1. |
2. |
3. Effects of high relative humidity and dry purging on VOCs obtained during breath sampling on common sorbent tubesMaxim Wilkinson, Iain R White, Roy Goodacre, Tamara Nijsen, Stephen Fowler, 2020 Opis: Offline breath analysis by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) requires the use of sorbent traps to concentrate and store volatile compounds. The selection of which sorbent to use and best practices for managing high relative humidity are important considerations to allow for reproducible, untargeted, biomarker discovery in water saturated breath samples. This work aims to assess three commonly used sorbent materials for their use in breath volatile sampling and determine how the high relative humidity inherent in such samples effects the capture of volatile compounds of interest. TenaxGR, TenaxTA/Carbograph1TD and TenaxTA/Carbograph5TD tubes were selected as they are the most commonly used sorbents in the breath sampling literature. The recovery of 29 compounds in a standard mix loaded using high humidity gas was tested for each sorbent and compared to loading in dry gas. Water retention and dry purge rates were determined for each sorbent for 500 ml and 1000 ml breath collections. Finally, breath samples were collected simultaneously on to each sorbent type using the ReCIVA and analysed by TD-GC-MS. All three sorbents exhibited acceptable reproducibility when loaded with the standard mix in dry gas (RSD < 10%). Loading the standard mix in humid gas led to reduced recovery of compounds based on their chemical properties. Dry purging performance for each sorbent material was assessed and was shown to be 1.14, 1.13 and 0.89 mg H2O min−1 for TenaxGR, TenaxTA/Carbograph1TD and TenaxTA/Carbograph5TD respectively when flushed with 50 ml min−1 of N2. A comparison of breath profiles on different sorbents showed differences in background artefacts (sulfur dioxide, cyclopenten-1-one and 3-nonene) and endogenous breath compounds (2-methyl-furan and furfural). This work demonstrates that high relative humidity during sampling reduces the ability of sorbent tubes to capture volatile compounds and could impact method detection limits during breath sampling. Sufficient water to impair accurate analysis was retained on all tubes. Minimal differences were observed between sorbent materials when used to sample breath, however, suggestions are provided for sorbent selection for future studies.
Ključne besede: VOCs, Breath sampling, ReCIVA
Objavljeno: 27.07.2020; Ogledov: 108; Prenosov: 3
 Polno besedilo
Ogledov v tednu: 46 |
4. |
5. |
6. |
7. ORR stability of Mn–Co/polypyrrole nanocomposite electrocatalysts studied by quasi in-situ identical-location photoelectron microspectroscopyMaya Kiskinova, Claudio Mele, Hikmet Sezen, Benedetto Bozzini, Mattia Fanetti, Andrea Goldoni, Luca Gregoratti, Belen Aleman, Matteo Amati, Patrizia Bocchetta, 2016 Opis: The stability of pyrolyzed Mn–Co/polypyrrole (PPy) nanocomposites towards the Oxygen Reduction Reaction (ORR)
in alkaline solution, was studied with a close-knit group of complementary microscopic and space-resolved spectroscopic
approaches: Atomic Force Microscopy (AFM), Scanning and High-Resolution Transmission Electron
Microscopy (SEM, HRTEM) and identical-location Scanning PhotoElectron Microscopy (SPEM). Tracking quasi-in
situ the morphochemical evolution of the Mn–Co/PPy catalyst upon electrochemical aging under ORR conditions
by this multi-technique approach, has allowed to clarify the key physico-chemical processes underlying
the dramatic impact of Co additions to stability improvement.
Ključne besede: Mixed manganese oxides, Polypyrrole, Oxygen reduction, Electrocatalysis, Nanocomposites, X-ray photoelectron microspectroscopy
Objavljeno: 25.07.2016; Ogledov: 2206; Prenosov: 0
Polno besedilo
Ogledov v tednu: 41 |
8. |
9. ORGANIZATION OF PROJECT MANAGEMENT IN AUTOMOTIVE INDUSTRY IN THE FIELD OF RESEARCH AND DEVELOPMENTSanja Ćorda, 2020 Opis: The automotive industry is facing new crises due to market shifting towards electric vehicles. In order to prevail in the market, global manufacturing companies need to be consistent in providing innovative products and services. If market is changing fast, companies need to make changes with the same velocity. The companies should focus on modifying their work processes and tools which are already outdated and implement new ones which will make their business more efficient. If a company is developing innovative products where work processes are causing big overheads, the company cannot be successful. Furthermore, a hindering circumstance for multinational companies is lack of team interaction and language barriers what can lead to inefficient and expensive projects. This case study analyzes and presents the current organization of work activities and the roles within two main project management processes in one company: Product Development Process and Product Pre-development Process. Based on the project management’s professional literature, examples of best practices, semi-structured interviews with project team members, this thesis will analyze current waterfall organization and suggest an organization model with the utilization of agile SCRUM framework which could increase the effectiveness of the project management organization.
Ključne besede: Automotive industry, product development process, product pre-development process, waterfall organization, agile SCRUM framework
Objavljeno: 04.08.2020; Ogledov: 36; Prenosov: 2
Polno besedilo
Ogledov v tednu: 36 |
10. |