Sökning: "degradation environment"

Visar resultat 1 - 5 av 304 avhandlingar innehållade orden degradation environment.

  1. 1. Environmentally Degradable Polyethylene : Effects of Additives and Environment on the Degradation and Degradation products

    Författare :Farideh Khabbaz; KTH; []
    Nyckelord :LDPE; polyethylene; oxidative degradation; photo-oxidation; thermo-oxidation; degradation products; photosensitisers; pro-oxidant; starch; master-batch; gas chromatography mass-spectrometry; GC-MS; solid phase microextraction; SPME;

    Sammanfattning : This thesis summarises and compares the influences ofdifferent additives (photosensitisers, pro-oxidants, abiodegradable filler) on blown low-density polyethylene (LDPE)films during photo- and thermal degradation with respect tochemical changes in the polymer matrices and identifieddegradation products. Additives studied were irondimethyldithiocarbamate (FeDMC), nickel dibutyldithocarbamate(NiDBC), carbon black, starch, a pro-oxidant that consisted ofmanganese stearate together with styrene butadiene rubber (SBR)or natural rubber (NR) and a master batch containing linearLDPE, starch and pro-oxidant. LÄS MER

  2. 2. Chemical Pollutants Released to the Marine Environment by Degradation of Plastic Debris

    Författare :Berit Gewert; Matthew MacLeod; Magnus Breitholtz; Merle Plassmann; Martin Wagner; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Plastic; microplastic; degradation; leachates; weathering; photo-oxidation; marine environment; toxicity; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : Since the beginning of the mass production in the 1940s, plastic has been manufactured in quickly increasing amounts. Plastic debris accumulates in the environment and lately much attention has been drawn to the pollution in the world’s oceans. LÄS MER

  3. 3. Controlling Polylactide Degradation through Stereocomplexation and Lactic Acid Based Additives

    Författare :Sofia Regnell Andersson; Minna Hakkarainen; Ann-Christine Albertsson; Marek Kowalczuk; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Polylactide; stereocomplex; plasticizer; degradation; degradation products; ESI-MS;

    Sammanfattning : The successful use of degradable materials in new applications depends on our ability to control the degradation process. A number of aspects need to be evaluated including degradation rate, the onset of degradation and the nature, formation and release of degradation products. LÄS MER

  4. 4. Användning av tillgängliga klimat- och miljödata vid livslängdsbedömningar av byggnader

    Författare :Kjell Westberg; KTH; []
    Nyckelord :service life planning; degradation environment; degradation agents; transformation; buildings; structures; maintenance intervals; meteorological data; climate data; environmental data; air pollutions;

    Sammanfattning : Since there is a demand to achieve improved precision ofestimations of the service life of a building and itsmaintenance intervals, in international organisations tasks arerunning to establish methods, models and standards for servicelife estimations. However, exact estimations are not feasibleat a reasonable cost. LÄS MER

  5. 5. Archaeological Perspectives on Risk and Community Resilience in the Baringo Lowlands, Kenya

    Författare :Nik Petek; Paul Lane; Matthew Davies; Uppsala universitet; []
    Nyckelord :HUMANITIES; HUMANIORA; Risk spiral; community resilience; archaeology; pastoralism; Baringo; Kenya; history; Ilchamus; Njemps; spatial statistics; East Africa; Holocene; environment; environmental degradation; colonialism; ethnogenesis; community conformity; survey; remote sensing; habitation; subsistence; Archaeology; Arkeologi;

    Sammanfattning : This historical ecological research provides a detailed insight into the risk avoidance and resilience building strategies in the Lake Baringo basin in Kenya through the lens of archaeology. It explores how changes in subsistence, habitation, and landscape shaped each other and how that affected the available strategies of risk avoidance and resilience building. LÄS MER