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621 Uppsatser om Heavy Constructions - Sida 42 av 42
Landvinning : scenarier för efterbehandling och gestaltning av Aitikgruvan, Gällivare
Open pit mining creates huge amounts of tailings and waste rock deposits. Due to it's content of sulphide minerals, predominantly pyrite (FeS2), there is a risk of oxidation and formation of acid water containing heavy metals, known as Acid Rock Drainage (ARD). To prevent the process of oxidation, the tailings and waste rock have to be reclaimed. The most commonly used methods of reclamation are a coverage of water or soil.
Mining also results in a large-scale interference in the landscape that will make an eternal change of its appearance.
Free cow traffic in automatic milking systems (AMS) : a case study on nine commercial dairy farms in Sweden
In Automatic Milking Systems (AMS), cows are kept in a free stall barn equipped with one or several milking units (MU). The cows? activities in the system are called cow traffic. There are three types of cow traffic systems: guided, partly-guided and free. Free systems have no gates, allowing the cows access to the feeding and resting areas at any time.
Naturvårdande skötsel (NS) - blir resultatet som man tänkt sig? : en fältstudie över föryngring, trädslagsfördelning och död ved 14 år efter åtgärd
A new Swedish political approach to forestry was initiated 1993, that put goals of production and environmental issues into equal importance to Swedish Forestry Law. Earlier nature conservation very often declaimed preservation the best way to conserve nature, but recently it is clear that many highly biological values are due to former land use or disturbance. Many old pastures or cultivations dominated by deciduous trees are today characterized by a dense overgrowth of Norway spruce. By actively paying attention to nature in forestry (nature restoration), it is possible to partly reconstruct habitats or disturbances that are necessary to favour the biological values.
The aim with this master thesis is to study the nature restoration, (NS, Swedish abbreviation), performed in 11 forest sites in the middle of Sweden 8-14 years ago. Since NS recently have become applied, it has never yet been evaluated.
Odlingens och lagringens inverkan på utsädes grobarhet :
At seed-growing the aim is to produce a commodity with high germination capacity, good soundness
and purity, and also slight admixture of seeds from other species. The capacity of germination and the
vigour of the seeds may become impaired in consequence of mechanical damage, infection of diseases,
growth of mould, attacks of vermin, high drying temperature, secret germination, sprouting in the ears
etc. The germ belongs to the outer and most unprotected parts of the seed, and consequently this is
much exposed. Even quite sound seeds can instantaneously have low capability of germination. It can
be due to the fact that the seeds are in rest of germination, i.e.
Kvickrotsstudier: 1. Kvickrotens reaktion på myllningsdjup, kvävemängd och kväveplacering i konkurrens med gröda. 2. Reducerad glyfosatanvändning på trädad åkermark :
1. Reaction on burial depth and nitrogen availability and placement in competition with a crop
In this trial it was investigated how couch grass (Elymus repens) changes its ability to compete in stands of wheat and barley with different burial depth and different amounts and placement of nitrogen. More knowledge in this area can be valuable in the attempt to decrease the use of herbicides and still keep the weeds under control.
The trial was carried out in the summer of 2004 as an outdoor pot experiment. The pots contained 15 litres of soil with a surface of 0,06 m2.
Kokvigeproduktion baserad på köttraser : en fältstudie
Most of the beef production in Sweden has been integrated with milk production. Since the 1990:s, the number of dairy cows has decreased. A specialised beef production has developed in purpose to compensate for this decrease. The consumption of beef have increased in the last decade, but the Swedish production has no followed this trend. In 2004, the percentage of beef self-sufficiency in Sweden was 60 %.