Sökning: "sampling methods"

Visar resultat 6 - 10 av 772 avhandlingar innehållade orden sampling methods.

  1. 6. Techniques to Calculate Exact Inclusion Probabilities for Conditional Poisson Sampling and Pareto .pi.ps Sampling Designs

    Författare :Nibia Aires; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sampling theory; conditional Poisson sampling; Pareto pips sampling; order sampling; numerical integration; algorithms; sampling theory;

    Sammanfattning : This thesis consists of five papers and treats two finite population sampling methods, viz. the Conditional Poisson and the Pareto .pi.ps sampling schemes. LÄS MER

  3. 7. Volatile metabolites from microorganisms in indoor environments : sampling, analysis and identification

    Författare :Anna-Lena Sunesson; Alvin Fox; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adsorbents; Analysis; Cultivation; Determination; Gas chromatography; Identification; Indicator substances; Indoor air; Mass spectrometry; Metabolites; Microbial volatile organic compounds; Optimization; Sampling; Sick buildings; Thermal desorption; Aspergillus versicolor; Cladosporium cladosporioides; Paecilomyces variotii; Pénicillium commune; Phialophora fastigiata; Streptomyces albidoflavus;

    Sammanfattning : Microorganisms are able to produce a wide variety of volatile organic compounds. This thesis deals with sampling, analysis and identification of such compounds, produced by microorganisms commonly found in buildings. LÄS MER

  4. 8. New methods for determination of airborne pollutants : Focus on tetrabromobisphenol A, organophosphate triesters and polycyclic aromatic hydrocarbons

    Författare :Johanna Tollbäck; Ulrika Nilsson; Peter Haglund; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air sampling; sampling methods; indoor air; SPE; SPME; extraction; dynamic extraction; online coupling; SWE; subcritical water extraction; GC MS; LC MS; organophosphate triesters; PAH; tetrabromobisphenol A; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : The work presented in this thesis concerns the development and evaluation of new methods of sampling and analysis of organic pollutants in the indoor and outdoor environment. In Paper I, the development of a new method was reported for the determination of the brominated flame retardant tetrabromobisphenol A (TBBPA) in air using sampling with glass fiber filter and polyurethane foam (PUF), ultrasonic solvent extraction and liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI/MS). LÄS MER

  5. 9. Aerosols of Isocyanates, Amines and Anhydrides : Sampling and Analysis

    Författare :Jakob Dahlin; Gunnar Skarping; Robert P. Streicher; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; isocyanate; amine; aminoisocyanate; organic acid anhydride; denuder; impactor; impinger; air sampling; LC-MS; LC-CLND; di-n-butylamine; DBA; thermal degradation; aerosol; particles; TDI; MDI; HDI; ICA; MIC; IPDI; exposure; occupational health; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : This thesis presents methods for air sampling and determination of isocyanates, amines, aminoisocyanates and anhydrides. These organic compounds are generated during thermal degradation of polymers such as polyurethane (PUR) or epoxy.Isocyanates, amines and anhydrides are airway irritants known to cause occupational asthma. LÄS MER

  7. 10. Unequal Probability Sampling in Active Learning and Traffic Safety

    Författare :Henrik Imberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; naturalistic driving; active learning; sampling weighing; optimal design; sequential sampling; probability sampling;

    Sammanfattning : This thesis addresses a problem arising in large and expensive experiments where incomplete data come in abundance but statistical analyses require collection of additional information, which is costly. Out of practical and economical considerations, it is necessary to restrict the analysis to a subset of the original database, which inevitably will cause a loss of valuable information; thus, choosing this subset in a manner that captures as much of the available information as possible is essential. LÄS MER