Sökning: "atmospheric chemistry"

Visar resultat 16 - 20 av 144 avhandlingar innehållade orden atmospheric chemistry.

1. 16. Ultra-short-chain perfluoroalkyl acids : Environmental occurrence, sources and distribution

   Författare :Maria Björnsdotter; Ingrid Ericson Jogsten; Anna Kärrman; Leo W. Y. Yeung; Tom Harner; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PFASs; TFA; TFMS; point sources; precursors; solar radiation; atmospheric oxidation; atmospheric deposition; flux; Arctic;

   Sammanfattning : Ultra-short-chain perfluoroalkyl acids (PFAAs) is a group of highly fluorinated and very stable chemicals. Their small molecular structure in combination with the acidic functional group result in highly polar compounds and concern has been raised as these substances may threaten our drinking water supplies. LÄS MER

3. 17. Detection and Structure Elucidation of Drug Metabolites in Biological Samples using HPLC-MS/MS Techniques

   Författare :Annica Tevell Åberg; Mikael Hedeland; Ulf Bondesson; Mario Thevis; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; Farmaceutisk kemi; analytisk farmaceutisk kemi; Analytical Pharmaceutical Chemistry;

   Sammanfattning : This thesis describes the structure elucidation of drug metabolites in biological samples by the use of high performance liquid chromatography (HPLC) atmospheric pressure ionization (API) tandem mass spectrometry (MS/MS). Due to their different advantages, various mass analyzers have been used in the different experiments. LÄS MER

4. 18. From source to the environment : Strategies for identification and determination of hydroxylated polycyclic aromatic hydrocarbons in complex particulate matrices

   Författare :Rozanna Avagyan; Roger Westerholm; Conny Östman; Marja-Liisa Riekkola; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; OH-PAHs; hydroxy-PAHs; particulate matter; PM; airborne particles; combustion particles; wood combustion; suspect screening; non-target screening; high resolution mass spectrometry; HRMS; atmospheric pressure photoionization; APPI; Analytical Chemistry; analytisk kemi;

   Sammanfattning : Adverse health effects have been linked to exposure to particulate matter, and wood combustion is considered as an important source of harmful particulate matter in the urban air and environment. Hydroxylated polycyclic aromatic hydrocarbons are a group of compounds with toxic, endocrine disrupting and carcinogenic properties. LÄS MER

5. 19. Localised corrosion and atmospheric corrosion of stainless steels

   Författare :Sukanya Hägg Mameng; Rachel Pettersson; Christopher Leygraf; Thomas Ladwein; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stainless steel; localised corrosion; atmospheric corrosion; alloy composition; surface finish; surface roughness; surface treatment; surface orientation; contamination; chloride; sulphate; temperature; chlorination; exposure conditions.; Kemi; Chemistry;

   Sammanfattning : This research is focused on defining limiting conditions for corrosion of stainless steels. The aim of the first part (Papers I-IV) was to understand the role of alloying level and environmental parameters on localised corrosion in aqueous conditions. LÄS MER

7. 20. Theoretical Studies on CO2 Reduction Electrocatalysts

   Författare :Xiaoyu Chen; Mårten S. G. Ahlquist; Sandra Luber; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computational Chemistry; CO2 reduction; electrocatalysis; Teoretisk kemi och biologi; Theoretical Chemistry and Biology;

   Sammanfattning : The atmospheric CO2 concentration has increased by more than 20% since 1980s and has now reached the highest level than at any point in the past 800 000 years. Electrochemical CO2 reductions are receiving particular in- terest as the apparatus are relatively easy to maintain and cheap to operate. LÄS MER