Browsing by Subject "pakkaukset"
Now showing items 1-3 of 3
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(2012)The purpose of this study was to examine the integrated climatic impacts of forestry and the use fibre-based packaging materials. The responsible use of forest resources plays an integral role in mitigating climate change. Forests offer three generic mitigation strategies; conservation, sequestration and substitution. By conserving carbon reservoirs, increasing the carbon sequestration in the forest or substituting fossil fuel intensive materials and energy, it is possible to lower the amount of carbon in the atmosphere through the use of forest resources. The Finnish forest industry consumed some 78 million m3 of wood in 2009, while total of 2.4 million tons of different packaging materials were consumed that same year in Finland. Nearly half of the domestically consumed packaging materials were wood-based. Globally the world packaging material market is valued worth annually some €400 billion, of which the fibre-based packaging materials account for 40 %. The methodology and the theoretical framework of this study are based on a stand-level, steady-state analysis of forestry and wood yields. The forest stand data used for this study were obtained from Metla, and consisted of 14 forest stands located in Southern and Central Finland. The forest growth and wood yields were first optimized with the help of Stand Management Assistant software, and then simulated in Motti for forest carbon pools. The basic idea was to examine the climatic impacts of fibre-based packaging material production and consumption through different forest management and end-use scenarios. Economically optimal forest management practices were chosen as the baseline (1) for the study. In the alternative scenarios, the amount of fibre-based packaging material on the market decreased from the baseline. The reduced pulpwood demand (RPD) scenario (2) follows economically optimal management practices under reduced pulpwood price conditions, while the sawlog scenario (3) also changed the product mix from packaging to sawnwood products. The energy scenario (4) examines the impacts of pulpwood demand shift from packaging to energy use. The final scenario follows the silvicultural guidelines developed by the Forestry Development Centre Tapio (5). The baseline forest and forest product carbon pools and the avoided emissions from wood use were compared to those under alternative forest management regimes and end-use scenarios. The comparison of the climatic impacts between scenarios gave an insight into the sustainability of fibre-based packaging materials, and the impacts of decreased material supply and substitution. The results show that the use of wood for fibre-based packaging purposes is favorable, when considering climate change mitigation aspects of forestry and wood use. Fibre-based packaging materials efficiently displace fossil carbon emissions by substituting more energy intensive materials, and they delay biogenic carbon re-emissions to the atmosphere for several months up to years. The RPD and the sawlog scenarios both fared well in the scenario comparison. These scenarios produced relatively more sawnwood, which can displace high amounts of emissions and has high carbon storing potential due to the long lifecycle. The results indicate the possibility that win-win scenarios exist by shifting production from pulpwood to sawlogs; on some of the stands in the RPD and sawlog scenarios, both carbon pools and avoided emissions increased from the baseline simultaneously. On the opposite, the shift from packaging material to energy use caused the carbon pools and the avoided emissions to diminish from the baseline. Hence the use of virgin fibres for energy purposes, rather than forest industry feedstock biomass, should be critically judged if optional to each other. Managing the stands according to the silvicultural guidelines developed by the Forestry Development Centre Tapio provided the least climatic benefits, showing considerably lower carbon pools and avoided emissions. This seems interesting and worth noting, as the guidelines are the current basis for the forest management practices in Finland.
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(2009)The literature review of this thesis deals with light, conventional light sources and the effects of light on the quality of foods. Impacts of light on the quality of frozen foods were also discussed. Effects of fluorescent light on frozen food have been previously reported in the literature, but effects of LED light have not. The literature review also deals with the quality changes of foods caused by freezing and frozen storage. The significance of package during frozen storage was reviewed. The aim of the experimental study was to investigate whether there are differences between the effects on frozen food when exposed to fluorescent or LED light. Frozen strawberries, shrimps, lamb loins and ice cream were exposed to fluorescent and LED light for 4 weeks. The samples were packed in transparent LDPE pouches except the lamb loins, which were vacuum-packed in transparent PA/PE film. References were packed in aluminium foil. Temperature of the samples was monitored by the sensors attached to the surfaces of the packages. The colour of the samples was measured every week using a spectrophotometer. Thiobarbituric acid (TBA) values of the shrimps and lamb loins were analysed after 0, 2 and 4 weeks of exposure. The odour of shrimps was evaluated with sensory evaluation using a multiple comparison test. Sensory evaluations of ice cream was conducted by trained panelists using a multiple comparison test. All the sensory evaluations were conducted after 2 and 4 weeks of exposure. In addition, ice cream was exposed to light under a yellow plastic film to find out the effects of riboflavin, which is known to operate as a sensitiser. After 4 weeks of exposure to the fluorescent light the total colour difference of the samples was higher than that of the products exposed to the LED light. Differences were pronounced especially in ice cream exposed to light under transparent film. The smell and taste of ice cream were affected when exposed to light under transparent or yellow plastic films. There were no statistically significant differences in the taste of ice cream when exposed to fluorescent or LED light for 4 weeks, but the smell of ice cream appeared to be more divergent from the reference when exposed to LED light under transparent film for 4 weeks than the smell of ice cream exposed to fluorescent light for 4 weeks. On the basis of this study, fluorescent light affected the colour of the frozen food more than LED light. Light sources did not differ from each other, when the results of the sensory evaluation of shrimps were considered. Because TBA values of lamb loins and shrimps also increased in reference samples, the effects of light could not be separated. Sensory properties of ice cream were affected by light exposures, but on the basis of sensory evaluation it is not possible to state which light source was more detrimental to the quality of ice cream.
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(2020)Maapalloon kohdistuu monia erilaisia ympäristöuhkia. Uhkia pienentääkseen Euroopan unionin yhtenä tavoitteena on ohjata jäsenmaitaan kiertotalouteen ja lisätä syntyvien jätteiden kuten pakkausten kierrätystä. Suomalaisten nykyisillä pakkausten kierrätysmäärillä ei vielä ylletä Suomen omiin eikä Euroopan unionin tavoitteisiin. Kierrätystä tulee siten lisätä. Tämä tutkielma pyrkii ymmärtämään kotitalouksien pakkausten kierrätyskäytänteitä. Tutkielman tavoitteena on etsiä käytänteitä, jotka estävät tai mahdollistavat pakkausten kierrättämistä kotitalouksissa. Kierrättämistä on aiemmin tutkittu melko yksilölähtöisesti, joten tutkielman teoreettisena viitekehyksenä käytetään käytäntöteoriaa. Käytäntöteorian mukaan ihmisten käyttäytymistä eivät ohjaa vain yksilön valinnat vaan myös historiallisesti rakentuneet sosiaaliset käytännöt. Pakkausten kierrättämistä ei ole aiemmin tutkittu käytäntöteoreettisesta näkökulmasta, joten tutkielmassa pyritään myös vastaamaan siihen, miten käytäntöteoriaa voidaan soveltaa pakkausten kierrätyksen tutkimiseen. Olen tutkinut aihetta etnografisin menetelmin. Aineistoni koostuu 14 virikkeellisestä teemahaastattelusta, haastateltavien ottamista valokuvista kotitaloudessa tyhjentyneistä pakkauksista ja haastattelijan ottamista valokuvista haastateltavien kierrätystiloista kotona sekä taloyhtiössä. Analyysissa on hyödynnetty temaattista analyysia. Tutkimuksen mukaan pakkausten kierrätys kotitalouksissa tapahtuu rutinoituneesti. Kierrätystä ei siten juuri mietitä, vaan se tapahtuu muiden arjen kotitöiden ohella. Jotkin kierrätykseen liittyvät käytänteet tekevät pakkausjätteen heittämisen sekajätteeseen helpoksi. Pakkausten kierrättämistä estävät tai mahdollistavat materiaaliosaaminen, aikaan sekä paikkaan liittyvät ongelmat ja merkitykset. Materiaaliosaaminen tarkoittaa pakkausten ominaisuuksia, omaa sekä tarjolla olevaa tietoa ja osaamista. Aikaan ja paikkaan liittyvät ongelmat taas tarkoittavat kierrätysastioita sekä tilan puutetta, pakkausjätteen määrää sekä likaisuutta, hektisyyttä ja elämäntilannetta. Merkitykset syntyvät ympäristöarvoista, halusta noudattaa normeja ja taloudellisista syistä. Tutkin kierrätyskäytänteitä kolmen elementin – materiaalien, kompetenssien ja merkitysten – avulla. Nämä elementit eivät riitä kierrätyksen tutkimiseen, sillä lisäksi ajalla ja sen puutteen synnyttämillä tunteilla on vaikutusta kierrätykseen. Käytäntöteoria soveltuu pakkausten tutkimiseen, kun ottaa huomioon, että käytänteen ajallisuus mahdollistaa sen rikkomisen.
Now showing items 1-3 of 3