Studies of some organo-nitrogen three-electron ligands in transition metal carbonyl complexes

The work to be described is a continuation of the study of organo-nitrogen-transition metal complexes with particular reference to ketimino and related derivatives. Earlier work by colleagues has shown that the nature of the product formed from the reaction of π-C(_5)H(_5)M(CO)(_3)Cl,[I] (M= Mo,W), with lithio-ketimines, R(_2)C:NLi, depends on the group R. Thus for R = Ph, the product is the aza-allyl/allene derivative π-C(_5)H(_5)M(CO)(_2)[Ph(_2)CNCPh(_2)] and for R = Bu(^t), the ketimino complex π-C(_5)H(_5)M(CO)(_2)NCBu(^t)(_2)is formed. Reaction of [I] with (p-tolyl)(_2)C:NLi, however, produced three types of complex, π-C(_5)H(_5)M(CO)(_2)NC(P-TOLYL)(_2)[ll], π-C(_5)H(_5)M(C0)(_2)[(P-tolyl)(_2)CNC-(P-Tolyl)(_2)] [III], and K-CgH^M(C0)2[(2-tolyl)2CNC(2-l:olyl)2](2-tolyl)2C:0 [IV]. Two forms of [III], (M = W) were isolated in the solid state but a common species was formed in solution. [IV]also gave the same solution species together with the free ketone. A mechanism for the formation of the complexes and the biproducts (P-tolyl)2C:0, NCO" and CN~ is proposed. All complexes failed to undergo substitution reactions with PPh^ and reaction of iodine with [II] caused total decomposition of the complex. Dimerisation of [II] to [rt-C^H^M(C0)NC(P-tolyl)2] could be achieved for M = W, but not for M = Mo.Reaction of [l] with RgCiNLi in the presence of RgCiO (R = Ph, P-tolyl) resulted in formation of the complexes jt-C^H^M(CO)2NCR2 to the exclusion of the aza-allyl/allene complexes, which are formed in the absence of R(_2)C:O. The possible role of the ketone in the reaction is discussed

Selection effects in optical quasar surveys

An investigation into the selection effects of optical quasar surveys is described. This is accomplished via the accumlation and comparison of optical quasar surveys o f d ifferen t types, which are then used to generate a su rvey free from selection effects.A visual search and an automatic computerised search for quasars using U.K. Schmidt plates were already available in a single high galactic latitude field of 23 degrees.An automatic search of a deep C.F.H.T. grens plate over 1 degree^ in the centre of the field was undertaken. Slit spectroscopic observations were made of 26 candidates from this survey. These data allow conclusions to be drawn regardin g the grens as a survey instrument.An automatic photometric su rvey was also undertaken, using direct plates in the five wavebands U, J, V, R, and I from the U.K. Schmidt telescope. CCD frames were obtained in each of the wavebands from various sources, to allow calibration o f data from the Schmidt plates. This has allowed the construction o f a conventional ultraviolet excess sample, as well as a less conventional colour space density search generated sample.Locating the various low dispersion spectroscopic su rvey candidates amongst the photometric su rvey data has brought to light various aspects o f these surveys: in particular, the eye discovers a smaller surface density of candidates at most magnitudes. Secondly, the automatic prism plate search has significant progressive object losses b righ ter than the plate limit, which are subject to complex selection effects. Large numbers of galactic stars are mistaken for quasars because of peculiarities in their spectra seen at low dispersion. Also prism dispersion variations force a su rvey limit brighter than the plate limit. Colour synthesis from the prism plate works well at brigh ter magnitudes, unless spectra are saturated. The method is also subject to limitations due to poor spectrum signal to noise at fainter magnitudes.Spectroscopy indicates that the automatic grens survey is complete, except for overlapped spectra. This is in part due to the linear dispersion of the transmission grating. The present survey is however subject to considerable contamination:- the reasons for this are examined and discussed. Conclusions drawn from examination of the grens sample colours are limited because the grens su rvey goes to a much fainter magnitude, over a limited area.The photometric survey readily identifies objects which have peculiar colours, but a detailed examination of the properties of these objects must await further work.Finally, a synthetic survey has been constructed, using all of the information available for each object. Redshift estimates were possible for about 30% of the 130 candidates - the higher redshift objects. Examination of the survey indicates that it is largely free from selection effects below a redshift of z = 3.4

Detection of breech presentation: Abdominal palpation and hand-held scanning by midwives

Background: The NHS Litigation Authority's ‘sign up to safety’ campaign aims to prevent undiagnosed breech birth and possible poor birth outcomes. An audit was completed following the introduction of hand-held scanning ultrasound examination. Aims: The hand-held ultrasound was used by midwives for all women in labour and before induction of labour to confirm presentation. Methods: A criterion-based retrospective audit, conducted over 6 months in 2016, with a sample of 2737 women. Findings: The audit demonstrated that 22 breech presentations were detected when using the hand-held ultrasound before induction of labour or in labour. The audit standard of 100% of women receiving an ultrasound scan was not met, and potential reasons are explored. Conclusions: The results support the use of hand-held ultrasound, as it did detect breech presentation before induction of labour or spontaneous labour and birth. Further work includes the audit of the reasons that hand-held ultrasound scanning was not used, to ensure that a targeted action plan can be created. Future research into midwifery values, cultural attitudes and the effectiveness of abdominal palpation is also needed, to develop the knowledge base on which scanning can be framed

Achieving carbon neutral structures through pure tension: using a fabric formwork to construct rammed earth columns and walls

The use of fabric to re-think conventional compressive containment for rammed earth allows the making of compressive structures through tensile means, saving weight, materials costs, and the importation of technology into ‘developing world’ situations. Fabric formwork achieves a permanent architecture that is defined with the most portable of tools. The need to develop a system that is tested and approved in the ‘developed West’ is important as a way of challenging the current stranglehold that the use of cement has on developing nations. To obtain mortgage loans in many situations cement use is a prerequisite by local funders, from urban situations in Botswana to dam relocation programmes in the Punjab, where for example displaced villages are required to build with imported concrete where earthen structures could provide secure and simple architecture that can be self built and affordable. If ‘Western’ methods are available for self-builders, then the perception of earth as ‘poor’ material can be questioned, with a chance that the cement dependent status quo can be challenged. The research programme at the University of East London School of Architecture and the Visual Arts led by Chandler and Keable has developed over 5 years a series of refinements to lighter weight, robust systems for rammed earth construction. This work has received a £10,000 grant to develop the research as a ‘Fabric earthform’ product, but also as a non-profit programme for Southern African states to promote the development of local variants of fabric formed rammed earth construction

Provide instructions and resources for assessment and training in earth building: the Pirate project

This publication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein.Earth is a unique building material which is easily accessible and available. Building products and processes using earth need little embodied energy during the whole life circle. The use of earthen building material reduces the carbon dioxide emissions and contributes to a healthy indoor climate. Moreover earth architecture has an aesthetic value. Historic and modern buildings take advantage of these technical, aesthetic, environmental and social benefits. There is a still small but growing market in earth construction. The advances obtained with PIRATE project, trying to contribute for the growth of this specific market, will be presented in this paper. The PIRATE project aims to disseminate the benefits of modern earth construction by creating lifelong learning opportunities, putting the emphasis on competence standards in this sector. Eighteen organisations from eight European countries, all active in the earth construction sector as professional associations, education and training providers or small companies, have come together to develop units of learning outcomes and get them recognised within national certified courses. The new standards comply with the European Qualification Framework (EQF) and the European Credit System for Vocational Education and Training (ECVET).The PIRATE project has been funded with support from the European Commission

La représentation sociale de l'appproche milieu au centre jeunesse de Montréal

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal