23 research outputs found
Micellar Head-Group Size and Anion Nucleophilicity in SN2 Reactions
No full textRates of reaction of OH- with methyl naphthalene-2-sulfonate (MeONs) in aqueous cationic surfactants (C16H33NR3OH), R = Me, Et, n-Pr, n-Bu, and cetylquinuclidinium hydroxide) increse with increasing surfactanta and hydoxide ion cocentrations. The variations of rate constants can be fitted to an equation that describes the distribution of both reactants between water and micelles in terms of Langmuir isotherms. The Langmuiur coefficients for OH- decrease in the head-group sequence Me3N > quinuclidinium > Et3N > Pr3N > Bu3N. The second rate constants at the micellar surface are not very sensitive to the bulk of the head group, although they increase at high added OH-Rate constants for attack of water on micellar-bound substrate increase with increasing bulk of the head group
Labour market regulation and professional sport: The case of the Victorian Football League’s Coulter Law, 1930-1970
No full textIn most professional team sports, salary caps – first used in the mid-1980s – stabilise the financial position of teams and promote balanced competitions. Teams that do not comply with labour market regulations face heavy penalties and there is a debate about whether such labour markets should operate like competitive markets in general – with wages directing players to the teams that value their contributions most. Analysis of earlier restrictions on the mobility of players and the movement of wages may raise new questions about the effects of noncompliance. The Coulter Law was a set of Victorian Football League (VFL) recruiting and payment rules that operated from 1930 to 1970. The conventional view – that most VFL clubs breached the maximum player wage rules to maximise the utility derived from winning games – is supported only by anecdotal evidence. A new data set reveals that the Coulter Law did restrict earnings in the VFL, except for a small number of elite players. Clubs allowed players to take up more lucrative jobs in other leagues and their subsequent on-field performance reflected the level of talent of replacement players.
Reação de substituição nucleofílica aromática em 1,2-dicloro-4,5-dinitrobenzeno
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciencias Fisicas e Matematicas. Programa de Pós-Graduação em QuímicaO 1,2-dicloro-4,5-dinitrobenzeno (DCDNB) reage com aminas primárias e secundárias, em acetonitrila, em temperatura ambiente, produzindo produtos de monossubstituição do grupo nitro, com rendimentos de 85% a 95%. A dissubstituição de um cloro e de um nitro ocorre quando usados excesso de amina e refluxo. Os reagentes amínicos piperidina, pirrolidina, dimetilamina e metilamina foram os mais reativos tanto na mono quanto na dissubstituição. A cinética da reação entre DCDNB e cicloexilamina, em dimetil sulfóxido, indica ausência de catálise básica. A geometria do estado de transição, obtida por cálculo teórico para a reação entre DCDNB e cicloexilamina, suporta a possibilidade de estabilização do estado de transição por ponte entre o hidrogênio amínico e um dos oxigênios do grupo nitro em orto, e também que não deve existir inibição de ressonância no estado de transição. Os alcóxidos substitutem prontamente o grupo nitro, monossubstituição, todavia, o produto dissubstituído (nitro e cloro) só foi obtido para a reação com metóxido, quando sob refluxo. 1,2-dichlro-4,5-dinitrobenzene (DCDNB) reacts with primary and secondary amines, in acetonitrile, at room temperature, to give monossubstituted nitro product with yield 85 % to 95 %. The chloro-nitro-dissubstituted product is formed when excess amine and reflux conditions are used. Piperidine, pirroline, dimethylamine and methylamine were the most reactive reagents in both mono- and dissubstitution. The kinetic of the reaction of DCDNB e cyclohexylamine, in DMSO, indicates no basic catalysis. The transition state geometry, obtained by theoretical treatment of this reaction, supports the existence of stabilization by the amine hydrogen bonding to the o-nitro group oxygen. Also, it is not observed any resonance inhibition in the transition state. The alcoxides promptly monossubstitute the nitro group, however, the dissubstituted product (of nitro and chloro) was only successful for the methoxide under reflux condition
Efeito de contra-íon em complexos poli(oxietileno)-dodecilsulfato :: determinação da concentração de contra íons aromáticos em micelas de cetiltrimetilamônio através da reação de decomposição de um sal de diazônio /
No full textTese (Doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas
Qualitative social research in addictions publishing: Creating an enabling journal environment.
No full textPyrolytic Studies in the Alicyclic Series
No full textThe thesis,concerned largely with pyrolytic elimination of esters through mechanisms other than the normal 1,2-route,is in three main parts: I Introduction, II Adamantanoid Series, and III Cyclohexyl-carhinyi and Decalyl Series. The Introduction first reviews a variety of mechanistic rationalisations advanced to explain data on 1,2-eliminations. In particular the Quasi-Heterolytic and Concerted mechanisms are critically compared. The author favours the latter,noting that ester pyrolysis can he related to the general Retro-Ene reaction. A literature survey (1900-1971) is made and twenty-two examples of reports of anomalous product formation on ester pyrolysis are recorded. Each is discussed. It appears that all recorded examples,other than those carried out under conditions likely to cause acid or surface catalysed rearrangement, may he explained by extensions of three, mechanisms namely: (a) - Elimination (as has been suggested for one example by Kwart; (b) 1,3-Elimination with cyclopropyl formation (suggested on poor evidence by Bunton); (c) 1,3-Elimination with 2-alkyl migration (suggested on good evidence by Bunton,though for one example only. ) The thesis which follows investigates aspects of the latter two mechanisms (a and b above) and structures derived by their application to model systems. II. Adamantanoid Series: 2-Adamantyl esters (i. e. tetracyclo-(3,3,1,1)-decyl-) e.g. 1 were chosen as a model. Pyrolysis of the acetate was unsuccessful,but the -S-methyl xanthate, toluene p-sulphonate, and methane sulphonate gave the products 2,4-dehydroadamantane 2 andprotoadamantene 3 ,predicted from mechanisms a and b above. (Yields and ratios varied,but maximum was 95% of 2 and 3 in the ratio 60; 40) Possible mechanisms are discussed. Other esters pyrolysed were 2-(8,9-dehydroadamantyl)-3,5-dinitrobenzoate 4 (the corresponding alcohol was produced by ozone treatment of 2,4-dehydroadamantane) and 10-protoadamantyl methane sulphonate 5. The former though eliminating ester failed to give identifiable products. The latter gave adamantane and an olefin thought to be A series of reactions was carried out on protoadamantene 3 namely epoxidation(and hydride reduction of the epoxides), hydroboration (and oxidation) and oxymercuration. The stereochemistry of 3 and its effect on the course of the above reactions is discussed. The europium shifted n. m. r. spectra of all four 4- and 5-protoadamantanols ,the 4- and 5-protoadamantanones, 4exo and 4endo-methyl protoadamantanols and 4endo-phenyl protoadamantanol are recorded and discussed. Configuration,conformation and C-C bond angle strain are among topics discussed in relation to information derived from the spectra. III Cyclohexylcarbinyl and Decalyl Series It had been hoped that a modification of the 1,3-elimination mechanism c above might explain the observation of (a) the reported formation of 1-methyl cyclohexene on pyrolysis of cyclohexylcarbinyl acetate 8 and apparent anti-elimination in some esters of cyclic alcohols e.g. 1-decalyl 11 (ref. 11) (see 8 and 11 with arrows over) The pyrolysis of 8 was,however,found to occur with formation of methylenecyclohexane 10 only,the product 9 only appearing through subsequent contact of 10 with acid. Pyrolysis of esters such as 11 did give A -1,9 octalin 12 but not by a 1,3-mechanism,since C9 -deuterium was eliminated. The anti-elimination product 12 does not appear to arise through isomerisation of ester or of the normal product t-A1,2-octalin. Various mechanisms are considered
GASKAP-HI pilot survey science I: ASKAP zoom observations of HI emission in the Small Magellanic Cloud
No full textThis is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.--Full list of authors: Pingel, N. M.; Dempsey, J.; McClure-Griffiths, N. M.; Dickey, J. M.; Jameson, K. E.; Arce, H.; Anglada, G.; Bland-Hawthorn, J.; Breen, S. L.; Buckland-Willis, F.; Clark, S. E.; Dawson, J. R.; Denes, H.; Di Teodoro, E. M.; For, B-Q; Foster, Tyler J.; Gomez, J. F.; Imai, H.; Joncas, G.; Kim, C-G; Lee, M-Y; Lynn, C.; Leahy, D.; Ma, Y. K.; Marchal, A.; McConnell, D.; Miville-Deschenes, M-A; Moss, V. A.; Murray, C. E.; Nidever, D.; Peek, J.; Staveley-Smith, L.; Tepper-Garcia, T.; Tremblay, C. D.; Uscanga, L.; van Loon, J. Th; Vazquez-Semadeni, E.; Allison, J. R.; Anderson, C. S.; Ball, Lewis; Bell, M.; Bock, D. C-J; Bunton, J.; Cooray, F. R.; Cornwell, T.; Koribalski, B. S.; Gupta, N.; Hayman, D. B.; Harvey-Smith, L.; Lee-Waddell, K.; Ng, A.; Phillips, C. J.; Voronkov, M.; Westmeier, T.; Whiting, M. T.; Stanimirovic, S.We present the most sensitive and detailed view of the neutral hydrogen ( HI ) emission associated with the Small Magellanic Cloud (SMC), through the combination of data from the Australian Square Kilometre Array Pathfinder (ASKAP) and Parkes (Murriyang), as part of the Galactic Australian Square Kilometre Array Pathfinder (GASKAP) pilot survey. These GASKAP-HI pilot observations, for the first time, reveal HI in the SMC on similar physical scales as other important tracers of the interstellar medium, such as molecular gas and dust. The resultant image cube possesses an rms noise level of 1.1 K ( 1.6mJy beam−1 ) per 0.98km s−1 spectral channel with an angular resolution of 30′′ ( ∼10pc ). We discuss the calibration scheme and the custom imaging pipeline that utilises a joint deconvolution approach, efficiently distributed across a computing cluster, to accurately recover the emission extending across the entire ∼25deg2 field-of-view. We provide an overview of the data products and characterise several aspects including the noise properties as a function of angular resolution and the represented spatial scales by deriving the global transfer function over the full spectral range. A preliminary spatial power spectrum analysis on individual spectral channels reveals that the power law nature of the density distribution extends down to scales of 10 pc. We highlight the scientific potential of these data by comparing the properties of an outflowing high-velocity cloud with previous ASKAP+Parkes HI test observations. c The Author(s), 2022. Published by Cambridge University Press on behalf of the Astronomical Society of Australia.The Australian SKA Pathfinder is part of the Australia Telescope National Facility which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Pipeline development was tested on the OzSTAR supercomputer under the project code, oz145, which is available through Swinburne University’s Centre of Astrophysics and Supercomputing. This research was supported by the Australian Research Council (ARC) through grant DP190101571. N.M.-G. acknowledges the support of the ARC through Future Fellowship FT150100024. G. A. and J. F. G. acknowledge support from the State Agency for Research (10.13039/501100011033) of the Spanish MCIU, through grants AYA2017-84390-C2-1-R and PID2020-114461GB-I00 (co-funded by FEDER) and the ‘Center of Excellence Severo Ochoa’ award for the Instituto de Astrofsica de Andaluca (SEV-2017-0709). C. E. M. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1801471.Peer reviewe
Do UK based weight management programmes cause weight loss maintenance in adults? A systematic review
No full textThe aim of this dissertation was to examine whether UK based weight management programmes promote weight loss maintenance (follow up of 12 months to assess effectiveness of intervention in weight loss) in adults through the process of a systematic review. The World Health Organisation (WHO) has described obesity as a "global epidemic". Weight management comprises two phases; weight loss and weight loss maintenance. The latter phase is the true goal for obesity and the most difficult element of weight management to achieve. However much less is know about this as compared with the weight loss phase. There is little purpose in committing time and money to reducing obesity if the weight is regained. This is counter-productive and weight loss maintenance is essential to combat the obesity epidemic. Searches were made for relevant information from a variety of scientific online databases and journals,. Seven articles met the inclusion criteria and were analysed in the review. All studies incorporated a multi-component (diet, exercise, behaviur modification) intervention approach. All control and internvetion groups reported weight loss at 12 months when compared with baseline. All groups recieved an intervention. One study reported a significant difference (P<0.05) between groups. Four studies reported on at least one component (diet, physical activity, behaviour modification) however there was not enough information to conclude whether they complied with national guidelines (NICE CG43 and SIGN 115). High attrition rates and loss to follow up are problematic for each study except one. Analysis on an intention to treat basis was common however this is problematic and there are alternative methods which may be more suitable for dealing with missing data
Young people and illicit drug use: A health promotion model to differentiate abstinence or recreational drug use from misuse
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 27/04/2004.The thesis is a study of illicit drug use and attitudes to drugs education amongst young people from different socio-economic backgrounds. The thesis reviews the existing literature and finds that there may be a link between poverty and drug use that hasn't been fully explored and that there has been a lack of attention to young people's perspectives and views on drug use. The findings are reported of an empirical research project that consisted of quantitative and qualitative research with 206 young people in five different settings: at university, in a youth club, in schools, in a pupil referral unit, and service for young offenders. The data from these different sources are analysed and a conceptual model has been developed, setting out some factors that are indicative of problematic or non-problematic drug use. The model was circulated amongst a small group of professionals in relevant fields for comment. The thesis concludes that young people in university settings reported using illicit drugs recreationally and apparently without problems, while the 'vulnerable' young people reported using more drugs, at an earlier age, and more frequently, and for reasons to do with boredom, depression and anxiety. The author suggests that 'vulnerable' young people are disadvantaged by their circumstances at home, including social deprivation and parental separation, and their lack of engagement with education. It is argued that health promotion models need to recognise the importance of contextual and broader structural factors influencing drug use among young people, and that health promotion efforts need to play a role in tackling inequalities and reducing deprivation, as well as making health promotion messages relevant to their target audience
Risk conceptualisations, trust and decision-making in the face of contradictory information: the case of MMR
No full textThis thesis investigates the process by which parents evaluate contradictory information about risk in order to make the decision whether to have their children immunised with the measles, mumps and rubella (MMR) vaccine. Contested reports associating the MMR vaccine with autism have resulted in diminished confidence and uptake of the vaccine in the UK. Interviews and focus groups were used to develop an in-depth picture of parental notions of risk, trust and decision-making processes. Cultural consensus analysis was used to probe the areas of consensus and divergence of opinion, and a large-scale postal survey (N=996) assessed the level of agreement with the qualitative findings. Parental ambivalence to the safety of the vaccine reflected wider social concerns, and was crucially related to trust in governmental medical authority and medical practitioners. Trust was particularly damaged when practitioners and policy makers failed to recognise parents' concern for their children’s health and their unique knowledge of their own children. A key tool for fostering trust is narrative: this played a central role in galvanising resistance to the vaccine, but was not well used to engender trust and cooperation between parents and medical practitioners. Three practical strategies to protect children from diseases and harmful vaccine side effects, to rebuild trust, and to cope successfully with similar controversies in the future emerged from this research: fully involving the public in framing scientific research agendas, streamlining the reporting procedures for suspected adverse reactions, and fostering trusting personal relationships between patients and health care practitioners
