Sökning: "Retention time"

Visar resultat 1 - 5 av 333 avhandlingar innehållade orden Retention time.

  1. 1. Retention time predictions in Gas Chromatography

    Författare :Yasar Thewalim; Anders Colmsjö; Torgny Fornstedt; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gas chromatography; computer simulation; two-parameter model; retention time prediction; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : In gas chromatography, analytes are separated by differences in their partition between a mobile phase and a stationary phase. Temperature-program, column dimensions, stationary and mobile phases, and flow rate are all parameters that can affect the quality of the separation in gas chromatography. LÄS MER

  3. 2. Non-career firefighters in rural areas - Exploring aspects contributing to retention

    Författare :Emelie Lantz; Avdelningen för Brandteknik; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Räddningstjänst; Brandman; Deltidsbrandman; Engagemang; Fire and Rescue Service; Firefighter; Part-time Firefighter; Retention; Commitment; Non-career Firefighter;

    Sammanfattning : The overarching aim of this licentiate thesis is to increase knowledge about the implications of working as a non-career firefighter in order to understand how challenges and commitment affect retention. Retention of non-career firefighters (for example volunteer or part-time firefighters) is a well-known, multifaceted challenge in several countries. LÄS MER

  4. 3. Particulate phosphorus accumulation and net retention in constructed wetlands receiving agricultural runoff : Critical analysis of factors affecting retention estimates

    Författare :Karin Johannesson; Karin Tonderski; Stefan Weisner; Uno Wennergren; Ben Surridge; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phosphorus retention; constructed wetlands; agriculture; sampling strategy;

    Sammanfattning : Övergödning är ett allvarligt miljöproblem, som bland annat orsakar omfattande blomningar av alger och blågrönbakterier. I söt- och brackvatten är fosfor ofta det mest begränsande näringsämnet för dessa organismer, varför en minskning av fosfortillförseln är nödvändig för att nå förbättringar. LÄS MER

  5. 4. Hydrodynamic control of retention in heterogeneous aquifers and fractured rock

    Författare :Hua Cheng; Vladimir Cvetkovic; Chin-Fu Tsang; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aquifer; Fracture; groundwater; First-order solution; Monte-Carlo simulation; Nu-clear waste; Heterogeneity; Retention processes; Matrix diffusion; Prediction; Evaluation; Travel time; Flow rate; ; Water engineering; Vattenteknik;

    Sammanfattning : In this thesis, fluid flow and solute transport in heterogeneous aquifers and particularly in frac-tured rock have been investigated using Lagrangian Stochastic Advective-Reaction (LaSAR) framework. The heterogeneity of the aquifer structure or fracture configuration, as well as the various reaction/retention processes have been considered in the modelling approach. LÄS MER

  7. 5. Developing tools for non-target analysis and digital archiving of organic urban water pollutants

    Författare :Cathrin Veenaas; Peter Haglund; Per Liljelind; Christine Gallampois; Mehran Alaee; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Digital archiving; non-target screening; organic pollutants; sewage sludge; GC-MS; GC×GC; LC-MS; time-trend analysis; retention indices; retention time prediction;

    Sammanfattning : This thesis describes efforts to develop robust methods for the creation and use of digital archives of environmental samples, and proposes guidelines based on the results. Digital archives are repositories that store environmental samples digitally. LÄS MER