition trans-[PtCl2(oxadiazoline-a)(oxadiazoline-b)]. The corresponding cis-configured complexes, however, do not undergo further cycloaddition. All reactions described occur without isomerisation of the stereochemistry around the platinum center, independently of whether thermal or microwave heating is applied.

  19. Epidemiological approach to the study of conditions of employment, labor and health in the Colombian immigrant population of Spain / Aproximación epidemiológica al estudio de las condiciones de empleo, trabajo y salud en la población inmigrante colombiana en España

    Andrés A. Agudelo-Suárez


    Full Text Available The objective of this paper is to analyze the employment, work conditions, and associated health problems of Colombian immigrants. Methods: an epidemiological and descriptive study was conducted in the Colombian immigrant population (employed and unemployed by means of a personal survey in a sample of immigrants. The survey concerned personal characteristics, working conditions, and health indicators. Results: there is an important percentage of immigrants with a temporary contract or without any contract, and working more than 40 hours per week. One fifth of the immigrants do not have social security coverage. The great majority of women (92% have incomes under 1,200 euros/month. Immigrants reported discrimination in work and social spaces. Immigrants report several health problems, with some differences between genders. Almost one third has not received information on accident prevention and health issues. Situations of social precariousness are demonstrated, which require strategies to guarantee social protection mechanisms for this entire collective.

  20. The constructive technique and its application in solving a nonlinear reaction diffusion equation

    Lai Shao-Yong; Guo Yun-Xi; Qing Yin; Wu Yong-Hong


    A mathematical technique based on the consideration of a nonlinear partial differential equation together with an additional condition in the form of an ordinary differential equation is employed to study a nonlinear reaction diffusion equation which describes a real process in physics and in chemistry. Several exact solutions for the equation are acquired under certain circumstances.

  1. Synthesis of Quinoxaline Derivatives via Tandem Oxidative Azidation/Cyclization Reaction of N-Arylenamines.

    Ma, Haichao; Li, Dianjun; Yu, Wei


    A new method was developed for the synthesis of quinoxalines. This method employs N-arylenamines and TMSN3 as the starting materials and implements two oxidative C-N bond-forming processes in a tandem pattern by using (diacetoxyiodo)benzene as the common oxidant. The present reaction conditions are mild and simple and thus are useful in practical synthesis.

  2. Predictors of employment after liver transplantation.

    Sahota, Amandeep; Zaghla, Hassan; Adkins, Rodney; Ramji, Alnoor; Lewis, Susan; Moser, Jennifer; Sher, Linda S; Fong, Tse-Ling


    Employment after orthotopic liver transplantation (OLT) indicates recipients' physical/psychosocial adjustment. Our aim was to determine clinical, socioeconomic and health-related quality of life parameters influencing employment after OLT. Questionnaire on demographics, medical conditions, alcohol and drug use before/after OLT, and a validated 12-Item Short Form Health Survey (SF-12) were mailed to 126 adult OLT patients. Stepwise logistic regression was conducted to identify best predictors of post-OLT employment. Among non-retirees, 49% were employed after OLT. The predictors of employment were: employment status, income, disability status before OLT and Model of End Stage Liver Disease score. These variables had prediction rate of 82%. Individuals working during the five yr prior to OLT were likely to return to work (p6 months prior to OLT (p$80 000 before OLT compared with or=6 months prior to OLT, were less likely to work (p=0.0005). Severity/duration of liver dysfunction prior to OLT did not correlate with employment. Sense of physical health was poorer in those employed after OLT than in unemployed (p=0.0003). Socioeconomic factors were the most important predictors of post-OLT employment.

  3. Entrepreneurship and Employment Stability

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke


    are identified and empirically explored: (i) job matching, (ii) labour market value, and (iii) personal commitment. Entrepreneurs appear to be more productive and thus better matched compared to wageworkers. However, they also appear to be locked in entrepreneurship because of their anticipated lower value...... in the labour market and because of their personal attachment to the venture. The counter-intuitive finding – entrepreneurship yields greater employment stability – only holds with respect to subsequent transitions to wagework and not for new venture founding. The results have implications for our understanding......This paper challenges the conventional belief that entrepreneurship is an unstable career path. Using longitudinal matched employer–employee data from Denmark, the analysis reveals that a transition to entrepreneurship decreases individual's employment turnover tendency. Three explanations...

  4. Rebirth through supported employment.

    Strickler, David C


    In this column, the author describes how supported employment was a conduit for employment for him, and allowed for a remarkable journey of recovery, involving discovery and empowerment, incorporation, purpose, and belonging. After two decades of unemployment or underemployment, he began to see that work was possible through supported education at college, where he excelled. Federal and state grants paid for two thirds of his college education. He periodically met with a vocational rehabilitation counselor, who was very encouraging. He also had a case manager through a private psychiatric organization who provided support. The author concludes that the root of his problems was the lack of supports to help him become incorporated into society-a lack that ushered in a host of problems, probably similar to what others experience. When supports were given, many of those symptoms disappeared.

  5. Small business & employment

    Lieshout, Harm van


    Understanding SMEs is essential to our aspired succes as an economic partner. Small enterprises are not small big enterprises, and differ substantially among them The key ingredient to our help from education remains the education of a new highly skilled generation of workers … and entrepreneurs. Entrepreneurs do not necessarily want to be employers, and are not necessarily good at it. But to ensure a healthy life in a healthy business, they need to be.

  6. Languages and Employability



    This report reviews evidence regarding the foreign language competences of European citizens and presents new findings about the relationship between foreign language skills and the likelihood of being in employment. In view of providing research evidence that can inform European Union (EU) policy initiatives, it reviews studies that frame knowledge of languages as a form of human capital, presents descriptive statistics about language knowledge and investigates whether this knowledge is rela...

  7. Soldiers’ employment attitude and employability: An exploratory study

    Peng Gao


    Full Text Available Purpose: Nowadays it is very difficult for Chinese retired soldiers to find proper jobs, and the primary reason is the significant gap between job requirements and soldiers owned job skills. Therefore, it is very important to improve the soldiers’ job skills and enhance their understanding of employment.Design/methodology/approach: This paper expands the study scope from the soldiers’ job skills to the employability, initiatively introduces the employment attitude which has obvious impact on the employment of soldiers, and analyses the influence that employment attitude can play on employability. At last, this paper develops statistical method to find the relationship between soldiers’ employment attitude and employability.Findings: The empirical analysis shows that soldiers’ employment attitude has the positive linkage with employability, which makes the employment attitude a measurable variable for the employability rather than an absolute standard.Research limitations/implications: According to the research purpose, more variables should be considered in the model, consequently, there are only three indicators to describe solders’ employment attitude and four indicators to describe solders’ employability.Originality/value: This paper takes research on soldiers’ employability in a new perspective. The soldiers’ employment attitude is served as the entry point, showing the influence that soldiers’ employment attitude has on employability.

  8. Investigating Ionic Effects Applied to Water Based Organocatalysed Aldol Reactions

    Joshua P. Delaney


    Full Text Available Saturated aqueous solutions of various common salts were examined for their effect on aqueous aldol reactions catalysted by a highly active C2-symmetric diprolinamide organocatalyst developed in our laboratory. With respect to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, deionised water was always a superior medium to salt solutions though some correlation to increasing anion size and depression in enantiomeric excess could be observed. Additionally, the complete inhibition of catalyst activity observed when employing tap water could be alleviated by the inclusion of ethylenediaminetetraacetate (EDTA into the aqueous media prior to reaction initiation. Extension of these reaction conditions demonstrated that these ionic effects vary on a case-to-case basis depending on the ketone/aldehyde combination.

  9. Water O-H bond activation by gas-phase plutonium atoms: reaction mechanisms and ab initio molecular dynamics study.

    Li, Peng; Niu, Wenxia; Gao, Tao; Wang, Hongyan


    A thorough description of the reaction mechanisms, taking into account different possible spin states, offers insights into the gas-phase reaction of plutonium atoms with water. Two possible reactions (isomerization and dehydrogenation) are presented. These reactions are found to be exothermic, with the best thermochemical conditions observed for the dehydrogenation reaction at around 23.5 kcal mol(-1). The nature of the chemical-bonding evolution along the reaction pathways are investigated by employing various methods including electron localization function, atoms in molecules, and Mayer bond order. Total, partial, and overlap population density of state diagrams and analyses are also presented. Reaction rates at elevated temperatures (T=298-2 000 K) are calculated by using variational transition-state theory with one-dimensional tunneling effects. In dynamics simulations, only the dehydrogenation reaction is observed, and found to be in good agreement with experimental values.

  10. Optimization of transesterification reaction conditions for the production of biodiesel from oil blend of castor bean and soybean; Otimizacao das condicoes reacionais de transesterizacao para producao de biodiesel a partir de mistura de oleos de mamona e soja

    Lobato, Ana Katerine de Carvalho Lima; Lima, Milena Gouveia Oliveira de; Pontes, Luiz Antonio M.; Teixeira, Leonardo S.G. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Almeida, Daniel Freire; Costa, Tales Santana Martins; Menezes; Mateus Della Cella; Santos, Iran Talis Viana; Almeida, Selmo Q. [Universidade Salvador (UNIFACS), BA (Brazil)


    Biodiesel is an alternative fuel to diesel oil, and industrially obtained by the transesterification of triglycerides of fatty acids from vegetable oils and/or animal fats. Currently, the main raw material used to produce biodiesel in Brazil is soybean oil. The inclusion of other raw materials from different cultures in this sector is important and aims to reduce dependence on a single oilseed, assign specific characteristics to the product and encourage the development of family farming. The use of blends of soybean oil and castor for biodiesel may prove an important strategy to minimize the negative effects and maximize the positives of each oilseed. In this work, we carried out an experimental study using full factorial design 2{sup 4}, to increase the conversion of esters, by conventional transesterification, using as feedstock a blend of oils containing 20% castor and 80% soybean. The aim of this study was to evaluate the influence of mixing ratio of oil: methanol, KOH concentration, temperature and reaction time in biodiesel production. It was found that the variation of these parameters affected the conversion of esters and quality of biodiesel produced. Conversions above 95% were obtained, and the best conversion was 99.05% at 25 deg C in a reaction time of 20 minutes using 2% KOH as a catalyst and a molar ratio methanol/oil 12:1. In order to reduce the costs of the process with respect to amount of methanol used without affecting the conversion of esters, we identified a second set of process conditions, which used the same conditions of temperature, reaction time and catalyst concentration and a different molar ratio methanol/oil (6:1) which gave a conversion of esters of 98.59%. (author)

  11. Shape and catalytic mechanism of RuO{sub 2} particles at CO oxidation reaction conditions. First-principles based multi-scale modeling

    Reuter, Karsten [TU Muenchen (Germany). Lehrstuhl fuer Theoretische Chemie


    For model catalyst studies on low-index single-crystal surfaces close agreement between detailed measurements and quantitative microkinetic modeling can increasingly be achieved. However, for 'real' catalyst particles, such structure-morphology-activity relationships are only scarcely established. This is prototypically reflected by the situation for RuO{sub 2}, as a most active catalyst for CO oxidation. Here, existing first-principles kinetic modeling is restricted to just one facet, namely the RuO{sub 2}(110) surface, which is not able to fully account for activity data obtained from polycrystalline RuO{sub 2} powder catalysts. The overarching objective of this project was correspondingly to close this gap and demonstrate that similarly close agreement as for individual single-crystal model catalysts can also be achieved for catalyst particles. Specifically, we addressed experiments where an intact RuO{sub 2} bulk structure is conserved, and establish the atomic-scale structure and reactivity of other RuO{sub 2} low-index facets under the gas-phase conditions characteristic for catalytic CO oxidation.

  12. Mixture formation and pre-reaction in an injection jet in Diesel engine boundary conditions; Gemischbildung und Vorreaktionen in einem Einspritzstrahl unter dieselmotorischen Randbedingungen

    Eisele, G.; Koss, H.J.; Knoche, K.F.


    To examine the mixture formation and combustion, fuel is injected in Diesel engine boundary conditions in a pressure chamber. Spectroscopic methods permit the noncontact investigation with high spatial and temporal resolution of the physical and chemical processes. The jet of an excimer laser is focussed in the injection jet for this purpose. The local mixture compostion is determined from the Raman spectra, and fluorescence spectra permit one to obtain qualitative information on the appearance and distribution of the OH and NH radicals in the injection jet. For example, it was found that with a chamber temperature of 500 C, the first clear OH fluorescence occurs about 1.8 ms after the start of injection at the edge of the jet in the area of lean mixture. (orig.) [Deutsch] Zur Untersuchung der Gemischbildung und Verbrennung wird Kraftstoff unter dieselmotorischen Randbedingungen in einer Druckkammer eingespritzt. Spektroskopische Methoden erlauben die beruehrungslose und zudem oertlich und zeitlich hochaufgeloeste Untersuchung der physikalischen und chemischen Vorgaenge. Dazu wird der Strahl eines Excimerlasers in den Einspritzstrahl fokussiert. Aus Ramanspektren laesst sich die lokale Gemischzusammensetzung bestimmen, Fluoreszenzspektren erlauben qualitative Aussagen ueber Auftreten und Verteilung der OH- und NH-Radikale im Einspritzstrahl. So zeigt sich zum Beispiel, dass bei einer Kammertemperatur von 500 C die ersten deutlichen OH-Fluoreszenzen ca. 1,8 ms nach Einspritzbeginn am Strahlrand im Bereich mageren Gemisches auftreten (orig.)

  13. Employment opportunities for the disabled

    Delsen, L.W.M.


    Policy makers in the OECD Member States have developed quite different programmes and institutional arrangements to create and promote employment opportunities for the disabled. These policy approaches include legal interventions, employment support services, financial support of open employment and

  14. The impact of Chilean migration on employment in Patagonia.

    Cariola Sanz, L


    This paper discusses the employment situation of Chilean migrant workers, their impact on labor markets in Patagonia, Argentina, and the government's past and projected responses to this phenomenon. In 1980, Chilean inhabitants of patagonia comprised 11% of the area's population. Chilean migration to patagonia was closely linked to economic activities that began to flourish in the 20th century, such as livestock raising, fruit and vegetable cultivation, and mining for coal and petroleum. No Chilean migrants work in a wide range of sectors. In Patagonia's southern provinces availability and ability to withstand rigorous climate conditions are the main factors which account for the prevalence of Chilean manpower. Chilean migrants do not in general displace local manpower. Legislation and the permeability of the border ensure that most workers enter the country as tourists. Clandestine migration is not an issue. Illegal migrants have provoked negative reactions for several reasons: 1) they comprise a marginal population without formal citizenship; 2) being employed as clandestine workers, they pay no social security, nor do their employers; 3) being illegal, they are obliged to accept lower wages and inferior working conditions which creates unfair competition within labor markets; and 4) as a result of these conditions, xenophobic and endophobic attitudes in relations with Argentine nationalists are reinforced. The government has attempted to solve these problems through various measures. Beginning in 1934, most foreigners entered Argentina with a tourist visa, becoming illegal when they stayed beyond authorized limits. Several measures over the years provided amnesty to illegal migrants. Currently, the law promotes immigration, monitors the admission of foreigners to the country and stipulates their rights and obligations. The law lists 115 articles on immigration promotion and on regulation of the movements of foreigners. Because of the present economic crisis in

  15. Employment and winter construction

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig


    Reduced seasonal building activity in the construction sector is often assumed to be related to hard winter conditions for building activities and poor working conditions for construction workers, resulting in higher costs and poor quality of building products, particularly in the northern hemisp...

  16. New Objective and Measures Needed to Promote Employment



    In 2006,China’s employment situation improved from three respects:1)employment and reemployment gained momentum;2)labour relations adjustment was further strengthened;3)peasant-worker conditions underwent positive changes.In 2007,China’s employment situation faces both sound growth opportunities and numerous acute contradictions in employment size and growth adjustment.Moreover,China also faces the daunting challenges of population aging,employment diversification and rapid urbanization.To better cope with such challenges,the government should set out new employment objectives and undertake a series of measures to promote employment.

  17. O Estado como empregador de última instância: uma proposta de pleno emprego, estabilidade e condições dignas de trabalho para o Brasil The government as an employer of last resort: a proposal for full employment, stability and fair working conditions for Brazil

    Zoraide Bezerra Gomes


    Full Text Available Este trabalho objetiva compreender a estrutura conceitual e teórica do programa empregador de última instância (ELR e fazer um levantamento dos argumentos pró e contra a implantação do programa no Brasil. Sendo o desemprego estrutural um problema que afeta as economias capitalistas do mundo inteiro, seria possível eliminá-lo da economia brasileira sem gerar um processo inflacionário? Como ainda argumentam os economistas do novo consenso, seria necessário para tanto promover uma política de flexibilização do mercado de trabalho? A hipótese fundamentada na teoria crítica de Minsky (1986 e Wray (2003 sobre o desenvolvimento contemporâneo do capitalismo é que, se o Estado atuar como ELR, o desemprego estrutural poderá ser totalmente eliminado da economia sem provocar um processo inflacionário ou incorrer nos possíveis malefícios causados pela flexibilização trabalhista.This paper aims to understand the conceptual and theoretical framework of the employer of last resort (ELR program and analyze the arguments in favor of and against its implementation in Brazil. As structural unemployment is a problem which affects all capitalist economies around the world, would it be possible to eliminate it from the Brazilian economy without generating an inflationary process? Or, as the economists of the new consensus argue, would it be necessary to promote a labor market reform policy? The hypothesis, based on the critical theory of Minsky (1986 and Wray (2003 on the contemporary development of capitalism, is that if the government acts as an ELR, structural unemployment could be entirely eliminated from the economy without provoking an inflationary process, nor experiencing negative effects caused by labor market reform policies.

  18. Reaction Graph



    The paper proposes reaction graphs as graphical representations of computational objects.A reaction graph is a directed graph with all its arrows and some of its nodes labeled.Computations are modled by graph rewriting of a simple nature.The basic rewriting rules embody the essence of both the communications among processes and cut-eliminations in proofs.Calculi of graphs are ideentified to give a formal and algebraic account of reaction graphs in the spirit of process algebra.With the help of the calculi,it is demonstrated that reaction graphs capture many interesting aspects of computations.

  19. 2007 Veterans Employability Research Survey

    Department of Veterans Affairs — The 2007 Veterans Employability Research Survey (VERS) was conducted to determine the factors that impact veterans' employability resulting from participation in the...

  20. 2007 Veterans Employability Research Survey

    Department of Veterans Affairs — The 2007 Veterans Employability Research Survey (VERS) was conducted to determine the factors that impact veterans' employability resulting from participation in the...

  1. Graduate Employability: A Conceptual Framework for Understanding Employers' Perceptions

    Cai, Yuzhuo


    This study provides a conceptual framework for understanding what employers think about the value of graduates with similar educational credentials in the workplace (their employability), using insights from the new institutionalism. In this framework, the development of employers' beliefs about graduates' employability is broken into a number of…

  2. Employment without Growth

    Nørgaard, Jørgen

    Employment is a central argument for economic growth in the Western world. But environmental problems like global warming points towards limits to growth. The presentation outlines the history of what has lead to this dilemma. Fortunately citizens attitudes now points towards a preference for less...... more work. There are no indication that growth at Western economies increases satisfaction or happiness. A new look at the full economy divides it into professional economy and amateur economy, and it is suggested that a reversal of the trend hitherto to draw still more of the whole economy...

  3. Challenging Scandinavian employment relations

    Ibsen, Christian Lyhne; Larsen, Trine Pernille; Madsen, Jørgen Steen


    and employment relations in the Danish, Norwegian and Swedish public sector. In this paper, we argue that although differences exist across the Scandinavian countries, it is evident that they have managed to adopt and implement NPM-inspired reforms without dismantling their universal welfare services and strong......Building on the convergence/divergence approach, this paper examines whether recent new public management (NPM) inspired reforms entailing inter alia cutbacks in the public sector, marketisation and management by performance measures have had significant implications for service provision...... traditions of collective bargaining in the public sector. However, this restructuring is taking its toll on the work environment....


    Valentina VASILE


    Full Text Available In consideration of the Lisbon Agenda, the Romanian Government drew up the National Programme for Reform for 2007-2010, which established national priorities, and ways and tools to achieve economic reform and growth. Transition in Romania implied a complex and extensive system of regulations and institutions for stimulating employment and creating a flexible system of social protection. The new regulations were focused on harmonisation with the Community labour law. Increasing investment in human capital is essential for a competitive and dynamic economy. Besides, labour market policies were formulated for correcting labour market imbalances.

  5. How do employers cope with an ageing workforce?: Views from employers and employees

    Hendrik P. Van Dalen


    Full Text Available How age-conscious are human resource policies? Using a survey of Dutch employers, we examine how employers deal with the prospect of an ageing work force. We supplement our analysis with an additional survey of Dutch employees to compare human resource policies to practices. Results show that a small minority of employers are taking measures to enhance productivity (training programmes or bring productivity in line with pay (demotion. Personnel policies tend to 'spare' older workers: giving them extra leave, early retirement, or generous employment protection: older workers who perform poorly are allowed to stay, whereas younger workers under similar conditions are dismissed.

  6. Life Sciences and employability

    Wynand J. Boshoff


    Full Text Available This article addresses unemployment in rural areas. South Africa is also characterised by skills shortage and high unemployment figures, especially in rural areas as compared to urban areas. The institutional reality of education is that every rural village hosts a high school which is primarily engaged in preparing learners for further studies, whilst the Further Training Colleges (previously known as technical colleges are mainly located in the larger centres. It is with this scenario as a backdrop that the possible role of high schools to alleviate the problem is being argued. It is clear that rural employers do not expect from school leavers to be in possession of applicable knowledge, but rather to be in possession of the ability as well as certain personal characteristics that would make them employable. Unfortunately, however, this is not always found in young persons who have completed their schooling successfully. Life Sciences educators can render a valuable service should certain nontraditional approaches be incorporated into the teaching practice. This will enable them to contribute to solving one of South Africa’s serious problems.

  7. Employability Skills Assessment Tool Development

    Rasul, Mohamad Sattar; Rauf, Rose Amnah Abd; Mansor, Azlin Norhaini; Puvanasvaran, A. P.


    Research nationally and internationally found that technical graduates are lacking in employability skills. As employability skills are crucial in outcome-based education, the main goal of this research is to develop an Employability Skill Assessment Tool to help students and lecturers produce competent graduates in employability skills needed by…

  8. Employment in the Public Sector.

    Organisation for Economic Cooperation and Development, Paris (France).

    This report synthesizes the findings from several areas of work undertaken to assess what impact public sector employment has had on both the level and structure of employment. It also examines the impact of the public sector as employer on the labor market from two viewpoints: the level and share of public sector employment and the structure of…

  9. Employability. NIACE Briefing Sheet 88

    National Institute of Adult Continuing Education, 2009


    Employability skills are central to gaining and keeping employment (e.g. whether paid or unpaid, as an employee or self employed) as well as career progression. The lack of such skills is regularly referred to as one reason for the United Kingdom's often cited long tail of underachievement. Employability skills are at the forefront of government…

  10. Severe photosensitivity reaction induced by topical diclofenac

    Akat, Pramod B.


    Albeit uncommon, photosensitivity reaction induced by diclofenac can be an unfortunate adverse reaction complicating its use as a topical analgesic. We here present a case of a patient who suffered such a reaction as a result of exposure to diclofenac, employed as a topical analgesic for low backache. The lesions healed with conservative management without extensive scarring or other complications.

  11. Severe photosensitivity reaction induced by topical diclofenac

    Pramod B Akat


    Full Text Available Albeit uncommon, photosensitivity reaction induced by diclofenac can be an unfortunate adverse reaction complicating its use as a topical analgesic. We here present a case of a patient who suffered such a reaction as a result of exposure to diclofenac, employed as a topical analgesic for low backache. The lesions healed with conservative management without extensive scarring or other complications.

  12. Employment Trajectories Beyond Retirement.

    Burkert, Carola; Hochfellner, Daniela


    Within the political and academic debate on working longer, post-retirement employment is discussed as an alternative to maintain older workers in the labor market. Our article enhances this discussion by studying determinants of transitions into post-retirement jobs within differing work environments of birth cohorts 1940-1942. We estimate proportional subhazard models accounting for competing risks using unique German social security data linked to pension accounts. Our findings suggest that individuals' preferences to take up post-retirement jobs are not mutually exclusive. Our study provides evidence that taking up post-retirement jobs is related to seeking financial security, continuity, and work ability, suggesting that public policy has to develop target-oriented support through a public policy mix of different measures aligned to the different peer groups in the labor market.

  13. 反应条件对钌催化剂和铁催化剂的氨合成性能影响%Effects of Reaction Conditions on Performance of Ru Catalyst and Iron Catalyst for Ammonia Synthesis*

    潘崇根; 李瑛; 蒋文; 刘化章


    Activated carbon-supported Ru-based catalyst and A301 iron catalyst were prepared, and the influences of reaction temperature, space velocity, pressure, and H2/N2 ratio on performance of iron catalyst coupled with Ru catalyst in series for ammonia synthesis were investigated. The activity tests were also performed on the single Ru and Fe catalysts as comparison. Results showed that the activity of the Ru catalyst for ammonia synthesis was higher than that of the iron catalyst by 33.5%-37.6% under the reaction conditions: 375-400 ℃, 10 MPa, 10000 h-1, H2: N2 = 3, and the Ru catalyst also had better thermal stability when treated at 475 ℃ for 20 h. The outlet ammonia concentration using Fe-Ru catalyst was increased by 45.6%-63.5% than that of the single-iron catalyst at low temperature (375-400 ℃), and the outlet ammonia concentration increased with increasing Ru catalyst loading.

  14. Difusão de contaminantes em condições de vento fraco empregando um modelo estocástico Lagrangeano Difusion of contaminants in low wind conditions employing a Lagrangian stochastic model

    Andréa Ucker Timm


    Full Text Available Um modelo estocástico Lagrangeano é utilizado para simular a dispersão e o transporte de contaminantes, sob condições estáveis, com velocidade do vento fraco, no experimento traçante realizado no Idaho National Engineering Laboratory (INEL. Neste trabalho é testada uma nova parametrização dos parâmetros que representam as freqüências associadas ao fenômeno de meandro do vento, presentes nas equações de Langevin para as componentes do vento horizontal. Esta nova parametrização é descrita em termos de uma quantidade adimensional que controla a freqüência de oscilação de meandro do vento e da escala de tempo, associada às estruturas coerentes em uma turbulência bem desenvolvida. As simulações demonstram que o modelo Lagrangeano considerado, incorporando esta nova parametrização, reproduz corretamente a difusão de escalares passivos em uma camada limite atmosférica estável com velocidade do vento fraco.A Lagrangian stochastic particle model is utilized to simulate the dispersion and the transport of contaminants under low wind stable conditions in the tracer experiment carried in the Idaho National Engineering Laboratory (INEL. In this work a new parameterization for the parameters representing the frequencies associated to the meandering phenomenon is tested. The new parameterization is expressed in terms of a non-dimensional quantity that controls the frequencies of the meandering oscillation and of the time scale associated to a coherent structure in a fully developed turbulence. The simulations show that the considered Lagrangian model, incorporating this new parameterization, reproduces correctly the diffusion of passive scalars in a low wind speed stable atmospheric boundary layer.

  15. Random incidence absorption coefficients of porous absorbers based on local and extended reaction models

    Jeong, Cheol-Ho


    Room surfaces have been extensively modeled as locally reacting in room acoustic predictions although such modeling could yield significant errors under certain conditions. Therefore, this study aims to propose a guideline for adopting the local reaction assumption by comparing predicted random...... incidence acoustical characteristics of typical building elements made of porous materials assuming extended and local reaction. For each surface reaction, five well-established wave propagation models, the Delany-Bazley, Miki, Beranek, Allard-Champoux, and Biot model, are employed. Effects of the flow...

  16. Flexible employment, economic insecurity and social policy preferences in Europe

    B. Burgoon; F. Dekker


    This paper examines how flexible employment, particularly temporary and part-time employment, affect political support for social policy protection. Although their implications are a priori uncertain, the paper lays out how flexible employment conditions can be expected to generate various kinds of

  17. N-Iodosuccinimide-Promoted Hofmann-Löffler Reactions of Sulfonimides under Visible Light.

    O'Broin, Calvin Q; Fernández, Patricia; Martínez, Claudio; Muñiz, Kilian


    Conditions for an attractive and productive protocol for the position-selective intramolecular C-H amination of aliphatic groups (Hofmann-Löffler reaction) are reported employing sulfonimides as nitrogen sources. N-Iodosuccinimide is the only required promoter for this transformation, which is conveniently initiated by visible light. The overall transformation provides pyrrolidines under mild and selective conditions as demonstrated for 17 different substrates.

  18. Optimum Process Conditions and Reaction Mechanism of Preparing Mo2C Catalyst%制备Mo2C催化剂的最佳工艺条件及其反应机理

    张建明; 张晓彤; 宋丽娟; 孙兆林; 刘丽莉


    Molybdenum trioxide as precursor was prepared by roasting ammonium molybdate. Then using molybdenum trioxide and the gas mixture of H2 and CH4 as raw materials .molybdenum carbide was prepared by the temperature-programmed reaction method.The best temperature of preparing molybdenum trioxide from ammonium molybdate was investigated as well as the best ratio of H2 to CH4 and terminal temperature in the temperature-programmed reaction; the final product was characterized by X-ray diffraction.The results show that the optimum process conditions for the reaction: roasting temperature is at 450 °C, V(H2)V(CH4) is in the range of 2 : 1 ~ 4 : 1, the final temperature of carbonization is at 700 °C; the reaction mechanism: firstly, MoO3 is reduced to MoO2, then MoO2 must be reduced to transition state Mo, finally Mo2C is gained.%钼酸铵焙烧制备碳化钼前驱体MoO3,以MoO3为钼源、V(H2)/V(CH4)混合气体为碳化介质采用程序升温反应法制备Mo2C催化剂;考察钼酸铵制备.MoO3适宜的温度,以及程序升温反应法制备Mo2C的最适V(H2)/V(CH4)比和碳化终温,用XRD表征分析产物。得出制备Mo2C催化剂的最佳工艺条件是:钼酸铵焙烧温度为450℃、V(H/V(CH4)为2:1~4:1、碳化终温为700℃;其反应机理是:MoO3先被还原为MoO2,MoO2需经历过渡态的单质Mo才能碳化生成Mo2C。

  19. Employability: Challenges for Education and Training Systems

    Perez, Elena Arjona; Garrouste, Christelle; Kozovska, Kornelia

    The recent crisis has taken its toll in terms of unemployment, especially among young people. This has revived the debate on the contribution of Education and Training (E&T) systems to the employability of young graduates. At European policy level, there is a growing interest in creating incentives for reforming E&T systems so as to make them more responsive to future labour market needs and short term adverse labour market conditions. One of the main challenges is finding valid measures for evaluating the contribution of E&T systems to employability, taking into account their diversity within the European Union. This paper presents an operational framework of analysis for employability and discusses some of the most important challenges related to the multidimensional nature of the employability concept, the lack of data for cross-country comparison and the difficulty of disentangling the role of education and training systems from other factors in evaluating labour market outcomes.


    Rubina Khan; Tazin Aziz Chaudhury


    Abstract: This paper presents a brief summary of a study which was carried out to investigate how employers representing major employment sectors in the Bangladeshi Industry view the skills and English proficiency level of the current employees. Opinions were also solicited on what skills are required for fresh recruits. Semi-structured interviews were conducted with 30 employers representing the major employment sectors in Bangladeshi Industry. Results revealed the importance of English as a...