24 research outputs found
Study of lone working magnetic resonance technologists in Western Australia
Objectives: It is recommended that magnetic resonance (MR) technologists should not work alone due to potential occupational health risks although lone working is legally acceptable. The objective of this study was to investigate the current situation of lone working of MR technologists in Western Australia (WA) and any issue against the regulations. Materials and Methods: A questionnaire regarding the issues of occupational health of lone MR technologists was developed based on relevant literature and distributed to WA MR technologists. Descriptive (percentage of frequency, mean and standard deviation) and inferential statistics (Fisherâs exact, chi-square and t tests, and analysis of variance) were used to analyse the responses of the yes/no, multiple choice and 5 point scale questions from the returned questionnaires.Results: The questionnaire response rate was 65.6% (59/90). It was found that about half of the MR technologists (45.8%, 27/59) experienced lone working. The private magnetic resonance imaging (MRI) centres were more likely to arrange technologists to work alone (p <0.05). The respondents expressed positive views on issues of adequacy of training and arrangement, confidence and comfort towards lone working except immediate assistance for emergency (mean: 3). Factors of existence of MRI safety officer (p < 0.05) and nature of lone working (p < 0.001-0.05) affected MR technologistsâ concerns. Conclusions: Lone working of MR technologists is common in WA especially private centres. The training and arrangement provided seem to be adequate for meeting the legal requirements. However, several areas should be improved by the workplaces including enhancement on immediate assistance for emergency and concern relief
Nutzerorientierte, gendergerechte und altersdifferenzierte Angebotsentwicklung der Gesundheitsförderung und PrĂ€vention fĂŒr ein multifunktional nutzbares Gesundheitszentrum im lĂ€ndlichen Raum
Palladium-Catalyzed Oxidative Borylation of Allylic CâH Bonds in Alkenes
This communication
describes an efficient palladium pincer complex-catalyzed
allylic CâH borylation of alkenes. The transformation exhibits
high regio- and stereoselectivity with a variety of linear alkenes.
A synthetically useful feature of this allylic CâH borylation
method is that all allyl-Bpin products can be isolated in usually
high yields. Preliminary mechanistic studies indicate that this CâH
borylation reaction proceeds via PdÂ(IV) pincer complex intermediates
Phenylpyridyl-fused boroles: a unique coordination mode and weak B-N coordination-induced dual fluorescence
Phenylpyridyl-fused boroles [TipPBB1] and TipPBB2 were synthesized and their properties investigated. [TipPBB1] forms a tetramer in both the solid state and solution. TipPBB2 contains a 4-coordinate boron atom in the solid state but dissociates to give a 3-coordinate boron species in solution. TipPBB2 shows interesting temperature-dependent dual fluorescence in solution because of the equilibrium between 3- and 4-coordinate boron species due to weak Nâ
â
â
B intermolecular coordination
Synthesis of Vinylâ, Allylâ, and 2âBoryl Allylboronates via a Highly Selective Copper-Catalyzed Borylation of Propargylic Alcohols
An efficient methodology for the
synthesis of vinyl-, allyl-, and
(<i>E</i>)-2-boryl allylboronates from propargylic alcohols
via Cu-catalyzed borylation under mild conditions is reported. In
the presence of commercially available CuÂ(OAc)<sub>2</sub> or CuÂ(acac)<sub>2</sub> and Xantphos, the reaction affords the desired products in
up to 92% yield with a broad substrate scope (43 examples). Isolation
of an allenyl boronate as the reaction intermediate suggests that
an insertionâelimination-type reaction, followed by borylcupration,
is involved in the borylation of propargylic alcohols
Application of a method for the sustainable planning and management of ground source heat pump systems in an urban environment, considering the effects of reciprocal thermal interference
The âMost Easy, Efficient and Low Cost Geothermal Systems for Retrofitting Civil and Historical Buildingsâ (GEO4CIVHIC) project aims to accelerate the deployment of shallow geothermal systems for heating and cooling purposes when retrofitting existing and historical buildings. Analyzing the implementation process of borehole heat exchangers (BHEs), allows the understanding of how to promote the long-term sustainability of shallow geothermal energy systems. The thermal interference between BHE systems represents a problem, especially due to the increasing deployment of this technology and its spread in densely built-up areas.
The main goal of this paper is to propose a conceptual model and to apply this to different case studies. The methodology includes phases to adopt an integrated approach for preventing long term thermal interference in neighbouring borehole heat exchangers, by providing management strategies and technical suggestions for design and operation.
The method developed follows the following steps: 1) literature review to determine what are the main drivers for thermal interference between shallow geothermal systems, in the context of the GEO4CIVHIC project case study sites; 2) to create a conceptual model to limit thermal interference at both design and operational phases; 3) to apply the developed method to real and virtual case studies in countries with different regulatory frameworks and to test its main strengths and weaknesses. The application of this conceptual model to specific case studies provides evidence of critical planning and operational characteristics of GSHP systems and allows the identification of measures to mitigate impacts of thermal interference to be identified
Shallow Geothermal Energy for existing buildings â overview and status of project GEO4CIVHIC
A major obstacle to decarbonisation in the building sector is the comparably low share of new construction, and the specific problems encountered when supplying heat and/or cold from renewable energies (RES) to existing and in particular older/historical, buildings.
Without a solution to the problem of RES in refurbishment, however, the decarbonisation of the building stock will simply take too long. Shallow
geothermal technologies have contributed substantially to decarbonisation in new construction. However, for a wider deployment in existing buildings, particularly in historical ones, the technologies need further development and innovative ideas must be tested and brought to the market. Within the EU-funded project GEO4CIVHIC a survey was done to identify and understand all other possible barriers to install Borehole Heat Exchangers (BHE) in existing building environment, be they technical or socio-economic, and the project partners work on suggestions for suitable solutions. Based upon this survey, the further work addressed two principal barriers, which are construction of ground heat exchangers under constrained site conditions, and adaption of heat pumps and other components to older heating/cooling systems. A specific emphasis is given to historic buildings, i.e. those dating from before the mid of the 20th century, including listed buildings, where the constraints are
even more severe. Development work is done to provide technical solutions for overcoming these barriers, e.g. with novel drilling tools and enhanced heat pumps. Several demonstration cases are undertaken to test the solutions found (4 real sites in Belgium, Ireland, Italy and Malta,
and 12 âvirtualâ sites, where theoretical case studies for renovation with borehole heat exchangers are performed on real, existing buildings). The COVID 19 pandemic hampered drastically the project timeline, resulting in delays of more than one and a half years.
At the time of writing this abstract, two real demonstration cases are finished and started operation (Belgium and Italy), while the other two are scheduled to be operational by July 2022. This paper gives an overview of the project, the rationale behind it, and the findings of the initial survey of barriers. It presents the experiences with less invasive, less costly and quicker drilling and installation methods for borehole heat exchangers (BHE), as developed within the project and tested both in the real demonstration sites and in dedicated test fields at some of the project partners. First results of monitoring and results from the "virtual" sites are presented. Other papers within the project also submitted to EGC 2022 address specific aspect in more detail, and are referenced in this overview paper
cAACâStabilized 9,10âdiboraanthracenesâAcenes with OpenâShell Singlet Biradical Ground States
Narrow HOMOâLUMO gaps and high chargeâcarrier mobilities make larger acenes potentially highâefficient materials for organic electronic applications. The performance of such molecules was shown to significantly increase with increasing number of fused benzene rings. Bulk quantities, however, can only be obtained reliably for acenes up to heptacene. Theoretically, (oligo)acenes and (poly)acenes are predicted to have openâshell singlet biradical and polyradical ground states, respectively, for which experimental evidence is still scarce. We have now been able to dramatically lower the HOMOâLUMO gap of acenes without the necessity of unfavorable elongation of their conjugated Ïâ
system, by incorporating two boron atoms into the anthracene skeleton. Stabilizing the boron centers with cyclic (alkyl)(amino)carbenes gives neutral 9,10âdiboraanthracenes, which are shown to feature disjointed, openâshell singlet biradical ground states
cAACâstabilisierte 9,10âDiboraanthracene â offenschalige Singulettbiradikale
Geringe HOMO-LUMO-AbstĂ€nde und eine hohe LadungstrĂ€germobilitĂ€t prĂ€destinieren die höheren Acene fĂŒr Anwendungen im Bereich der Organoelektronik. Die LeistungsfĂ€higkeit derartiger Verbindungen steigt hierbei dramatisch mit der Anzahl anellierter Benzolringe. GröĂere Acenmengen sind synthetisch bisher jedoch nur fĂŒr Acene bis Heptacen verlĂ€sslich zugĂ€nglich. Theoretischen Studien zufolge besitzen (Oligo)acene offenschalige Singulettbiradikal- und (Poly)acene polyradikalische GrundzustĂ€nde. Eindeutige experimentelle Belege fĂŒr diese Vorhersagen sind hingegen Ă€uĂerst selten. Durch den Einbau von zwei Boratomen in das AnthracengrundgerĂŒst konnten wir den HOMO-LUMO-Abstand von Acenen dramatisch verringern und zwar ohne die Notwendigkeit einer Ausweitung des konjugierten Ï-Systems. Stabilisierung der Borzentren durch cyclische (Alkyl)(amino)carbene lieferte hierbei neutrale 9,10-Diboraanthracene mit disjunkten, offenschaligen Singulettbiradikal-GrundzustĂ€nden